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Thread: Building the EX3 - Tips & Hints

  1. #21
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    Default Re: Building the EX3 - Tips & Hints

    COVER

    Rudder

    We are going to refer to the COVER MANUAL, Page 81 to show us a couple of things that are really different on the rudder from the other tail-feathers. Pay special attention to how the fabric wraps around the different tubes and how the tapes go on the edges. NOTE THAT THE DROPBOX MANUAL HAS BEEN UPDATED FOR THIS PAGE WITH NEXT NUMBERING LIKE “SECTION A-A”, ETC INSTEAD OF THE INSET NUMBERS IN MY ATTACHMENT,

    P1050650.jpg

    Since the fabric is an envelope, we are only going to attach the fabric to the tubes at the 1C3-1 and 1DC-3 areas shown in the manual so the SECTION B-B in Dropbox showing the fabric glued edges are incorrect. Since this is a rudder with more air blasting from the left side of the plane, I suppose that is why the joints are where they are for the fabric (with the outside piece of fabric ending on the RIGHT side of the rudder) and notice how 2 of the 2" tapes are used for the outside tapes on this same tube. SAME HERE.....WAIT FOR THE UPDATE.

    Same thing......the 2 pieces of tape start on either side of the tube in the center and then overlap in the inside, center of the tube with the top overlapping tape going to the INSIDE of that tube (which is the RIGHT side of the plane).

    NOTE THAT THE VIDEO IS WRONG. THEY SHOW GLUING THE LEFT SIDE FIRST (which would put that joint on the bottom) and YOU SHOULD DO THE OPPOSITE AND GLUE THE RIGHT SIDE FIRST......... which would put the edge of that right side fabric glued on the left side first.....which would then let the left side fabric overlap that joint and glue on the right side.....keeping it out of the prop blast (that means start with the right side UP to start. The RIGHT side is the side with the wire coming out).

    Also notice the strange way section 1D3-1 shows for putting the 2" tape on the top, underside piece of the rudder. Here the tape is ONLY on the LEFT SIDE and UNDER SIDE of this piece ending where the fabric ends. So, there are NO TAPES at all on the RIGHT SIDE. The fabric also overlaps so the top layer is going from the left side to the right side (so no edges into the air blast that hits the left side of the rudder I suppose).

    Also, if you are installing the LED LIGHTING PACKAGE, you will need to look at your LIGHTING MANUAL, Page 18 to see how you need to prep by the rudder by drilling and tapping 2 holes as well as installing the wire harness.

    First, match drill the 2 holes where the rudder light goes with a #43 drill bit and then tap it with a 4-40 NC tap.

    P1050653.jpg

    Next follow the manual photos and put electrical tape where shown and attach the wiring harness. Note that the end of the harness that has the 4 pins and 1 bare wire end is the one that will go out the front of the rudder to connect with the connection in the fuselage later. The harness should come with the plastic end connector piece but don't install it at this time as you will have to burn a small hole in the fuse by the tail and run this end of the wire through it into the fuse before you can put the connectors on it.

    P1050654.jpg

    You can follow the video now for the cover.

    For rivets, the fig. C5 on Page 81 is not exactly correct (it's showing rib stitching). From the top, the first row will have 2 rivets and the next 3 ribs will have 4 each.

    When marking the tape locations, note again the way the 2 two inch (2") tapes go on the fabric seam there at 1C3-1. Take a 2" piece of tape and lay the rudder with the LEFT side up. Hole the tape so that the side that goes down and around the tube goes just past the center (see the 1C3-1 cross section of Fib. C5 in the Cover Manual). Then use the compass and mark that line on the top (left side) where the top edge of that 2" tape will go. I just make myself a note for now on the fabric. This 2" tape will be put on LAST.....or over the top of tape coming around from the other (RIGHT) side.

    P1050657.jpg

    Same thing on the RIGHT side. With that side facing up, wrap the piece of 2" tape around the tube until its just past the center of the tube. Mark the right side edge of the tape down the fabric and a note to yourself that we will INSTALL THIS TAPE FIRST. So install this 2" tape and then the 2" tape from the LEFT SIDE will overlap this one in the center per the figure.

    P1050656.jpg
    Last edited by Daveembry; 10-15-2019 at 06:50 AM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  2. #22
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    Default Re: Building the EX3 - Tips & Hints

    WINGS

    Leading Edge Skins

    OK, we now have a set of the leading edge skin clamps (THANKS MARK!) so we can now install the leading edge skins on both wings. As I said before, please only get a set of the clamps after you have BOTH WINGS ready. It only takes a couple hours to install the skins so don't tie up a set of clamps by getting them when you first get the kit and then sit on them until you have both wings done. When you know you are close to getting both wings ready, get a set of them coming your way and then pop the skins on both wings in 1 day and then make them available .

    As I said before, CubCrafters had 22 set of these they made and now I could not locate a single set available. Where are they? Most likely people got them and are just sitting on them while people that are ready for them are stalled trying to get a set. CubCrafters was kind enough to make the sets up and loan them out at no charge so let's keep them circulating. Mitch has sent me enough of the materials to make up a few more set which I will do and get them back out into circulation. Please keep them moving.

    The way it works is that the person sending you the clamps will pay the shipping to you and then instead of reimbursing them, you will ship them "FORWARD" to the next person on your dime.

    I think there is a lot of apprehension on installing these skins. However, it is really quite easy and fun because the wing really starts to look like a wing here. With all the holes pre-drilled for rivets, it's pretty much a no-brainer now as you just line up the holes with the centers of the nose ribs......AND IF..... you have marked the centers of the ribs with your SHARPIE.....it's quite easy. Be sure and mark the center of the TOP and the BOTTOM of the nose ribs.

    P1050658.jpg

    To start with, you DO still have the outboard end of your rear spar sitting up 1" higher than the other 3 points on your sawhorses right?

    Following along in the Dropbox Wing Manual (yes, it's different than the current printed version I have) to layout the skins as shown on the Fig. W63 on page 173.

    I do NOT like to put duct tape on the skins like they say. The stuff sticks so good to those skins that I spend more time trying to get the sticky stuff off them later that it isn't worth it. Since these skins overlap the top and bottom of the front spar, they will almost stick in place by themselves and I just use a few spring clamps to hold them generally in place until I get the top rivet in place.

    The rivet holes that go into the nose ribs are pre-drilled. The side of the OUTBOARD skin that goes DOWN has the wider spacing between the 2 holes. It's the opposite for the next 3 skins.....the wider spacing goes UP. Also note that the outboard skin does not wrap all the way around and connect under the front spar. The other 3 do.

    Per the manual, start on the outboard skin and let it overhang the #12 rib by 1". You really won't have to worry about this because the holes are already pre-drilled, so place that skin over the top of the spar and slide it back forth until the pre-drilled top holes are aligned over the tops of the 1st rivet hole (down from the spar) is directly over the center of each of the nose ribs. You should be able to see the BLUE LINE (if you used a BLUE sharpie like me) inside the top hole. Don't worry about the other holes yet. At this point you are not worried about the bottom of the skin at all.....just leave it where it is.

    P1050661.jpg

    Be sure that the skin portion that is INSIDE the bay (the part that overlaps the top of the spar and wraps down into the bay) is flush against the spar on the side and also flush with the bottom of the spar bulb area. See Fig. W62. Clamps work good just as we did on the flap false spar.

    P1050660.jpg

    P1050659.jpg

    Next, take a #30 drill and drill the top rivet hole (1st hole down from the spar). Careful not to press too hard so you push the nose rib out of the way and that you are drilling into the BLUE LINE you marked. At this point, you can still reach up under the skin and move/hold the nose ribs in place while you drill if you need to. Install a cleco or rivet. Don't drill and rivet/cleco the inside edge yet. The next inboard skin will overlap this skin and rivet all at once. It's not as important on the new EX3 because these skins are thicker than the EX2 skins which would "tin can" more, but it's still best to generally start your drilling and riveting in the center of the skins and move inboard and outboard.

