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-   -   Brushless Motor recommendation (https://www.rctech.net/forum/electric-off-road/769964-brushless-motor-recommendation.html)

route -n 11-06-2013 02:41 AM

Brushless Motor recommendation
 
I'm looking for a Brushless Motor that meets the following requirements
  • High Torque
  • 12V
  • < 5A
  • Low speed possible, say 30 ~ 800 RPM

Any shop (online) recommendation?
Thanks

Jstall7543 11-06-2013 02:54 AM

I'd look into crawler motor's for this application. Possibly...

ThePanda 11-06-2013 03:52 AM

What will this be used in? I think it's easier to. Pick the best motor if there is a known application.

route -n 11-06-2013 05:47 AM

For the purpose of a demo, we want to build a small (goods) elevator that has the following requirements
  • 12V : for the sake of safety
  • No gear, for the purpose of the demo
  • Low to medium speed: 30~800 RPM (may have high acceleration - sake of demo)
  • High torque, able to lift heavy things (say > 0.5 Nm)
  • Quiet, will run permanently

We made a prototype with a stepping motor, which was great, but the problem with such a motor, is that at higher speed (say 300 RPM), heavy loaded, the motor may sometimes "miss" a step, and in this case just get stuck (and vibrate instead of rotating).

So the solution seems to be a brushless motor (sloted?), with a proper controller.

chucko 11-06-2013 07:52 AM

a-main has a contact on line page go to there site. ask away.

1967Typhoon 11-06-2013 08:32 AM

I don't think they make 66KV motors. :)

800RPM / 12V = 66KV

That being said, you need to get a sensored motor, lowest KV possible, and somehow program the controller to really low throttle level. It may work, but you will need to know programming, or buy some sort of industrial brushless controller.

EDIT!!!! - I got it! Buy a cheap sensored controller (capable of 3S) a cheap low-turn sensored motor, and a cheap flysky radio. Set the fail safe on the receiver to a really low throttle level. Then, just turn the transmitter off! The failsafe will continue to send that low throttle signal to the ESC! It will go forever!

DsWright 11-06-2013 08:38 AM

Try contacting Servo City. They might have some info for you. Maybe a servo modified for 360° rotation will do the job for you. He would be the guy to go to for robotics ?'s :)

www.servocity.com

route -n 11-06-2013 09:45 AM

Thanks for the replies.

Actually, programming is what I do best :-) I plan on purchasing a Roboteq BL controller.

So the most "difficult" part for me is to find the right motor, given the specs above.

A BL motor working best at 12V, not burning with 5A in the veins (~0.5-1 N.m), with Hall sensor... and that can be controlled thanks to the Roboteq controller ...
is all I need.

Finding a Stepping motor that fits those specs was pretty easy.
Unfortunately, finding a BL motor seems to be a much harder task :-(

ThePanda 11-06-2013 01:21 PM

im not sure any rc oriented brushless motor is going to do what you are asking of it. They are just to fast. or too big

The servo option, modified for 360 degree rotation is a good idea.

egobrkr 11-06-2013 01:28 PM

What about a brushed high turn motor?

Dave H 11-06-2013 03:28 PM


Originally Posted by DsWright (Post 12701151)
Try contacting Servo City. They might have some info for you. Maybe a servo modified for 360° rotation will do the job for you. He would be the guy to go to for robotics ?'s :)

www.servocity.com

Great site, I’m thinking that’s a good place to look too.

Agree most RC motors are just too fast in direct drive. If you try to throttle back to low RPMs there will likely be much larger current use under load spikes than what you are looking for. The slowest brushless RC motors are typically outrunners, more popular in airplanes, Cars mostly use inrunners. As mentioned look for a very low kv value, rpm per volt.

I think you will likely need to use a geared setup of some kind to get the combination of low rpm, high torque, and low current use though.
Brushed gearmotors here.
Belt drive may help with noise.
Or possibly worm gear drive, I think they are generally fairly quiet.

Don’t know what might be involved in mounting various brushless motors to these deals. Good luck!


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