Re: Heat-PROOF engine mount tubing?

Gordon S. Hlavenka wrote:
> I've been experimenting with a no-wadding chute packing/deployment
> method and run into a snag.
>
> What I've done is to run a stuffer tube all the way up to the
> nosecone,
> ...
> This scheme has worked nicely, with one problem: I'm using Estes BT20
> for the stuffer, and it burns completely through after 4 or 5 flights.

What motors are you using? Larger motors have a larger ejection charge since the manufacturers assume the rocket has a larger volume to evacuate. Confining that ejection charge to a BT-20 means the heat doesn't dissipate as fast as designed.

If you can afford it, buy plenty of BT-20's and (re)build the rocket so that the stuffer tube is easily replaced.

Or, buy a full-length BT-20 coupler (or a bunch of regular couplers) to line the BT-20 to prolong its life. Use epoxy to glue the coupler(s) in place, thereby adding another layer of protection. Or buy a T-20+ (Totally Tubular) or T-20Q (BMS) to slip over the outside of the BT-20 to increase the lifespan of the stuffer tube.

Or get some Nomex paper (Totally Tubular) to line the stuffer tube. Here's how I do this: Use the thinnest paper, long enough to reach past where you've observed the charring of the burnt tubes. Wrap it into a cylinder and tape it to the end of the motor. Then insert the motor as usual, slipping the paper up into the stuffer tube first.

--
Steve Humphrey
(replace "spambait" with "merlinus" to respond directly to me)
.