Linear stepper motors

[307startup]

Does anyone have any experiences with linear stepper motors? I have found a few sources, but not sure if the available motors have enough power to be used on a milling machine.

[307startup]

*BUMP*

[CarbideBob]

not sure if the available motors have enough power to be used on a milling machine.

The short answer is probably not.
The long answer depends on how much force you need.
What kind of milling machine, what kind of ways, how much resolution do you need, what's driving the machine now.

Do you actually mean linear steppers or linear servos? Linear steppers are used for no load positioning devices (semiconductor stages and such) while linear ac servos are used on ultra high speed milling machines (mega buck machines).

Linear motors with decent thrust force also have very high attraction forces between the magnet track and coils. This force pulls down on the table and will clamp down conventional sliding ways so tight that the table won't move. Linear motor machines are constructed with linear roller ways. Assembling a machine with a 900 lb magnetic attraction can be interesting to say the least.
Ironless core motors have no attraction force but max thrust loads are only about 40 lbs.

A linear motor is simply a regular motor cut open and laid out flat. As a result you loose the torque and resolution multiplication you get from the ballscrew and gearing.
Designing with these is not easy, but they are wicked fast.
Bob

[307startup]

I actually mean linear steppers. I don't really want the servos, as I'm trying to plan a design that is AFFORDABLE. Linear rollers/rails is a given. As for cutting the motor open and laying it flat...not sure why the steppers have to be "weak". A stepper motor has more torque at a lower speed than servos...without the need for gearing. Rotary steppers can't compare to rotary servos at high speeds...above 3000 rpms due to loss of torque. But below 3000 rpms, a stepper will have more torque than an uprated servo any day of the week.