    The 2nd skin (from the outboard end) has the cut-out on the top for the pulley bracket that is on the top of the spar. Just bend, push/pull and it will go over it. Then just line up the pre-drilled holes in outboard end of this skin with the pre-drilled holes that are in the inboard end of the outboard skin. Check now to be sure you have again lined up all the top rivet holes for this skin with the BLUE LINE on the nose ribs. Move things around and then clamp in place again being sure to have the inside portions of the skins flush with the side and bottom of the spar bulb.

    Drill and rivet or cleco (I rivet.....if you are unsure....cleco for now!) all the top rivet holes on this skin.

    Just continue doing the same on all 4 skins.

    At this point, you should have all the top holes riveted. Now we are just going to go on down and do the 2nd row down from the spar. Same thing here........ reach up under the skin if you need to and move the nose rib around until you can see your BLUE LINE in the hole.......then while holding it there, take your other hand (your LEFT hand if right handed) and press down on the top of the skin with your fingers on EITHER SIDE of that rivet hole. When you press DOWN hard.....that rib will stay put while you reach up with your RIGHT HAND and get your drill (which of course you did leave sitting on your cart real close where you could easily reach it while still holding down on the skin) and drill the hole. Again....start in the middle of your skin and work out on either side of it. Don't press hard with your drill either as you may push the rib over to one side or the other.

    BEFORE I rivet it, I put the rivet in the hole and then reach around again and feel it to be sure the hole and rivet are near the center of the nose rib before I pull the trigger. Do all the 2nd holes of the rivets.

    OK.....now before we wrapped the skins around to the bottom of the spar, you DID install your landing light fixture right? (if you ordered it) in between ribs 5 & 6 right. It doesn't matter how it sits up there for now......You will reach up later and install it so just stick it up there and tape it loosely (not too much tape as you will have to take it off all shortly!).

    Next I take the outboard skin (the one that does not wrap all the way around the bottom of the front spar) and just wrap it around the nose skins, lift the end of the wing at that spar and then just set the spar back down and let the skin sit there for now. All we are doing now is just getting the skins into a position so we can install the clamps.

    P1050663.jpg

    P1050664.jpg

    Go to the next skin (from this outboard skin) and then just wrap it around and kindof horse it around until you can get that lip of the bottom of the skin to go around the bottom of the spar and pop up in place. You can then just put some clamps there for now to hold it in place. Note that the ends of the intermediate nose ribs will go inside the cutouts in the skins.

    P1050665.jpg

    The last, inboard skin (in the fuel tank bay) is pretty thick and harder to get up there so just so the same as what you did in the far outboard skin and just wrap it around the nose ribs and let it sit on the top of the sawhorse for now. Again, all we are doing is getting them up so we can get the clamps started.

    P1050666.jpg

    Go to the outboard skin, next to one of the 2 middle center ribs (there are 4 main ribs in each section with the last, inboard one being shared with the next skin) and put on 2 of the clamps LOOSELY. Just put them on enough to get the nuts started on the bolt going through the clamps. Put them about 1" or so from the vertical line of rivets in the skins that you just installed. This is to be sure and give you enough room on the bottom so you can still drill and rivet so don't get the clamps too close to the holes you intend to work on.

    Then, go under the skin and look up and line up the nose ribs.....again looking for the BLUE LINE ......in the holes. The outboard skin is no big deal because since it doesn't wrap around the spar, you can still get to the rib and move it a little each way to get the rib centered on the hole.....you can't do that with the other 3 skins. Once you wrap that skin around the bottom of the spar, you can't EASILY reach those ribs again.

    If you got the top 2 holes centered up nicely, then the bottom 2 holes should be real close. If they aren't lines up on the 3 more inboard skins, you can always push something down through the ends of the nose ribs from either the outboard or inboard end....and push on the nose rib a bit. Not fun....but it works if you have to. Try to line these up the best you can BEFORE tightening up the clamps because they are pretty hard to move once the clamps are tight.

    If the rib isn't lined up right.....be sure the clamps are loose on that skin and try using a sharp awl (if you can see at least "part" of the nose rib through the hole). Stick it up in the hole and poke it into the rib and then try to gently pry/nudge it in the right direction. If that doesn't work, you can also take a long screwdriver, etc. from the inboard side of the spar and run it down the nose rib where it sticks out under the spar. See if you can "nudge" it over this way. If that doesn't work, then take a long "something" and you can come in through the end (either at the wing root or wing tip end) and do the same thing. I actually have a "Hawaiian sling" that I use to spearfish with. It's a long fiberglass pole that fits nicely down through all the nose ribs. Just be sure you have doing all your moving with the clamps off or loose. Once they are tight it's pretty much impossible to move those nose ribs.

    Once they are lined up, just tighten the clamps until they are up flush around the skin all the way around (top, bottom and at the nose). If there is a gap on one side, tighten that end (top or bottom) until there is no gap. DON'T OVER DO IT..... I never use a wrench but just finger tight on the wing nuts are plenty enough. You can reach over the nose skins/ribs with one hand and let the front (outside) of the clamps hit you in the sternum and just push/pull the clamp towards the spar with your chest and using your other hand, tighten the wing nuts. When it's almost tight and only a small gap, then just use your fingers on the wing nuts to get it the final little bit. Don't over tighten or you will see the bends in the skin! Nice and snug is all you need. You will probably need to "wiggle" it left and right a little to be sure it is square with the wing. If you see a gap on 1 side and not the other, wiggle it until the gaps are equal left to right and top to bottom.

    Then add another clamp to the outboard end and snug it up. Lastly, add a clamp over the joint on the next skin but just to the right of the joint. DON'T TIGHTEN THIS CLAMP YET..... just get the nuts started and leave it loose. If you tighten it now, you might have gaps in the next inboard skin so we will wait and move the clamps over to the next skin.....start in the middle again and tighten the 2 middle ones.....then move back to this clamp at the joint and tighten it.

    P1050668.jpg

    P1050669.jpg

    So in this photo above, the 2 center clamps were installed and tightened first (after being sure the nose ribs blue line lined up with the holes on the bottom. (You can move these around some if you have to now since you can reach up and grab them.) Then the left one was installed and tightened. The far right one is on the inboard side of the joint. NO RIVETS OR HOLES WILL BE DRILLED ON THIS “JOINT” YET. WE WILL DRILL AND RIVET THE JOINT WHEN WE DO THE NEXT INBOARD SKIN.

    Here below you can see how the clamps are installed. Here you can see where one of the drag wires is in the way so I stacked some pieces of wood between the inboard side of the spar and the outside member of the clamp so it would clear the wire.

    P1050671.jpg

    P1050670.jpg

    So just drill the pre-drilled rivet holes and install the rivets in each section until you are done. Again......BEFORE INSTALLING THE BOTTOM RIVETS ON THE 3 INBOARD SKINS THAT WRAP AROUND THE BOTTOM OF THE SPAR, BE SURE THE LIP INSIDE IS FLUSH WITH THE SPAR BULB (Fig. W62).

    Lastly, just secure the "lips" that go over and around the spar top and bottom just like you did on the flap false spar using the jig or being sure the bottom of the skin is flush with the edge of the spar bulb.

    That's it. Who needs some clamps?????? :-)
    Last edited by Daveembry; 07-03-2018 at 09:27 AM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  3. #23
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    Default Re: Building the EX3 - Tips & Hints

    WINGS

    Leading Edge Skins - Finishing


    One nice thing to do before drilling the skins to the spars is to first put a little masking tape under the top part to catch the drilling metal when you drill the holes. If you don't the chips will all go down in the bottom spar channel. We will blow all this out really good before covering anyway but might as well as keep it as clean as we can to start with.

