Electric Motor Secrets

[Peter Lindemann]

Iron Ring

Hi Peter,

In the video you had a coil that you used to run a motor. This motor would pull the metal into the center of the coil then release.

You strenghten the power of this coil by putting as I recall a ring around the coil and then a lid on top of the coil, then stated you could futher increase the efficiency if you had not glued down the coil to the mount.

My question is, how did you make the ring? Could an iron cup do the same thing? I wanted to test this with my SSG, but I did not know if it would have the same effect on my coil.

Thanks.

Mart

Mart,

The outer ring was made of two different diameters of clear plastic tubing, defining the outer and inner walls, and a flat donut section to define the bottom. These pieces of plastic were super glued together. Once dry, the area in the ring was filled with iron shavings from an engine rebuild shop. These iron filings were compressed down as tightly as possible and super glue was pours on top to form a sealed upper surface.

All I was trying to do was create a magnetic path back around the coil that would be better than the air. Adding the iron plate on the top helped too. If I could have completed the iron pathway around the bottom of the coil also, the torque would have increased dramatically for the same electrical input.

A properly sized iron cup could work. But this is not going to make your SSG run better. That is a different system altogether.

Peter

[theremart]

Question to Peter about Electric Motor Secrets

Hi Peter,

In the video you had a coil that you used to run a motor. This motor would pull the metal into the center of the coil then release.

You strenghten the power of this coil by putting as I recall a ring around the coil and then a lid on top of the coil, then stated you could futher increase the efficiency if you had not glued down the coil to the mount.

My question is, how did you make the ring? Could an iron cup do the same thing? I wanted to test this with my SSG, but I did not know if it would have the same effect on my coil.

Thanks.

Mart

[theremart]

[Jetijs]

They stacked the stator core in a lathe and used a very sharp cutting tool with small passes, a little bit deeper each time till the surface was smooth
Jetijs

[Schpankme]

machined smooth

... my stator core with the inner surface machined smooth.

Hello Jetijs,

What method was used to smooth (finish) the core inner surfaces ?

- Schpankme

[Jetijs]

Hi lighty,
Machining plexiglass is easy and fast as long as I don't subject the machined pieces to any kind of solvents, oils or other chemicals, that makes the material to crack on the weakest points. I had some problems using epoxy resin, that cured too fast and exposed the plexiglass to pressure and heat, making cracks. This last design is machined so that I do not need any kind of glues or other chemicals, so the material should hold fine. My cnc machine has very high RPMs, the lowest I can get are about 9000RPM, of course this is too much for any kind of plastic, because at these speeds it would just melt. So I need to use a liquid cooling system, to cool the endmill bit and flush away any chips.
Thanks,
Jetijs

[lighty]

Nicely done Jetijs.

BTW - did you have any problems machining plexiglas?

[Jetijs]

Hi all. Today I received back my stator core with the inner surface machined smooth. Looks very nice.





Now I am waiting for my shaft. I gave them my drawings today, it can take up to a week till they make it, because I am not the only customer
Thanks,
Jetijs

[theremart]

Re Dc12

I searched all around googe for this DC12, all I could find was only the vacuum cleaner with this motor inside, but no spare parts. The cost for this vacuum cleaner was about 500-600$ and I found them only in some Japanese stores. Isn't it suspicious that they announced this mode in 2004 but now, four years later, this model still seems so rare.

Dear marthale,

Dyson Dealers are the only place to find the DC12 Motor. The factory has not opened the market to distributors and wholesalers. Thanks Marty

This what the seller on Ebay sent me.

[Jetijs]

I searched all around googe for this DC12, all I could find was only the vacuum cleaner with this motor inside, but no spare parts. The cost for this vacuum cleaner was about 500-600$ and I found them only in some Japanese stores. Isn't it suspicious that they announced this mode in 2004 but now, four years later, this model still seems so rare.

