Installing boom cover - nervous

[lucidchaos]

I am a bit nervous about installing the boom cover. Specifically, it has maybe a half MM of clearance between the cover itself and the frame. To get the boom properly secured I normally torque the longer screws a fair amount.. I would think the CF deformation would stress the cover.


It sure is pretty now. I want to make sure it stays that way when it is all put together.

[willlig756]

Ill have my boom cover and canopy this week and see how it fits. I got the same blue one as you did.

[Simon_S]

Mine was the same, perhaps worse about 1mm of clearance between frame and cover. It went on fine but after a few flights a hairline crack started to appear underneath. I added a bit more epoxy on the inside of that area and all is well so far. (for at least 20 flights now).

[lucidchaos]

Thanks for sharing, Simon. What do you think of shimming between the cover and the frame? I would think some wide shims would work well. I am unsure where to get them though.

[Simon_S]

Maybe shims would work, I don't see any harm as long as they're not metal. I'd prefer my method, as a stressed part actually becomes stiffer, and just put it on as is. If you're too worried, perhaps apply a thin layer of epoxy on the inside of the cover which can act as a shim,

[lucidchaos]

Originally Posted by Simon_S

Maybe shims would work, I don't see any harm as long as they're not metal. I'd prefer my method, as a stressed part actually becomes stiffer, and just put it on as is. If you're too worried, perhaps apply a thin layer of epoxy on the inside of the cover which can act as a shim,

This isn't a bad idea. I tested the fit again and the only real gap is where the bottom screws go.

I'm probably just a little OCD... I have all the parts and haven't even started the build yet.

[rcflyerheli]

Another idea is to take some epoxy resin and some fiberglass cloth and essentially build up the inside of the boom cover where there is a gap. It will also reinforce the boom cover.

Depending on the thickness (weight) of the cloth, you can do it in multiple layers, just sand the inside of the previous layer to insure the next layer will stick. I do this as a matter of recourse with my Goblin canopies at the sharp curve where they usually crack from putting them on and off. What I actually use in this application is unidirectional CF which is .007 in thick. I have never had one crack after the mod.

[lucidchaos]

It looks like these boom covers, while pretty, do require a bit of work for installation. I will need to cut/grind/sand the front left corner of mine to clear my tail servo block.

For the time being I went back to boom struts until I have a few flights under my belt with the new build. I'm glad I did too, as I had a wicked tail vibe/resonance issue I need to solve first.

FWIW, the bottom of the CF looks very well reinforced, but adding a wet layer of fiberglass and epoxy when I bolt it on should help it retain the shape. I've elected against shims.