MSR Tire Truer Sanding Plate Reciprocation Machine

Update 3/22/23 - Added sliding plates and extra clamp for the front edge. Use these to restrict the sanding plate from racking by using a piece of paper or razor blade as a shim when setting the clamps against the sanding plate. 

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A customer wanted one of my reciprocators for his MSR Tire Truer. He was kind enough to let me borrow it in order to modify my machine to fit that tire truer!

While this was completely redesigned from scratch, I still owe thanks to OXO_Cube for his original machine that I based my first Tire Razor Reciprocator from. I also owe some thanks to Kev Ster, who remixed my version for the RSM machine, and made some clever changes. I took some inspiration from his changes to further improve and simplify this one for the Tyre True machine, which I then applied to my V2 Tire Razor machine, and now to this version.

As the motor can warm up during use, I recommend a temp resistant material such as PETG or ABS for the gantry and rotating arm parts. The rest can be PLA if you want. I usually print the base in PLA, and all the small parts in PETG.

This uses a GA12-N20 gearmotor. Get the lowest RPM at the highest voltage you can. E.G. a 15rpm at 6v would be good. You will also need some m1.6-0.35mm x5mm screws to mount the gearmotor. Since the only ones I could get quickly at a reasonable price were 6mm long, that's what I designed the gantry for, so that they can be snug without interfering with the gears of the gear motor. 5mm long screws will probably work fine, but not longer than 6mm. One screw is also used in the end of small rotating arm, against the flat of the motor shaft, to act as a set screw.

The rest of the screws I used are just M3 socket head cap screws as are popular on various 3D printers like my Prusa. Any M3 screw should work, just be careful that the head does not collide with anything prior to use. I use a 6mm one to secure the long arm to the short arm. I would recommend 10mm for the screws on the clamps so they are less likely to strip when tightening the clamps down. A 6mm screw is also good to secure the gantry to the base.

When attaching the ball joint to the end of your sanding plate, try to get it as centered on the end of the sanding plate as possible. This will ensure that the reciprocator arm lines up nicely with it. You can use a strong glue, or thin double-sided tape. Putting a ball joint on both ends of the sanding plate will allow you to easily turn it around and possibly use fresh sanding surface, depending on the wheels/tires you are truing.

The STL files are all provided in the ideal print orientation. No supports should be needed for any of the models if printed in the provided orientation.

A STEP file is also included to make it easier to modify for your particular machine if needed.

If you would like a machine, feel free to contact me at [email protected] to order one.

Customer Assembly Video: