Can I lengthen cables?

[marcrunner]

Hello all,
I have been moving my bot around more than I like lately, and was wondering if there was any harm in bridging the original wires going to/from the stepper motors in order to connect and disconnect from the PC kiosk. I have an electronics store here that could supply me with the correct pin adaptors. Any reason why this shouldn't work? Thanks, Marc

[dana_swift]

Marc- I would not be afraid to give it a go. Especially since you can buy "extension" cables for the stepper motors right from oriental motor. SB may sell them too. My regular SB cables are "right sized" and just go from the box to the motor, but the indexer has a very long cable on it, and it works fine.

I cant think of any electrical reason not to extend it again. I have been thinking about resistance and inductive effects, and basically the long wire has resistance effects, and may need a larger gage to compensate. That is about the worst probable case I can think of.

Inductively there is an effect also, and that will combine with the resistance to eventually create a physical electrical limit. The worst case (extremely unlikely) would be that this added inductance would cause the electronics in the drivers to become unstable and cause problems (including driver failure). The motors have such high inductance compared to the wire, I wouldn't worry about that either.

The only other factor is the cable bandwidth, with micro-stepping the motor signals are more sine-waves than square waves. With max frequencies in the kilohertz, transmission line effects wont occur until the line reaches lambda/10 as a rule of thumb, and the system is nowhere close.

My suggestion: Give it a try! Let us know-

D

[chiloquinruss]

The only cable that I think might have a length issue would be the USB cable. ShopBot makes many size models and all use the same set of motors etc,. Russ

[marcrunner]

thanks guys, I will give it a go-Marc