On my K40 I have a very noisy air assist and its a real pain to have on when not needed. I have been going through all the details of how LightBurn works and noticed that on the cut/scan/image page there is an option to enable air assist. Looking at the generated G-Code they are using M106 and M107 (fan on off). I also noticed that they are not using the S option to set the pwm value. So my question is can I go into the config.txt file and change switch.fan.output_type from PWM to digital and not mess anything up? I have an SSR for switching 120V that I could use to turn the air pump on and off. I am already using one on my 3D printer with a 120V bed heater which draws way more power the the air pump.

Also looking at the board I need to hook up one of the aux power header pins. The SSR will take an input voltage for 3 - 32 volts so where would be the best place to pick up power to hook up to the Aux Header?

“Wild Bill”



Wild Bill January 23, 2018 06:43

Looking at it some more does the aux header for +5 already have an internal connection? Then I could just use the +5 pin on the mosfet connector as is.


Wild Bill January 23, 2018 18:11

Not one to sit idle - I went into config and enabled the switch and made it digital. Wired up the SSR and have it working - so now my air assist pump only comes on when cutting.

So how I did this was take a small extension cord and slice the middle open, cut the white wire and put lugs on it. Then I mounted the SSR on the back of the K40 just above where I removed one of the plug so I can run the control wires out through the hole. In the end it was quite simple and I can work in quiet except for when the laser is actually working.

images/8fc6794459823a8190edcf75a70f8e65.jpeg


Wild Bill January 23, 2018 18:23

Picture of the connection to the mini

images/b396b0f22320108783bab50077de930b.jpeg


Wild Bill January 23, 2018 18:24

Picture of SSR mounted on K40 and working.

images/6bcd63091ca5d2a77a73ddaccd0b09a2.jpeg


Ray Kholodovsky (Cohesion3D) January 23, 2018 19:57

Cool.

Yes, those things sound good and the +5v in both fet 3 and fet4 and the aux headers are all from the onboard 5v regulator.


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