# 38mm to 29mm DIY adapter

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#### dhbarr

##### Amateur Professional
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.

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#### Evilash

##### Well-Known Member
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
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.

#### tomsteve

##### Well-Known Member
Or is there something else I should try??

Thanks,
yup, PM evilash and thank greatly for the generosity.

#### rockets

##### Well-Known Member
yup, PM evilash and thank greatly for the generosity.
Did so, and made sure to thank him many times.

Thanks,

#### Evilash

##### Well-Known Member
No problem Man, I'll probably send it to you over the weekend.

#### Gary Byrum

##### Overstable By Design
Hey Evilash. Got any more of those laying around?

#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
I could see 3d printing as an option.

#### qquake2k

##### Captain Low-N-Slow
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.

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#### T-Rex

##### Ordinary Average Guy
TRF Supporter
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.