It's been a while to get to this point. But, here is my Open Builds CNC with a 10 watt laser diode riding along. The challenge was getting Mach3 and appropriate hardware to be able to do photo images. Images are made possible with Mach3 by using parts and software from JTechPhotonics.com. Now I can do photo images when I get those details of how to do it best worked out. The next challenge is how to also do normal engraving and cutting using SketchUp and SketchUcam. Before the JTech hardware, I was using the spindle to control the laser output. Now, it's being controlled thru a mix of the Mach3 B axis step and dir outputs to create a PWM signal. But, now the spindle control I was using isn't in the control path any more. So, the question is, any ideas on how to do this?
Hi If you can give me some example Gcode (with explanation) showing exactly how the laser is controlled then I can add this mode to SketchUcam for all JTech users. Maybe 2 examples. A small photo of course, and one with just simple shapes like a square and a circle at different powers. Thanks
Hey! Thanks for working with me on this!! I'll provide the Gcode for the examples you requested tonight. The photo image Gcode is created by JTechs's PicLaser Photo Engraving software. Here is the link on how JTech's PicConvert hardware works. The theory of operation is on page 4. https://jtechphotonics.com/wp-content/uploads/2013/05/Pic-Convert-Manual-V2_6.pdf
Here's some initial info to start with. Stuff you already know. Mach3 is the CNC controller software. SketchUcam is using the spindle command “S” to control laser power level. Power level commands with the JTech hardware uses the Axis letter. Which axis depends on the specific machine setup. In my case, I use the B axis. So, the command is “Bxxxx” to set power level. The normal m5/m3/m4 commands do the off/on. To set JTech laser power levels, the default B value range has 256 values and is something like: Max output: B-0.0256 (Note the minus sign) Min output: B-0.0001 (Note, each setup will have it's own min power setting where the laser just turns on. Then, the max value is that plus 255. So, for example, if the spindle value was S50 for 50% power, the similar power setting for the B value is B-0.0128. This part is very encouraging. It appears that in the SketchUcam gcode, we could substitute “B” for “S”, and enter the respective power setting value. I created a simple engraving file with SketchUp/SketchUcam. Did a search for S50 in the gcode and replaced with B-0.0128 and the process worked thru the JTech hardware. The results were identical as far as I can tell. So, if SketchUcam would allow entry of 1. the power level character. (B in my case) 2. the max and min power values. 3. the power level for this engraving/cutting project 4. and for flexibility, the on/off commands (M05/M03) I think we would be in business!! I’ve attached a PDF file showing the range of B values for 1% to 100% power levels. As you can see, putting in a value with 4 decimal places plus the minus sign, could be seen as a pain. If SketchUcam would do the math, and be configured so the user can put in a percentage value, seems that would be much easier and more intuitive as compared to the long values shown in the PDF file. Attached are the sample gcode files. They are all images. All of them were created by PicLaser. As you will see, the circles and squares are mostly with a laser value of B-0.002, or essentially off. Then you see the occasional B-0.0258 (for the dark versions) for full on. What do you think? Let me know what other info I can provide. Thanks.
SketchUcam V1.5 was released on 24 Dec 2020. You can download it from github https://github.com/swarfer/sketchucam/releases/tag/v1.5 The place to go for support is Openbuilds
I am very grateful to all the developers of phlatscript / sketchucam ... Why was the new version also not available in this Forum, where you were born? Hugs and good 2021
I think there is a bug in this new version. I made a drawing in Sketchup 21, the oval part was a circle that I used the scale tool. I generated Gcode and when simulating in Mach3 the sides of the oval surface were curved ... https://imgur.com/sGzA23n
Sorry Marco, that is not exactly a bug, it is Sketchup lying about the nature of the arc we are processing, and since Gcode can only do either straight lines or real arcs, we do need to know exactly what we are dealing with (and this is a segment of oval, for which there is no gcode). At this time the only thing you can do is to increase the number of segments in the arc and then explode it into line segments. How many segments do you need? This depends on the radius of the arc and the size of cutter, you want each segment to be about as long as the radius of your cutter as a starting point, you will need to do some test cuts so see what works best for your projects.
Because this forum is not read by many people at all anymore, all the action is on http://openbuilds.com . Also, the release is on github, just one place, otherwise it gets confusing as to which version is being used or downloaded.