38mm to 29mm DIY adapter

The Rocketry Forum

Help Support The Rocketry Forum:

rockets

Well-Known Member
Joined
Nov 18, 2014
Messages
1,252
Reaction score
31
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,
 

Flyfalcons

Well-Known Member
Joined
Apr 14, 2015
Messages
2,523
Reaction score
735
Spend the five bucks. You're messing with high power motors so do it right.
 

dhbarr

Amateur Professional
Joined
Jan 30, 2016
Messages
7,273
Reaction score
1,705
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:

Evilash

Well-Known Member
Joined
Jun 25, 2014
Messages
319
Reaction score
1
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.
 

NateLowrie

Well-Known Member
Joined
Jun 28, 2016
Messages
667
Reaction score
4
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.
 

Evilash

Well-Known Member
Joined
Jun 25, 2014
Messages
319
Reaction score
1
No problem Man, I'll probably send it to you over the weekend.
 

cwbullet

Obsessed with Rocketry
Staff member
Administrator
TRF Lifetime Supporter
Global Mod
Joined
Jan 24, 2009
Messages
27,137
Reaction score
4,594
Location
Glennville, GA
I could see 3d printing as an option.
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
38
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

T-Rex

Ordinary Average Guy
TRF Supporter
Joined
Jul 22, 2011
Messages
3,014
Reaction score
60
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.
 

swatkat

Down these mean skies, a kat must fly!
Joined
Jun 25, 2014
Messages
1,679
Reaction score
301
Location
Sactown, CA
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.
 
Top