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Build your own DC Motor

34K views 90 replies 22 participants last post by  Beshires1 
#1 ·
I'm in the process of building a DC Motor Entirely from scratch. Every piece of this motor is made from salvaged parts. The armature shaft is actually a TH350 input lockup shaft from a transmission. Anyone with helpful ideas please help me out. I'm keeping up with the process on my web site: http://sites.google.com/site/diydcmotors/ :rolleyes:
 
#2 ·
Wear your safety glasses, might even recommend a helmet with face sheild encase anything broke apart!

You had my whole desk vibrating with that video!

Very impressed with what you have made from junk! What RPM are you hitting? Got pictures of the motor, hard to see what's what in the video


I'm in the process of building a DC Motor Entirely from scratch. Every piece of this motor is made from salvaged parts. The armature shaft is actually a TH350 input lockup shaft from a transmission. Anyone with helpful ideas please help me out. I'm keeping up with the process on my web site: http://sites.google.com/site/diydcmotors/ :rolleyes:
 
#3 ·
Etischer, Yes I take precautions (It makes me nervous as hell testing these creations). This small three coil rotor design uses 1" rare earth magnets (field) The brushes used in this one are Volkswagen generator brushes.I rely on Goop Glue to electrically insulate and to hold things in place. Here is a better video of this one so you can see the BB pole shoes in the armature, the commutator and the magnets. http://video.google.com/videoplay?docid=5384542111527841740
 
#4 · (Edited)
I see the DC motor as a supreme torque motor like a diesel ICE would dream to be so wouldnt it be better to make full use of its qualities or shortcomings and design it as a pancake style instead of a cigar?

Then it could be direct driven with a driveshaft and run at less rpm, less heat and less wear. Armature will be shorter and lighter, Copper windings
will cool themselves better, no?

Imagine two 13inch by 7 inch motors side by side each connected to a wheel to power and acting like an LSD. Max of 1500rpm wouldnt
that work?
 
#9 · (Edited)
I have been thinking amorphous steel nanopowder . made with a plasma torch , cooling gas and scrap steel . the super fast cooling makes amorphous non
crystalline
iron or steel said to be 4% improvement in
efficiency
. the
evaporating
metal on
condensing
makes
nanoparticles
that are amorphous . how about a 96% pm motor . how come I get these green split up posts.
 
#7 ·
manic monkey, You guessed it the core will be filled with cast steel shot and epoxy. I have ordered 20 lbs Cast Steel Shot/ Grit - S-280 Amasteel. I'm thinking about filling the entire 4" Pipe full with this mixture. The strips of PVC that are screwed to the outside can also be cast and replaced with this epoxy steel mixture.
eticher, this larger armature will have six coils. But that's the beauty of this design I will be able to remove three coils or run the planned six coils, by changing the coil to commutator jumper cables ( I Haven't got to this part yet). I'm planning on this motor to be slightly modular in that I won't be stuck with one motor and its preformance. Thanks for the Interest
 
#14 ·
Skullbearer, definitely, Go for it! Just use good building practices, over kill is recommended. Ya wouldn't want the armature chasing you around your shop at 40,000 RPM. I think I would have one hell of a grin if I survived and would have to clean the crap from my pants!
 
#17 ·
My reasoning is that It would be more difficult (for me) to build a AC motor that really can't deliver the torque in the lower RPM range, as most medium sized DC motors can. I'm going to use permanent magnets as the field mainly because I happen to have two 2"X1" N 50 Rare earth magnets rated at 14,700 Gauss and have a pull force of 210 lbs. each. Recon how much energy would be used in a series wound DC motor energizing the field coils, to produce this much Gauss and pull force in one of the field coils?In four field coils? These Neodymium magnets can last forever with proper care. But they are dangerous to work with as they can break bones and crush fingers and hands or any other piece of you that happens to get caught between two of these when they slam together. They will fly threw the air a couple of feet when one is brought near the other, and slam together with enough force to shatter themselves.
 
#21 ·
good to see you are still alive well done ;)

Please take care with the beast
 
#52 ·
Beshires -
You're a freakin' maniac! I love that thing!

I've been swamped elsewhere, and haven't been here in a while. I just saw your motor project. Yeah, it looks a bit like a monster and less like a regular "store bought" motor, but it's a damn sight more than any other "homemade" motor I've seen.

Of course, you've already gotten all the cautions about wearing a protective suit of armor and signing a full legal disclaimer, but I'd still like to add a "be safe" on top of the pile. I admire, respect, and sometimes emulate your decision to build. I've also had the feeling of "Well, I can't afford or don't like what I can buy, so I'll make my own."

