Chuck and Ryan's Build Tips

[PBY Catalina]

Relocating the Kannad ELT. ......

Thanks Chuck ! Another very good suggestion !
But now I don't know what I'll do any more !
I will show you my final mounting.
Now, I'm busy building a wing-rotator from scrap...

Two questions induced by your last pictures Chuck:

1- The VELCRO that you use for the fire-extinguisher, is that the one from CC ?
2- I see you build an EX2. Will you use the std forward stick ? Me, I don't like the PTT position on that one (too low!) and I'm looking to put a better grip. The EX3 one is very nice, but apparently not suitable for the EX2. Any suggestion ?

[ceslaw]

Two questions induced by your last pictures Chuck:

1- The VELCRO that you use for the fire-extinguisher, is that the one from CC ?
2- I see you build an EX2. Will you use the std forward stick ? Me, I don't like the PTT position on that one (too low!) and I'm looking to put a better grip. The EX3 one is very nice, but apparently not suitable for the EX2. Any suggestion ?

1. Yes indeed the velcro comes with the CC fire extinguisher kit. The price was not much more than ordering just the fire extinguisher from another source. Note that CC has two different sizes available. I opted for the larger.

2. I am using the standard CC stick. It worked just fine, except the PTT seemed a bit awkward. That was solved by machining replacement throttle knobs with a PTT. The PTT on the throttle seems much more natural so we almost never used the stick mounted PTT. With that mod we have been quite comfortable with the stock CC stick.

Here is more info on the PTT knobs. https://forum.cubcrafters.com/showth...ll=1#post11693

There are after market replacement handles that can be made to work. Tosten is one that will make one to fit the CC stick. https://tostenmanufacturing.com/prod...aircraft-grip/

[ceslaw]

Options

Once the Cub is covered, extending any wires or cables to the rear of the plane presents a challenge. So, a chase was created by placing a six-foot length of fuel line with an ID of 3/8” on the left side, extending from the forward end of the extended baggage to above the location of the access port five feet forward of the tail. If we opt to add a locking tail wheel, which requires a cable, this will make that project much easier. https://tundratailwheel.com/

I like options.

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[ceslaw]

Boots. The electronic ignition circuit breakers are located below the seat on the left side. Cub Crafters provides white rubber boots to insulate the screws holding the wire terminals in place. Those boots do not seem up to the task. We replaced the boots with heat shrink.

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[Andy]

Cub Crafters provides white rubber boots to insulate the screws holding the wire terminals in place. Those boots do not seem up to the task.

No insulation at all on the ignition circuit breakers of my FX-3. All wiring installation is done by the factory. Did they forget or are the boots a special bonus for kit builders?

[aeroaddict]

I did not recieve enough boots to cover panel electrical hardware in my kit. But I did not do the CC panel, did my own Dynon panel. You might not get the boots for breakers unless you do one of their panels.

I did not use heat shrink or boots on my breakers. It would be difficult to use either if doing a bus bar configuration.

[ceslaw]

No insulation at all on the ignition circuit breakers of my FX-3. All wiring installation is done by the factory. Did they forget or are the boots a special bonus for kit builders?

Don't know Andy. The boots were included with the CC wire harness for the EX. Perhaps they are no longer used since they were not really suited to that application. That is a protected location under the seat so likely no covering of those terminals is needed.

[ceslaw]

A Pressing Decision. My wife’s expensive iron was used to shrink the fabric on our first Carbon Cub. It worked fine except for one thing: the temperature had to be constantly adjusted, fluctuating significantly. For our current Cub a Fabric Pro Digital Covering Fabric Iron was purchased. What a difference! The temperature holds within a couple degrees of the set temperature. It is more compact and easier to maneuver. This needs to be at the top of the list of mandatory tools for this project.

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With the more precise temperature, shrinking was done in smaller increments, starting at 250, than 295, than 320, 330, and finally the final shrink. This reduces the possibility of overstretching one side despite alternating side to side. The repeated ironings also reduce the possibility of missing an area. Finally, one needs to justify the purchase by using it as much as possible.

Aircraft Spruce is one of several sources. https://www.aircraftspruce.com/catalog/cspages/fabricpro09-05728.php

[ceslaw]

Fabric Issue. In Mitch Travis’ now classic video as well as the current EX2 build manual the fabric forward of the fabric spacers is glued to the longerons, so fabric ends up between the boot cowl and the interior panels. With the G3X this creates a problem on the right side, since that fabric interferes with the G3X backup batteries.

The solution was to cut the fabric leaving a half inch extending forward of the fabric spacer and folding a half inch onto the back side. But extra care was taken to assure there would be no issue of the fabric pulling loose when shrunk.

The first inch of the leading edge of the fabric spacer was buffed with sand paper and a gray Scotch Bright pad to roughen the surface for better adhesion. As per the manual, Poly Tack was painted on the leading one-inch edge of the fabric spacer, using tape to assure a sharp line. After it dried a second coat was applied. Poly Tack was applied to the back side of the frame as well.

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Days later, when the fabric was applied, another coat Poly Tack was applied, the tape removed and the fabric pressed into place, leaving the forward piece of fabric hanging. The surface was then rubbed with MEK activating the several layers of dried Poly Tack and assuring a solid connection.

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After the first 250 degree shrink the leading edge of the fabric was cut with the pinking shear a half inch forward of the fabric spacer. The leading edge of the fabric spacer was pressed with the hobby iron to assure a sharp line when the fabric was folded over on the back side. The half inch section was then pressed into place with a liberal (I hate that word) amount of Poly Tack.

The decision to make this modification was the source of some concern that the connection would not be strong enough to withstand a 350 degree shrink. But this connection is functionally equivalent to those around the two windows so it seemed like a good option. We saw no issues whatsoever when the fabric was shrunk.

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The final result is a nice clean line with no fabric to interfere with the fuel lines, wiring, or back up batteries.

Addendum. After the fabric was installed, I watched Mitch Travis’ G3X installation video. The EX3 wired in that video had the fabric secured the same way. Although I have not seen any documentation elsewhere, it appears Cub Crafters has already adopted this revision.

[Andy]

Although I have not seen any documentation elsewhere, it appears Cub Crafters has already adopted this revision.

Fabric on my FX-3 ends in the same place shown in your photos. I have the right front panel removed so I'll check if I can see the wrap round the fabric spacer next time at the hangar.

Thanks for adding to my knowledge base. I had no idea what that piece of sheet metal should be called.