Laser / Spindle Control

LowRider CNC Advice
1

My current Lowrider setup uses the M106/M107 commands to switch the blower fan output to drive a solid state relay for turning the router on/off. This gives me a switched extension cord plug at the tool location on the machine. I shortened the cord on the router so there’s not a lot of extra cord coiled up at the tool location.

I’m adding a 5W laser module to my available tools but want to use PWM for intensity control. I want to location the power supply and control module for the laser right where the router was mounted. I’ll be using the router base to hold the laser stuff. My end goal is to mount the power supply and laser control module on the tool plate, plug the power supply into the switched outlet and add another 2 conductor cable to feed the PWM signal to the tool location.

Are we able to use D8 or D10 with the modified Marlin firmware? What I need when I am done is one switched output for relay control and one PWM output for laser TTL control.

2

The reason for not using D8-D10 is the 12VPWM, Leo found an unused 5V PWM capable pin. If your stuff can handle the 12V then no need to even modify the firmware.

3

Was going to use a 7805 voltage regulator to convert the 12VDC to 5VDC and send that to the TTL. What’s the 5VDC pin and how do we control that? If I stay with the D8 or D10 outputs, what M codes do I use for those and do I have to worry about any temperature feedback when using those?

4

https://www.v1engineering.com/the-2-8-watt-100-laser/

Always easier to remap a pin vs add hardware.

5

Thanks for that link Ryan, that’s a great write up and will get M106/M107 to control 5V.

I still need a full 12VDC switched output to driver the spindle relay. I need both 5V PWN and 12V on/off to two outputs total.

Is it possible to remap D8 to pin 44 and then what M code would I use for that?

6

It should all be in the page, I followed it and that is how I use it. I do not remember off the top of my head.

7

If I were to change #define POWER_SUPPLY 0 to 1, I could use M80 / M81 to run my solid state relay. By default the power supply pin is mapped to pin 12 and supplies 5VDC. I’ll connect that to drive my relay to turn 120V power on and off for the spindle.

Then I use the laser tutorial linked above and remap the fan control to pin 9 to 44 so I have 5VDC there for the TTL laser control.

Then a little post processor editing in Fusion 360 and M80 / M81 will control the spindle on/off.

Does that pass the sanity check?

8

Or better yet, could M42 P44 S### work to control pin 44 without having to make any changes to the firmware?

9

So the M42 P44 command works great. I have the whole laser module and power supply sitting at the tool location and ran another small cable out there to get TTL 5VDC out there. Working great so far…

https://youtu.be/DgcDd725A9g

1 Like
10

Interesting, I wonder if both pins activate still or just P44. Either way that makes it super easy. Thanks for testing that out.

11

Depends on how your post processor is set up. I’m using Fusion 360 for my CAM work so I made some changes to how it works. I use M106 to turn on 120V to the extension cord that runs out to the tool location and then M42 P44 S255 to turn the past TTL on to full power for the cut. The M42 commands the TTL on and off throughout the run then M107 turns the whole thing is at the end.