    When drilling the holes, be sure you use a drill stop to keep from drilling into the spar web and keep the skin lip up tight to the spar so the drilling metal/chips won't get stuck between the skin and the spar (since we can't take it off and blow out the chips first). Here is where you will wish you had bought some of the "good, sharp bits" instead of those cheap, dull ones!

    P1050673.jpg

    P1050674.jpg

    Drill and rivet one of the center holes first and pull the rivet. Then drill a hole on either side of that rivet working to the outside in both directions. With one hand, push down on the skin material between the rivet you installed and the one you are going to drill next to be sure to get it lying flat and not bowed out. I also like to drill at just a SLIGHT angle outward...away from the rivet I already installed. Then when I put the rivet in the hole it will tend to "lean" towards the rivet. I then take my pneumatic rivet gun over the rivet and then make sure it's straight up and completely against the skin/spar when I pull it. This is just a way of keep the skin lying flat without little gaps and bows.

    P1050675.jpg


    LANDING LIGHT LENS HOLDER

    This is pretty straight forward. You are going to drill with #40 bit for the small pop rivets and instead of changing the head out on the micro-stop when I only have a few holes to countersink, I just use my deburring tool here.

    P1050676.jpg

    P1050677.jpg

    You are pulling this rivet into plastic, which is soft. If you happen to have one of these small rivets pull through the plastic, you can always put a small washer on the backside of the rivet before you pull it.

    Use the denatured alcohol and q-tips to clean up the meth are you put it in the bottom of the lens holder.

    I have 48 hours and 45 minutes in total build so far to this point.
    Last edited by Daveembry; 07-21-2018 at 08:26 AM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  4. #24
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    Default Re: Building the EX3 - Tips & Hints

    WINGS

    Wing Tip Bow

    I think all the trimming is now done at the factory so there is probably no trimming to be done. Just fit it up in place and see if it fits OK.

    Be sure you read this completely as you must first set the distance from the trailing edge tip bow to the false spar before setting up the rest. This is indicated below and not in the manual descriptions!

    One thing that is also NOT in the written part of the manual or in the figures is that the measurement from the false spar to the tip of this aft end (point) of the tip bow should be 12.625 +/- ..063. This is shown way later on page 195 (Dropbox manual) in the Checklist. So you actually need to set this distance and clamp it in place before doing the rest of the tip box positioning.

    Figure W75 on Page 189 (In Dropbox) is a little confusing and is missing 2 rivets.

    Looking at the figure where (top left) it shows 5x holes and has 2 arrows....... they are references here that there will be 3 on top and 2 on the bottom.

    2 goes through the outboard leading edge skin into the bow tip on top (.063 from top edge of skin); 1 goes through the outboard skin into the bow tip on the bottom (5.55" down from the 1st hole); 1 goes on the top and bottom of the center #13 rib. Dimension for these locations are on the lower detail drawing. The first top bow tip hole is .63 from the skin edge and then 2nd hole is down 5.55 from that hole. The bottom one goes through the leading edge skin into the wing top bow and is just .35 from the skin edge.

    The 2 holes into the #13 center rib are centered on the rib and .30 in from the edge of the tip bow. These are not shown in the drawing but confirmed by Mitch and seen in photo 244 where you can see them riveting it.

    P1050679.jpg

    The diagonal cross tube will go inside the tip bow and use the same first rivet for securing the tip bow to the machine tail rib on the bottom so line it up with the .72 mark to be sure it fits. I had to move my mark in just a little to make it work best.

    Also, the drawing insert/detail shows "3X min....." (NOTE the word "MIN") in regards to the rivet on the leading edge (the 2 on the top and the 1 on the bottom). So I went ahead and added 1 more on the bottom ....... so I have 2 on top and 2 on the bottom. The bottom ones I just put right next to the rivets that were there joining the leading edge skin to the nose rib.

    P1050683.jpg

    There are 2 holes top and bottom of the end of the bow tip. I can't really see where the holes go.....the drawing only shows the distance BETWEEN the holes.......So I will assume the first hole will go on the bottom so that it goes through the diagonal cross brace into the machines rib and wing tip bow. If you have set the outside tip of the wing tip bow to the 12.625" from the false spar, if you then measure BACK from the inboard edge of the wing tip bow .72", it looks like that should put you right in the center of the diagonal cross brace.

    The 2nd hole on top is 2.0 from that hole and the bottom is 2.1 from the first hole. The reason for this difference that you can watch for is to be sure when you install the rivets that they don't hit each other inside the machined tail rib. You can see there isn't much clearance top to bottom so if you put them the same distance, the tails of the rivets would hit each other, so just be sure you are offsetting them.

    So....in summary, I just drill the 1st hole on the bottom to be sure it's going through the end of the diagonal cross brace into the machined rib/wing tip bow, then measure back around 2.0" top and 2.1" bottom from that one and put the 2nd rivet. I don't really thing the position is that big a deal except for the one with the cross brace.

    Also note that these 4 rivets (2 top and 2 bottom) are different than the rest of the SS rivets used on the tip bow. They are HDW-97525.

    P1050681.jpg

    Then if you notice the photos in the manual (NOT on the drawing for some reason), there should be a rivet top and bottom of the #13 tail rib into the tip bow. Just center on the rib and make it the same .30 edge distance. This was confirmed by Mitch.

    Once you drill and cleco, then get your meth ready and put a good bead inside the leading edge skin where it will glue up to the tip bow when you install it as well as the ends of everything else as shown in the manual. Note that you want to leave a hole in the very aft end of the tip bow where it goes over the machined tail rib for drainage. You will later burn a drain hole in the fabric here to let any water drain out so be sure while the meth is still wet that you stick something up there and clear it out so it's not stopped up with the meth. Easier to do it now than to have to drill it later. This is why you will notice there is a gap between the very end of the aft end of the bow tip and the machine rib tail.

    P1050680.jpg

    One thing that is also NOT in the written part of the manual or in the figures is that the measurement from the false spar to the tip of this aft end (point) of the tip bow should be 12.625 +/- ..063. This is shown way later on page 195 (Dropbox manual) in the Checklist. So you actually need to set this distance and clamp it in place before doing the rest of the tip box positioning.

    Just use clamps to hold everything in place before you drill. Put your hand up into the front of the tip bow where it goes inside the leading edge skin there and push it up as tight against the leading edge skins as you can.

    P1050682.jpg

    Be sure and stick your nav. light wire ends through the hole in the tip bow before you rivet and glue.

    P1050684.jpg

    P1050685.jpg


    ADDITIONAL NUT PLATES NEEDED TO BE INSTALLED AROUND THE FUEL TANKS

    THIS IS NOT IN THE MANUALS. Mitch is currently updating the DropBox manual to show this but it's not on the manual anywhere now except a small note on the WING MANUAL, Page 133, FIG W50. You will see in the top right side of the page a small note saying there are 4x nutplates......and that's it.


    P1060818.jpg


    So, you will add 4 nutplates to the 4 corners of the fuel bay. The 2 corner nutplates you add onto the #1 rib will have the center hole (#20 bit) aligned with the nutplates that are on the flap false spar for the aft corner and the leading edge skin nutplates for the forward corner, BUT WILL NOT ALIGN WITH THE REST OF THE NUTPLATES WE ADDED ON THE #1 DOUBLE RIB. Instead, align both the corner nutplates here with the OUTBOARD rib of the double rib where the row of rivets are that go into that rib through the capstrip.

    The 2 nutplates that will go on the #3 double rib corners will be aligned with both the leading edge and flap false spar nutplates AND with the nutplates we installed on the #3 double rib (which are on the inboard side of that double rib.


    P1060817.jpg

    You should do this before installing the leading edge skins.
    Last edited by Daveembry; 04-01-2019 at 02:20 PM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  5. #25
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    Default Re: Building the EX3 - Tips & Hints

    WINGS

    Fuel Tanks

    Here is a post I previously did on installing the fuel tanks. The manual is good showing you how to get the tanks into the fuel bays.......it didn't tell you how hard it was to get those straps on!! It was really tough until I figured out a system.

