Hi everyone!
I wonder if you can give me an advice - I am looking for a linear motor (12V sealed), nothing outrageous: 3-5 cm travel, 100n linear force, preferably self-retracting if power is lost. Size is not the main issue as long as it's somewhere within the 3"Dx10"L margins.
Thank you in advance!

 

You could try linear actuators. You can find these on:
http://parts.digikey.com/1/parts-kws/linear-actuator

If you have time and a drilling machine probably you could couple a bolt and nut with a metric thread to D.C. motor so that you get finer pitch.

Wonder if solenoids could be used?

 

If you have time and a drilling machine probably you could couple a bolt and nut with a metric thread to D.C. motor so that you get finer pitch.

It is a common misconception that metric threads are finer than inch threads. Remember, in inch, we have two common series (plus others); the most common metric has just just one choice. Of course, you can make any thread you want in either system.

Compare some common metric sizes that might be used for a hobby lead screw with corresponding inch sizes using the very common series of fine pitches.

Inch Size      Metric Equiv.      Approx. Metric Equivalent

1/4-28           6.35x0.91            M7x1 or M6x1
                                     
5/16-24         7.03x1.06            M8x1.25

3/8-24           9.5x1.06             M9x1.25

7/16-20         11.1x1.27            M11x1.5

Thus, the inch fine thread series has a slightly finer thread than metric. More important, hardware for it is more widely available to consumers in the US and usually considerably cheaper.

John

 

Iruss - Check these out - http://www.surpluscenter.com/sort.asp?catname=electric&keyword=EALD

 

Pls choose an inch thread as per John’s advice. I didn’t know inch threads have finer pitch and cheaper in US.