forum.cncdrive.com

Ok, so I'm trying to get spindle control figured out for my G540/UC100 based controller. I purchased a cheap 400W Spindle and DC Motor Speed Controller combo off ebay and I've got it "working" in a super hacked up way. I have essentially replaced the POT with the analog VFD output circuit in the G540 (PIN 7, 8, 9). This is a 5V circuit instead of the 10V called out in the G540 manual, but it works and the speed changes as commanded by UCCNC. The problem is I can't get full speed (or any accurate spindle speed) with how I have it setup. Basically, I'm getting about half speed (ie: S10000 measures out at 5000 RPM).

When measuring with a meter I get 4.99V across PIN 7/9, but at full spindle speed I get 4.2V across PIN 7/8. I can't get it to give me all 4.99V. I am also thinking I should probably use the Mach3 PWM input, but I'm not sure on how to proceed on that front. Your input would be greatly appreciated on how I should proceed.







PS: Here are the specs I was able to get from seller regarding the speed controller... Analog: 0-5V control (unplug the pot plug, signal line connected PWM PIN, ground connection GND PIN); PWM: Level 3.5-12V VPP, Frequency 1K-10KHZ suitable for Mach3 spindle control.

For what input voltage what motor speed does your motor controller produce?
I mean I would measure the input voltage to the controller first to see if the volage level is OK for different programmed S values.
Then you could decide if the issue is with the motor controller or with the signal it receives and go on from there.