Spindle speed working backwards <resolved>

[Blades]

I just hooked up my spindle for program control, but I can't figure this one aspect out. It's a BLDC motor running off a WS55-220 DC motor controller. I previously ran this manually (not controlled by Acorn or CNC12). I've mapped the PWM voltage output per the installation instructions. So the motor is turning on, but as far as the speed goes, - speeds the motor up, and + slows it down. Any idea what could be causing this? I've played with every PWM & Spindle setting I could find, to no avail. Motor turns off/on as it should, but the speed control is backwards, and it's not running at full speed.

On the 'Control' terminal, BLK/WHT go to relay 6 on the relay board, and RED/YEL to the PWM output on the Acorn.

[centroid467]

Red goes to the Acorn power supply COM?

Are you using PWM from output 2 or are you using the analog 10V from H8?


I think your problem is that you have the analog or PWM output referenced to the 10V DC output of the drive rather than logic ground. That would explain why the speed control is inverted.

If red goes to the Acorn power supply COM or to H8 COM pin then you need to move it over to the same terminal on the drive as the black wire.

[Blades]

Thank you for the response. I'm not sure I completely follow you though, so here is hopefully a more direct explanation of the wiring, and some additional info:

Are you using PWM from output 2 or are you using the analog 10V from H8?

I guess this question sort of confused me... I thought H8 was PWM output (one in the same), but apparently that is not the case since you question makes a distinction between the 2.

This is using the analog 10v output from header H8

On the driver Control header:
BLK (GND) goes to relay board output 6 COM
RED (+10v) goes to H8 +
WHT (EN) goes to relay board output 6 N.O.
YEL (SV) goes to H8 COM with another wire going to COM on the Acorn power header

BLK & WHT to the output 6 relay are just to turn the spindle ON/OFF
The spindle driver is on its own 48v power supply - however note YEL wire note above. I don't know if that additional jumper was necessary or not. Doesn't seem as though it was, and it didn't make any difference with/without it.

I previously had PWM on output 2, but have since removed that output designation, with no change to current operation.
SpnFWD is assigned to Output 6

To recap, spindle powers on/off just fine, and speed adjusts, but reverse from the +/- speed control.
Hope this clarifies things somewhat. At this point, I wasn't sure exactly what to change based on your previous post.

Many thanks

[centroid467]

Thank you for the additional info and clarifying your wiring.


Your issue is that you have the H8 analog output positive wired to the fixed 10VDC output on the drive. The H8 analog output return is wired to the drive's analog input positive. The end result is that when the Acorn output is 0V, the drive sees 10V at the input. When the Acorn output is 2.5V, the drive sees 7.5V, and so on.

To fix this:
* Move the yellow wire to the COM-GND terminal on the drive. It will share that position with the black wire. I would keep the jumper from H8 COM to power header COM.

* Move the red wire from the +10V terminal to the SV terminal.

[Blades]

@centroid467, thank you so much for your reply, that did the trick! Very grateful for your willingness to share your expertise.

[cnckeith]

thanks for reporting back!

I invite you to make a build thread, here is how.
viewtopic.php?f=60&t=6928

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