    First of all, the straps and bolts, etc are the CORRECT LENGTH. You may not believe that but it is true. They are designed to be very tight. As I said below......the nuts are not torqued on here.....you actually tighten them as far as they will go!! Until they bottom out on the bolt.

    The trick is how to get the bolt up high enough to get the washer and nut on and started? I've found that using some big pliers and safety wire will work pretty easily.

    If you left the fuel tank bracing unattached at the spars as I previously went over, then the tanks should pretty much just drop into the fuel bays with minimal pressure on the #1 & #3 ribs. You may have to pull one out a little to get them in and the grounding wire tab but it won't be too hard.

    Be sure you have your wires started (but not sticking out at the inboard ends yet) and all your strap short ends out of the way and drop in the fuel tank next to the #3 rib and then pry the #1 double rib out enough for the tanks to drop in. The #3 won't move if you already secured with the braces we put in unless you didn’t screw them into the spar web yet. You can unscrew the braces from the web spar for now and that will let that rib flex a little as well. Usually a small "pry" right where the front fuel fitting will go (lots of welds around it and it's strong there and the fuel tanks won't bend/flex there probably) will do the trick.

    Before starting, set the fuel tanks in place and then place alot of weight on it. I used 2 of my 25 lbs weights from barbells and sandbags and lead bags and about anything else heavy I could use. This helps alot. Just place the weights right on top of the fuel tanks so it will press them down tight against the bottom straps. I also pre-bend the straps just a little where they hit the tanks on the corners.

    P1050692.jpg


    Check the bottom straps and be sure they are straight. The weights help take the slack out of them. Center the tanks in the opening and just look at the bottom where the cross over tubes (the short hoses connecting the 2 tanks if you have extended fuel) and be sure they are over the cut-outs in the #2 false spar and not touching anywhere.

    Take a look at the photo on the very bottom (can't get it up here for some reason) of this post of the pliers holding both ends of the straps. Do this first and just try and pull them together as much as you can before starting. It will get the slack out a little.

    It's probably a little easier now to go ahead and get your drag wires through the plastic tubing in the tanks and through the attach points but don't tighten them back up yet, just get them in place and tighten after you've installed the tanks.

    First, I use these small pliers to hold the bolt too get it started up through the bottom round strap fitting and then have some masking tape ready and wrap around the bolt just above the lower fitting to keep the bolt from slipping back out until I have the safety wire in place. Using the pliers, just get it started into the bottom hole and then you can get your hand up under the spar and push and hold it up from the bottom.



    Have the masking tape ready and just stick in on enough to temporarily hold the bolt in place until you can get the .041" safety wire around the 2 parts.



    Just get your wire into your safety wire pliers with a big loop on it and loop it over the top and bottom fitting while pushing the top fitting over the bolt. Then just snug it up to hold it all in place. Don't try to twist it and tighten it up....it's not strong enough and will just break the wire.





    Then take your big pliers and put the bottom over the whole bolt head and then just get onto the outside edge of the top round fitting and squeeze them together until you get plenty of bolt head above the top fitting. Then (while still holding it together with the pliers) grab your safety wire pliers and start twisting to take up the slack and hold what you've got and then you can remove your big pliers.






    Next you will notice that the bolt is too close to the fuel tank fitting to get the washer and nut over the top of it. I used a chisel against the small pliers handle to gently pull the bolt away from the fitting (there is lots of room inside the fitting as it's much bitter than the bolt diameter for some reason) enough to get the washer and then nut onto it and the nut started.



    Then I took a 3/8" open end wrench and bent it in the vice so I could get it in and onto the bolt head.





    The nut is not torqued but should be tightened until completely bottomed out on the bolt.

    This bolt is completely bottomed out so you can see the distance between the straps and the number of threads exposed past the nut. (about 6 or 7 threads exposed I think).

    P1050693.jpg


    Lastly, push the drag wires back through and tighten back to their original distance (around 1" right?) and lock them down and apply torque seal. Put a couple of wraps of friction tape on the outboard end of the plastic drag wire sheath that goes through the tanks and I put a small tie wrap tightly around the wire (over the electrical tape) just outside where the plastic tubing ends on the outboard end to keep it from sliding outboard. Like photo 258 in Dropbox Wing Manual except I add the tie wrap to be sure it doesn't slide. The friction tape doesn't hold all that well by itself.


    NOTE that the photo below shows how you can take your pliers before you even start and grab both ends of the straps and just pull them together as much as you can first. It will get them tighter before you start.


    Attached Images
    Last edited by Daveembry; 03-30-2019 at 06:11 PM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  6. #26
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    Default Re: Building the EX3 - Tips & Hints

    WINGS

    Finishing Up

    Pulleys and cables. Be sure to use some white grease on all the pins, etc that go through pulleys that have to turn of course. Sometimes putting the cotter pins in the pins that rotate can be hard unless you get a grip on the pin with some vice grips first to hold the pin while you bend the cotter pin.

    NOTE that where this bracket on the big pulley mounts to the tab we installed on the front spar.......you split the bracket so that it goes over the top and bottom of the bracket on the spar (with the hole in it that the screw goes into). If you don't, the pulley won't be able to spin inside the pulley bracket. You can see this in photo 270 on page 201.

    Also be sure you install the SC15000-041 bushing inside the TC9010-001 pulley as shown in Fig. W79, Page 201.

    P1050694.jpg

    When you secure the ends of the cables in the wings, just visualize where the cable is going and try to get it close to it and not just start wrapping it around drag tubes and wires and stuff and putting lots of tape all over it because in the end you are going to be reaching your hand and arm up into a 5" inspection hole to get the cable routed right and all that tape off. I always turn the ends of the masking tape back onto itself so I can grab the end easily months from now when it's gotten all hard and stiff and doesn't want to come off.

    P1050697.jpg

    This is the right wing but it's the same place here inside the wing where the cable will go. This cable that is at the top of the front spar will go DOWN and out the BOTTOM, under the rear spar and connect to the aileron so route the cable so it will be close to that spot. The length really doesn't matter as you will can slide as much cable back and forth as you need when you connect it.

    You will notice the threaded end of the cable goes out on the wing to attach later to the aileron.

    P1050696.jpg

    Also note in the photo the orientation of the pulley where it mounts onto the bracket. I start it out here at 90 degrees but of course the nut is castellated on here so it shouldn't be too tight so as not to allow it to move to where it wants to go later. Make sure you haven't gotten the nut too tight where it won't move.


    Fuel Tank Ground Wires

    Use a #28 drill bit to drill the holes in the ribs (just under the fairlead holes) and also ream the holes in the fuel tank tabs as they are too small. You can very easily bend those tabs out a little if you need some working room.

    A must for this tight work is a small pair of pliers with the angled tips. I use these $2 Harbor Freight pliers a HUGE amount throughout the build.

    P1050698.jpg

    I also keep a magnetic pick-up tool handy for all those times I drop a washer, screw, nut into a spar channel or other places that are hard to reach.

    P1050699.jpg


    Rib Spacer Blocks


    Being a retired builder I had some cedar "shims" laying around that work perfectly instead of the foam. They are made from lightweight cedar and a bundle is really cheap at Home Depot. As you can see, they are beveled so you can put 2 together and just slide them back and forth to make the 2 of them thicker or thinner to fit the exact distance you need between the tank and the #1 rib.

    P1050700.jpg


    P1050701.jpg


    P1050704.jpg


    After you slide them in and get them tight, just mark them on the sides (the width really isn't important, just that they are tight) and being soft cedar, they cut very easily (with a razor knife even).

    Mix up a little epoxy and glue the 2 blocks together and then put some on the front and back and stick them in place. Cleanup with denatured alcohol and some q-tips as always.

    P1050705.jpg

    These blocks are to keep the rib straight when you put on the fabric and shrink it as it will pull tightly (same reason for the #3 rib braces).


