Linear Motors for a home made machine?

[NEATman]

Has anyone here in "the zone" ever used linear motors for a machine?
I ask, as I have recently "rescued" several (at least 14) new old stock Baldor linear motors (coils and tracks) from a dumpster, and I wanted to know if they have been successfully used with a home built machine, and say Rutex or Gecko drives. I have some ideas, but I wanted to see if there was anyone out there who has achieved this already.

Neatman

[turmite]

Neatman I don't think they'll work. So that being the case why don't you just send them to me and I'll dispose of the properly and that way you won't have to worry about all that extra work you're about to do????


All kidding aside the first thing you'll have to do is determine if they work and the second would be to determine how they are driven. If they work and you can drive them inespensively................what a find???

Mike

[jimbo]

I thought linear motors are essentially stepper motors unrolled. The picstep guy, (Garfield?), has driven a linear motor with his picstep. Not sure if he had specialized firmware. http://www.fromorbit.com/projects/picstep/index.php and look for video.

[cncnick]

cheap sst 1500 servo drives from ebay say they work

[NEATman]

They should all work, as they are new in thier original wrappers.
We use them on several systems where I work, but I was just currious if anyone had used them at home.
They are essentially brushless DC motors that are unrolled. Linear steppers are a different design.

Neatman

[Geof]

You have fourteen (at least), brushless DC which is effectively the same as variable frequency AC synchronous (I think). Okay you mount all fourteen sets of coils on a long frame. Wire them up to a nice powerful power supply. Throw in a bit of control software so you can put a small bit of track on the first motor and start it moving. The next one picks it up and accelerates it and so on. I saw an article once about linear servoes on a laser machine that could generate several g's of acceleration. Your bit of track could be moving at a fair speed when it left the 14th set of coils. Don't point it at anything important.

[NEATman]

Geof-
I never thought about making a rail gun!

Intersting thought...
Neatman

[Geof]

Originally Posted by NEATman Geof- I never thought about making a rail gun! Intersting thought... Neatman

I am not sure it should go past the thought stage.

[daedalus]

i have seen commercial systems using linear motors for cnc grinding before, but never diy. I would guess they would be great for a home mill, just they are hard for hobbyists to get hold of. One thing to consider though is ferrous swarf will be a real pain with these, so you might have to watch what your cutting, or take more precautions with regard to swarf guards.