Motor Retainer

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A

Austin

Well, after the CATO of my Harpoon, I was left without a PML Motor Retainer for 29/38mm. I had some sheet metal around, so I decided to make my own. About 2 hours later, it is cut out, shaped, sanded, drilled and ready to use. I used the hole pattern from my 54mm retainer for the bolts as my rocket uses the same mounting hole spacing. Even looks like the PMR retainer from Public Missiles; Now I can launch this weekend! ;)

Here are some pics:

<a href="reviews/ret/ret1.jpg">Pic 1</a>

<a href="reviews/ret/ret2.jpg">Pic 2</a>

<a href="reviews/ret/ret3.jpg">Pic 3</a>

<a href="reviews/ret/ret4.jpg">Finished</a>
 
Good job!

I've got a PML 29/38, are the mounting holes the same pattern for a 54mm retainer? You've inspired me to make my own also for my PML Tethys. Thanks!
 
Swimmer,

Yes, the PMR 54mm has the same hole pattern and size as the PMR 29/38mm...they both use 8-32 bolts and I actually used the pattern from my 54mm for the holes on this replacement as my old one was deformed beyond recognition.

Also, I use both the 54mm and this new 38mm Retainer on the PML Amraam 4 ; it got tested two weeks ago when I launched the A4 on a Pro38 J360 38mm and it worked well. The beauty is I have enough sheet metal to do many more if needed; I just need to get some more asbestos cutting wheels for my Dremel as I went through one wheel making this retainer and am now running low. I do want to tell you the retainer for the 54mm is different in shape, but the mount holes are the same.

Cya,

Carl
 
Thanks, Carl, for the info. I, like you, like to fab things myself. Did you use PML inserts for the retainer bolts?
 
Swimmer,

Even though it's a minor part, you will have fun building them...fabricate away and if you enjoy it like I do, good for you!

I have used PML inserts for two of my rockets, a small set for my PML Amraam 2 and the large set for my PML Amraam 4. The only reason I used them is because they came with the retainer kit. I liked the inserts, until I tried some of the ones at the hardware store for other rockets. Bad move! They are thinner and less dense, so the brass inserts break during installation. The PML inserts alone are WAY too expensive to even consider buying.

Since those bad times, I have incorporated Blind Nuts (T-Nuts for you rocket guys) into all my rocket designs and builds. I install the T-nuts into the bottom CR prior to gluing it into the bodytube. No chipping of paint trying to install inserts and no breaking during install. I use them exclusively for all my rockets now, except L3 birds.

Carl
 
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