Question on Aerotech Arreaux build

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... You brought up something I just started thinking about --> with motor selection in general, and reloadable motor systems in particular, how do you put in a motor retainer when the various lengths...vary?

The aft closure on reload hardware is a larger diameter than the MMT, so it is a stop. A motor retention system for MPR/HPR typically has a permanent male threaded collar bonded to the aft end of the MMT that the aft closure fits into. A female threaded ring is screwed onto the permanent collar and secures the aft closure on the motor. Works for single use as well (if it has an large motor ring at the base).

Greg
 
I just flew my arreaux stock on a HP G138 yesterday. Had to walk like two miles to retrieve it but it was in perfect condition. I would add a retainer if nothing else though. It'd be nice to put an H in it!
 
dpower said:
I've always used the cooling mesh & baffle arrangement, works fine. Ditto for the included shock cord. I do recommend leaving off the motor hook & block, since they really limit motor choices. I prefer masking tape retention or Estes retainers on AT kits, both work great. The Estes retainers don't work so well with AT HPR style cases, though.

What happens with the HPR cases? I ask because I got a Leviathan recently and hope to put my beloved 29/180 in there. I suppose I could spring for an Aeropack though the retainer would cost more than I spent on the whole kit to begin with!

I just flew my arreaux stock on a HP G138 yesterday. Had to walk like two miles to retrieve it but it was in perfect condition. I would add a retainer if nothing else though. It'd be nice to put an H in it!

Awesome! I did L1 on a near stock Arreaux, H128. It was a great flight and I encourage you to let it rip! At least, if your tracking skills and hiking shoes are up for it.
 
What happens with the HPR cases? I ask because I got a Leviathan recently and hope to put my beloved 29/180 in there. I suppose I could spring for an Aeropack though the retainer would cost more than I spent on the whole kit to begin with!

Wildman sells them for cheaper...
 
What happens with the HPR cases? I ask because I got a Leviathan recently and hope to put my beloved 29/180 in there. I suppose I could spring for an Aeropack though the retainer would cost more than I spent on the whole kit to begin with!
The Estes retainers are designed for aft closure thrust rings about 1/4" in height, which includes the AT 29/40-120 RMS case, and all the 29mm MPR single use motors. The AT HPR style cases have aft closure thrust rings about 3/8" in height (0.368" exactly), such that there is only about one turn on the threads before tight (even less in some cases). Some folks have used them OK, I'm uncomfortable with only 1 thread. The Aeropack (and presumably the new Aerotech) retainers allow for the thicker rear closure. The CTI Pro29 cases have 1/4" rear closure, so they'll work fine.
 
The Estes retainers are designed for aft closure thrust rings about 1/4" in height, which includes the AT 29/40-120 RMS case, and all the 29mm MPR single use motors. The AT HPR style cases have aft closure thrust rings about 3/8" in height (0.368" exactly), such that there is only about one turn on the threads before tight (even less in some cases). Some folks have used them OK, I'm uncomfortable with only 1 thread. The Aeropack (and presumably the new Aerotech) retainers allow for the thicker rear closure. The CTI Pro29 cases have 1/4" rear closure, so they'll work fine.

Great; thanks for the information.

CzTeacherMan said:
Wildman sells them for cheaper...
Hah, I got my Leviathan even cheaper than that!
 
Specifically, regarding the "permanent cooling mesh" and ejection gas baffle...I think I have read people stating that their Arreaux's (and other Aerotech kits) have lawn-darted or had other problems, with the suspicion that the "permanent cooling mesh" was getting clogged with engine ejection debris over time.

Have people here found this to be the case? If so, would I just be better off not installing the mesh, but instead using a nomex chute protector? Or are there other work arounds? Or is the mesh not a problem?
Ive used the mesh in all my AT rockets with never a problem. Pulled out the mesh once on a Initiator. Didnt need to and havent done it since on any AT rockets. As long as I can blow air thru the frame and out the back with no problem I leave it alone.But If your rocket warrants the nomex by all means go for it.
 
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