TeamJaeger

Thanks @Mousepotato01 ! I did 3d print the body of the gear box. I modified it a bit after I printed it, so the 3d files would not be totally accurate and it would be very specific to this exact gear train. That said if you are still interested, let me know, I can post it. If you use a brushless motor with less speed and more torque you could get away with a simpler setup, basically using a timing belt going from a timing pinion pulley (coming from the motor) to a hub mount timing pulley (on the top roller). ( https://www.servocity.com/motion-components/rotary-motion/pulleys-belts/timing-pulleys-belts ) The two rollers would still each have a gear to mesh with each other so the top roller rotates the bottom one in the opposite direction. This setup would be more quiet and durable (less ...

Thanks @Mousepotato01 ! I did 3d print the body of the gear box. I modified it a bit after I printed it, so the 3d files would not be totally accurate and it would be very specific to this exact gear train. That said if you are still interested, let me know, I can post it. If you use a brushless motor with less speed and more torque you could get away with a simpler setup, basically using a timing belt going from a timing pinion pulley (coming from the motor) to a hub mount timing pulley (on the top roller). ( https://www.servocity.com/motion-components/rotary-motion/pulleys-belts/timing-pulleys-belts ) The two rollers would still each have a gear to mesh with each other so the top roller rotates the bottom one in the opposite direction. This setup would be more quiet and durable (less complexity = less to go wrong) - but in my case, way too fast (the rubber rollers exploded at this speed) and I so decided I would rather build a gear train than get a different motor - because I work at servocity and I am into the idea of "eating our own dogfood"... I had not built a gear train on x-rail yet and it seems like a good time to do it.

I used a MakerGear M2 3d printer. I did end up going with LiPos with a higher mAh rating for longer runtime. I found that as far as weed trimming string goes, the really thick kind for string trimmer mowers worked the best (longevity-wise). Ultimately though I did try switching to plastic blades and really liked it. Then I added wheels and basically used it as my lawn mower for the last half of the summer.

I use Autodesk Fusion 360, my co-worker and friend who jumped in and designed the battery boxes and motor enclosure on this project for me uses SolidWorks.

Hi Jed, The short answer is "yes" it certainly would be possible. Just about everything you want is already there is some form. Adding that functionality would mostly be a matter of copy/pasting and making a few minor adjustments. An SPST (as opposed to a DPDT) toggle switch or rocker would be sufficient to toggle between two endpoints. Codewise it would be exactly the same as the latching pushbuttons. So you could simply copy/paste the code for the latching pushbuttons to add a third "button". Then you could simply modify the POSITION_CONTROL mode. The main difference is how the target is set (line 104). If the toggle switch is high, then you would set the target to position1, else you would set the target to position2.