In all seriousness, make sure to get and post video of any failure modes and what you learn from them. I've worked in product development for years, and sometimes that's the most valuable information. (Also often the most expensive...) And yeah, it can also be the most entertaining.

Anyone who wants to appreciate the effort it takes to make something should try to design and build one themselves.

-Mark
 
#24 ·
Looks like all going to plan.

Can I ask how you secured the Tranny shaft on so it wont move?
All I can see is that the glue keeps it secure meaning the surface
area of the shaft is the only contact throughout to keep it from
spinning.
The reason I ask is because if this is the case I think the glue will
eventually give way unless there are fins or protusions on the shaft.

This is a learning experience for me too and thank you for your efforts.
It has made me see that lighter weight armatures should the next
evolution of the DC motor to increase efficiency and response.
 
#25 · (Edited)
OHM, Thats a good point. the shaft is connected only by surface contact with thick 1" Goop Glue caps. The entire inside is filled with The epoxy and steel shot mixture. I let a thick layer of epoxy only cure around the shaft (This was left very rough} Then packed the entire PVC full of the steel shot and epoxy mixture. After this fully cured I filled the other end with a 1" Goop Glue Cap. Both the Epoxy (for steel) and the Goop are unreasonably Tough and exceptional bonders. I do not think the shaft can possibly break free from the death grip to the armature body. But... I would suggest maybe attaching a couple of cable clamps, large enough to fit around the Shaft. I thought of dimple drilling the surface of the shaft and drilling small holes completely through the shaft and driving steel pins thru the shaft. But I thought that this might weaken the shaft. And remembering how hard the epoxy gets when cured (I've had to file this stuff down after it had cured not a pleasant job! )I figured I would put it to the test.If you decide to build a motor by all means use what ever means for securing and structurally strengthening that you deem necessary. I don't think one can over build something that if it fails could kill him. Always remember balance, and lack there of can cause catastrophic failure.
 
#26 ·
Great thread!

Do you know what RPM and torque numbers your motor has yet?
 
#28 · (Edited)
Just looking at the Armature of other common Dc motors and it looks like it could be hollow if designed properly. If a lightweight Armature can be manufactured with removable shaft and hollow alloy sections then this could be a revolutionary design no?

Eg instead of using the PVC like pipe an aluminum pipe could be used with three thick alloy walls on each end and three piece shaft. The shaft ends could be changed to suit splined, keyway or other designs without removing the centre section.

Armature drawing just to get my thinking across. The shaft I can get made up from small auto tailshafts or rear live
axles the rest from billets except for the alloy tubing which is available from an industrial supplier. Could I go this way?

 
#29 · (Edited)
OHM, yes this looks like it will work very well. Don't forget to add threaded holes around the outer aluminum pipe. You will need a way to securely fasten the armature poles around this outer pipe.If you properly space the holes say using 4 or six holes per pole section you will be able to change the number of poles of the armature. For instance, if you have a six pole (3 sets of two poles) motor you could remove The pole pieces (coils) add a taller double pole piece and make the motor into a 12 pole motor (six sets of two poles). I think 12 poles is enough to allow you to use a four brush, brush holder. Hey remember me as your inspiration, I'd love to get my hands on one of your armature designs (just to tinker with). LOL
 
#30 ·
OHM, yes this looks like it will work very well. Don't forget to add threaded holes around the outer aluminum pipe. You will need a way to securely fasten the armature poles around this outer pipe.If you properly space the holes say using 4 or six holes per pole section you will be able to change the number of poles of the armature. For instance, if yow have a six pole (3 sets of two poles) motor you could remove The pole pieces (coils) add a taller double pole piece and make the motor into a 12 pole motor (six sets of two poles). I think 12 poles is enough to allow you to use a four brush, brush holder. Hey remember me as your inspiration, I'd love to get my hands on one of your armature designs (just to tinker with). LOL
LOL thanks! but since I have no experience with building any DC motors Im just tinkering with ideas to hopefully help improve them.
My background is in dinosaur auto mechanics and Ive finally made the change toward this area after almost giving up with LPG/propane.

Thank you for the tips on the armature I will keep plucking away with ideas. I just thought about the ones i posted after looking at your
website properly and observing your armature again.

Since aluminum is not really moving up in prices compared to steel there could be a bonus for aiming for a lighter weight armature design.
Also car axles are throwaway items that if used properly could work well.
 
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