38mm to 29mm DIY adapter

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

rockets

Well-Known Member
Joined
Nov 18, 2014
Messages
1,277
Reaction score
56
Location
Denver, CO
Is anyone built a 38mm to 29mm adapter? I could buy one from LOC for $5, but I'm going to see if there's a cheaper way to do it.
Should I wrap masking tape around the motor, until it fits the 38mm MMT?
Should I wrap a 29mm MMT tube in masking tape, until it fits into a 38mm MMT?
Or is there something else I should try??


Thanks,
 
Spend the five bucks. You're messing with high power motors so do it right.
 
That much tape would add a fair bit of mass. You'd likely have to balance it out by adding nose weight, which ( usually ) means less altitude, always lower speed off the rail, always lower top speed. If rail speed drops too far and you can't extend it, smaller wind gusts can weathercock or Landshark. So you upsize the motor, more nose weight.

A good MMT adapter is both light and strong.
 
Last edited:
I think I have a bunch of these laying around. PM me your address and I'll send one to you. Don't wrap a motor with tape as an adapter.
 
Is anyone built a 38mm to 29mm adapter? I could buy one from LOC for $5, but I'm going to see if there's a cheaper way to do it.
Should I wrap masking tape around the motor, until it fits the 38mm MMT?
Should I wrap a 29mm MMT tube in masking tape, until it fits into a 38mm MMT?
Or is there something else I should try??

Thanks,

Do not do the tape. Your motor has a lip or external snap ring on the nozzle end that seats against the MMT to transfer the forces of the motor thrust to the rocket. If you just use tape, you lose that transfer. The LOC adapter uses a piece of 38mm tube that's glued to the coupler as a thrust ring.

Just pay the 5 bucks for it and be done with it. You aren't going to make one cheaper.
 
No problem Man, I'll probably send it to you over the weekend.
 
I've made several in different sizes. But I have the scrap motor tubes and pieces of plywood. More importantly, I have the tools and the experience. I wouldn't attempt making them if I didn't.
 

Attachments

  • 98_adapter.jpg
    98_adapter.jpg
    165.2 KB · Views: 52
  • 99_adapter.jpg
    99_adapter.jpg
    144.9 KB · Views: 54
  • 100_adapter.jpg
    100_adapter.jpg
    179.2 KB · Views: 62
  • 101_adapter.jpg
    101_adapter.jpg
    151.2 KB · Views: 53
  • 102_adapter.jpg
    102_adapter.jpg
    126.2 KB · Views: 59
  • 103_adapter.jpg
    103_adapter.jpg
    71.3 KB · Views: 51
  • 143_adapter.jpg
    143_adapter.jpg
    47.9 KB · Views: 55
  • 144_adapter.jpg
    144_adapter.jpg
    53 KB · Views: 42
I agree with qquake, to a point. It isn't all that difficult to purchase a piece of tube and a couple rings. The rings can be cut with fairly simple tools (drill, jig saw/coping saw, and sand paper) if you put forth the effort.
If I am not mistaken, a couple years back someone was cutting rings with a hand held drill and a HF fly cutter by putting the plywood vertically in a vice.
Probably cheaper to buy an adapter in the long run.
 
You can 3D print them as well, I always line mine with a 29mm motor mount tube to keep the direct heat from the metal reload casing off the plastic. Never had one fail or melt. But for all that effort, the 5 buck MMT adapter from LOC is going to be just about as cheap and far less time consuming.
 
Back
Top