circuit boards for signal distribution

[nisma]

Hi, i´m designing some board for building a mechmate.
Basically i don´t want use long motor cables, i want use power cables and ethernet cables inside the chain and driver near the motor instead of having a central driver with long and costly cables.

Do i should make more boards and distribute it to those members requesting it, if there is a interest in such electronic or not.

[MetalHead]

Regular ether cables are not rated for continuous motion. The MM needs to have wires that can flex for many cycles.

[nisma]

The same is true for motor cable. I see some savings in $$ and further it allows
to go above the 4khz limit. That why i have asked, if this can be useful for others or not. If not, then just delete the tread.

[bradm]

Hi Chris-

Mike pointed out one of the issues to be solved. Here's some more: The MechMate is an electrically noisy environment, a dusty environment, and certain areas are high temperature environments. Moving the driver near the motor requires that you handle all of these issues, as well as the wire issue mentioned.

The UIRobot drives in particular are apparently designed to run attached to the motors, although I think the MM examples we've seen to date keep the drives in the control box.

For the wire, you should choose a wire that will flex well. Regular ethernet cable (the kind designed for use with crimped plastic connectors) does not flex well, because it has a single, fairly brittle copper strand inside it. For the mechmate, you should choose something multi-stranded.

Since you will be in a known electrically noisy environment (the spindle or router power also runs through the cable chain), you should plan carefully how to protect the low-voltage input signals to the drivers, perhaps with shielded cable.

It is a good practice to run a separate pair from the power supply for each driver.

I suspect you'll find minimal savings in wire between wiring drivers in a box close to the table, and drivers near the motors, if you are paying attention to good power distribution and signal shielding practices in both cases. Flexible, shielded wire does cost a little more, but not that much if you aren't going overboard.

I'm not sure what 4khz limit you feel you will be able to exceed, and why it would be valuable to do so?

I'll be interested to see how your design evolves and turns out.