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Topic: Motors for robot (Read 744 times) previous topic - next topic

nmac2011

Mar 05, 2017, 08:25 pm Last Edit: Mar 05, 2017, 11:15 pm by nmac2011
I am looking to build a small robot that will be able to go over the lawn; probably about 20 pounds max, wheels of 6in, 12v, and a desired speed of about 1.5m/s. I also plan on using 4 motors in total. I used this tool (http://www.robotshop.com/blog/en/drive-motor-sizing-tool-9698) to determine my torque and it is 3-3.5Nm per motor depending on the max incline.

I am trying to find motors that meet those requirements for around $10-15 a piece but I am having trouble. Is this reasonable or will I have to spend more? Where should I be looking if they are in that price range.

PaulS

Quote
I am trying to find motors that meet those requirements for around $10-15 a piece but I am having trouble.
What kind of motors? Stepper motors? Servo motors? Standard DC electric motors?

With suitable gearing, you may really not need that much torque.
The art of getting good answers lies in asking good questions.

nmac2011

I am trying to build a RC lawn mower, so I am looking at DC motors. Any help is greatly appreciated:)


MarkT

Firstly that seems a little excessive, I make it more like 1.5 to 2Nm a wheel, at 200rpm, unless you're going
for vertical climbing, and yes gearmotors of that power rating will not be dirt cheap.  Something
around 20:1 reduction ratio seems plausible, as you'd expect 4000rpm motors of that class to be
fairly common.

What about 2 motors each driving two wheels using a belt? (I guess getting clogged up with grass is
the issue)

Are there other forces we need to consider from the cutting mechanism though??
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]


PaulS

Quote
This also looks good but I am not sure how I would go about gearing it.
The product description says 30000 RPM, while the picture shows 18000 RPM inked on the motor. Stay away from that liar.
The art of getting good answers lies in asking good questions.

nmac2011

I found this: http://www.robotshop.com/en/12v-118rpm-9582oz-in-hd-planetary-gearmotor.html

it seems like it should work. Is Robotshop reputable and would this work?

Slaghton

I've bought from robotshop in the past when I first started messing with my robots.  I never bought any servo's from them but everything I got functioned and appeared as it should.

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