ActingLikeAKid
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- Joined
- Nov 16, 2015
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Title says it all. About to start in on building a Wildman Mini kit. I'd love to avoid the weight and expense (OK, mostly the expense) of an Aeropack retainer, but there isn't a ton of room between the motor mount OD and the body tube ID (if my math is right, about 3.5mm; it's downstairs right now and I'm tired.) Wildman's prescribed DIY retention method for their stuff is to glue nuts to the top of the lower CR, but that won't work here. I looked and a 4-40 nut is 1/4" wide, too big for the gap; I'm not sure that I'd feel confident in anything smaller being strong enough to hold the motor on. So that won't work.
Right now, the best idea I have off the top of my head is to - after assembly - VERY carefully drill a hole through the aft CR, (of a size that I could tap with a #8 screw), then get a long #8 set screw (i.e. threaded, but with no head and an indentation for an allen wrench at the top) from McMaster. Drive the screw into the CR, epoxy it in place once it sticks out half an inch or so from the bottom of the rocket, then, to launch, add a washer and a nut to retain the motor.
But even with that idea, I'd have to be damn careful not to get the screw too close to the mmt tube, lest I not be able to get the motor fully inserted.
Yeah, the more I think about it, unless someone has something brilliant, I think I just need to buy a retainer from Wildman.
Right now, the best idea I have off the top of my head is to - after assembly - VERY carefully drill a hole through the aft CR, (of a size that I could tap with a #8 screw), then get a long #8 set screw (i.e. threaded, but with no head and an indentation for an allen wrench at the top) from McMaster. Drive the screw into the CR, epoxy it in place once it sticks out half an inch or so from the bottom of the rocket, then, to launch, add a washer and a nut to retain the motor.
But even with that idea, I'd have to be damn careful not to get the screw too close to the mmt tube, lest I not be able to get the motor fully inserted.
Yeah, the more I think about it, unless someone has something brilliant, I think I just need to buy a retainer from Wildman.