29mm md motor retainer

29mm rocket motor retainer for a minimum diameter rocket

Perfect way to retain your 29mm dms motor in your rocket! No external bolts are needed! Has all of the advantages of an aeropack, without the need to epoxy/bolt it into your airframe!!

It simply uses two pieces that compress an o ring that pushes against your body tube from the inside, therefore preventing your motor from falling out the back when ejection charge fires. 

Use instructions:

You simply put the motor in, and then you just “screw it in”. That causes the retainer to squeeze the o-ring, which expands it and clamps your motor in place.

Bill of materials:

• 212 metric o-ring
• 3 m3 12mm bolts
• 1 m4 20mm bolt
• m4 nut

You can even attach your shock cord to it!!

Additional parts needed for the shock cord version (last picture) :

• m4 nut
• m4 washer

Assembly:

1. Put the bottom piece (has 3 radial holes for bolts) over the charge well (yellow plastic part at the top of your motor), and use a 7/64th drill bit to drill through the charge well.

   

2. Put the m4 bolt into the charge well bolt holder

   

3. Put the charge well bolt holder into the charge well, and secure it with 3 m3 bolts

   

4. Press the m4 nut into the top part of the retainer

   

5. Put the o-ring on top of the bottom part of the retainer (the one that is bolted to the motor), and place the top part (the one with the nut) on top of it. Screw it on until it barely squeezes the o-ring

   

6. Optional: Put a nut on the end of the bolt that is sticking up above the retainer.  Make a little loop on the end of your shock cord and put it over the nut. Use another nut to clamp the loop in place. I AM YET TO SEE HOW WELL THE SHCOK CORD STAYS ON, SO USE THE SHOCK CORD METHOD AT YOUR OWN RISK!!!