Centroid Community CNC Support Forum

For those of you who have found success with the CNC4PC C86ACCP board https://www.cnc4pc.com/c86accp-clearpat ... ller.html for their Clearpath motors, if you are running 10'+ cables, how did you go about wiring in the 1k resistors as recommended by Teknic?

I'm not using their board and am just running the clearpaths directly from the acorn as per Centroid's schematic (with the addition of the afore-mentioned resistors), but to be honest, I'm surprised that C86ACCP board doesn't have them built-in. Seems like a nice improvement for the next rev. Are there any drawbacks to implementing that other than the BOM cost?

I am as well. I submitted a ticket on their site about their recommendation for that wiring, and posed the same question as to whether they're already built in. A tech rep said he/she would look into it and get back to me.

CNC4PC's owner I think is on this forum as well. Hopefully he'll spot this topic

PaulWall,
I am using 10" cables on my mill and lathe.

If I needed to run longer cables I would change the pins on the Molex connectors and add in a resistor in the Molex connector (Acorn end). You should also be able to peel back the insulation on the pins and solder on a 1/4 or 1/2 watt resistor.
Chuck

Not sure you all saw my separate post on resistors, but I'm only using 10' cables (Teknic's cables) and noticed "jittery" movement at super low speeds on one of my drives. It was immediately resolved by adding a resistor, so be aware that the resistor is not only of use on runs longer than 10 feet. I'm sure it's more about noise and inductance and a bunch of other things I don't understand....

In virtually all conditions I use the resistors, as they are recommended. I wire them direct using no 3rd party adapter boards

I just ordered their board and will be installing it soon. I used the Clearpath cable and cut it in half so I think they are 22.5’. I don’t have the resistor and have been running for 2 years and no problem. How do you all like the Cnc4pc board?

I wired 1K resistors from + to - for S and D on all cables longer than 10 ft, as recommended, right at the Acorn board. No jittery operation at all.

The 1K resistors are "termination" resistors to prevent reflected signals and should be placed at the end of the signal path. Step and direction originate at the Acorn so the termination resistor should go at the driver end.

Look at RS422/RS485 examples.

tblough wrote: ↑Sat Jul 04, 2020 1:28 pm The 1K resistors are "termination" resistors to prevent reflected signals and should be placed at the end of the signal path. Step and direction originate at the Acorn so the termination resistor should go at the driver end.

Look at RS422/RS485 examples.

Are you saying they go at the cable end near the Acorn or near the Clearpath motor? The Clearpath manual would seem to indicate they go at the open collector driver output at the Acorn end of the cable.