Overdrive RSM4 Sanding Plate Reciprocation Machine

A customer wanted one of my reciprocators for his RSM4 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 thanks to Kev Ster, who remixed my version for the RSM3 machine, and made some clever changes. I took some inspiration from his changes to further improve and simplify this one for the RSM4 machine.

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, so that they can be snug without interfering with the gears of the gear motor. 6mm long screws will probably work fine, but not longer. 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 pusher arm to the rotating 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.

Due to the large gap between the sides of the sanding plate and the channel in the RSM4 base, the clamp at the front of the reciprocator has oblong holes. Using a scrap of paper or razor blade as a shim between the plate and the clamp, push the clamp into the sanding plate and the plate against the back of the channel, then tighten the clamp screws. This may also be necessary on the right side of the machine, so it's a good idea to also print the Guide Clamp and a second Sliding Clamp plate to use on that side. 

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.

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

Customer Assembly Video: