3D Printing Estes motor retainer thread specs?

[SolarYellow]

Does anyone know the thread specs for the Estes motor retainers? I measured a 24mm fin can and in those sizes, couldn't adequately distinguish between 1 1/4-12 and M32x2.0. Could be either, given my measurement methods.

I'm interested in resin printing some new caps to work with Estes threaded parts.

 

[49markt]

I'm looking for someone who could print me a BT-80 - BT-60 transition. Anyone willing???

 

[Gunstar]

I scanned mine at 600dpi and measured the thread pitch from that by pixels. It looks like 12 threads per inch for the BT50 (50px) and 30 threads per inch (20px) for BT20.

 

[Gunstar]

These thread settings in Tinkercad matched the base well enough to screw into the Estes cap for the BT50 retainer:
Diameter: 30.85
Pitch 2.12

And the cap
Diameter: 33.85
Pitch 2.12

 

[Gunstar]

These thread settings in Tinkercad matched the base well enough to screw into the Estes cap for the BT20 retainer:
Diameter: 22.25
Pitch 1.525

And the cap
Diameter: 23.5
Pitch 1.525
I'll be uploading 3d printable BT-50 and BT-20 motor retainers that are Estes compatible to Printables soon.

 

[Huxter]

Cool - thank you for posting that!

 

[SolarYellow]

Saw your thread with the Printables link.

That looks to me like standard nominal thread sizes.

BT-20: M22x1.5
BT-50: 1.25-12

Did you try that, apply standard thread fit clearances, account for shrinkage in your slicer, and see if it screws on?