Ultimarc Spintrak Rotary Control - Lock Nut Size

[brakertech]

Does anyone know the proper size for a replacement nut for the Ultimarc Spintrak Rotary Control?

I lost the gray nut and am not sure where to find a replacement (or what size I should purchase).

The diagram on the manufacturer site says it is 28mm, however I tried a 28mm nylon nut for a Happ button and it screwed on for a couple threads and then wouldn't go any further.

I would appreciate any advice.

Thanks!

[bollwerk]

Maybe this is a dumb question, but did you contact Andy at Ultimarc? He usually responds within a day or so, based on my experience.

andy@ultimarc.com

[brakertech]

I contacted Andy and he got back to me right away.  He is shipping me a replacement.

Great support!

Thanks!

[PL1]

The diagram on the manufacturer site says it is 28mm, however I tried a 28mm nylon nut for a Happ button and it screwed on for a couple threads and then wouldn't go any further.

It's probably a difference between Imperial and Metric thread sizes.
- The thread pitch on a Happ button is 13 threads per inch ==> 1.9538mm/thread.
- An M28x1.5 nut is 1.5mm/thread.
- An M28x2 nut is 2mm/thread.

If you have a metric thread pitch gauge, use that to verify the thread pitch on the SpinTrak.



If you don't have a metric thread pitch gauge, use calipers to measure the pitch.
- Set the calipers to 6mm and measure the SpinTrak threads.
- If there are 3 threads between the jaw points, it is 2mm pitch.
- If there are 4 threads between the jaw points, it is 1.5mm pitch.



If you have access to a 3d printer, you can make a custom nut using OpenSCAD and a thread library like I did for this rotary encoder mount.




Scott
EDIT: I'm glad Andy is shipping you a replacement.   

[Fursphere]

Lol, the thread pitch gauge or the calipers will cost more than a replacement spinner!   

Based on the design of the lock nut and how it scraps the wires very tightly on the Ultimarc SpinTrak - I've been considering machining a new nut, then splitting it with screws.   So it can be installed / removed without scraping the wires.   More out of fun than necessity. 

[PL1]

Lol, the thread pitch gauge or the calipers will cost more than a replacement spinner!   

  If you think that, you really need to shop around more.   

https://www.amazon.com/OriGlam-Measures-Stainless-Cutting-Measuring/dp/B07PGGV5Y8
https://www.harborfreight.com/carbon-steel-metric-tap-and-die-set-40-pc-62832.html

https://www.amazon.com/LOadSEcr-Stainless-Precision-Shockproof-Woodworking/dp/B08K34ZG71/
https://www.amazon.com/Zoostliss-Digital-Electronic-Calipers-Micrometer/dp/B07J6PX2FL/
https://www.harborfreight.com/6-in-composite-digital-caliper-63586.html
https://www.harborfreight.com/6-in-dial-caliper-63730.html

If someone is really pressed for funds, they can measure the threads with a ruler.
- Measure the distance across 5 or 10 threads and divide to get an accurate average per thread.


Scott

[Fursphere]

For the sake of argument, you showed a picture of Mitutoyo calipers, not harbor freight junk. 

Thread pitch gauges aren't too bad.

[PL1]

For the sake of argument, you showed a picture of Mitutoyo calipers, not harbor freight junk. 

Fair enough.

I just picked a picture that showed the tool so readers wouldn't think I was referring to some other type of calipers like these.   

 

Of course, if you want really cheap, junky, pain-in-your-keyster calipers, get the plastic vernier ones.^*         
https://www.harborfreight.com/6-in-utility-caliper-63664.html

* Friends don't let friends buy vernier calipers.


Scott

[Fursphere]

Of course, if you want really cheap, junky, pain-in-your-keyster calipers, get the plastic vernier ones.^*         
https://www.harborfreight.com/6-in-utility-caliper-63664.html

* Friends don't let friends buy vernier calipers.


Scott

*shudder*

No, just no.   

[Fursphere]

For reference....

 I broke out the Mitutoyo thread pitch gauge set.   Its a 16 TPI thread.   Not metric, which I thought was interesting.