SparkFun Forums

[sofiadragon1979]

Could someone recommend a dc motor strong enough but @ the same time gentle enough to be used for power assist. The item will be a custom built dolly used for lugging around camera equipment. The total weight will be approx. 50 - 75 lbs. Thank you to those that help.

[waltr]

A wheel Chair motor meets your requirements.

[sofiadragon1979]

A wheel Chair motor meets your requirements.

Do you know how epensive they are, & where I would be able to aquire one.

[Maxwellfire]

Try searching in google and amazon.com.

[Duane Degn]

I hear Craig's List is the place to check for wheel chair motors. Search for power chair.

I think you could get by with a much smaller motor. You'll likely need some sort of encoders to measure the speed of the wheels so you can adjust the power delivered to the motors appropriately.

I was very pleased with how much adding encoders to my Mecanum wheeled Rover 5 improved its performance.
I have a video of the robot using the encoders in post #49 of this thread.
http://forums.parallax.com/showthread.p ... ost1078740

[tranquills1]

A motor controller rated at 320 AMPS (stall current taken into account) would handle a 1HP wheel chair motor whose running current would be about 40W. Variable speed and direction of rotation would then be quite easy.
Motor controllers rate for 320 AMPS sell for about $200 US.

s

[Joeisi]

Or you could pick up a bunch of Power MOSFETs and make an H-Bridge or something.

[fll-freak]

Or you could pick up a bunch of Power MOSFETs and make an H-Bridge or something.

I suspect building a motor controller to handle 10 amps let alone 300 might be pushing the OPs skill level. A pre made device sounds in order.

[Joeisi]

Ok maybe so...

[tranquills1]

difficult to build a motor controller with load, polarity, voltage protection and heat sink all in one.
there are controllers out there with dual chips that can be jumpered so the two can act as one and double the load to 600 AMPS.

s