View Full Version : Stator Laminations
02-09-2007, 09:54 PM
In all the threads I could find I cannot figure out if there is an insulator between the plates of the stator. A few times the laminations have separated when pulling the stator off of the hub and it does not look like there is any insulator there. It seems to me somewhere I saw a build up guide from someone in Europe that was making his own plate stampings and he was using an insulator sheet between them. The thread was in German so I could not determine what material and for what purpose he was using. I have been letting the smoke out of a few rewond cd rom motors and would like to stack a few stators together. Yes I know you can mount them end to end on a common hub, but I would like to make use of the damaged units if possible. I have found that the "liquid tape" products found at hardware stores works great to insulate between the stator poles and the windings but I am still in the woods on this between the plates deal.
02-10-2007, 05:55 AM
Technically the stator plates are insulated from each other.
However this is achieved by a thin layer of varnish on the stator material from the factory.
So if you take a stator apart don't clean off the film on each plate.
the film is very thin. It is thin so that the film ,which is electrically useless in a motor, does not take up too much space. You want any space taken up with magnetic material.
If there was no film or insulation between laminations then you would get very high losses due to eddy currents.
02-10-2007, 05:00 PM
OK I understand the Eddy current principle. Separating the plates was not an intentional act. The stators were bowed while removing them from the hubs. My thoughs here were to machine a longer hub and combine two maybe three of the stators together. I can straighten the plates and the liquid tape I mentioned works well to insulate the poles from the windings. I would assume the varnish you refer to is specific to electric motors and generators which would make it problematic to find in small quantities. Is it possible to use something like CA gel or thined epoxy to re-laminate to stators and join them together? I can make an alignment tool and press to compress everything I just don't know what insulating medium to use.
02-11-2007, 12:59 AM
I used a pressure pack of clear urethane for convenience ,when we used to make laminations proffesionally they were dip washed in a solution of water and phosporic acid wich left a whiteish surface, even thin paint will suffice as previous post noted its to stop radiacal lines of force going sideways into adjoing laminations and is not meant to be a voltage insulator.yep by all means use a jig to compress together if done while still sticky that will work ;)
02-13-2007, 07:28 PM
I'd recommend against using CA on the stators if possible, as some folks have reported that over time, the CA can slowwwwwwly eat away at the enamel insulation of the windings leading to potential shorts.
Never happened to me personally, but it would be a bit of a PITA. ;)
02-15-2007, 02:36 AM
My use for CA would be between the laminations of the stator. The windings would be insulated from the stator poles and therefore the CA by the Liquid Tape I mentioned earlier. I found that if you thin the Liquid Tape with enamel paint thiner it will flow well around the poles without being so thick that it takes up space that would be used for the windings. So far it has stood up to the temps my little home winds are creating. That includes the ones that have been over-proped or over-volted to the point of letting the smoke out of the winding. I think the issues you refered to were when they used CA to anchor the windings or the leads going to the ESC connections. In these cases they are applying the CA directly to the enamel of the winding.
02-16-2007, 02:05 PM
Correct, the issues i referred to most commonly happen as a result of people securing the windings with CA. But if you have CA on the stator (there's no way to make sure you get it JUST on the surface of the lams) there's a remote chance that it can still have a negative effect on the wire insulation. Just trying to make sure you're aware of EVERY possibility so you don't have to troubleshoot a short later on, if it happens. :)
Have you considered just hitting each lam with a bit of varnish? That's really all it is anyway. I don't believe that will have any effect on the wire insulation.
02-16-2007, 05:44 PM
Engine Paint works well. same stuff I use on my chevy blocks.
Comes in a spray can, good to 500 degrees & can be purchased at any auto supply shop.
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