I have gotten much further along and have a working version of the Spoke Tensiometer Calibration Rig. It is still missing a part (Thrust Bearing) and there are a couple of things I would change but here it is:
In the picture above the spoke is being pulled with 102.7 kg so the spoke tension is 1000 newtons. I double checked my Park Tool TM-1 chart together with my rarely used TM-1 and it was close. The TM-1 was one marking too low with a 1.8 mm spoke. So here is the parts list.
- 2 - 2020 Series x 500 mm T-Slot
- 4 - 2020 Series Corners (or 3D printed equivalents)
- 8 - M5 x 10 mm Button Head Screws
- 8 - M5 T-Slot Nuts
- 1 - M8 x 35 mm Button Head Screw
- 1 - M8 Washer
- 1 - M8 Flat Thumbscrew
- 1 - M8 x 200 mm Threaded Rod
- 1 - M8 Hex Bolt
- 2 - M8 Acorn Nuts
- 1 - 8 mm Roller Thrust Bearing
- 2 - M8 Clevis Rod Ends
- Small Crane Scale (150 kg or more capacity)
- 1 - Brass Spoke Nipple
- Some 3D Printed Parts
This list will build the model with the items I would do differently. The difference is that the pictured version uses an M6 Threaded Rod and that should change to an M8 or M10. It is not a strength issue, it is a space issue. Besides this you need a few drill bits and a way to drill straight holes. Some Allen Head Hex Wrenches and some time to print the 3D parts and putting it all together. Total cost building this was under $80 USD.
If someone wants to post this in the mechanics forum please feel free to do so.