AXBB pwm 0-10v

[rewster]

I've searched past threads but haven't found anything detailing this exact issue, so apologies if this has been covered and I missed it.

Running a gecko g540, and decided to ditch the parallel port and switch to an AXBB and UCCNC. Struggling with PWM issues now. Per the manual, I'm using AO1 and 5VO to feed my kblc spindle control board the 0-10v that it needs (this was done via the g540 previously). I'm only getting 2.5v between AO1 and 5VO at full duty cycle. This is proportionate to spindle speed and pwm settings, so that's functioning. The jumper is removed, and all power supplies are isolated and outputting proper voltage. I'm reading 5.0v on the dot on 5V+ (not sure if that matters). Spindle PWM ->analog ch is set to 1, and I've played with different pulley setups. Still only 0-2.5v variable. Any ideas?

I'm just a dumb mechanical engineer - electrons are dark magic to me .

rewster

[ger21]

What voltage are you getting at half speed?

Need to see all of your spindle settings.

[rewster]

See attached. ~1.25 volts at 50% speed. PWM is functioning, just can't get enough voltage from board. Possible defective component? Thanks

[ger21]

What speed are you commanding when you see the 2.5V?
What are your pulley settings?
What happens if you put the jumper back on?

[rewster]

100%, 4500-infinity
1 pulley- min 1, max 4500, ratio 1
Haven’t thrown jumper back on, will in the morning. I’m curious too. Something is screwy.

[ger21]

So on the Run screen, Sact says 4500?

[rewster]

No, Sact is 0. No encoder or tach feedback, open loop. It stands to reason that Sact would remain 0. Sset is 4500 (max on pulley setting), and voltage varies when I drag the override slider. Bench testing, so motor control is out of equation. With motor connected, I get roughly half max speed per my tach.

Reinstalled the jumper, which cut the voltage in half.

[ger21]

Sorry, I meant Sset.

If you disconnect the wires from the speed control, and measure the voltage at the AXBB terminals, do you then get 0-10V?

[rewster]

Sorry, I meant Sset.

If you disconnect the wires from the speed control, and measure the voltage at the AXBB terminals, do you then get 0-10V?

No worries. No, I get the same readings (0-2.5v) directly at the terminals also, regardless of ground. Eliminated possibility of wiring issues. Double-checked supply voltages on 24v and 5v input terminals, all is good there. Played with different frequencies and pulley settings to no avail.

[rewster]

Running the mill spindle on a pot now, have to sling some titanium chips today . It just makes tool changes less fun. I'd still like to get this resolved, I'm stumped. Gerry, thanks for your continued feedback. I'm hoping someone else may be able to chime in as well.