Hello everyone, new user hear learning the ropes. I recently purchased a 4w laser from JTechphotonics. Their shop is close to where I live so I had the opportunity to pick mine up in person and meet J. He was a very nice and helpful guy that showed me around his awesome shop. Anyways, I am having a feet rate problem with two different 3d printers with two different controllers on one of them. The results are fairly similar with all 3 controllers. I am hoping that I am just overlooking something that can be corrected so I may use this awesome technology. I'll list some more details with the trial and error thats been done so far.
Two of the boards are Arduino based MKS 8 bit boards. The third is a smoothieboard 32 bit clone, also by mks. On all boards I have checked the pwm signals for laser triggering. Ironically on the two 8 bit boards will fire the laser with either the M03 or M106 commands plus the S value. I have not tried this with the 32 bit. I increased my jerk and accel setting to ridiculous levels. This has helped more than anything, but I still can only get up around 900 mm per min. I increased my baud to 250000 with little to no difference over usb and the problem is identical with running on sd card. I have scoured the firmware for marlin and smoothie, trying to find anything that would cause a dwell anytime the pwm level was changed. It seemed to me that the 8 bit controller just couldn't handle that much information. I have the Pic Engrave software set to .1mm for laser width (pixel width?) which in turn breaks up all G1 command into .1mm segments with a M106 Sxx or M03 Sxx in between. This is why I concluded that it was simply to much for that card so I purchased the 32 bit with much confidence that it would solve my problem. Nope, same thing. I did however, set the 32 bit for 32 microstepping. I will try it on 16 later this week. I have been able to produce some really nice pictures engraved on some birch plywood, it just takes a really long time to do them. The outlines, if I have that option enabled, runs at the speed it should. When it starts the raster paths is when it slows down. I think i've noticed when a part of the picture being engraved has a more dense area of contrasting pixels (such as a in between shade whithin a dithered photo) the speed problem is more noticeable and erratic. If it helps, everything seems to run like butter when vector engraving.
Thank you for listening to my incoherent babbling.