ES Motor Project?

[Thud]

Good morning Miles,
From my searchings, the magnets & frame components are the easyest things to source/make....the hardest thing to source is thin laminating material.

The places thast responded to my personal inquires only had materials stating at .010 thickness which is nearly 2x as thick as the lams in my turnigy's. After that, the cost for having a coil split to a handlable width & Minimum order sent me down the road with my tail between my legs.

I would need to find a backer & go into the laminations buisness full time to justify it. I really have no experiance with attemtping to source stators out of china.(way out of my skill set)

That is the stumbling block for any DIY motor builders. Any idea's how to clear this hurdle?

 

[Miles]

Afternoon Todd,

Yes, I'm sure your right.

Either we buy as laser cut laminations, or even even bonded stacks, or we have to all get together and order whatever is the minimum run of steel from Arnolds, split to the exact width we want.

Ref: http://www.arnoldmagnetics.com/Non_Grain_Oriented_Electrical_Steel.aspx

 

[Miles]

The places thast responded to my personal inquires only had materials stating at .010 thickness which is nearly 2x as thick as the lams in my turnigy's.

.010" is 0.254mm that's pretty thin...... Most of the cheap outrunners use 0.35mm lams, I think.

 

[Thud]

the turnigys are .2mm thick. I can't vouch for the alloy but they are thin.....

 

[Miles]

the turnigys are .2mm thick......

Arnon 7 Thin Gauge would be the equivalent to that.

It really depends on the maximum fundamental frequency we want to run the motor at, as to whether it's worth going below 0.35mm.

 

[Miles]

A 100mm stack of Arnon 7 would require 535 laminations...........

 

[Thud]

Max possible

I do think its important for a motor to perform as good as it possibly can over the widest operating range...The thiniest lams will open up the rpm range.
I do think in quantity, its is sold by weight With an up-charge for coatings. so prolly not a signifigant differance in pricing for exactly what we want. it will just be a question of min quantity & the ability to handle a heavy roll of steel, getting it proccessed...you know the details.

But being a slave to economics....I admit I would entertain options.

 

[Miles]

How practical would it be to stamp 112mm dia. laminations, ourselves.....?

 

[Thud]

The operation is a simple one...the tooling is the issue.

A proper single hit stamp die is going to be a bit pricey, prolly more than the custom broach for for the freewheel project. After my research, I found nothing as cost effective as photo-chemical etching for prototyping, (unless you already own a cnc laser)

I can make screens for printing, amazinly cheap..with a standard printer & some transparancys for design changes. Items this thin cut quickly....the dangerous chemicals are a nuciance....but affordable. Then there is the burdon of time for the actual handling/printing (2-sides for max speed in the etch tank) & stator assembly.....I can print over 100 pc an hour (maybe double that with an optomised screen on a final design) but I havn't run a production senario in the etch tank for real world #s.

I do have a board for building a Pulsed EDM machine. This will put large die making in my grasp...i just need to turn off the computer & get into the work shop :lol:

 

[Miles]

The ability to make the dies would be great.. With stamping, would we need to anneal afterwards, though?

 

[Miles]

Ref: The influence of cutting technique on the magnetic properties of electrical steels
M. Emuraa, F.J.G. Landgrafb,*, W. Rossc, J.R. Barretac

 

[Thud]

Most likely yes,
Depending on the state of materials prior to stamping....& I am sure the thickness of materials come into play also on how much stress is induced in the stamping opperation. Industry adds anealing as a standard & would be the right thing to do.

what i don't recall is how the anealing affects any pre-coated materials.
I do know laser cut or photo-etch side steps the anealing requirment.

 

[TylerDurden]

I found nothing as cost effective as photo-chemical etching for prototyping, (unless you already own a cnc laser)

Would this do it?
Epilog 50W

http://www.maker-works.com/content/walk-through-check-out-class-mystery-undone

 

[Arlo1]

The operation is a simple one...the tooling is the issue.

A proper single hit stamp die is going to be a bit pricey, prolly more than the custom broach for for the freewheel project. After my research, I found nothing as cost effective as photo-chemical etching for prototyping, (unless you already own a cnc laser)

I can make screens for printing, amazinly cheap..with a standard printer & some transparancys for design changes. Items this thin cut quickly....the dangerous chemicals are a nuciance....but affordable. Then there is the burdon of time for the actual handling/printing (2-sides for max speed in the etch tank) & stator assembly.....I can print over 100 pc an hour (maybe double that with an optomised screen on a final design) but I havn't run a production senario in the etch tank for real world #s.

I do have a board for building a Pulsed EDM machine. This will put large die making in my grasp...i just need to turn off the computer & get into the work shop :lol:

Methods wife is a laser physicist. Maybe she can help?

 

[TylerDurden]

Methods wife is a laser physicist. Maybe she can help?

She makes stuff that blows holes in armor.

 

[Thud]

TD,
their documantation says no....
http://www.epiloglaser.com/laser-cutting/laser-cutting.htm
(i actualy have one of the aztec calanders you see on the website I picked up at a wood machinery show where they were demonstraighting these units)

but at the thickness's we are looking at I don't know. (my favorite pastime is surpassing equipment specifications) I wish that shop wasn't 2-1/2 hoaus away form me.

 

[Thud]

Arlo

Methods wife is a laser physicist. Maybe she can help?

would be cool it some stuff was avaialable......but i aint holding my breath

 

[TylerDurden]

I can ask the makerworks folks their opinion about thin metals. They are quite amenable to people pushing the envelope for DIY projects.

If the material can be cut, I'm willing to receive/send the materials.

What I am also not sure of is how much machine-time would be required for a motor's worth of lams. A prospective sheet layout of a few lams might help estimate.

Makerworks usually allows 2hrs per user at a machine at a time. They do make special arrangements, so people have a fair shot at access for bigger projects.

 

[Miles]

Here's the Alibre model file, Tyler. There's also Thud's DXF, above.

 

[TylerDurden]

Thanks, Miles.

What size does the lamination stock come in?

I presume we are considering a nested design (2 sizes of stator, concentric) to maximize material use. (?)

 

[Miles]

What size does the lamination stock come in?

A roll of whatever width we want, I think.

 

[Farfle]

We do have a 75 watt epilog laser in our school, it may cut lam stock if its thin enough.

 

[Miles]

If someone wants to just do their own, fine. The trouble is that, even for a few motors, we are talking about thousands of laminations.....

I'll get some quotes for professionally cut/assembled stacks, once the core is finalised.

 

[Farfle]

If someone wants to just do their own, fine. The trouble is that, even for a few motors, we are talking about thousands of laminations.....

I'll get some quotes for professionally cut/assembled stacks, once the core is finalised.

Wow, didnt think there would be that many

 

[Miles]

Wow, didnt think there would be that many

Approx. 5 laminations per mm of stack..... So, 500 laminations for a 100mm stack...