Setting up picLaser and j Tech DAC PWM

[Skotty58]

I've been following along with all you got going on here in this forum, but I think Im still not quite on the right track here.
Just got my new 2.8W laser from J Tech and the DAC. Set it up on the A axis as recommended. Remapped the key board so I can Job the A axis. Have the A axis coming out of pins 14 and 1 on the BOB(because they next to each other), plugged the wires from the DAC into those pins, and Im not surprised that that doesn't do anything to the laser in regards to on/off signals.

I was under the impression that I had to use a PWM signal to control the power signal to the laser, is this not correct? Also in the PicEngrave program which Engraving Profile should I be using?

I had success with my other laser using the TTL Laser with the Z axis and I could do B&W images (no greyscale) that came out great, but now that I have the A axis set up for the laser I feel a little lost.

I do have my X & Y motor axis settings a lot different than you do. My X & Y are at 6000/120 5 & 5. According to what you have above my machine will barely move. I did set the A axis to 10000 per what you said above

[Picengravertoo]

The PicConvert board will output PWM or Analog. There is a jumper on the board to set it either way. Did you wire a 0v/5v signal to the board so it will come on/off with a M03/M05, or did you jump the enable so it stays on all the time?

Use the Analog/PWM engraving profile. Earlier in this thread I stated what the Min & Max settings are. The depth settings will be the same in PEP5 as in PL. I assume you have Mach3 set with Imperial units if you have set the A axis steps per at 10000. There is also recommended settings in the Tutorial so you can read what they do.

Each machine will be set different for the X&Y axis in motor tuning.

[Skotty58]

Thank you for all your help. While I was waiting for a reply I set the DAC to ICM/TTL and with A- the laser is on and A0 off. I did a couple test runs and it burns real good and has a tight point and it runs fast and still burns. Much better than the other laser I was using. I think we are moving in the right direction now. Then this morning I changed the settings and enabled the spindle on pin 1. Now the laser is on with M3 and off with M5.

I have Mach3 set to Imperial yes.

Is the A axis and the spindle supposed to be one and the same? (Shaking my head at that) If I now jog the A axis negative the laser will come on but only as long as the axis is moving in a negative direction.

I just loaded a photo in PicEngrave and used the Analog/PWM, (set up the way the tutorial says). Saved the gcode and now looking at it it shows M03 in the beginning of the code to turn on the laser then no more M codes until the end of the code.

So I guess whats really confusing here is that you say to use the A axis, but in the code for the Pic I just made it shows a Z-.0255 using the Analog/PWM profile. So what we have here is the A axis and the spindle. A negative Dir turns on the laser as well as M3. A positive and M5 turn it off.

So whats really controlling the power to the laser here?

Maybe Im overthinking this?

Thanks again.

[Picengravertoo]

Were is there a ICM/TTL on the Pic-Convert DAC/PWM board? I only know of a PWM/Analog output jumper.

Capture.JPG (58.46 KiB) Viewed 18385 times

So I guess whats really confusing here is that you say to use the A axis, but in the code for the Pic I just made it shows a Z-.0255 using the Analog/PWM profile. So what we have here is the A axis and the spindle. A negative Dir turns on the laser as well as M3. A positive and M5 turn it off.

The M03/M05 is for turning on/off anything (spindle, laser, solenoid, ect with a relay). The Pic-Convert board varies the modulation to the laser driver with Z, A,B or C axis step and direction signals to laser engrave grayscale. It has a relay on the board to turn it on/off with a M03/M05 too. I use the A axis because my Mach3 machines have a Z axis you move the laser's focal point up and down based on material thickness. You can change the 3rd axis letter in PEP5.

I suggest you read through my instructions in this thread again and the J-Tech laser driver & Pic-Convert manuals.

https://jtechphotonics.com/wp-content/u ... c-V1_2.pdf

https://jtechphotonics.com/wp-content/u ... l-V2_6.pdf

Here is the Mach3 manual if you don't have it. http://www.machsupport.com/wp-content/u ... l_1.84.pdf

Jeff

[Skotty58]

Thank you.. i'll get to it and let you know how I make out..

[cstmwrks]

Thank you.. i'll get to it and let you know how I make out..

I think the biggest issue with some one new to CNC is that most all the systems are very flexible. More than one possible way to set things up and have it still work.

In my case I made no changes to the jumpers on the DAC board. Having a Z axis in use already ( and wanting to be able to jog for height ) I used the A axis to control the DAC. So it was just a case of assign the ports and pin outs in MACH3 for step, dir and enable.

[Skotty58]

Ok so I had some success with the direct output to the DAC from the A axis. Got the laser to fire and run a couple files. Didn't burn like Im wanting it to though. So in followup to your suggested reading, Ive done all that and tried setting up the system with the Pic-Convert board and after much frustration I finally got the the laser to fire using the spindle M3 signal. But now the A axis is doing nothing.

Am I to understand that using PWM via the spindle control that we use M3 to turn on the laser then the A axis to control the varying PWM signal?
Or do I have that thought process wrong?

Ive followed your directions and have the following set up: And I think i have something still wrong.

Using the Pic-Convert board I have the jumper on PWM, output from the BOB to the Pic-Convert is Pins 1 (-Dir), Pin 14 (-step), Pin 17 is output #1 and goes to the enable (+), Ground goes to enable (-)~(+ Dir)~(+step). So now when I activate M3 the output is 2.36V on the PC board. Is that what its supposed to be?

Couple photos of my setup:

[Picengravertoo]

You have the polarity reversed from pin 14 & 1. They go to the positive +Step & +Dir on the PicConvert board. The ground from the BOB should go to -Step, -Dir, Ground In & Output Enable-. We made jumper wires to tie all the grounds together with the prototype PicConvert board we tested. I don't know if Jay fixed that on the production boards or not.

The M03/M05 only turns on/off the PWM output to the laser driver.

The full range of the PWM output is 0v-4.72v? so when it first powers up with the powers supply the digital potentiometer goes to half of that range (2.36v)? You have to jog up the A axis positive to 0v which should be more then a positive A axis move of A+.0128, then zero the A axis there. Then use a min of 0 and max of -.0255 depth setting in PEP5 to get the PWM range to the laser driver of 0v-4.72v?

[Skotty58]

Thanks... ill fix that.. I also think I have the Enable1 + wired wrong, or is that supposed to be on Pin 17 to the Enable + on the PicConvert board?

For some reason I cannot not remember how I had the PicConvert board wired up before but it did work to a degree.

[Skotty58]

Ive got this set up just as you instructed. But something is either not right or Im not understanding whats supposed to happen. Guess i'll try to burn something and see how it goes.

So heres what I have now.

Input to the Pic-Convert from the BOB Pin 14 + step, Pin 1 + Dir, Pin 17 + Enable, All other inputs are to ground. The board is set to PWM and Relay on. Output to the DAC. I have a dedicated power supply at 12v for the voltage input. M3 turns on the laser. Jogging the A axis does nothing.

Mach3 A axis is set for Pin14 = Step, Pin1 = Dir. Dir low active is checked, Ive tried this both ways and I got nothing.

Enable1 is on port 1 pin 1 Active low does nothing whether checked or not.
Output1 is on Port1 pin 17 active low not checked and when M3 is active it will fire the laser.

Honestly though, thanks for all the help and advice