Pwm voltage on so4

Having a problem with the pwm voltage on a 3.0 board in an SO4.
sent $30=24000, $31=0
sent m3s0, 0v
sent m3s100 through m3s500, semi linear voltage increase to .2v.
m3s500 should give around .104v
sent m3s501, voltage jumped to 4.82v and stayed there up to s24000.
verified by hooking up the vfd. m3s500 shows 850 rpm, m3s501 shows 24000 rpm.
Voltage verified at Bitrunner pwm pin and the pwm hole at the “spindle” pinouts.
second board. Carbide voided warranty because I was going to use a third party vfd/spindle, so I had to purchase the board.
What am I missing/doing wrong?
ANY help will be greatly appreciated.

When setting up my laser I found that exact same voltage to be the top I could get at the PWM pins.
My $30 value had to be played with to get it to 5.82 but that’s the highest it would go…

edit, should have read 4.82 was the highest it would go…

yeh, carbide 3d 5v=4.82v, not Arduino standard.
the problem is the voltage jump from .2v to 4.82v with speed change of one rpm (500 to 501).
board does NOT give a linear voltage increase for speed changes from 0 to 24000 as grbl and Arduino should.
It appears that C3D has made changes to either grbl or the Arduino board that are not within the Open Source licensing framework,
No support from C3D, very frustrated.

Update.
Used UGS to connect to machine, set vfd to accept external signal.
actual spindle speed was about double of requested speed up to about s2500, then was about triple of requested speed (eg m3s8000 gave actual speed of 24000).
So, CM modifies the m3sXXXXX request/signal internally. Cute.
Now it’s just getting the vfd to work correctly, DAC’s on order.

Update.
Changed a few settings, UGS now gets the correct rpm (plus about 1%).
If I use MDI in CM, and preface commands with a backslash, I get the proper response.
If I run a spindle warmup file, I get the odd voltages as in the original post (any speed request over 500 rpm gives 24000 rpm).
It appears that CM parses the speed requests and “changes” the pwm signal in a proprietary way.
I have some DAC’s coming, we’ll see how that goes/
No help from C3D, not even any responses.
May have to rethink future purchases from them.

Update 2:
Installed CNCjs and set it up.
Homes correctly,
Spindle on manual runs correctly.
Ran a spindle warm up file, ran perfect.
So the problem, all along, was that CM modifies the speed request through software. Not nice.
Installed the two bitsetter macros.
Set the X and Y coordinates for bitsetter in the initial macro.
Initial tool and new tool macros run bitsetter properly.
Now have to learn CNCjs, not as simple as CM. But everything works the way it should.
Looks like I’m not going to be needing those DAC’s that arrive tomorrow, LMAO.
And all of this without ANY support or help from C3D.
Will definitely effect my purchases in the future.

2 Likes

This topic was automatically closed after 30 days. New replies are no longer allowed.