Newbie needs motor and controller advice

Hello all! I’m Sam and brand new to the world of robotics, however I do have some experience with electrical work. I’ve rewired a house and I did set up my own solar array on my off grid tiny house. Regardless, it doesn’t seem to translate for me into the world of robotics, and this gal is at a bit of a loss and in need of assistance.

I’m attempting to make my own professional grade closed loop lure coursing machine. Essentially a motor is directly connected to an approx 11" pulley that has a line half wrapped around it and up to approx 10 external pulleys that make up the course. Attached to up to 500m of line through out the course is a plastic lure that dogs chase for exercise. With tension on line, the motor must be able to spin the pulley clockwise, counter-clockwise, very quickly, change directions very quickly in order to keep the dogs engaged, and stop very quickly for safety. Most of the motors in the professional boxes are 12v or 24v. The good ones have cooling fans inside for longer run time. I’ve seen some that have RC controlled speed, which would be cool but is not necessary.

Here’s what I’m struggling with: all of it :woman_facepalming:t3:. I don’t know what type of motor I actually need. I’ve been looking at the upgrade/replacement motors for the power wheel toys to use for my motor. They’re either 12v to 24 v around 40000RPM Electric Motors but some seem to have a special connector and honestly I’m not sure if it is overkill. I looked into the brushless RC motors but they’re way out of my price range for what I assume I’d need.

In terms of the speed control, the PWM looks really clunky and I’m not sure if it’s even the best application for my needs. I’ve been looking at drivers and controllers and have been trying to understand it all, but I’m realizing I am out of my wheel house and I need to call in the pros.

Any advice is welcome and grately appreciated. Thank you in advance for offering me your mind space. Hope you are all well.


P.S. Incase anyone needs a visual, here’s a link to a youtube video: The Renegade Loop Lure - YouTube scrub forward to the 1:30 mark


Unfortunately, offering advice on broad project design advice is beyond the scope of our support, but in general, it seems like the key thing you need to do is figure out some constraints for the type of motor you need (speed, torque, size, etc.) and then you can work from there. It is not immediately obvious to me how you might determine the amount of torque your motor needs to be able to handle, but I suspect setting a target accleration/deceleration rate and figuring out the total mass of the rope would probably be a good starting point. From there, there is probably some combination of classical mechanics type calculations that can lead you to a torque value.

By the way, your motor speed control system will almost certainly use some kind of PWM if you use a brushed DC motor. I do not know exactly what you are referring too when you say something “looks really clunky,” but using PWM signals probably was not the issue.

- Patrick