ES Motor Project?

[TylerDurden]

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

Still, if 500 could be done in a few hours, it beats the cost of a die; until the design is finalized.

[liveforphysics]

I've been looking for a reason to mount a cutting laser head on my CNC.

I have the laser power supply to run up to a 5kw solid state laser, and it has blanking control that is sub 1ms.

Its just a 13" x 42" table though, so only maybe 30-40 lams per sheet loaded. It is a fast machine though, I would imagine with a powerful enough laser it could do a sheet in 5-10mins.

[liveforphysics]

It doesn't say it on the list of materials it can cut, but 150w should zip through 0.2mm like its air.

Seems like its cheaper to just buy a laser cutter all together than assemble your own for the power levels we would need.

http://www.ebay.com/itm/CO2-LASER-ENGRA ... 371wt_1058

[liveforphysics]

I'm not saying an $8500 machine is cheap, and shipped and setup likely $10k.

However, I bet a stamping die is 10k, and then it can only do a single type of lam, and requires somebody else to run it.

If we all chipped in 10K and landed a machine like that at Thud's house, we could have huge flexability in our prototype development.

10k into a run of say 100 motors is only $100 overhead per motor, and then you still have the machine.

[TylerDurden]

How about the other bits? Cans, shafts, etc?

Sourcing hundreds of them could get interesting.

[thepronghorn]

http://www.mfg.com/
Is one place to find a company that will make the shafts/bells/etc.

Etotheipiplusone.net has used mfg.com for this exact purpose and found them reasonable

mfg.com could also be the place to source companies who can do the stamping or lasering or whatever for stators

[Thud]

Shaflts are simple, flux cans are based on standard DOM tubing sizes & easy to cut to any length. A bearing carrier & motor mounting are also easy & afordable parts....only real decision is whether a skirt bearing is enough benifit to justify the additional parts required on a 50mm motor. (prolly would be required for a 100mm length stack)

I have contacts in several small cnc houses in the area...manufacturing is not the problem. Its getting a reasonable amount of the correct materials in hand....& then finding the capital to finace a run of motors.

Its the reason I am such a DIY guy....I allways have more time than funding for projects. It is far better for me to photo etch a batch of stators for myself & maybe a couple motors...but that is nothing like running a batch of 10 motors.

For compairison & to get back to motor design parameters here is some additional info
The C80/100 is only a 52mm stack in length & the magnets are only 50mm in the can.
the 80/85 has a 34mm stack & magnets

the closest motor for direct compairison will be the CA120.
A CA120 has only a 30mm stack & magnets.
The 18t 16p Miles proposed (I like it too) is bigger, with fewer poles. it ought to be the Nutz for a starting platform. With a 50mm stator stack its going to be monster. I have nothing to judge it against If we stack it to 100mm in length.....but I would sure like to try it

& if its anywhere near controllable, I have an "oil mist" active cooling system all designed ready to impliment for some serious BTU disapation if we decide to load it into "semi efficancy"
here are some teasers of the gear pump parts:

[TylerDurden]

Nice pump!

I also would much rather see the bits get made by various members, than jobbed out on complicated group buys.

The laminations seem to be a taller hurdle for individuals, but if member could break even or make a buck doing lams with a laser...

[Thud]

Miles said:

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

Are we looking for a FEMM model to zero in on some of the stator variables? (tooth width, head area, maybe model some copper senario's?)

I downloaded FEMM software but may as well have downloaded a chineese book on philosophy for all i understand of setting parameters in my 10 minute looky look

[mdd0127]

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 know it can seem like there's a big demand for this stuff but from my experience with higher end unique bits like this, there just isn't enough demand to resort to group buy and outside parts sourcing action. Most of the people that would want a motor like this and have the skills to implement its use would easily be able to machine a bearing tube, mount, and can. Speaking of the can, due to the issues that the mini colossus motors had, I'd highly recommend running it through a lathe just to true it up and make sure it's round. Still not a difficult task but it would be good, just for good measure.

On this size motor, regardless of stack length, I really think that it will be a good idea to have bearing support on both sides. I don't like the large diameter skirt bearing idea though and think a modular design with a smaller diameter bearing would be better. Also, it would be a good idea to implement cooling fins in the can endcap design. I could simplify and scale up the mini colossus model and repost it if anyone is interested.

