Custom electric motors

Im trying to upgrade my Filastruder with stronger motor. So I took a look inside the gear box to figure out the shaft and it turns out it has a custom head.



I checked for motors with gearbox but in the range of torque im looking for (50-100 Nm) they are super expensive. I was wondering where I could find a online shop which one can order motors with special shafts and cogs.

Have you taken the motor off and looked at the shaft? It's hard to tell in the picture, but it looks like the helical gear has a gap between the bottom of it and the motor. It's possible that gear is pressed onto the shaft, so you'd just need to find a motor with a similar shaft, rather than a motor with the same helical gear. You probably could tell if it's pressed on just by wiping off the grease on the top and looking for the shaft end.

Yes i didnt see anything which leads me to believe that its not pressed. Its probably not that hard as well to find this helical cog somewhere else, but most producers only are B2B only thats really annoying.

Another thing: would you worry about the gear itself having a limit in its power transmission? It was suggested to me that I shouldnt switch motors because the gear wasnt rated for higher load, but I think with such a high reduction and distributed over 5 cogs this gear should take quite a load before it gives in.

Quote
sungod3k
Yes i didnt see anything which leads me to believe that its not pressed. Its probably not that hard as well to find this helical cog somewhere else, but most producers only are B2B only thats really annoying.

Another thing: would you worry about the gear itself having a limit in its power transmission? It was suggested to me that I shouldnt switch motors because the gear wasnt rated for higher load, but I think with such a high reduction and distributed over 5 cogs this gear should take quite a load before it gives in.

The problem isn't the gear on the motor, its the rest of the gears (the white plastic gears and the final drive gear) as well as the gearbox housing itself that isn't rated for increased torque.

20N-m is quite a lot of torque. That's what a car engine produces a little above idle.

@ greenman: youre right it is lot (interesting to know the comparison with a car motor ) )

I found this one [leisonmotor.en.made-in-china.com]
the most powerful version of it has almost 60Nm stall torque and I hear from other people using the same motor that they run in with 19V instead of 12 so there seems to be some space.

You cannot run those motors at stall torque, you will break the gearbox in short order.

Yes, you can run the beta motor at 19v, beyond that you will shorten the life of the gearbox drastically. I assumed that since you already posted over on Soliforum about running at 19v that you were looking to increase beyond that, for which there is not very much headroom.

Yes I actually mailed with Tim and he layed out his thought behind the beta motor. Its much what you said about the gear box and stall torque.
The beta motor has quite a reduced reduction compared to the first and he thinks that any more power would kill the gear box over time.

One would need a motor with a reduction somewhere between 700:1 and 1200:1 which can generate 10-20 rpm and endure upwards of 20Nm.