Okay. I need a motor that will go at walking pace (and preferably a bit more - I can take it up and down using PWM if needed).
It’ll need to be driving 10KG, possibly more.
As always, cost is an issue with me…so the cheaper the better!
Could you maybe post some motors and some specs that would create the above effects so I can look for motors in other places as well?
Thanks in advance.
theChipmunk
lynxmotion.com/Category.aspx?CategoryID=11
^the spur gear head motors
lynxmotion.com/Category.aspx?CategoryID=71
^the planetary gear motors
they have specs right below the name
Yes, but which one!?
Please help!
theChipmunk
hmmm, if you want to go with the Spur Gear head motors, i think you should go with the ghm-13s they have the greastest amount of stall torque, and also they should still give you a decent speed with 152 RPMs
heres the URL:
lynxmotion.com/Product.aspx?productID=250&CategoryID=11
if you were going with that choice, id slap 4 motors, maybe 6 into the roverbecause 10 kg is approximatley 22 lbs, and thats still around 3.6 lbs per motor if you put 6 motots in it, (to get that i just divivded 22 by 6, simple math)
the planetary motors are quite a bit stronger though, but they also are longer too
lynxmotion.com/Product.aspx?productID=418&CategoryID=71
this one may be a good choice, its got 271 RPMs and its a pretty high stall torque at 7.41 ft-lb
actually before i talk more, how exactly do you determine how much the stall torque is, is it, for this motor, for centimeter that something is away from the shaft, the strength lowers 1 kg? please help, i dont want to be given chipmunk bad info 
I need to only use two motors. I’ll be building my own chassis as well.
Thanks for all the help so far Chunga!
theChipmunk
well, idk how accurate my information is, so you shouldn’t be thanking me just yet, some one should be coming in any time to dissprove me 
Ok, I’ll jump in… That’s an awful lot of weight for two gearheads… even with the strongest ones from Lynxmotion. 5Kg per motor??? I don’t know about that.
Richard
thats wat i thought, thats y i suggestedd 4
I’m not sure 10kg at a walking pace is realistic for even the 12V planetaries.
(Please correct me if I’m wrong, guys.)
I’d say, go with some Harbor Freight drill motors and buy some cheap hobby speed controllers.
They’ll go a lot faster than you’ll probably need, but that can be corrected in software.
They should definitely have the torque to roll 10kg around with them, which is the most important part, I’m guessing.
However, I’ve been told they draw up to 50ish amps, so you’ll need a pretty decent speed controller(s) for them.
If cost is an issue, you may want to consider a riding kids toy like below for a starting platform. It should support 10kg and already has some features you would spend a lot of time on making from scratch.
Wouldnt that be one motor though?? I wish they could show the inside too, for us robotic enthusiasts.
i can see it now:
Walks up to store clerk
“excuse me sir, can you tell me hot many motors are in this vehicle?”
“1, why do you ask?”
“well…i sorta…need the motors for…LOOK, points to price check WHATS THAT?!?!??!”
“what? looks away”
sprints away and hides among the stuffed animals
Im thinking if that store clerk was being a jerk, I’d sik my rover robot on him and chase him down the power tools aisle.
Is there no way that I could get away with two lynxmotion motors?
The weight will probably be a bit less than 10KG.
If I try and use four, the speed controlling and PWM will get a lot more complicated!
Mind you, if someone could point me in the direction of a nice, cheap microprocessor that could easily monitor and put out four PWM signals, then I’d be happy to get four motors and do it that way.
theChipmunk
Why can’t you just parallel 2 motors on each side? You would be pulsing 2 motors a side instead of just one.
Richard
thats exactly wat i was thinking rryerson, thats how they set it up on the Rovers
Exactly what I was about to say. Just solder two motors together with a pair of wires running from one motor to another, than a pair of wires running from the motor to the microprocessor. Simple 
Thanks guys!
So, would the PGHM-20 do the job if I had four?
What sort of battery do I need for that and how many amps would the MOSFETs on the motor controller need to stand?
Thanks again - I couldn’t do this without you guys…
theChipmunk
I would recommend 4 of these motors…
lynxmotion.com/Product.aspx? … egoryID=11
All the motor’s specs are listed at the bottom of the page.
Richard
yeah, they are realy powerful.