[theremart]

Dyson DC07 DC14 Complete motor

Dyson DC07 DC14 Upright Vacuum Cleaner Complete Motor - (eBay.ca item 190184386802 end time 15-Feb-08 11:43:18 EST)


$45.00

Yes it is not the DC 12, but hey I sent an email to this guy to find out if he sells the DC12 motor.

[Schpankme]

Dyson DC12 Digital Motor

... Checking on the tolerances for the Dyson Motor is a great idea. Seeing if it available as a replacement part is an even better idea! Thanks for following up on this and letting us know what you find.

Dyson DC12 Digital motorover-molded

[Peter Lindemann]

Dyson Motor

Jetijs et al,

Excellent recovery on your bolt holes; beautiful work. Would vibration damping (thin rubber washer) allow the bolt heads to distribute the stresses between the Acrylic to metal intersection?

Note: an uneven shoulder cut of the bolt heads, may produce stress cracking of the assembly (path of least resistance) during operation.

Dyson motor:

Is that a set of (4) coils behind the Stator (left), on the Dyson motor ?

I'd also have to say the Tesla Turbine Pump would be a much better match for the Dyson.

I'll make some phone calls in the morning and try to obtain "Build Quality /Tolerances) for the Dyson. They may even have a catalog of replacement parts

Best regards,

- Schpankme

Schpankme,

Checking on the tolerances for the Dyson Motor is a great idea. Seeing if it available as a replacement part is an even better idea!

One thing about this motor that I am still not certain of is the exact shape of the rotor. The exploded diagram obscures the rotor image so I can't see it completely. The motor Jetijs is building will not START in all positions, but the Dyson Motor probably does, so there must be some differences.

Thanks for following up on this and letting us know what you find.

Peter

[Peter Lindemann]

Need More Information

Yes this could very well be. Especially for the rotor since that solid steel will not loose it magnetic alignment very fast - to say the least. But the amp draw is (in my opinion) due to the voltage ruling over the ohmic resistance of the coil.

Side note: You know these expensive Dyson vacuum cleansers? Well some types have switched reluctance motors in them.
MOTORS, FANS & BLOWERS: New Market: New Motor - Archives - Appliance Design

Regards,
Steven

Steven,

Thanks for posting the films of your motor. I'm glad to see you working on it again.

I haven't commented on it so far, because there really isn't enough information presented to evaluate. It would help to know what the full schematic of the test circuit is, as well as the switch timing. Your film emphasizes a relationship between input current and rotor speed, but this is not enough to say anything about WHY it might be happening.

In general, I agree with your statement that the current limit is set by the ohmic resistance of your coil. This is true of ALL motors, including the ones we are building here.

If you recall from my latest film on YouTube, the motor performed the worst when the energy of the coil collapse was just shorted out with a diode. Under these circuit conditions, the motor turned the slowest and drew the most current. You may also recall that the speed went up and the input current went down when the recovered energy was used to power a light bulb. So, what you do with the inductive collapse affects the motor performance quite a bit.

So, I'd be glad to comment when I see:

1) the complete schematic of the circuit you are testing
2) a complete explanation of your timing sequence that includes the number of degrees of rotation defined by your stator pole faces and the ON time/OFF time positions of your two power coils, and
3) an explanation of how your circuit is handling the energy of the inductive collapse.

Peter

[Schpankme]

Here's a bigger picture:... The stator/rotor pieces look indeed like my motor..

Jetijs et al,

Excellent recovery on your bolt holes; beautiful work. Would vibration damping (thin rubber washer) allow the bolt heads to distribute the stresses between the Acrylic to metal intersection?

Note: an uneven shoulder cut of the bolt heads, may produce stress cracking of the assembly (path of least resistance) during operation.

Dyson motor:

Is that a set of (4) coils behind the Stator (left), on the Dyson motor ?

I'd also have to say the Tesla Turbine Pump would be a much better match for the Dyson.

I'll make some phone calls in the morning and try to obtain "Build Quality /Tolerances) for the Dyson. They may even have a catalog of replacement parts

Best regards,

- Schpankme