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Topic: Small 3v dc motor and servo (Read 2638 times) previous topic - next topic

Anduino

Hello All

I've slavaged a small 3v dc motor from a dvd drive, and I managed to track it down on the web http://www.ewinson.com/image/draw/rf300ch.jpg.

Now Im planning on gearing this down and using the motor sheild from adafruit to control it. Would it be possible to pull the revolutions right down so it rotates around 60 pm? Or would this be off the question and if so would a stepper motor be better for such a slow speed?

If it is suitable can I drive this and a small hobbie servo on the same motor sheild?

To put the questions into some sort of context heres a little about my concept/project:

I'm building a device which monitors activity, be it network traffic or tweets, depending on how Iconfigue it. The device will resemble a sort of old school seismograph. So with this in mind I thought I would require a small dc motor for driving the paper feed (needs to be a slow constant speed) and a small servo attached to a pen of sorts creating the graph/peaks depending on the size of the activity.


http://www.ewinson.com/rf300ch.htm
http://www.oomlout.co.uk/index.php?main_page=product_info&products_id=207

Hope someone has the time to help a newbie out

Many thanks

Andrew

keeper63

Your best bet would be to use a gear train of some sort on it, rather than attempt to reduce the speed thru excess PWM; you can keep the motor speed (and thus the torque) high, in order to turn the paper roll. A stepper at such a low RPM might also be a tad "jerky". Were there any gears or such used with the motor in the DVD drive? Salvage those as well; with the proper arrangement, you might be able to achieve the RPM needed. Note that, however, designing and building a geartrain is not easy; you might find it better to search for a gearmotor that meets your requirements instead.
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

Anduino

Thanks for the reply cr0sh, alas foolishly I didnt salvage the gears so I will look into buying a geared motor.

Thanks again
Andrew

keeper63


Thanks for the reply cr0sh, alas foolishly I didnt salvage the gears so I will look into buying a geared motor.

Thanks again
Andrew


Well - you could always try a belt drive, if slip isn't an issue for your application (though I think it will be).

For buying a motor, if you can get it surplus, it will be a lot cheaper - I personally like All Electronics and Electronic Goldmine for surplus gear-motors (that is, if I am not buying surplus locally in-person). For instance:

http://www.allelectronics.com/make-a-store/item/DCM-390/62/124-RPM-DC-GEAR-MOTOR/1.html
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16300
http://www.goldmine-elec-products.com/prodinfo.asp?number=G17877
http://www.goldmine-elec-products.com/prodinfo.asp?number=G17949

...each come close to your stated specs for RPM; you might also look on Ebay, and there's also a place called "American Science and Surplus" you might look into...
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

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