Frazatto's Mod DIY Electric Bike (more customizable)

thingiverse

This is my attempt to make a more generic/customizable version of Tom Stanton's original DIY Electric bike, besides a new feature that REALLY adds to the stability of the solution. First of all, thanks Tom for releasing the files to the community, I really enjoyed and appreciated the chance to iterate on your work. Without it I think I would never have started this project. Welllll....almost three years working in this thing (lots of time waiting for parts, not actual work, SO MUCH to learn as you go) and today is the first time I took the bike for a test and NOTHING failed catastrophic!!! So I think it's a good opportunity to share my solution. No, I can still not use the bike in the street, I still have lots of things to check and right now the motor don't output enough power to keep me going. Please keep in mind this is a work in progress and it fits my needs and my bike, your experience may vary!!!!! Feel free to modify it for your needs and share the result with the rest of us!!! The main file here is "motor_mount_mod.scad", you will also need Tom's original files if you want/need to modify anything. The project is not at all simple to customize under OPENScad, I did my best but it is a complex task. If you have some experience with the tool, you will see everything you need is in place and appropriately commented out, let me know if you have any specif doubts that I can help with. My first modification is changing the size of the clamping hole, you can measure your bike frame and it should fit nicely. Remember to put a little extra space for any material you will use to protect the paint on the bike. You also find an option now to use a different motor, I made a close enough model of the motor I have and did my best to visually align it with the original motor fitting. I'm pretty sure I didn't nailed it......but it is VERY close to the correct position. The second modification is creating a shield to the right side of the motor (when installed on the frame). I wanted to use a saddlebag and without a protection the bags would just keep banging on the motor. But what I consider the most needed addition to the original project was a anti torsion bar. The number 1 frustration I had so far was correctly aligning the motor with the belt and the pulley, there is no visible reference anywhere and getting it close is not good at all (any deviation will make the belt slip) and you will only discover your error at high speed. The number 2 frustration was finding the optimized point of balance between the strength of the printed part and the clamping force necessary to keep the motor in place. Long story short, I couldn't find it! I only have PLA at my disposal and if I made the clamp really nice an tight, the plastic would crack after one or two days and if I let it fit just a little loose the whole thing would collapse toward the wheel when braking, creating a really dangerous situation at any speed. The anti torsion bar helps fixing both problems, now it is VERY stable. I'm using a 8mm stainless steel bar because it's what I had in hand, but I believe a 5mm would have been enough. I have no idea regarding the variety of bike frames models and standards, my bike have a 40° angle where the back wheel is mounted and both upper and lower tubes are aligned, your bike PROBABLY is different. If, like me, you also have a problem of the mount slowly slipping down the frame, I also added two M3 screws to bite on the frame (I needed only one though), it is commented out on line 64 if you want to try it (you will also need a square nut). Okk than, to the people still with me this far, what I would ask of you: - Check my code, see if I made any obvious and stupid mistakes. - Print and let me know what you think of it. - Make it better and let's work together to create a truly open source DIY electric bike. And my plans to the future: - I would like to try the BIG pulley Tom uses on the next version (not the new bike). Does anyone knows how to create one??? I know it creates a problem on the motor side and the belt starts skiping, but I would like to try using two tensors to easy the problem.