nylon tube o-rings

[dbailey]

Coach Chuck,

In your knot tying video, I think that you advocated for using RC antenna tubing as the o-rings. Did I understand correctly and is that a good choice for SO helis? If yes, I found some online that are 3mm OD and 1.5mm ID. Is that the right size? Seems moderately hard to get the ~3mm wide rubber through the first time. But seems even worse to get the ring over the hook on the heli while it is stuffed w/ said rubber!

DB

[bjt4888]

Coach Chuck,

In your knot tying video, I think that you advocated for using RC antenna tubing as the o-rings. Did I understand correctly and is that a good choice for SO helis? If yes, I found some online that are 3mm OD and 1.5mm ID. Is that the right size? Seems moderately hard to get the ~3mm wide rubber through the first time. But seems even worse to get the ring over the hook on the heli while it is stuffed w/ said rubber!

DB

Here's the tubing you'll want for SO helis: https://www.dubro.com/products/30-pushrod-housing

It's 3/16" outside diameter and 1/8" inside diameter. To effectively use this type of o-ring, you'll want to use a "reverse-s" style shaft hook. This shaft hook centers a hard plastic o-ring nicely. The plastic o-ring tends to climb and wrap around a rounded or diamond shaped shaft hook. There's a video on NFFS for bending the reverse-s hook. I use them too for AMA class airplanes that my students build.

Coach Brian

[coachchuckaahs]

Coach Brian posted the correct material for these helis. The 3mm tubing is good for planes using motors no more than 3/32" wide.

For the 3/16 tubing, I have found a thickness of 1.5mm is needed, or the o-ring will twist and fail.

I use a piece of 0.018" wire folded in half to pull the rubber through the ring, like a needle threader

Coach Chuck