    Section 55, Drilling Additional Hole for Fabric.

    There are some problems here.

    First of all Fig. W82 makes no sense at all. I have a feeling that this is an old figure. I see no reason to drill another hole in the top tail ribs as the holes are already pre-drilled correctly. Perhaps this is an old figure when the tail ribs left this hole out for some reason. So I just skip that figure.

    None of the TOP tail ribs have holes directly OVER the rear spar and none of the caps should either. All of the bottom tail ribs and caps DO have fabric rivet holes over the spar.

    Double check that you did drilled the fabric holes in the tops of #5 and bottom of #3 capstrips. I just take a quick look at all the ribs top and bottom looking at the rivet holes. They should all be there and all line up except for the 1 on the tail end of the #5 rib clip on top since that one is centered on the rear spar because we had to rivet the back of it for the clip AND for the tail rib under rib #8 which we had to move aft per the manual Fig. 83. We have to add a rivet hole here because the one we normally use is directly under the spar attach fitting so we want an additional one.


    P1050708.jpg



    P1050707.jpg

    Again.....just take a stroll along "wing build lane "and look at each rib and see if the holes are all there and line up with all the other ribs both top and bottom.

    The last thing to do is get your alcohol and rag and remove all your sharpie markings and clean it up all nice. If you leave these markings on the metal and after fabric you use some alcohol to clean the fabric before or between brush/spray/paint coatings, it will melt the sharpie marks and bleed into the fabric! Ask me how I know.

    If you are going to cover now, blow out every inch of it. I use a leaf blower first and then use an air nozzle to get down in the spar channels, up in the false spars, all along each rib, etc. to be sure it's all out. You don't want metal chips, washers, rivet heads, etc. showing up later.

    I'll divert to tell one story Mitch told me once. A builder (in Europe I think it was) ask Mitch to take his newly finished plane up to test it. I don't think it was a Carbon Cub but Mitch of course is an aerobatic pilot so he flipped the plane upside down (that would be "inverted") and he said all kinds of "stuff" came falling out of the nooks and crannies over them where the builder had not cleaned it up good.

    So if I'm ever missing a dropped washer, etc. I look and look and look for it just to be sure it didn't end up in some part of the aircraft that I didn't see. I’m not going “inverted” but I still don’t want stuff rattling around.

    Go over everything on the wing with close examination to be sure you have every nut, bolt and rivet installed and torque sealed (except not castellated nuts of course) and you are ready to cover.

    LASTLY, I like to jump ahead to the finish manual and go ahead and install some of the hardware onto the inboard end of each wing cable now as it's a little easier than later having to do it standing on a ladder, leaning over the wing and there is no reason we can't do it now while it's really easy. Finish Manual in Dropbox, Page 223; Section 60 Aileron Cables. The very last couple of sentences are what we are going to do.

    Now let's just install 1 of the shackles AN115-21 onto each end of each cable in the wing. You will have to bend it open with a couple of pairs of pliers and then bend it back together. You can go ahead and pull the bolt AN23-10 and castellated nut AN320-3 and just stick it into one of the shackles holes and snug it up for now. Disregard photo 474 as we will be doing it by connecting 2 shackles together like photo 475 if you have extended fuel.

    I HAVE 30 HOURS AND 40 MINUTES TOTAL BUILD TIME ON THE WING.
    Last edited by Daveembry; 04-16-2019 at 12:08 PM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  7. #27
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    Default Re: Building the EX3 - Tips & Hints

    WINGS

    Getting ready for cover.

    If you are installing the AOA pitot tube in the RIGHT WING, then you will also need to install RUBBER GROMMETS MS35489-19 on the bottom of ribs #3, 4 and 5 for the 2 (green and blue) pitot tubes running down the inside of the front spar. This is shown in the Executive Glass Manual on the page 34 showing the installation of the pitot bracket, etc. Note that the drawing is only showing STANDARD FUEL and not the extended fuel with the 2 tanks so it only shows installing the grommets in ribs #4 & 5 but if you have extended fuel then you will also have to install one in rib 3. Cubcrafters only sent me 2 so I had to get Mitch to send another one but this may be corrected in your kit now. If not, call Mitch.

    P1050710.jpg


    COVER

    Check out the COVER MANUAL pages starting on 83 and going to 95. (Note again that Mitch has updated the Dropbox Cover Manual so page #'s and figure #'s may be different than I have listed)

    Page 87, Fig. C11. If you are installing the Executive Glass, look in that MANUAL to see the location of the magnetometer in this right wing bottom. It will have a grommet and patch. The new update has the magnetometer cover location on Page 89, C13.

    Page 87, Fig. C11. Same thing here. If Executive Glass you will have a patch that will go over the area where the AOA mast will come down through the wing behind the leading edge wing. The new update has the magnetometer cover location on Page 89, C13.

    Page 92, Fig. C16 is done at the factory so disregard.

    Page 93, Fig. C17 is partly wrong I think. It shows drilling a hole in the center of the clip (which is centered over the rear spar) and this one is correct. Look on the other tail ribs and you will see they all have this rivet hole. BUT.....the additional hole they want you to drill into the machined rib does NOT align with the other others on the other ribs. I moved it to drill it about 2.25" FORWARD of the most AFT hole already in the machined rib, or you can just take a long straight edge and put it in line with all the other tail rib holes in that location.

    P1050720.jpg


    P1050721.jpg


    Page 94, Fig. C18 is partly right. It was originally done for the EX2 wing which has a different flap false spar (it has a tank extension that is not in the EX3 kit.) The only thing you need to do here is to drill a rivet hole in the outboard side of the inboard edge of the flap false spar on rib #4. There is no need to add this hole for the tail ribs on ribs 1-3 because the fabric is going to be cut and glued there around the outsides of the fuel bay.

    P1050723.jpg

    First take your alcohol and clean rag and clean the wing entirely (after blowing out really good). Any little piece of metal shaving that gets under the fabric YOU WILL SEE.....and it's ugly.....so blow it out really good. Be sure and use the alcohol and remove any ink stampings that are on the aluminum (like leading edge skins, false spar, etc) because it will come off later if you use alcohol to clean the fabric before or between coats.

    Next, we will put tape over all the SS pop rivets, edges of all the leading edge skins; edges of tip bow and any other areas where the metal could be rough and might damage the fabric. In the VIDEO in Dropbox Mitch shows you all the places to tape except that YOU DO NOT HAVE TO PUT TAPE ON THE TOPS OF THE RIBS IF YOU ARE USING RIVETS INSTEAD OF RIB STITCHING. The tape is only used if you are going to rib stitch.

    So get out your glass cutting board, lay out some lines and get your razor blade handy. Wait.....we ARE talking about TAPE right?

    Take some of the green tape that came in the kit and lay lines out then use the compass and mark 3/4" lines on either side and use your razor blade and metal ruler and just cut across all the lines of tape. This leaves you nice little squares of tape which fit nicely over all those SS pop rivets everywhere.

    P1050712.jpg


    I also like to take something like the butt end of a drill bit and go around each rivet head and stick the tape uniformly down all around it. You can also use it to take out any little wrinkles in the tape. Remember, the fabric is going right over this and any wrinkles may show through to the finished job.


    P1050713.jpg


    Rib Lacing

    To keep the center ribs straight during the install and fabric shrinking, we will install the rib lacing. COVER MANUAL Page 94 shows you how as does the cover video. Be sure to straighten the rib good when you wrap it with the tape and before going to the next rib. Note how it goes straight across the top and bottom between #8 & 9 ribs (over all those drag tubes). Use the RM9031-001 Inter-Rib Bracing Tape in your kit. Note that I taped around the edge of the tip bow curve and I didn't need to do that since that inside edge is under the level of the fabric. I'm going to remove it around the curve but you do leave it at the leading edge where the fabric will touch that edge.

