Chuck and Ryan's Build Tips

[Daveembry]

Dave:

You questioned how I curved the tape at the base of the rudder. The tape that makes the bend where the top of the fuselage and base of the rudder meet was probably the most difficult. Here is how I did it.

1. About a 10” length of tape was used. The forward end was cut straight and the aft end was rounded.

2. The aft end of the fuselage tape was cut rounded and goes over the 10” tape, over the straight cut edge with about an inch of overlap. The aft rounded end of the 10” tape goes over the forward end of the tape at the base of the rudder, which was cut straight.

3. Gently fold the 10” tape in half to create a ‘soft’ centerline.

4. Using the small iron, shrink the center only of the tape along the centerline. This takes a bit of patience and care. Avoid shrinking the outside edges. This will cause the tape to curl, which is exactly what you need to make it conform to the curve. It may take several attempts to get a satisfactory result.

5. The width of the tape where the center is shrunk will be a bit less than typical, but no one will ever notice once it is done. The final ‘massaging’ may require a higher temperature to get a proper fit.

Attachment 5672

Once the final paint is on the imperfections will all but disappear.

Attachment 5671

Hope this helps

Thanks much! I could see in the dropbox CCK picture/cover file a picture that looked like there were 2 pieces and I just couldn't get that to work. Works great with the 3 pieces like you say. Thanks again. Another place a simple manual mention would have saved alot of time and cursing!

[ceslaw]

Engine Heat

During the first ten hours of flight the engine was run hard to keep the cylinder head temperatures around 420 degrees as part of the break in procedure. On the first flight we noticed that forward cylinders ran significantly cooler than the aft cylinders. To equalize the temperatures foil tape was placed on the lower three quarters inch of the cylinders to direct more air aft. This worked well equalizing the CHTs, but was a less than elegant solution long term. So we decided to fabricate a permanent solution.

All the hardware was left over from the parts supplied by Cub Crafters. Here is the list:

1. (2) thin aluminum plates, cut to 5” x 2 5/8”
2. (6) AN526C832R6 screws
3. (6) MS21059L08 nut plates
4. (12) HDW-04-00981 rivets
5. (6) 960-6 washers

Two aluminum plates were cut 5” x 2 5/8” from scrap used used on the leading edge of the wings. The corners were rounded. Holes were drilled as noted, 3/16” diameter.

IMG_8898A.jpg


Three nut plates were placed on each of the engine air intakes, spaced 1 ¾” apart and ¾” below the top edge. Cherry pop rivets were used to secure them. On the starboard side be careful not to drill through the adjacent carbon fiber.

IMG_8884A.jpg

IMG_8887A.jpg

The extra holes in the aluminum plates make adjustment easy.

IMG_8921.JPG

A dab of orange Torque Seal will make any loosening of the screws apparent when completing the pre-flight inspection. Ryan vetoed the idea of painting the aluminum plates with high temperature black to make them less conspicuous, noting the paint would deteriorate from being hit by bugs and cleaning.

[Daveembry]

Screw up

After gluing the grommet and applying the doily for the aileron cable cover on the top of the wing, I discovered it was about an inch off. So the issue was how to remove and replace them.

I brushed a liberal (I hate that word) coat of Poly Brush reducer over the doily to soften the Poly Brush and it quickly came loose making it easy to peel away. MEK was not used because it is a bit too aggressive. The plastic grommet was also loosened with the reducer brushed along the edge and popped off easily.

Attachment 3812

A bit of clean up with the reducer and only a faint shadow of the misplaced items remained.

Attachment 3813

A new doily was made from a scrap of light weight fabric. It is nice to know that screw ups can be fixed.

Attachment 3814

Chuck. Just wondering how you were off an inch? I'm about to attach mine but I just used one of the covers as a guide and want to be sure I have t missed something.

[ceslaw]

Been a while, but I suspect I used the cover as a template, placed a pencil mark on the fabric, then put the doily edge on the pencil mark, failing to take into consideration that the doily needs to be centered under the cover. Stupid error, but fortunately easily corrected.

Made the error on only one wing, so I don't think it had any thing to with the manual or the diagrams showing the locations. My error.

Chuck

[Daveembry]

Been a while, but I suspect I used the cover as a template, placed a pencil mark on the fabric, then put the doily edge on the pencil mark, failing to take into consideration that the doily needs to be centered under the cover. Stupid error, but fortunately easily corrected.

Made the error on only one wing, so I don't think it had any thing to with the manual or the diagrams showing the locations. My error.

Chuck

OK good. I was looking at the original position you had and it looked as if it was almost correct (not centered ...but off-center which meant you must have used the cover). I can see a mistake if not using the cover as a guide and just centering the grommet over the bracket instead of using the cover but like I say....it did appear as though you had used the cover so just wanted to be sure I wasn't missing something. Thanks!

[Cubrath]

Make sure the grommet is far enough forward to allow the aileron cable to enter without touching the grommet. I took a welding rod, sharpened the end and ran it between the two pulleys so I was sure it would clear. After I marked that hole, I taped the aluminum cover to the grommet and positioned it in line with the aileron hanger so it was lined up as close as possible when you do the the final assembly. If I remember correctly, it needs to go farther forward than you think to clear the cable.

Mike

[ceslaw]

Mike

Excellent tip!

[Daveembry]

Make sure the grommet is far enough forward to allow the aileron cable to enter without touching the grommet. I took a welding rod, sharpened the end and ran it between the two pulleys so I was sure it would clear. After I marked that hole, I taped the aluminum cover to the grommet and positioned it in line with the aileron hanger so it was lined up as close as possible when you do the the final assembly. If I remember correctly, it needs to go farther forward than you think to clear the cable.

Mike

Mike, I've just installed that and read and re-read this info but I can't seem to visualize it. What 2 pulleys did. You line up? I guess this pulley bracket will have the cable that comes up the strut and come in through the patch on the bottom side of the leading edge? But at this point in the build, there is no pulley there. Did you just align it with the patch where the cable will go through.

The manual basically says ..... "install the grommet and patch using the cover as a guide". No mention of this of course.

I put the cover over the grommet/pulley bracket and it will only move so far where it lays flat onto the grommet and doesn't hit the top of the bracket. I could move it just a little bit more forward but not much. Because then, the cover hits the bracket and won't lay flat.

P1010541.jpg

[Cubrath]

Dave,

Thats what I get for using my memory. You are right, the second pulley is the one on the strut. I was thinking it was the one on the back of the front spar and it's not. Take a thin rod and lay it over the pulley above the rear spar and run it down to the approximate exit of the cable. It does not have to be exact. I can't tell for sure but your grommet does not look far enough forward. Sorry for the crude drawing, couldn't find a good picture!

Mike

[Daveembry]

Dave,

Thats what I get for using my memory. You are right, the second pulley is the one on the strut. I was thinking it was the one on the back of the front spar and it's not. Take a thin rod and lay it over the pulley above the rear spar and run it down to the approximate exit of the cable. It does not have to be exact. I can't tell for sure but your grommet does not look far enough forward. Sorry for the crude drawing, couldn't find a good picture!

Mike

Thanks! You are right. I did that with a rod and sure enough....it was not far enough forward. Good catch and thanks so much! Why isn't this stuff in the manual (well...."video" I guess since there is no wing cover manual)? I guess you wait until it's installed and painted and later find it out. How many have done that I wonder? Thanks again....save my rear on that one just in the nick of time.