If it looks like this is going to become a reality, I'd happily sell my 3220 and use the funds to buy a stack of stator lams, some wire, magnets, and some stock. I wish I had a bunch of money and could really help finance the project though!

[ElliottE]

While browsing about looking at stuff related to laminations, I found this website:

http://laserlaminations.com/index.html

They seem to do the kind of stuff we're talking about. Maybe worth checking out?

E.

[Arlo1]

2 months ago i got a quote to get custome lams for my gfs scooter and the total was going to be ~ 450$ for a 3/4 inch thick stack!!! But maybe this will help? http://www.buildlog.net/blog/2011/02/bu ... 2-x-laser/

[Miles]

Are we looking for a FEMM model to zero in on some of the stator variables? (tooth width, head area, maybe model some copper senario's?)

That's the idea. Eric handled all that on my last design. It was much more complicated to do an axial flux model, though.

[Miles]

Re. shaft size, I was thinking 20mm diameter. Hollow? You can get 20mm dia. precision linear shafting with 14mm bore. How about that?

[nieles]

the hollow shaft (20mm OD 14mm ID) will be about the same strength of a solid 18mm shaft.
but you lose the ability to use a keyway.

[Lebowski]

What's the point of making our own motor ? Is there some specific feature that is needed that is not available on commercial motors ?

[Miles]

What's the point of making our own motor ? Is there some specific feature that is needed that is not available on commercial motors ?

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

[Miles]

6204 bearings? [20mm x 47mm x 14mm]

[Miles]

the hollow shaft (20mm OD 14mm ID) will be about the same strength of a solid 18mm shaft.
but you lose the ability to use a keyway.

There's still the option of a 20mm solid, keyed shaft, of course. BobC's collet type locking system seems to be the way to go, though....

[Jeremy Harris]

What's the point of making our own motor ? Is there some specific feature that is needed that is not available on commercial motors ?

I think there is a bit of a gap between the largest, affordable, lightweight and reasonably efficient RC type motors (like the 80-100) and the either expensive, or heavy, more powerful motors. The 4 to 10 kW region is attractive for a lot of fairly light bike/moped conversions, yet the choice of motors in an affordable price range is small. The fairly affordable CA120 from Hobbyking has been shown to have poor efficiency and by tricky to drive well, the Hacker and the Plettenberg are both pretty expensive.

If we could come up with a DIY motor that was around the same size and weight of these motors (2 to 2.5kg), had an efficiency that was reasonable and cost maybe $500 or so, then it would suit quite a few people interested in higher power builds. For example, my moped conversion stalled because the size and weight of the 6kW motor, controller, etc I used was just too great for the frame. If I could get a reliable 6 to 8kw motor that weighed around 2 to 3kg instead of the 16kg monster that's in there now then the bike could be transformed.

[Miles]

We know we can get 3mm x 10mm x 20mm magnets as a stock size. I propose we design for 4 stator lengths in 20mm increments. 40mm, 60mm 80mm & 100mm. The 40mm size could be done without the extra skirt bearing. What do you think?

[Thud]

That is in line with my thinking Miles.
I haven't added a skirt bearing to any of my more complete design sketchings.
But again, I hadn't planned to ever build a stack more than 50mm.

A hollow shaft is not a pressing criteria....but a logical step to weight savings so no objection...I can only assume taper locking sprockets or pulleys are easy to source.

[Miles]

Hollow or solid shaft doesn't matter that much. I just wanted to set the shaft dia. at 20mm, so we can choose bearings etc. Any objections to that?

[Jeremy Harris]

I can't see a reason for a skirt bearing on a relatively short stack motor. If someone wants to build a long stack version, then it should be easy enough for them to add a larger bore bearing set into an internal, removable, base end cap. The thin section, large bore bearings the Chinese motors use as skirt bearings are pretty horrid things, IMHO. Not only do they limit rpm, but being thin section they distort very easily and can create a fair bit of bearing drag. 20mm sounds sensible for shaft size.

[Thud]

I concure on the 20mm bearing ID.
But i am not hung up at all on any of the mechanical variables. With a stator this diameter, we are very free to tweek a parameters for an application.

my #1 priority is a functional stator & magnet packadge that is in grasp for reasonable costs. has Eric signed in lately? (i assume he is swamped with school year end activities)