Laser Engraving with M3 kit with Jtech Laser

[cheistand]

Hello, 1st time MillRight CNC user here!

I have the M3 kit set up with the Jtech laser and have successfully connected to UGS and controlled some basic movements from there. I created a design in Fusion 360 and created a CAM setup using the {1 - 0.015" laser cutter} tool that is built into the software.  I would like to use the laser cnc setup to etch my design so I selected the Etch option from the cutting mode dropdown menu. I have simulated the toolpath and am happy with the results, however, I cannot for the life of me figure which post process configuration I should be using to create the g codes. I tried the Smoothie one and it causes the cnc to jerk around whenever any directions are given. I think there might be a combination of things wrong. Here's a picture of my setup in Fusion 360: (not sure why the first picture is so small...)





My first concern is that I have the coordinate system setup incorrectly. If that appears to be correct (which I based off of several of the MillRight YouTube tutorial videos so it should be correct I would think) then I just haven't found the right post process configuration yet. I tried the GRBL Laser one from autodesk but it doesn't support etching, only through cutting, so it doesn't meet my needs. Anyone know what I should be using? Any and all advice on using Fusion360 to design for the Jtech laser mounted on the M3 is welcome!

[Derek the Admin]

I would suggest Inkscape for this kind of work with the jtech extension. We have a tutorial on this on the vid tutorial sticky.

I think you could just use the contour tool path and turn sideways compensation off. Just set the spindle speed to the intensity that you want the laser to be at (12k is max in our firmware).

[cheistand]

OK so I downloaded and installed Inkscape to see if I can figure out how to use it. I followed the tutorial video and created a simple file. When I used the Jtech extension I was able to get gcode output but it still doesn't make sense. The first move command gives positive values for x and y which causes the machine to hit the limit sensors immediately with my current setup. Now it's possible I've got this setup incorrectly or something but it seems to me that the origin on my machine and the origin on my design are not in the same place. I've taken a picture of my machine with the spindle in the home position (used $H in UGS to place it at the home position). I've marked the picture with arrows showing what direction of movement I get when X/Y commands are given from UGS. I am wondering if we possibly have the machine setup incorrectly?

[deepdivetc]

Just for clarification, when you issue a y+ command in USGS the Router position moves towards the back of the machine? When you issue a x+ the router position moves to the right? Next question, after you create your GCode and go into USGS I understand you run a homing command, but do you also set the home position of the work piece to the lower left of the work piece in USGS after the homing command? Also are you using USGS platform or classic?

[cheistand]

When I send a y+ command the table moves towards what I would have called the front of the machine (or the bottom of my photo). X+ moves the router to the right of the machine as oriented in the photo. I am using "UniversalGcodeSender-v2.0.0-stable", it has July 23, 2017 as the last update.

I am not sure what you mean but set the home position of the work piece. Do I not just use the machine home? I think I am probably missing a key setup step here. My inkscape drawing has the origin in the lower left hand corner.

[deepdivetc]

Ok, yes I think you are missing a step. You can look up WCS and do some reading on that, but I will tell you the down and dirty. After running the homing command then move the position manually to the lower left of your wood. Then in USGS you will click reset zero under machine control. Then you should be good to go I think.

[Derek the Admin]

I need to see your g code too please.

Your machine is moving correctly. I think the issue is that you don't have the origin set for the work piece. The machine home is totally different than the work position origin.
Homing positions are used to create a known position to offset from. For instance, if you wanted to make several of the same thing and had set up a clamping jig to hold say a precut wood plaque of the same dimensions, you would home then designate the origin of that part as the origin of a work coordinate system. You could come back to that every time, even between power downs.

If you are doing just a "one off" piece and you don't care that the origin gets saved, you can use G92 to create a temporary origin point. If, like in inkscape, the origin of your file is the bottom left, then you would set the workpiece up such that the laser impact is at the bottom left of the piece you are working on. You would adjust the laser to the desired high from the work piece, then type G92 X0 Y0 Z0. This tells the controller that the position it is currently at will be the starting point for the file.

The below video is pretty in depth but it explains everything you wanted to know and more about work coordinate systems.

[deepdivetc]

Yeah, Derek explained it much better than I did lol

[cheistand]

Wow I really should have figured that out myself... That video and your responses have be super helpful though! Thanks!

I have attached my g code to this post. The design for this code is a basic spiral approximately centered in a 3in high by 5in wide rectangle. This is just a test design to learn how to use the laser. Ultimately I intend to use the cnc to create more complex work but I didn't want to try to run anything super complicated until I figured out how it all works.

Attachments:

swirly_gcode_0003.txt (1.06 KB)

[deepdivetc]

Well we all have to learn, trust me when I started out I was not knowing what the heck I was doing. The people here are super helpful and very knowledgeable. Did you try setting your workspace to 0 and rerun it. I am pretty sure that is the only step that you were missing is clicking that one button before sending the code.

[cheistand]

Thanks for all the help! After watching the video and correctly setting up an origin point in the bottom left corner of the work area, we were able to get up and running and laser engraved our very first drawing! We just used a scrap piece of plywood from the shop.


We are hoping to ultimately use the laser engraver to make the save the dates for our wedding this year so I can't wait to play around with the tools and see what we can make!

[Derek the Admin]

Congratulations!

You are now on the track to success.

[deepdivetc]

Glad it all worked out for you. It is always the little steps that we miss that cause the hardest falls.

[kerry]

Thanks for this....helped me out tremendously! Duh...Reset 0....all makes sense now.