John in CR wrote:Voicecoils,
Thanks for sharing your misery. I have an extra set of gears, so I was going to light mine up at 80V+, so now I'll wait until we have a replacement gear solution or get a 48V 20A controller. If you need participants in a group buy of metal gears just let me know. Also, I'll bring an extra gear over to my machine shop and find out how much they would charge for copies. I wonder if any more durable composite materials are available that come in a machinable form. Could a machinable or castable ceramic work, because I happen to have some impact resistant ceramic that I picked up for use as a piston in a stirling engine.
I'm not sure, and nearing the end of my engineering degree I'm not ready to start enough in material science or mech eng !!!
If you can find a solution that would be awesome. A few people are now looking at options. The more the merrier
I think the basic engineering dilemma is this:
The sun gear and pinion are steel. Steel on steel wears fast and requires lubrication. Lubrication requires sealing, and sealing requires close manufacturing tolerances and additional measures to make the casing oil-tight.
An alternative is a non-metal gear. A non-metal gear may not require lubrication which is factor for consideration. The nylon ones supplied have not worked for me. Higher quality nylon or another plastic might do the job. I don't know about ceramic on metal and bad how noise or wear would be.
I would hold off on 80V operation for SURE. I was hoping that my spare gears would last me a long time. I figured if the first set lasts a year, then I'm set for 3 years! Turns out I was set for less then 20min total. I have one set remaining and I don't want to load them in until I either have a new stronger gear replacement, or a low power option for running them.
JRH has not had problems at 40V 40A. Nogwin has not has problems at 66v 35A (and has clocked up 1k miles). See here: viewtopic.php?f=6&t=4925&start=75#p106208
Maybe I have an isolated case? The high voltage seems to be a major factor.