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Can anyone recommend a hobbist linear motor?

The motors are often described as being a rolled out version of a DC motor (is that true btw). If this is the case then how does one "drive" a linear motor. I'm trying to understand what kind of signals need to be sent to the coils to make it move.

Any info welcome.

EDIT: For clarity, I'm asking about the "stepper" type linear motor

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    \$\begingroup\$ It's effectively a stepper motor (you drive it with the same waveform). As for cheap ones, surplus is your only bet, I think. I've never seen them go for less than a few hundred dollars. \$\endgroup\$ Mar 12, 2011 at 13:34
  • \$\begingroup\$ They are driven with with same driver as a stepper motor, really? Would that include microstep capability? \$\endgroup\$
    – user3045
    Mar 12, 2011 at 22:32
  • \$\begingroup\$ Sure, I don't see why you couldn't microstep it. \$\endgroup\$ Mar 13, 2011 at 5:36
  • \$\begingroup\$ I found a 20" one in an old high-end electric typewriter. (your requirement for 9' is a little harder to meet.) \$\endgroup\$ Mar 16, 2011 at 0:32
  • \$\begingroup\$ I'm told that they can be joined to acheive virtually and unlimited length. \$\endgroup\$
    – user3045
    Mar 16, 2011 at 4:01

3 Answers 3

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There are a number of kinds of linear motor. Which are you referring to?

Baldor makes a number of varieties, and their page has an excellent overview of the different types.

I'm most familiar with linear stepper motors, which are a type of linear motor. However, there are Brushless DC and even AC Induction varieties.

However, I will say that they are generally as or more expensive as a comparable stepper/servo motor and lead-screw arrangement, and are much less common on the surplus market.

Given that, I think you would be better off trying to snag a long leadscrew on ebay, rather then find a similar sized linear motor. Then, just add end supports, a motor, and some linear bearings.

What are you trying to do, anyways?

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  • \$\begingroup\$ Sadly, noone on ebay seems to have a 9 foot acme leadscrew, and some of the suppliers I've talked to consider that a special request. The intended purpose is for CNC Milling. Yes I know that lead screws are the dominat drive system, however I have encountred difficulties in obtaining them, and have not been successful thus far. Btw FakeName, what's ya real name? lol \$\endgroup\$
    – user3045
    Mar 13, 2011 at 23:34
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Any stepper with a threaded rod and captive nut will make a low speed linear motor with up to about 3 foot reach.

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  • \$\begingroup\$ Yes it would but I need 9 feet. \$\endgroup\$
    – user3045
    Mar 12, 2011 at 22:33
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you can buy a central locking motor used in cars from a car spare dealer. It costs approx 5$ . Some models have limit switches build into it. Any car with central locking will have atleast 4 motors . 1 each in each door. I am from india. We can buy one with out limit switches for 3$/ea and with limit switches at 5$/ea. The stroke distance is about 7 cm. Sorry I will not reply for mails. or may not vist this page in the future

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