    P1050714.jpg


    P1050715.jpg


    NOTE: For some reason, the Wing Cover Video is only 1 hour in length when I go to the EX3 DropBox file from my PC, yet when I access it from my Ipad it is the correct length of over 1-1/2 hours. Don't know why. Anyway, just be sure you are looking at the full video length.

    THE VIDEO IS NOT CORRECT IN THE PLACE THE FABRICS ARE STARTED ON THE FRONT LEADING EDGE.
    The reason it moved was to allow more room for the fabric to go all the way to the aft side of the tip bow so no patch is needed there (as shown in the video). Here is the new starting point.

    First, I like to lightly scuff with scotchbrite pad the leading edge skins here I will be applying the glue on the first, top fabric and clean well with alcohol.

    We can mark our lines we will use to start the fabric on the leading edge. From the 2nd row of rivets down from the top, mark a line 3/4" below this row of rivets and snap a chalk line (or a yardstick and pencil) all the way down the leading edge and tip bow and then put a piece of masking tape on the bottom side of that line. This represents where the TOP wing fabric will start. It will install FIRST and the bottom fabric will overlap it by 1-1/2" and be on top.


    Mark a 2nd line 3/4" ABOVE that 2nd row of rivets and put some more tape ABOVE that line. Then you will apply PolyTak in the 1-1/2" area between the 2 lines of masking tape as you install the top fabric being SURE to remove the top line of masking tape (that would be under the fabric) as you go.


    P1050718.jpg



    P1050719.jpg



    AFTER INSTALLING THE TOP FABRIC, we will go back to this same row of rivets and measure UP 3/4"; snap another chalk line (this one will be on top of the top fabric) and put another strip of tape there to make a straight line and edge to start out the bottom fabric.

    So now you should have a line snapped 3/4" BELOW the 2nd line of rivets and a strip of tape BELOW that line. The bottom strip of tape will be our starting point for the top fabric and the top line of tape for now will simply be a nice edge for us to apply our glue to so it will be a nice, neat, straight line of glue under the fabric.

    Just follow the video here and put the aileron machined rib patch on and then start with the top fabric.

    To start the BOTTOM fabric, just do as I described above and re-snap your chalk line over the top fabric 3/4" above that 2nd row of rivet and then put another strip of tape below the starting edge of that top fabric on the leading edge to give you a straight glue line. Once again, glue between the tape lines and REMEMBER TO REMOVE THAT BOTTOM ROW OF TAPE AS YOU APPLY THE GLUE. IT SHOULD NOT STAY UNDER THE FABRIC.

    ALSO NOTE......At this point on the first fabric side (top fabric), only glue it along the leading edge skins and NOT along the carbon fiber wing tip bow. The video doesn’t show this until later when they show ding the bottom fabric......but the wing bow tip isn’t cut and glued down until the 2nd, bottom fabric is installed.

    SCUFF the carbon fiber wing bow tip areas where it will be glued (edge all the way around and the at, inboard end).

    Another thing we have to do is pre-glue a 1" wide strip around the landing lights; over the rib #3 capstrip and the forward and aft sides of the fuel bay. We will "activate" these areas later with MEK. Put plenty of glue in these areas.

    NOTE: I like using the smaller "specimen" cups to use when I'm not doing too much gluing at one time but what I did notice is that the glue seems to really dry out super fast in the small cups. So I use one of the larger paint mixing cups when I know I'm going to be working with alot of Poly-Tak for a longer period of time. Just let the brush dry in the container overnight and then pull it out the next day and it will be as clean as new. I don't use MEK, thinner, etc to clean these as it works better to just let it dry.

    Here is what Chuck posted in his post which is excellent. I'll just copy it here to make it easier....thanks again to Chuck & Ryan: (I also hate the word "liberal")

    1. The wing in the video does not have a landing light or extended fuel so a few tips follow. Before covering the top of the wing, Poly Tak is placed on the inner rib, and forward and aft locations where the fabric will eventually be cut out to expose the fuel tanks. A liberal ( I hate that word ) coat is applied and left to dry. I taped off the areas to assure a perfectly straight glue line, removing the tape before the glue was completely dry. (Dave Note: You can make it about 1" glue line between the tapes. Apply the tak and then pull the tape off before it dries.)



    Glue is NOT pre-applied in the notch with the nut plates on the forward and aft edges in which the cover is placed.

    After the first 250 degree shrink, the glue that had been pre applied is activated with MEK. After it dries the fabric over the tank is cut open, leaving about a 3/8 inch piece of fabric around all four edges. We cut notches in the fabric to avoid interference with the nut plates on rib number three.



    Gluing fabric on the underside of the third rib is a challenge made easier by using a flat piece of metal. On the first rib we simply trimmed it flush using a razor blade since the fabric is under no tension. (Dave Note: This is a great tool to make from some scrap aluminum and will be used in numerous places. After gluing and tucking in the fabric under the rib, I used the clothespins about every inch here and just left them until it dried good.)



    The fabric needs to be tightly secured to the notch where the cover sets. A tongue depressor was used to make sure the fabric was tightly secured to the notch as the Poly Tak dried. (Dave Note: DO NOT shrink any fabric here with the iron after you glue it as it will pull up from the glue. Glue the depressed area with the nut plates first and let it dry, then use your iron and iron the very edge down like it will glue before glueing)




    2. The same technique was used on the landing light.



    After the 250 degree shrink, the fabric over the landing light opening was marked with a pencil line about ¼” from the edge all the way around. The line was then dabbed with Poly Tak to prevent it from fraying. An Xacto or razor blade was used to cut along the line, keeping it as straight as possible. This was then glued in place to create a neat, straight edge.

    Aileron valley. (More from “Chuck & Ryan’s Post)

    The concave area behind the aileron can be problematic. It needs to be solidly glued with no bubbles. To assure a solid seal we deviated from the video in the following respects:

    a. No seam tape or masking tape was applied on the seam or over the rivets. Since the fabric is not shrunk in this area and it will end up with a total of three layers of fabric, I did not consider this to be an issue. This will assure maximum area of adhesion

    b. A coat of Poly Tak was brushed over the aluminum and permitted to dry thoroughly before any fabric was applied. Sort of a ‘primer’ coat.



    c. After the top fabric was secured along the top edge per the video, slits were cut at approximately 17” intervals with a straight scissors (not a pinking shear) so that smaller sections could be glued carefully one at a time both in the aileron valley and the flap area.



    d. The fabric was glued in place by brushing a heavy coat on the ‘primed’ metal, and then pressing the fabric in place. We thinned the Poly Tak slightly with about one part MEK to five parts glue. Thinning it really made it go on smoother and it sealed it tightly to the ‘primer’ coat of Poly Tak. Poly Tak was not brushed on top of the fabric at this time. Extra effort was made to assure the fabric was smoothed in place without any bubbles, using a plastic hotel door key as a squeegee. (I always keep those hotel keys. They come in handy for projects like this.)





    e. After the top fabric dried, a coat of thinned Poly Tak was brushed over the fabric from the top of the wing to serve as a ‘primer’ coat for the fabric overlap from the wing bottom. After it was dry, the same technique was followed to glue the fabric from the wing bottom to the valley

    f. The area was carefully inspected after it was thoroughly dry. Shining a light at an angle may reveal bubbles not otherwise visible. MEK was rubbed in those areas where we had the slightest concerns.

    g. An iron was NOT used anywhere in the aileron valley. Any shrinking of the fabric could create a bubble that will be hard to repair.

    It really came out well: smooth with no bubbles or bulges.

