3D Printing Motor Retainers BT-20 and BT-50 Estes compatible

[Gunstar]

https://www.printables.com/model/514768-motor-retianers-bt-20-and-bt-50-estes-compatibleZ
These motor retainers are designed to be interchangeable with Estes BT-20 and BT-50 motor retainers, so if you have lost a cap, you can just print a replacement and use that. If you have an extra cap for some reason, you can print a base to pair with it.

The base glues onto the body tube and the cap screws on to keep the model rocket engine in place.

I included a taller version of the cap because I like to glue a thrust ring in the body tube so ¼ inch of the motor sticks out past the end of the base, making it easier to remove. When you do that you need a longer cap.

I would not recommend printing this with PLA due to the heat exposure. PLA+ might work well enough, ABS for sure. No supports are needed. I printed with a .4 nozzle and .2 layer height with the Outer Wall Line Width to .3 For the BT-20 a .2 nozzle might give a smother result but isn't a must.

Thread specs:
BT-20: pitch 1.525mm, base diameter 22.25mm, cap diameter 23.5mm
BT-50: pitch 2.12mm, base diameter 30.85mm, cap diameter 33.85mm

 

[Gunstar]

Made a small update to give a tighter fit on the BT-50 caps

 

[Gunstar]

Had an idea. I could make another BT-50 cap that is an inch longer. Then you could switch between a D and E engine by changing the cap you use rather than using a spacer. It would shift the CG of the motor back a little bit to put in an E that way, but that likely won't be a problem for most rockets, and for those it is you could add a weight in the front.
Should I make it?