ES Motor Project?

[Miles]

These are the dimensions we have, so far - in case anyone wants to reproduce it in their own CAD software:

Magnets: multiples of 3mm x 10mm x 20mm

Can: ex 5" x 1/8" wall tube

Shaft: 20mm dia.

Core: 112mm OD 60mm ID

Provisional slot dimensions: see pic below.

[TylerDurden]

What similar sized motors are there? It would be good to make a list.
- http://www.hobbyking.com/hobbyking/stor ... c_eq_.html
- http://www.hacker-motor-shop.com/e-vend ... &c=36&p=36
- http://www.plettenberg-motoren.com/UK/M ... /Motor.htm
- Colossus

These popped up here, they look decently made. Lowest kv is 395, but perhaps they might be re-terminated for lower?
KDE700XF-395
NEODYMIUM N45SH, 395Kv
5.5kW continuous
56mm dia., 75mm length, .2mm laminations
$368.95

viewtopic.php?f=30&t=40225

[bigmoose]

I know it doesn't seem like it but 100 motors is probably about 90 more motors than there are people that would be interested in them.

I'm not so sure about that conclusion. Watching the sales of colosus and the German motor development, there may be a bit more "sales to outsiders" present in the equation.

Earlier in this thread Luke mentioned the commutation capability of the Sevcon and Kelly controllers. Has that limit been integrated into the expected design and max speed? (not sure I saw a concluding response) Just a thought that this motor should be wrapped around an existing controller and not a vaporware controller. Might help with implementation into a vehicle so that it is not an orphan motor.

[Miles]

Earlier in this thread Luke mentioned the commutation capability of the Sevcon and Kelly controllers. Has that limit been integrated into the expected design and max speed? (not sure I saw a concluding response) Just a thought that this motor should be wrapped around an existing controller and not a vaporware controller. Might help with implementation into a vehicle so that it is not an orphan motor.

Only in as much as it was behind the original decision to go for 16 poles, rather than 20...

Nobody has said how fast they want it to go, yet....

Orphanos would be a good name for it

[Miles]

Just as some design info, the Sevcon is limited to ~500hz commutation freq (if I remember correctly).

The Kelly Ultra-High-Speed option is limited to 1100hz (in my testing, and it was getting glitchy past 1000hz).


I think the "infinions" can do something around 2000hz (but there have been so many versions and chips used by this point, I have no idea what current ones do).....

4000 rpm / 60 x 8 pole pairs = 533Hz commutation frequency.

[Thud]

I would prolly like to be able to spin it up to 8k on the rpm chart for a performance motor.....(or to the absolut imit of the best controller out there) I could just drop the pole count like they did to the KD motor linked above

[Miles]

I could just drop the pole count like they did to the KD motor linked above

That's ok, if you want to get involved in distributed winding patterns and more inactive copper.

Edit: Actually, 12t 8p still has a winding factor of 0.866. Not so bad...

[deVries]

Some folks reading this exciting new motor thread will recall all the excitement about the Colossus motor designs that many on ES contributed their time & efforts to "make happen".

Did that project & completed motors run into problems, so adopting wide use of that motor was very limited or impractical? I think there were various issues that were discovered after the motors were built & received.

Is there anyway this new motor design can avoid all the pitfalls the Colossus ran into, so as not to repeat those mistakes??? What are the major issues to avoid, so this doesn't become a Colossus mistake???

I'm excited to watch this development move towards a super design and finished product that is matched perfectly with some excellent controllers too. Good luck ES geniuses.

[Thud]

Given the lack of responce on my previous questions regarding the inductance & winding patterns. We know the collosus has some rediculas low inductance & was swallowing Arlo's controllers like candy when wound thusly:
AaABbBCcCAaABbBCcC

Question:
if we maintained the turn direction to beter keep inductive path continuous, would there be a benifit?
example:
A-AB-BC-CA-AB-BC-C (spaces are empty teeth)

With none of the counter wound teeth & their inductance canceling effects in play,
would the feild colapse during switching be any more forgiving on the controllers?

EDIT: the engraving lasers linked in the thread earlyer will not cut steel laminations acorgding to the reply from the e-bay seller....but i would like to drop a some foil in one to find out LOL! I think I will give my laser guys a phone call today.

[Miles]

Given the lack of responce on my previous questions regarding the inductance & winding patterns............

I wish I knew more about this... I found this general reference (see below).

