Newbie- max length of stepper wiring

[brent48]

Can anybody tell me what the maximum length of wiring from stepper motors to breakout board is? I would like to run it about 5 metres (15 feet). but read somewhere 6 feet was the max.

[_AR_]

There is definitely a max length issue, and it depends on many variables. I don't have direct experience with this, but my electronics background leads me to think of a few things right away:
-Resistance of the wire used
-Power of serial port pulse output

The resistance of the wire will obviously depends on what wire you have, and the output of the serial port does vary some from computer to computer (I believe). Basically, you will just have to find the max length of wire you can use through trial and error.

[Nefastor]

If you really need long control runs from your PC to your driver, may I suggest the optical route ?

For very, very cheap you can get multi-mode optic fiber. I live in France, where everything is damn expensive because of the Euro curse, and here's a few examples :

* 25 meters of plastic fiber : 45 euros. Doesn't need specialty tool : cut to length and polish a little, and you're in business.

* SFH450 : IR LED, cylindrical, with a hole to put the fiber in. 2 euros a pop.

* SFH250 : IR photodiode, same packaging, 2 euros a pop.

These components have been used many times in the past by Elektor magazine, in projects such as an RS-232 optical cable. Use these projects to understand how to use them. They don't need lots of electronics.

They are rated for 500 KHz bandwidth (1µs switching time) so you really shouldn't have any trouble with them.

Simply use one fiber to replace one twisted pair : that's two fibers per stepper motor. Maybe more expensive than copper wire, but I garantee you'll never have to worry about signal quality, even if you somehow decide to put your machine tool 50 meters away from your computer.

Toodles !

Jean