Retired BMW mechanic here bought a 650# tracked 24V 22hp Chinese slope mower and has promptly roasted the 450W drive motors, which are sadly undersized. This thing makes Harbor Freight stuff look like it’s made in Switzerland. Basically it’s a tracked RC tank carrying a 31" mower deck powered by a 22hp 600cc single cylinder that also runs a 24V alternator. Gas motor powers mower blades and 24V alternator, alternator powers 2 12V motorcycle batteries, which run 2 450W 1800rpm gearmotors stepped down 40:1, which each drive a track from a rear sprocket. In theory it will mow until it runs out of gas, travel 3-4 mph, and mow 3’ grass/weeds on slopes up to 45*. All true, except the slope part. Drive motors are underpowered overheating junk, as are the gearboxes. Motors are now burned up and gearboxes trashed (metal failure/teeth off) after 25 hours, maker is clueless. So I need 2 new motors. Math makes it look like I want 2 2000W 48V DC gear motors with a resulting track drive speed of 3-4 mph, so I need gearmotors, controllers, and a 48V alternator that won’t overheat under constant use (ideally not a $4K one from a boat/plane). I am clueless as to how to identify what I’m looking for or where to look and I’m hoping one of you wizards knows a source. Big thanks and Mods, please put this post where it belongs.
Hi @andyleonard and welcome to our forum.
Sorry to hear about the problem with the motors.
I’ve seen several projects with customer made robotic lawn mowers where users used motors from electric wheelchairs. I didn’t find any that have 2000W of power. Here is an example of the motor with 800W power:
If you really need 2kW, maybe you can look into something like this:
48-60v 1500w-2000w mid drive motor with foot - UU Motor Webstore
I hope this helps a little bit.
Thank you Igor. Much appreciated. We are using this mower commercially and have concerns about using $100 2000w 48v scooter motors, as we suspect they’ll last about 20 mins.
We’ve managed to also destroy the little gearbox/reducers that came on our motors, so we’re hunting something heavy duty that we can’t kill and doesn’t need chains or jackshafts. It HAS to exist out there somewhere.
@andyleonard thank you for your reply.
Do you have any photos of your machine or a link to the product?
This link above IS NOT mine but would be excellent to have next. It didn’t exist when I ordered the one I have and if I had the 48V alternator and motors I’d be happy.
What I have now is basically a 24V 450W version of the above and it would probably be fine on level ground or or mild slopes, but the walking motors are useless for our work. The chassis/gas motor/mowing/tracks/control mechanisms on the above and on mine are very similar.
This is a great machine. Looks like a good quality. I see they sell replacement parts. Could you maybe order motors from them?
I thought about it, but a 48V alternator, 2 motors and 2 gearboxes - without controllers - would be over $3000. I guess they have a healthy markup.
I guess then you would have to order these parts from Chine again to save up some money 
It’s tough sorting out who makes what in China. I imported 2 10# motors and the freight alone was $328. So there’s that too.
I would recommend using a pair of wheelchair motors. They are already geared appropriated to give you the ground speed you want, are more robust, and have more thermal mass than the little gearmotors you have. The largest, most powerful wheelchair motors out there are rated 445 watts for 15 minutes, 1200 watts peak.
If you don’t want to scrounge an old wheelchair locally, I’d go with one of these (there are left and right versions of each):
A great resource. Thank you.
The larger motor is a match for what we have now, with the addition of the brake, which is a good add.
Math indicates, to run a 650# tracked mower at 3-4 mph up a 45* slope (which is what we have to do here) we’ll need 2000/3000w motors. We tried the stock 15# 24V 400w motors and cooked them immediately. The replacement 450w motors are barely still running at the end of the tough job and we have stripped teeth off gears in both gear boxes.
I THINK we need to up the power game considerably and I’m not sure wheelchair stuff will get it. Our motors were 1800rpm and the gearboxes were 40:1 which gave us a slow walk for mowing at full speed. Full power is used at all times, only the direction of mowing changes; forward, backward, forward, backward … a tank of gas lasts 2 hours. Stop, refill, back to full power. Work load goes up with slope increase or height of grass/brush.
What other machines use gearmotors like this? Tugs, racing karts, ?? We can convert to chains if we have to but…
The HD version of this machine made by another company has 2 X 2500W 48V motors. I believe we need that as a minimum.
We’re looking at treadmill motors and cart motors. We have a pal with 3000w 48V German gearmotors on a movie crane rig but the cost of 2 motors exceeds the cost of our machine.
You are talking big power now. Of course for long duty cycle applications it is better to over spec a motor and have it live happily in its torque-rpm range than overburdened and overheating. Drive motors of this caliber are a bit out of my wheelhouse but I am familiar with decent motors of the power range you’re talking, but no attached gearbox. You’d be looking at a home brew, multi-stage chain, belt, or gear reduction.
Have a look at some options here. Some battlebot teams are using them with success. The ME0909, ME0708 etc we’re talking 100 amp continuous ratings at 48V.
http://www.motenergy.com/brdcmo.html
I got lucky and bought a pair of these. It isn’t the 2000W 48V solution I want but it will get the machine back in service for light work for short money and we will continue the hunt
OQEnhBYXDGtp8xmgMIyflM1kMKdFBtwgDxteXtsN%252FPs%7Campid%3APL_CLK%7Cclp%3A2047675
It seems the next step up from wheelchair gearmotors (250W) is commercial floor scrubber motors (500W) and they’re’ everywhere. Who knew?
Thanks for the help. Andy
Sorry, Bad link.
Keep us up to date on how these work for you! Thanks for the link.