    DAVE NOTE: I didn't find it necessary to cut it in strips here but the key to notice is that this area is different because it's CONCAVE.......you do NOT try and stretch it or get it tight. When you glue it down, notice in the video how you apply the glue to the area and then DRAPE the fabric up over the concave area and keep it tight BEFORE it touches the glued area. (Don't let the fabric touch any of the concave area yet.....start from the bottom) You need to press down the fabric FIRST on the edge that is already glued and then work your way into the concave area being sure the areas in the glue are good with no bubbles before going further. Keep working towards the top edge being sure there are no bubbles as you go and don't pull on the top or try and get it tight or you will pull the fabric UP....out of the glue and it won't adhere to the concave area. (watch the video how he does it)

    UPDATE: This last wings (kit #4) I just did I tried something new and it worked really well. The problem (as I said) with this concave area is to get the fabric down tight with no air bubbles in the glue. You can’t pull, stretch, shrink it here because it will pull up. So what I did was to work on 1 section at a time.....say like from the flap bay over to the aileron hangar.

    The fabric at this point should only be glued to the very edge of either the top of bottom of the aileron cove depending on which side of the wing you are working on. You want to work on this area with the top of the wing down.....so you have good access to the cove.

    Now, take a wider brush (like 2”) and some very fresh poly tak that is nice and thin. A cool temperature helps too. Apply liberal amount of the glue from the glued edge only about half way into the aileron cover from left to right (like from that flap bay to the hangar or from the hangar to the wing tip bow section). Work quickly and use plenty of glue but smooth it out quickly with the brush so no big globs are there.

    Then lay the fabric up into the glue and just use your gloved hand to spread and smooth the fabric into the glue working from the glued edge to the end of the glue line. I don’t tape it off or anything, just get that glue about halfway up that cove (so just a couple inches or so). Work quickly and the main objection is to get that glue into the fabric and the biggest thing.....work the air bubbles out by pushing and rubbing into the fabric SIDEWAYS ONLY (from side to side) to get the fabric firmly glued and no air bubbles. If you do it quickly you can work any air bubbles out.

    Remember, you can’t push on the fabric much up or down towards the edge of the glue or you will actually pull the fabric UP out of that concave area and make air bubbles and pull it away from the concave cove. So keep that in mind. The main problem here is remembering this and that it’s concave so you can’t pull, push, stretch or iron this concave area so get it right now....with the fabric glued good and no air bubbles.

    ALSO, in the video Mitch says you can come back and iron out bubbles and wrinkles.....YOU REALLY CAN'T. Remember, the iron SHRINKS the fabric, so if you have a bubble or area not glued to the concave area, the iron will shrink and pull it tight and make it worse! You CAN use the very tip of the iron at 250 and shrink up any wrinkles or little bubbles by shrinking them down but just be careful and don't shrink any areas that are already tight or you will be sorry. Only use the iron on areas that have too much fabric (wrinkle).

    If you get a big bubble, it's best just to pull the fabric away and start over if still wet or if it gets dry, get a rag really wet with MEK and soak the bubble so it will reactivate the poly tak underneath, then work it in with your gloved hand until you can see the dark color through the fabric.


    Attached Images Attached Images
    Last edited by Daveembry; 06-18-2019 at 06:26 AM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  8. #28
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    Broken Arrow, OK
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    Default Re: Building the EX3 - Tips & Hints

    WING COVER

    NOTE: For some reason, the Wing Cover Video is only 1 hour in length when I go to the EX3 DropBox file from my PC, yet when I access it from my Ipad it is the correct length of over 1-1/2 hours. Don't know why. Anyway, just be sure you are looking at the full video length.

    OK to summarize what we did and the order we did it:
    • Blown out/cleaned the wing
    • Thorough last inspection for all parts, rivets and fabric rivet holes
    • Installed patches on the outboard rib and flap/aileron machined rib
    • Scuff and then pre-glued around the landing light; 3 sides of fuel tank bays; inside aileron cove.
    • Install top of wing fabric after scuffing leading edge skins and cleaning well.
    • Shrink at 250 and then use a soldering iron to burn through the protrusion (aileron pulley bracket).
    • Used MEK and saturated the pre-glued areas around the fuel tank to activate it and secure the fabric
    • Cut out fabric all around the fuel tank bays and glue them in using clothes pins on the inboard and outboard sides.


    P1050724.jpg


    • Use the small iron and MEK to go over all the glued edges to be sure they are flat with no wrinkles and no excess glue sticking up. I like to iron and then finish with a rag wet with MEK to go over the edges and glued joints to clean and smooth the excess glue. Careful not to saturate it, just a good wet rag and wipe over it. If it slides easily, leave it alone...it's good. If it's dry and rough and doesn't slide good, wet the rag more and go back over it.
    • Install bottom fabric. Note that by us moving the starting points of the fabric on the leading edge that we no longer have to install a patch on the inboard, aft end of the wing tip bow because the fabric will now reach to the end of it.
    • Shrink at 250 and use soldering iron to burn through the protrusions (see the video).
    • Shrink both sides at 350 degrees working from 1 end doing 1 bay at a time and then going to the other end and doing 1 bay.....work back and forth. Use small iron to get into small places.
    Last edited by Daveembry; 07-21-2018 at 07:50 PM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  9. #29
    Senior Member
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    Jul 2015
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    Broken Arrow, OK
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    Default Re: Building the EX3 - Tips & Hints

    WING

    Tapes, Grommets & Fabric Patches

    NOTE: THE COVER MANUAL IS WRONG JUST A LITTLE. Figures C9 is for STANDARD FUEL but note that it gives you the dimensions on where to put the pulley bracket covers on the top of each wing. Fig. C10 and C11 were replaced because of the changes in the leading edge skins. (because on the EX3 the skins go all the way around the bottom of the front spar and the measurements are given from that point and the figures in the cover manual are for the EX2 in which the skins did NOT extend to and around the spar and the measurements were from that point.) The patches go in the same places, it's just the reference points that changed.

    I have attached the 3 new EX3 drawings here. (in 1 pdf attachment) Here are photos of those attachments with my notes but you can download and print them clean from the attachment.P1050727.jpg

    P1050726.jpg

    P1050725.jpg

    So refer to these drawings and NOT the ones in the manual. Also, if you have extended fuel tanks (on the EX3) there are 1 additional patch (2 patches if you have the EX2) we have to add to the bottom of each wing (NOT shown in the Cover Manual but IS shown on the new drawings attached) and if you have the G3X we are going to add a grommet and patch for the magnetometer (2 total........1 round and 1 square) and a patch for the AOA pitot tube mast. These locations are shown in the Executive Glass Manual Page 38.

    UPDATE: AFTER I WROTE THE ABOVE, MITCH UPDATED THE DROPBOX COVER MANUAL BUT I NOTED SOME ERRORS ON THE FIGURES ON PAGES 86-89. IF YOU REFER TO IT. HERE THEY ARE:

    C10. LEFT WING. FOR THE FORWARD LEADING EDGE ROUND GROMMET AROUND THE BAY 4 AND FORWARD JURY STRUT TEARDROP PATCH, DELETE THAT PATCH IF YOU ARE USING THE EXECUTIVE GLASS G3X OPTION. THIS PATCH IS FOR THE STANDARD PITOT TUBE IF YOU DO NOT HAVE EXEC. GLASS. YOU WILL ALSO BE ADDING THE G3X PITOT PATCH AS SHOWN ON C13.

    C13. THIS IS FOR THE EXECUTIVE GLASS/G3X. YOU SHOULD DELETE THE SAME PATCH HERE ON THE DRAWING COMPLETELY. THERE WILL BE NO FORWARD PATCH BY THE FORWARD JURY STRUT PATCH IF G3X. NOTE THAT ON THE RIGHT WING YOU WILL BE ADDING THE RECTANGULAR AND A ROUND PATCH THERE ON THE OUTBOARD END FOR THE MAGNETOMETER.

    C14. ON THIS FIGURE, YOU WILL SEE A NOTE ON THE LEFT THAT SAYS "OMIT FOR STANDARD FUEL" AND HAS ARROWS POINTING TO BOTH THE FORWARD AND AFT PATCHES. THIS IS WRONG!. THERE IS NO STANDARD FUEL FOR THE EX3. YOU SHOULD DELETE/OMIT THE FORWARD PATCH THAT THE ARROW POINTS TO BUT DO NOT DELETE THE AFT ONE AS YOU WILL STILL NEED THAT ONE.



