There is a pedal power project that I've had in mind for awhile now, but I'd like to make it shaft drive.
Would an angle drive out of an electric angle grinder be able to handle a maximum of roughly 120 foot pounds of torque?
Pic not really related.
And if speed isn't an issue how much would wheel size matter? I've got some wheelbarrow sized wheels kicking around that would help keep the project compact.
>>990570
Instead of using a bike chain for part of the driveline.
I'd like to use a right angle drive out of an angle grinder, but instead of running at the thousands of RPM they usually run at. It would be low speed high torque.
>>990591
bad ideal, the motor won't get enough cooling and will burn out like it were torque stalled
just run it through a reduction gear set
>>990599
It would be the gears only. The grinder motor is dead.
Bike pedals > angle drive > angle drive >bike wheel.
>>990551
I don't think it will handle that amount of torque for very long. The gear ratio seems like it will be roughly 1:1 so the pedaling you'll be doing will be really difficult. That is why the chain drive is better, you get to use a better gear ratio to make pedaling much easier. If you have a gear ratio in mind, remember that the bigger the difference in the gears mean more torque on the gears of the angle grinder. So, long as you are moving it won't be as bad when you start pedaling, but if you start from a dead stop things will have lots of stress. However, since you can't apply more force on the pedal than your own weight, you should be able to measure the gears and calculate exactly the amount of torque involved.
I'd really like to see someone do this though. It is a neat idea and the thought of using a dead-motor angle grinder for its gears is intriguing for a number of projects.
>>990551
Actually had someone try and do exactly this in a thread some weeks ago.
My opinion was that it would break, fast. Angle grinder motors generate hardly anything in terms of torque, certainly nowhere near what you'd get out of a human bouncing on the end of a ~6" lever. Even if there was a very generous safety factor engineered into the gearbox (protip: there wasn't), you'd, at best, see the gears worn out too fast to be worth it, and, at worst, they'd strip immediately upon trying to use it.
>>990603
You're probably right. The grinder motor produces almost no torque, but like 10'000 rpm.
On a side note the drives are closer to 4 to one, not one to one.
I figured out that if I stood on the pedals perpendicular to the ground I could theoretically produce 125-ish foot pounds of torque.
I was kinda thinking of just clamping the drive in a vice and seeing if it would handle roughly that much torque.
>>990610
Hmm… So basically it's a dumb idea and probably won't work, so just do it for the lulz?
>>990616
>so just do it for the lulz?
Do it for science and report back. Design it so that if it breaks you can replace it with something that will work.
>>990551
can you find an old outboard trolling motor shaft? that might work better then a grinder. and would be easy enough to mod.
>>990616
if you can find an old lawn mower transmission there are some bevel gears in the differential and input shaft that can easily be used if you can do a little fabricating
self propelled lawn mowers also have little trans you can use but most of the front wheel drive ones are worm gear so their use might be limited.
>>990724
Another good idea, but even bashed up mowers are coveted by fellow scavengers here.
Not related to this project, but I was wondering about a source for a worm gear drive for something else. Thanks.
>>990551
Shaft drive bikes have been around since the 19th century so you could try sourcing the proper parts. But there's a reason they've never been popular.
>>991913
>buyfag logic
