Centroid Community CNC Support Forum

Jay Morris wrote: ↑Thu Aug 15, 2019 2:39 pm From my understanding the hardware is there, just need some software to pulse a digital output on the db25 connector. I wouldn't think you would use an opto between the analog out of the Acorn to that board. Can you make the pwm board produce a pwm signal using a battery, 9volt, 1.5volt, etc

Hi Jay,
Thanks for responding. But the way Marty answered the question above "PWM is in the Acorn hardware as previously mentioned. Matt, Centroid's Engineer snuck it in the latest hardware revision and forgot to tell the programmers
SO, it will eventually be added in a future release of CNC12. Stay tuned."
makes me think it was a hardware add-on. It's hard to tell from Marty's response, so I was trying to get clarification.
I know they all get hammered with questions, but it's frustrating when someone in an active thread asks a question and it doesn't get a response.
Thanks again

Jay,
You were right! I searched again on PWM and found the following quote from Keith:

"right now, 0-10 vdc and 0-5 vdc analog out is the only way to control a spindle motor with Acorn.
we are adding PWM out and the ability to use an axis output (step and direction) to Acorn CNC12 software which will be backward compatible with all Acorn hardware!. so yes with a future software update you will be able to use PWM or step and direction to command a spindle motor in addition to 0-10 vdc analog out...."

So yes, the PWM feature (future) is in all Acorn hardware.

I had read Keith's post about the pwm output. I took Marty's post as more of toung in cheek response since the digital output has always been there, the thought or need for a pwm is new.

So as it turns out the board I was attempting to connect was not a Voltage to PWM board but a PWM to Voltage board. The board Jay posted earlier tipped me off that something was wrong.

With the new board, I now get a varying output from the PWM connection, as the voltage from the Acorn spindle out varies from 0-10 volts. Here is the wiring.
I set up a test to try and evaluate the effects of varying the spindle voltage on the output results. See attached Ignore the missing box lines and portions of the text, that was an error in the post-processor that I've since corrected. The most visible difference in output seems to be in the range from 25% to 50%

I'd now like to see if I can, in the post processor, vary the laser output as a ratio of feed speed as actually observed to programed.
Spindle Power=actual feed speed/programmed feed speed. This I feal will minimize the overburning that occurs when the CNC slows down to change direction.

The fun continues.

Nice work, keep it up! I too am interested in adding laser capability to my Phoenix 2x2 CNC Router. I'm kicking the tires and looking at laser options with optics good enough to give fine lines for small font engraving.

Marty

I have a JTech 7watt laser.
Can it be adapted to Allin1DC. It appears setting it up to coolant or something to turn on and off is not an issue but not having PWM output to very the laser output is the problem.
Does allin1dc have other capabilities that Acorn doesn’t?
Maybe this topic should be in another thread?

Rob

Rob,
I have heard of folks trying to use an anlog to PWM converter:
KNACRO Voltage - to - PWM module/0-5V/0-10V voltage converted to 0-100% PWM
by KNACRO
Learn more: https://www.amazon.com/dp/B06VVVGGBN/re ... RDbRJZB4QE

I have no personal experience. But in theory, you would port the spindle analog signal output to it, and use the M3 Sword to control it. M5 to stop it.
Search laser here on the forums to see if anyone has been successful.

I have a NEJE 20W LED Laser head I would like to adapt to my 2x2 Phoenix Router eventually....Once the PWM software is added to CNC12 I will give it a go......

A friend of mine refitted a Chinese laser engraver and he uses https://lightburnsoftware.com/
He likes it quite a lot.

Marty