Building Up The Thickness Of The End Of A 1/2" Nom. Dia. Body Tube

On my X-wing, for the engine pods, I'd like to build up the thickness of the 0.544 O.D. BT's.

I've got some 1/8" thick balsa, but not sure the best way to cut small donuts out of it?

Also thought about simply laminating paper, glued to the inside.

Any ideas on how to do this, without adding a lot of weight?

Thanks in advance!

Couplers glued in?

That's an option, but they aren't thick enough. I'd still have to glue something else inside of the coupler.

Burn some 13's then punch out the nozzles?

Oh: 1/8 balsa can probably be disced with a piece of sharpened brass tube.

dhbarr said:

Burn some 13's then punch out the nozzles?

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That would work..

Wanted: 13mm engine casing... ;-)

dhbarr said:

Oh: 1/8 balsa can probably be disced with a piece of sharpened brass tube.

Click to expand...

I'll give that a try.. I've got lots of little pieces of steel tubing I can use as punches... great idea.

Thanks!

Umm, why?

If it is for cosmetic reasons, just cut out 1/8” segments of body tube, trim to fit snugly, and glue them is on the front and the back of the body tube just inside the edge. Could also buy some engine blocks, more expensive but a bit more elegant,

All of the above or you could build up layers of tape cut to your exact requirements.

BABAR said:

Umm, why?

If it is for cosmetic reasons, just cut out 1/8” segments of body tube, trim to fit snugly, and glue them is on the front and the back of the body tube just inside the edge. Could also buy some engine blocks, more expensive but a bit more elegant,

Click to expand...

Yes, simply for appearance and durability reasons. As it is currently it's really thin and flimsy.

I was wanting a nice smooth radius in the inside, to simulate the housing of a jet engine, something aerodynamic.

Hmmmmm.
Functionally these are the opposite of aerodynamic, as small long tubes, even if left with nothing inside, they will function aerodynamically as if the had plugs in them.

I am a bit surprised, if these are standard body tubes, that they are so flimsy. They aren’t structurally weight bearing, so not sure they really need to be built up for strength.

Cosmetically you won’t be able to see very far INSIDE the tube. I would just paint the inside black, with your inside nozzle piece a contrasting color so it shows up well.

One idea would be to cut two “nesting” inserts, larger 1/4”, put it inside maybe a millimeter back from the edge, painted a contrasting color from the outer tube (yes I mix English and metric units.). Second is 1/8” nested just inside the 1/4” piece a millimeter further back, another contrasting color. It will not add much mass, it will strengthen the forward edge of your tube (although I am not convinced you need it.)

Will kind of look like the textured look on your first pic. Not sure if that was intentional or not.

How about BT-5 centering rings or plywood blocks?

https://www.erockets.biz/semroc-plywood-block-bt-5-pkg-of-6/

https://www.erockets.biz/semroc-centering-rings-bt-2-to-bt-5-6pk-ra-2-5/

https://www.erockets.biz/semroc-centering-rings-bt-1-to-bt-5-6pk-ra-1-5/

6 for $1.39, three day priority mail delivery . First class is cheaper, maybe a day longer to deliver.

Inside the bt-5? 13mm engine blocks. You might want to peel the insides a little, but soak CA into them and sand 'em smooth.