Also Arlo's thread: www.endless-sphere.com/forums/viewtopic ... 2&start=15

[Miles]

Thud I played with leaving the counter wind out and it does not hurt inductance. If you have 4 turns on one tooth then 4 the opposite way on the next tooth and 4 turns the first way on the third tooth in a roe it all adds up so if each tooth gives 5uH then all three will add to 15uH I played leaving the second tooth out and just trying the first and last of the 3 and in that case it would be 10uH!

interesting Arlo. Did you measure with all 3 teeth rwond in the same direction?
That is slightly in conflict with the video you linked in the 1st page of this thread.

Ref: viewtopic.php?p=457932#p457932

Was this confirmed?

[Miles]

has Eric signed in lately? (i assume he is swamped with school year end activities)

Not since 19th March - a few days after his last post on my thread. I hope he's ok..... I'll send him a PM.

[John in CR]

Why not just add another turn to the windings to solve the inductance issue? Then you can increase the voltage if you want the higher rpm. It's not like a hubmotor where we have such a strict limitation on gearing ratio (wheel size).

[mdd0127]

Some folks reading this exciting new motor thread will recall all the excitement about the Colossus motor designs that many on ES contributed their time & efforts to "make happen".

Did that project & completed motors run into problems, so adopting wide use of that motor was very limited or impractical? I think there were various issues that were discovered after the motors were built & received.

Is there anyway this new motor design can avoid all the pitfalls the Colossus ran into, so as not to repeat those mistakes??? What are the major issues to avoid, so this doesn't become a Colossus mistake???

I'm excited to watch this development move towards a super design and finished product that is matched perfectly with some excellent controllers too. Good luck ES geniuses.

The main mistake that the colossus guys made was contracting the production work out to a chinese company. While I've never met a chinese person that I didn't like, I've never been satisfied with a product I've received from a chinese company. The quality control standards and pride in their work just isn't there. I don't see those mistakes happening on this build. Even though I sold my cnc and mill/lathe combo, I still have access to the mill/lathe and met a very cool guy with some neat CNC equipment the other day. If there's any way I can help people make parts for these, I'll be glad to help in whatever way I can.

The next issue will be figuring out the perfect wind so this motor doesn't become a "controller killer". That part of things is beyond me but we have the best of the best here working on it.

[Miles]

This is a crude outline to illustrate the problematic issues with the support bearing. I've deliberately avoided looking at existing designs...

We could reduce the diameter of the main bearings from 47mm (as shown) to 42mm.

Thoughts?

[Miles]

With 42mm bearings:

[mdd0127]

I think that it's very important to stabilize the can from both ends but I don't like using the large diameter bearing like the hk outrunners use.

What about having the can riding on bearings on a non moving hollow shaft? The phase wires could exit through the shaft and the shaft could have a mounting flange on one end. The drive sprocket mount could be machined into the endcap. I can see it in my head....I might have to draw it. It's been so long since I've used any of those programs it might take me a bit though.

[mdd0127]

I tried to open my drafting program and it's expired. Sooo here's a really crappy paint drawing instead! Lol

[mdd0127]

The one in my head looks a lot better! The sprocket mount could bolt to the end cap so the end caps could be exactly the same, making machining easier.

[Miles]

What about having the can riding on bearings on a non moving hollow shaft?

Sort of like a hub motor?

I'm not that happy with the sprocket being the opposite end to the mounting flange......

[mdd0127]

I always design in an outboard support to go on the other side of the sprocket, even if it's mounted right next to the flange. At these power levels, you probably wouldn't want to put the shaft in single shear anyway.

[Thud]

its too long with all that jazz in there. for a bicycel app I would want to stay inside 120mm (less is more here)

The skirt bearing is the simple way to rout the wires out & have some "open" area if you intend to have any meaningfull air flow, but the skirt bearings are going to be a real limiter for higher rpm motor.

[Miles]

You could have the air flow exiting radially, through the can, before the support bearing assembly.

I think my version would be the 40mm stator with no additional bearing, though...

[mdd0127]

I was thinking about the 40mm stator stack too. The only width difference between the hubbie design and a standard skirt bearing design would be the width of the hole to run the phase wires through. My drawing isn't anywhere near scale but with a 40mm stack, it should be very easy to get a sub 100mm overall width.

The main thing is figuring out the stator plates though. That would allow people to come up with all kinds of different ways to build the rest of the motor.

[Farfle]

Large diameter inrunner would solve that problem... Does it have to be an outrunner?