AT M1350 motor assembly

[David Schwantz]

Upon assembly of my 4 fuel grains in the liner I have a gap at one end. Orings are installed between the grains. forward closure insets into liner but not as much as the gap is. Should the remaining gap be placed against the nozzle or at the top near the delay grain?

 

[mikec]

forward closure insets into liner

Not supposed to, the seal disc goes into the liner on the forward end and the nozzle with its O-ring goes into the liner on the aft end. Check the instructions again.

[Oops, never mind, I read M1315. Sorry.]

 

[Steve Shannon]

Upon assembly of my 4 fuel grains in the liner I have a gap at one end. Orings are installed between the grains. forward closure insets into liner but not as much as the gap is. Should the remaining gap be placed against the nozzle or at the top near the delay grain?

Doesn’t matter.

 

[Steve Shannon]

Not supposed to, the seal disc goes into the liner on the forward end and the nozzle with its O-ring goes into the liner on the aft end. Check the instructions again.

[Oops, never mind, I read M1315. Sorry.]

Good catch. I thought he was talking about the seal disk when he clearly said forward closure.

 

[anbhtblr]

Do you have the forward closure far enough into the case so the case edge and forward closure shoulder are even and will allow the forming of an effective epoxy seal? I struggled to achieve this when assembling an M1350, it took a lot of force/effort. If you have the epoxy seal under control then I don't think a small gap is a problem.

 

[David Schwantz]

Actually upon looking into the case with a flashlight, at the nozzle there is a counter bore. 1/4" of the liner slides over this and around the nozzle. I installed the liner with grains and the large gap down into the case first, towards the nozzle. This allowed the case to slide over that counter bore. I then used a dowel large enough to cover the grains but still go into the liner and pushed grains down onto nozzle. So now all that was left is the gap that the forward closure goes into. Everything now fits tight and is butted up to nozzle and closure. And yes, before epoxy went in, I made sure the closure and the case were even. All looks really good. Can't wait to light her off.

 

[n3tjm]

I really really want to fly an AT M1350 . Good luck with your flight and make sure you post plenty of pics and videos.