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Seeking advice for design of homemade DC Motor

  1. Sep 1, 2009 #1

    I need help deciding how to design my DC motor. I know about series wound and shunt wound motors. I want to design a motor for the highest speed at no load. The limitations are 12V and 1A.

    I can only use copper wire (0.315mm, 0.2212 Ohm/meter) and shimstock for the electromagnet (0.003 Inches and 0.005 Inches thickness), and other general items to form the commutator, rotor and stator. From my research I conclude that if I can get a series wound motor to operate at very low amps I will get a high speed. However I have no idea how many windings to use for the electromagnet, how many windings for the poles (i am using a 3 pole design because I want it to be self starting) and the length of copper wire to use. I am not even sure that my conclusion that a series wound motor would be best.

    I would like any advice that you can offer on the design that will get the best chance of achieving a high RPM. Also I know about laminating the sheets of shimstock and keeping the air gap the smallest possible to increase flux, is this correct and is there any other tips to maximise the design performance.

    Thanks in advance
  2. jcsd
  3. Sep 3, 2009 #2


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    Science Advisor

    Most of the parts for a serious motor have to be manufactured for best performance and cost.

    So, I don't know where you could go to get these.

    However, if you just want to make a motor and see it spin, you could try typing
    "DIY ELECTRIC MOTOR" into Google.

    A lot of these replies are for the same motor.
    You get a coil of 1 mm stiff enamel coated wire and suspend it so it balances from the two ends sticking out of the coil. You then scrape the enamel off the bottom side of the wires when the coil is vertical.
    It is suspended on a couple of paper clips which act as contacts.
    A strong magnet is placed under the coil.

    The exposed copper where the enamel was scraped off will allow current to flow when one side of the coil is above the magnet. The coil is heavy enough to keep rotating because of the force on it from this current flow near a magnet.

    I have made these motors and they work well if you get them heavy enough and well balanced.
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