    After shrinking the fabric with the 350 degree iron and having ironed any wrinkles, bubbles, glued edges of fabric, etc, then I start to mark the fabric where the tapes and grommets/patches go. Use Fig. C12 on Page 88 to see the tape locations but NOTE THIS: Do NOT use this diagram for the patches used. There are several shown in the diagram you will NOT use. Use the attached drawing to show what patches to use. On the right wing we will add the magnetometer grommets and patches (2 total........1 round and 1 square) and on the left we will add the AOA pitot mast. On the attached figure for the Bottom View of the LEFT WING, note that you will omit one patch if you have the G3X.

    All the tapes on the center ribs (where you will install the rivets) will be the 2" tapes; the outside of the wing bow tip; the leading edge fabric joint and the inside of the aileron cove and flap false spar will be 3". Note that the leading edge 3" tape that goes over the fabric joint will be more forward than the drawing shows because we moved it forward. Unlike the video where Mitch says they put the 2" rib tapes OVER the 3" front leading edge tape, I like to put mine UNDER the tapes to keep that joint always out of the wind. Just take a straight edge and pencil and draw the locations of all the tapes, grommets and patches in. Use the grommets and trace them as well as the patches. I like a flexible metal 36" ruler to draw the lines on the center ribs since it bends and flexes easily. Center the tapes on the rivet holes. The ends of the 2” tapes I put about 1/2” short of the lower (most forward) line of the 3” leading edge tape and the aft end just drape over the back of the wing for now with enough tape to go halfway into the aileron cove 3” tape. I put the joints of the 2’ center rib tapes right in the center of that 3” tape and cut with straight scissors and then just butt the end of the top and bottom of the wing together there. You ever see it.

    I like to just take the drawings and lay them on the wing and use a pencil and mark everything. After I'm done, I recheck them and then I recheck them.

    P1050729.jpg


    Just draw the front, leading edge skin tape lines centered on the rivets which should be the center of our fabric joint. In the photo below, you can see where 2" tapes from a center rib will meet with the 3" tape on the fabric joint on the leading edge.

    P1050730.jpg

    These lines don't have to be perfect, they are just a guideline for us to put 2 coats of PolyBrush down and then the tapes and then another coat of brush over the top. Don't worry about pencil marks......they will cover up.

    TOP LEFT & RIGHT WING

    - Aileron Pulley Bracket cover grommet and patch. Note that the video is incorrect when it says to center the pulley cover over the pulley. That would not work. You want to follow the dimension directions where is says to come over 51.1" from the INBOARD SIDE OF THE #12 RIB to the center of the point of the aft end of the grommet and that same point is 6.8" from the aft edge of the false spar. You will note that this does NOT leave the pulley centered but to the inboard side of center.....which is correct.

    P1050732.jpg

    Put the cover in place and look and see that the slot cut in the metal cover aligns both with the top, center of the pulley in the bracket and also is in line with the center of the aileron hangar coming off the back side of the wing. (remember that the measurement to the center of that hangar should be about 51-1/8" from either side?) The aileron cable will come up through the wing from the bottom, front side and go over that pulley and then out the slit in the metal cover and then install on the aileron right where that center slot is on the aileron hangar.

    When mine was installed correctly it was like the photos below with about 2" from the top of the pulley bracket to the top, inside of the grommet and about 1/2" from the outboard side of the pulley bracket to the inside of the grommet





    ......but what will matter is that on YOUR build...that the cable will go from the top of the pulley, through the slit in the metal cover and right down the center of the aileron hangar.

    P1050733.jpg


    Next we will need to do the same as we did installing the reinforcement tapes on the tailfeathers. I like to take a sharp pencil first and poke a hole through the fabric in all the rivet holes (this leaves a mark with the pencil easy to see); then mark the holes well with a sharpie, then apply the reinforcement tape; burn the rivet holes through the tapes with the soldering iron and then install the fabric pop rivets (HDW-09-18900). Refer to the previous post about how to do all this.

    Put these tapes down nice and straight......you will see them when finished and a crooked line always attracts the eye (as does a straight one). If you get it crooked, pull it up and put it back down. Don't worry about it sticking, it will be held in place with PolyBrush and tapes.

    Note that you will not put rivets in the 3 intermediate tail ribs down between ribs 6, 7 & 8.

    P1050736.jpg


    Also, you will see that the last 4 aft rivet holes in the #5 capstrip will not be in line with the rest of the rivet holes on that double rib. The reason is they had to go down the center of the hangar. Just angle your tape over a bit as you get to those rivet holes.

    P1050738.jpg

    Put a 2" tape on the outboard and inboard sides of the fuel bay where the tank cover will fit. Just put it flush on the top with the inside of the bay and let it go outwards for the 2".

    P1050737.jpg


    FROM CHUCK & RYANS BUILD

    Landing Light Detail

    After the 250 degree shrink, the fabric over the landing light opening was marked with a pencil line about ¼” from the edge all the way around. The line was then dabbed with Poly Tak to prevent it from fraying. An Xacto or razor blade was used to cut along the line, keeping it as straight as possible. This was then glued in place to create a neat, straight edge.





    The shiny carbon fiber landing light support was not painted. We liked the look of the shiny black carbon fiber. But the line where the white painted fabric and the black carbon fiber came together did not align with the edge of the plexi glass. We wanted to clean up the look even though no one had noticed.



    Before


    The manual describes running a bead of clear silicone around the perimeter of the clear plexi. We skipped that part and instead sought a different solution to seal the light. We found an answer to both issues.

    McMaster-Carr is a terrific source of all sorts of items. www.McMaster.com. A roll of quarter inch wide by 1/16” black foam adhesive tape was used to provide both a straight line and a seal covering the line separating the white fabric from the black carbon fiber. Part number: 8694K111. Be careful applying it: It really sticks and there are no second chances.


    Tape in place.

    Now here is a little secret you won’t find anywhere else. Over time the non-adhesive side of the foam tape may stick to the plexi glass and separate if you ever have to remove it. To prevent that from happening, rub silicone lubricant on the surface of the foam tape. (Armor-All works well).

    I was pleasantly surprised at how tightly this tape sealed up the light. And the black edge now lines up with the edge of the plexi glass




    TROY BRANCH DID HIS A DIFFERENT WAY. He let his fabric go to the edge and painted it all black along with his leading edge.

    I cut mine toward the inside and glued it in the corner. If you look close you can see the fabric line. You want to make the cut as neat as possible to make it look good.




    It looked like this when finished.




    Next......We will mix up some PolyBrush and put down 2 coats in all the areas where the tapes will go. We will thin the PolyBrush 3 to 1 with the Reducer. Note that you can mix up plenty of "Brush" in advance and use a little as you go...it will not go bad. Just be sure you are storing it in an airtight container (old paint can or something I have alot of.......empty ice cream containers!!)

    Always keep the "brush" covered when you aren't actively using it. It's made with MEK/Reducer and it will evaporate very quickly and get thicker.....so best to just pour a little at a time in a smaller container to use when applying tapes, etc. I do not like the "chip brushes" for applying tapes as the bristles come out too easily and is a pain to get out of the PolyBrush and they will show up if you don't remove them. I use a more expensive, 2" natural bristle brush for this work. You can clean these in some MEK.

    I like to also use a small paint mix container with a lid that I can seal it up good between coats.

    P1050734.jpg


    Attached Files Attached Files
    Last edited by Daveembry; 10-25-2018 at 02:10 PM.
    Dave Embry
    "You only live once.....
    ..but if you do it right.....
    ....once is enough."..

  10. #30
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    Join Date
    May 2018
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    Ramona
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    34

    Default Re: Building the EX3 - Tips & Hints

    Dave... as usual your information is priceless!
    i only wish I had emailed the forum sooner.
    many,many thanks.
    Dewey

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