zombiess wrote:Do you have any idea why your axle stripped? Was the nut the correct size / thread pitch / cross thread? Did you over tighten it? I recently had a over tightening scare myself on one of my hub motors and thought for sure I killed the axle threads but I got lucky and only stripped the nut leaving the threads safe. I was crossing my fingers as I removed it that the threads on the axle were OK. I hope your machinist friend can get you back up and running fast. I think you are the first to get one of these up and running. 58mph is really hauling. Even if your machinist friend can't fix your axle for you, he should be able to design a clamping dropout for you that does not require a nut so not all hope is lost. It looks like you have quite a bit of axle sticking out to work with.
I have no idea why it stripped. I can only wish it was the nut, but i tried the nut on my other hub and it works great. In regards to "overtightening", i have tightened my other hubs MUCH more than this without issues. But i guess its possible. Either way, why on gods green earth is my axle material softer than my hardware?
My machinest is making new dropouts for me. He told me to come by with what i have. I went over to his shop on my bike. He looked at the bike for about 15 minutes and said "i have ideas". then he told me to come back tomorrow with the bike again for measurments b/c he was too busy to do it today. He has built many 6-7 second cars from the ground up. I trust him with my life. i normally have torque arms on both sides but for some reason they wouldnt fit on this axel.
zombiess wrote:If you want to up the voltage with that 26" wheel you are probably going to want a 36 FET IRFB4115 controller, I don't think a 24 FET will handle the amp demand that motor is going to require unless it's tweaked really well like I've been doing to my controller builds. Having the FETs matched for the same turn on voltage is critical for them to load share evenly, otherwise they can turn into FET popcorn. The more FETs your parallel the more critical the matching becomes. Even with the mods I do to my controllers I don't think I'll push my 36 FET controller much past 200A battery/250A pase and would stop at 150Abattery/200A phase on a 24 FET IRFB4115 setup, probably even less due to the extra load of it being a 26" tire vs the 20" tires I like to run. Your best bet might be to step up to one of the newer Kelley controllers or a even a Sevcon, but the Sevcons cost $1k and only go to something like 116V max (I just looked at one myself but can't justify the cost). Throttle control is amazing on it though.
Im not going to act like i know much about controllers. Ive opened one up before, but immediatly closed it back up due to mass confusion. Lyen has been VERY helpful and he is very confident that the 24fet 4115 will last if kept under 100amps. Ive given him all the details, 26" rim, speed winging etc.. He still says, 100amps and under, im fine. "200amps". LOL! I really have no desire to go above 100amps. I wonder how long a 135v 20ah pack would last at 200amps WOT. 5 minutes? But like i said earlier, i really dont know much about controllers. 200amps sounds really excessive to me. Im 100% fine with a reliable 135v 100amps.