Liner length question

[peter_stanley]

I was prepping for this weekend's launch last night and assembled a 38mm reload in a snap-ring motor. I've assembled these before, but the liners have always been pre-cut before I got them. When I test fit the forward closure, liner, nozzle, and thrust washer, there was about 1/8" gap between the thrust washer and snap ring groove.

I wasn't sure if this was safe so I cut another piece that fit perfectly. My question is, is the one that is short safe to use in the same motor later, or should I cut it down for a shorter motor. I don't want to waste it if not necessary.

thanks,

Peter

 

[blackjack2564]

You do not mention the maker of the re-load. That said, it is common in the AMW loads I use on a regular basis. I just pull the forward closure tight to the snap ring to avoid the sudden jolt forward, caused when the motor pressurizes.

Not stated as necessary by any means, but makes me feel better.

To be more direct to your question......yes its by design and yes you can fly the 'shorter" liner safely.

The flange or recessed part of the nozzle and forward closer will fit inside the liner, leaving the wall of the case protected. The 1/8 play is there for ease of assembly. You may also notice that most motors once assembled , when shaken, the grains rattle, they also are not a tight fit too allow for expansion that can be caused by any number of reasons.

 

[peter_stanley]

Thanks Jim! That answers my question. The reload is from a Thunderflame mix kit, made by me. I believe the snap ring case I'm using is similar to the AMW hardware. Btw, you may not remember, but I met you at Orangeburg a couple months ago. Are you going to be there this weekend?

 

[blackjack2564]

Hi Peter!
Won't be able to make it, still have not made it back yet after LDRS.

Good luck with your upcoming flight. Yes they are very similar cases and Tom does a nice job with the class.
Semper Fly!