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DC Electric Motors
liam.mccaffrey - 5/5/11 at 10:28 AM

I need to run a shaft between 0 rpm and approx 90 rpm. The shaft moves a carriage back and forth on a machine and is under fairly low loadings. I'm thinking a PWM board for speed control.

Windscreen wiper motors are rated for continuous operation but any one know what speeds they output at? and what the stall torque is like. Got loads of these laying around.

Any other good DC motor sources anyone can think of, plus any advice from those more in the know?



This is unrelated to my earlier post about replacements lathe motors btw

[Edited on 5/5/11 by liam.mccaffrey]


BenB - 5/5/11 at 10:33 AM

Do you need accuracy? If so a stepper motor is a good place to start.


HowardB - 5/5/11 at 10:51 AM

quote:
Originally posted by BenB
Do you need accuracy? If so a stepper motor is a good place to start.


as above, I did find a website that goes through the whole process of making stepper motor controlled plasma cutter, perhaps it might be possible to use some of that info,..

linky-thinky

hth


liam.mccaffrey - 5/5/11 at 10:53 AM

don't really need to go stepper motor control I don't think, just need to move the carriage at varying speeds in real time


mangogrooveworkshop - 5/5/11 at 11:34 AM

Use a 3 phase motor and a inverter with speed control built in


liam.mccaffrey - 5/5/11 at 12:05 PM

How much is that going to cost? I was looking to do this on a shoestring with a £20 PWC controller off ebay.

quote:
Originally posted by mangogrooveworkshop
Use a 3 phase motor and a inverter with speed control built in


[Edited on 5/5/11 by liam.mccaffrey]


athoirs - 5/5/11 at 01:02 PM

http://www.technobotsonline.com/motors/mfa-geared-motors.html


dinosaurjuice - 5/5/11 at 03:56 PM

wiper motor or even a window winder motor is ideal. cheap pwm controller off ebay should be alright. about 15amps should do it - fuse the supply (not the motor) just in case.


rf900rush - 5/5/11 at 04:15 PM

If the speed does not need to be constant the any simple PWM should work fine.
Some DC motor controllers can use the Back EMF to give a more constant speed.

If you need speed regulation then you will need a sevor type controller with motor feedback.

Just done that on my lathe to make it CNC.
Not so cheap though, but I can control the DC motor like a stepper motor.

A wiper motor should be able to give you 90rpm with speed control.


liam.mccaffrey - 5/5/11 at 06:24 PM

some good info there guys I'll let you know how it goes