Homebrew PCBs

Robert Hedan wrote:

> Uh, change in plans.  I've been fiddling around with the 24V motors I have
> on hand and they appear to be VERY demagnetized.  I didn't notice this until
> I picked up a set of smaller steppers and noticed a drastic difference in
> resistance.
> 


   LOL..  If by 'resistance' you mean cogging, that has nothing to do with being 
demagnetized.  Short all the wires on one of your motors together, and see if it 
isn't pretty damn hard to turn.

   You should forget these and get some 5V 1A or so motors, but for other 
reasons rather than this.


> So now I have to get myself decent steppers.  I'm not going back to the
> local surplus store, I'll just get the same problem (dozens of steppers all
> piled in the same box).  I'm going to buy larger motors for the CNC machine
> later, but for now, I'm looking for decent intermediate motors that will
> make my drilling station work as well as machine wood and plastics.
> 

   They're usually in a can, and even if they weren't just tossing them in a box 
isn't likely to demagnetize much of anything.  They're shipped in boxes of 50 or 
100, about as close as just tossed together.


> I was checking these pulls from Xylotex:
> http://www.xylotex.com/DoubleStepper.htm
> 
> Problem is now I have to reconsider a totally new driver circuit 'cause
> these are bipolar steppers.  Can I modify my schematic without TOO much
> trouble?  Or am I better using a new design?
> 

   Probably better to find some good solid 5V unipolar motors and get using them 
until you've learned a bit more about steppers in general.  Some of it simply 
comes from getting and using all types, start simple.

Alan