Linear motors from old typewriters

[gmcurrie]

Hi all,

I remember reading a webpage a while ago re the author finding an old electric typewriter in the attic that had a carriage that turned out to employ of a linear stepper motor - a metal bar went the length of the carriage with a fine machined/(etched?) series of grooves perpendicular to its length.

Upon this stator was the moving element of the carriage - wound electromagnetic coils equivalent to the quadrature stator of a stepper motor (- indeed, the mirror of the arrangement of a stepper motor.)

I can't find that article now, though the Brother website, tantilisingly, has this (see reference to 'EM-1'):

Brother Company History - Brother Australia

I notice that there are a fair few Brother electric typewriters on Ebay - is it known whether the later models used this technology?

Any leads?

Failing that, any ideas as to selection of correct grade steel/experience with etching steel? & 'forcer' construction/winding etc?

This is the kind of thing I'm aiming at:

[nomedia="http://www.youtube.com/watch?v=AjkT6VgaQLo"]YouTube - 01 H2W Technologies XY Linear Motor Stepper Motor Gantry[/nomedia]

(just look at that, eh?!?, - beautiful bit o' engineering - poetry in motion

[vger]

Getting the stator magnetized might be fun...

[gmcurrie]

Getting the stator magnetized might be fun...

The stator/platen is not magnetized - rather, the moving part ('forcer') incorporates a magnet along with 2 coils. The phasing and polarity in energising the coils causes the forcer to step across the teeth of the platen: