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Making a large electric motor from scratch Answered

I searched the archived threads and found quite a bit already
discussed here about making very simple and small electric motors from
scratch. What I want to do is to make a fairly large and powerful one
(say, somewhere around the size of a coffee can). This is for a
sculpture project, and the motor will be driving a kinetic mechanism.
I'm pretty handy, have a extensive range of tools and am comfortable
working with high voltage. What I am not, however, is knowledgeable
about designing or making electric motors; hence my questions.

I understand that I'll need to wind armatures and so forth, but I
don't know what the advantages/disadvantages would be of making a DC
versus an AC motor (either power could be supplied), nor do I really
understand the differences between the various types of those two. The
motor needs to be able to start by itself under load (as opposed to
some homemade electric motors that seem to need a nudge to get going).
Simplicity, low maintenance and ease of construction would be a plus.

I had thought of making a homopolar motor such as they have at the
Exploratorium (
) but it seems that homopolar motors like this cause considerable wear
to the part that acts as a brush, which will work against my goal of
low maintenance. Unless...perhaps I could use a rolling conductor
(like a precision bearing) as a brush? Does that make any sense?

Thanks for any advice!


I'm guessing that a DC motor would be easier, especially since you seem to be a beginner, but I've never tried to build a motor of any real consequence. Why are you determined to build your own? There are many motors that size available...old appliances if you want AC, or a treadmill if you want DC.

I want to eventually build a dc motor that can produce 30 HP continuous. the cost of buying a one new spurs me on.

Thanks for the link! That looks like a pretty amazing motor.

I'm trying to build this motor sorta modular where the core of the armature will be able to have add ons. Larger coils, different configurations of coils, ability to run with two brush, 4 brush, or 8 brush If I desire. I see things as I go along, so at the end of this project I'll post the things that I think will make the motor better.

What sort of specs are you looking at? that looks like quite a job you've got ahead...