Electronics gurus please help

hi,

i am building a stepper driver for my homemade mill, that i am going to use with EMC.

i have salvaged some steppers (60ozin, 6 wire), and also the driver chip from old printers.
the driver is a sla7026, 3A max chopper, unipolar.

question1: is a chopper unipolar driver much worse than a chopper bipolar drive?

question2: a bit longer, and i badly need advice here:

i have built an axis drive on veroboard, with rather long wires, etc, and it worked ok.
then i made a rather simple pcb, built a sigle axis on that, and after correcting some errors, it works ok.
then i made a final design for the pcb, built one axis, and it does not work. built another, and the with same symptoms it is not working.

so experts: at a chopping frequency a couple 10Khz, could the pcb layout have this much influence? i checked all the components, all the connections, spent about 2 days on it, so i am 98% that the
working and not working circuit only differs in the shape of the traces.

i am no EE, but have some electronics building experience, more from the digital world. and i do not have a scope, so cannot check if the timer is working ok or not.

any ideas are welcome,

thanks,

vajk

John wrote:

> You could take it all the way through to completion and add.... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=1765766667 :-) A CNC Myford mill/drill/lathe.
>
> John H.
> P.S. I have more BBC stuff in my house than I know what to do with! Give me a shout if you'd like some more disc drives.
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