Using Roomba Motors And Maybe Wheels?

Question

Hello all, i previously asked another member about the tracks on rad 2.0 he indicated that it could probably pull the robot but motors may not last. My idea hear is probably replace the motors. I have a omnibot 2000 on the way and im looking for a good alternative to the loud 1984 motors in the omnibot. Roombas wieght 6.5 pounds , so 4 roomba motors shou,d support 13 pounds and 8 motors 26. I would run 4 on each side i guess in parrallel. Are roomba drive motors themslves very loud? Im looking for lower noise options because downstairs i have hardwood and some tile any ideas appreciated thanks

bret.tallent · Answer

The Roomba motors are fairly quiet, but any geared set up is going to be noisy. I think a better way to go might be a stepper motor (you can get a lotta torque out of one unit). They are very quiet, and you can get them on ebay pretty cheap. You would only need two (one on each side) to move that around with ease and get really good speed control out of the PWM. You would need stepper motor controller but those are very cheap on ebay as well and typically you can get them in a dual H bridge type setup. That is actually what I am thinking about doing with BOB. I will just need some help on hooking it up to the EZ-B

jstarne1 · Answer

I was thinking they are quiet , thats what industrial bots used. Honestly ive never used anything other than brushles outrunner , rc servo or reg dc motor. So a sepper i would connect direct to shaft of the wheel? Assuming this bot wieghts 25 to 30 total pound loaded with batteries what kind of steppers do i need? I have plans to use the tracked base off a rad 2.0, thanks alot

bret.tallent · Answer

I would think a NEMA 17 or 23 would be a good size and you are right, just connect it directly to the wheel. Here is a NEMA 17 on ebay for a good price: https://www.ebay.com/itm/CNC-Nema17-1-7A-3400g-cm-40mm-length-4-Lead-2-phase-Wantai-Stepper-Motor-/170704612100?pt=LH_DefaultDomain_0&hash=item27bec9ab04

jstarne1 · Answer

What controller would i use wit that to interface with ez b?

bret.tallent · Answer

This would work, but I'm not quite sure how to hook it up to the EZ-B. I will need some help with that. https://www.ebay.com/itm/150717338614?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

jstarne1 · Answer

Maybe dj will see this and have an idea of how to power two motors sufficient to push a 30 pound bot around with a vacuum on the back. Im sure resistance of suction on carpet adds a tiny bit of resistance too so a fairly torqued motors a must. So dj have any ideas? These steppers are 2 amps each whats the best way to connect to ezb?

jstarne1 · Answer

I like the idea of steppers if ezb can handle speed control somehow on the pwm for the stepper. Done need alot of speed control maybe 3 to 4 speeds plus stop. Id like to eventually figure out soft stoppes, where it runs through speeds 3, 2 , 1 then full stop to reduce jerkyness and unstable sharp movement. Im a noob at the robot stuff i just know dc electronics and rc

DJ Sures · Answer

I haven't added default stepper motor support. You'd have to code it yourself right now. Wait a few weeks and i'll have a control for stepper motors. I've added it to the list now

bret.tallent · Answer

SWEET! DJ you are the man!

jstarne1 · Answer

Ok cool , I plan on buying the ezb , maybe 2 soon so maybe by the time I get them you will have support. Thanks

jstarne1

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