Electric Motor Secrets

[Necchi]

Hub motor?

Is it possible to swap the stator and rotor as in the drawing I've attached?

[Jetijs]

Hi Chris

This was my previous stator shape:


And this is the new one:


The main difference is that this design will allow me to use prewound cores. I calculated that with this design I should be able to use bifilar coils with 30 turns (50 turns total) of gauge 14 wire. Will see if I was right soon
The rotor plates are the same shape as in my previous motor.
Thanks,
Jetijs

[LowTechIsCool]

Update

Hi,

Nice work on the stators, JetiJS. The outer diameter looks larger than before. I would be glad to hear about the changes you made.

I figured out my problems.

Done with finals and now I get to work on the motor. Machine shops close on Friday, so I get to see how much I can cram in till then.

-Chris Corkum

[Jetijs]

A quick update.
I finished gluing the stator plates together. I used "Bison epoxy metal" for this. The epoxy is rather thick, so I had to dissolve it with some solvents, after that it is not as thick anymore and you can easily apply it on the plates using a paint brush. This works well. This epoxy is also dissolving in water when not cured, so I could easily wash off all the epoxy that squeezed out when the plates where pressed together with bolts. I used two endplates made out of 4mm thick iron to distribute the pressure evenly. The big hole on the inside is just 2mm bigger than the rotor diameter, this is because this way the lathe job guys wont be able to mess anything up as they did last time (separating plates) while making the inner surface smooth. Only after all the core machining is done eill the plates be removed, hopefully leaving a good stator core.



My rotor cores are also glued together ready for machining. Unfortunately I wont be able to progress until after holiday season, because all the machinists are already at holidays.
Thanks,
Jetijs

[LowTechIsCool]

winding coils

The mylar I am using to cover the stator poles works very well at preventing wear to the wire coating and is very thin, so I am reluctant to replace it with an epoxy coating, but I may have to. Im going to see how a glow gun holds to the mylar. The glue gun doesnt really bond strongly to the wire, but it may be enough to hold it in place, which is all I need at this point. I am not a fan of the glue gun because it comes out in relatively large globs, but I may be able to work around it.

On prewinding the coils:
I have a block that is the same size as the stator which I tried use to prewind. I found that I had trouble getting the coil off once I knocked it tight around the corners. Additionally, it was difficult to put the prewound coil onto the stator. I am ingnorant on this topic, so your advice is most appreciated

I use a tool I made to get the coils to hug tight around the corners. It is basicly 0.5x0.5x2 inch block with a 90 degree wedge cut out of one end. It has mylar on the wedge. I set the tool on the corner of the stator, where the wire is, and i tap the tool with a hammer. It makes the wire form a sharp angle, and doesnt harm the wire coating. This is partly why I have a hard time getting prewound coils off.

In the next week I will have a nice report on building the mechanical aspect of the motor, so that people will have a place to go for a summary of all the information that has accumulated on this forum and wont have to scan 30+ pages to get a single question answered. I hope this is in the spirit of the forum.

-Chris Corkum

[broli]

I consider myself now much wiser since my last post here . So I'm going to drop another suggestion.

I have searched this thread for something similar but I didn't find it. (maybe I haven't looked to good). But I think most know the principle in the picture. You use a permanent magnet and a coil. The coil serves as a path switcher for the PM. In the off state the permanent choses the smallest loop being through the coil but when the coil turns on the PM switches to the longer path through the rotor. I think the main guys behind this idea are Flynn and Hilden-Brand.

So this is a rather small addition (on paper) that could bring interesting results. That is besides the fact of recollecting the collapsing field you might have a substantial increase in torque which can lead to other ways to extract energy from that torque.

[Jetijs]

Hi Chris
I would suggest to grind round all the sharp edges of the core so that the wire can not be damaged in the winding process. Also after grinding, coat the grinded area with some epoxy resin of some coats of varnish. The sharp edges for me was the biggest problem that made the winding process twice as long. Also make sure if you can not wind your coils outside of the stator and put them in the stator later. This would make things much easier. You already have a pole shape suited for this. To secure the coils in place you can use some epoxy or just a hot glue gun.
Good luck!

[LowTechIsCool]

Stator windings

Hi,

I am wrapping coils for my stator this week. The design is the same as Jetijs version 2, but the stators dont flare out at the end, they are just straight. What can you suggest. I am doing the following.

1.Have other people to help.

2.Put adhesive backed mylar, so they wire coating does wear

3.Have made a few tools for getting the coils on straight and tight as I wind, and dont damage the coating.

I want to know how I can secure the coils as tight as possible. What I want is to get a coil in position and basically super glue it in place, but super glue, apparently, doesn't stick to the mylar. I could use some help on this. Ill ask others at my school as well for suggestions.


I'll be presenting my pictures sometime soon, but I could use the suggestions sooner.

-Chris Corkum

[Archer Newlun]

I have AutoCAD at my work, but I never used it. I will give it a try this week. Hopefully I will be able to show some drawings of my motor.

[Archer Newlun]

Yes, Sorry I was thinking about (2) 2-rotor design. It will have a 45 degree offset.

[Jetijs]

Unfortunately solidworks is not a freeware and is rather expensive software (several thousands dollars). I just have access to a computer that has this software installed.
Also, are you sure about 90 degree? Don;t you mean 45 degree offset?

[Archer Newlun]

Solidworks

Is solidworks freeware? Where can I get it? I would like to use it to create my drawing so I can give you an Idea of what my motor will look like. I want to make my motor casing cylindrical in shape. I will have (2) 4-rotors offset by 90 degrees just like you motor. I want to make the motor as compact as possible. I also want to be able to adjust speed of motor so my timing system has to be adjustible. I was going to wait untill after the New Year to start working on my motor again, but I have a burst of inspiration to try and get something done! Thanks jetijs

[Jetijs]

I am using solidworks to make my CAD drawings. I find it the most easy software to make 3d objects.
I am glad to hear that your design will be similar to mine, I had this idea almost year ago when I made my second attraction motor. The 100% ON time should provide excellent torque and it will also be self starting
Keep us updated on your work
Thanks,
Jetijs

[Archer Newlun]

Motor Setup

@jetijs

Sorry, I don't have pics yet, but I will try to get some up soon. I'm still waiting on some more electrical steel to come in, and after that I'm going to get my stator cut out of it. I actually was thinking of a similar setup as the one you just showed me. I was going to design a dual attraction motor setup also. What program do you use to draw up your designs? I'm glad that someone is still working on this project other than me!!!
Let me know if you need any parts, I might be able to help!

[Jetijs]

Hi Archer Newlun
I was just thinking about this thread and that no one has posted in it for a long time. What a coincidence

I am now working on a new design of this motor that will have 100% ON time and no inertial movement. It will have a mosfet for each coil thus making it more powerful and it will have a timing adjustment system that will allow me to adjust timing on the fly. I just thought that if I am working on this, I might as well give it the best try I can. I already had my stator cores made, but those guys who did the lathe work, messed everything up. So I had to get new plates, get them laser cut, which took about a month and now I need to glue them all together again. That is why this thread is so quite for all this time. The new design will basically be two attraction motors coupled together with offset timing so that when one motor rests, other does the work. The stator plates now are made so that I can use prewound coils as Lighty suggested. Here is a picture of how this might look like:

This one has two flywheels, but since the ON time will be 100%, I don't think that I need them. Also the timing system will be a bit different, but you're get the idea.

I am glad that someone else is also working on this. Could you maybe tell me more about your setup? What will the motor look like? What materials will you be using, do you have any pictures?

Thank you
Jetijs