Quote Originally Posted by jstrack2 View Post
Great I'm glad to hear it got you excited!

I don't think it is the stepper or a rigidity problem, but I don't know what it is. Some layers the laser moves smooth, some it shakes. Sometimes half way through a layer it is smooth then shakes. It doesn't appear to be caused by a layer being too complex for the speed am moving the mirrors at. I think this because some times a layer will be smooth then basically the exact same layer will have a bunch of shaking. Maybe the PWM I am doing (instead of the normal analog voltages) is causing problems. I don't know. I will just have to debug it with various tests.
Hey Jstrack2
Big Thanks from me and everyone at Peachy for all the awesome work your doing!
At Peachy we have been using cura to slice models into g code.
Just the other day we noticed that cura seems to be be injecting very short movements where the laser is told to turn off while the mirrors are told to move less than a mm.
It dose this at every vertices on the back of the owl model we are slicing. We dont know why it dose this( could be a feature we dont know about for fdm printers or a bug) but it definitely causes shaking because we have a laser on/off positional offset in our analog circuit. You have built your own circuit (awesome!!) so I dont now how yours reacts to twitching the laser off 20 times during a layer, but its probably not helpfull. We implemented a quick hack that solved it. our hack is an if statement that goes something like this: If a gcode tells the mirrors to move with the laser off for a distance that is less than the laser spot size, ignore that gcode and move on to the next one.

Hope that helps take the shake out of your printer.
If not try doing something really really repetitive like repeating 4 g-codes drawing a square and printing a column, your printer should be able to do a column like this one from update 13 (https://www.kickstarter.com/projects...5305991&page=7) :
3fd04d54221c7945338e8b55a3af3f8b_large.jpg

If it can do that then you likley have a software problem not a hardware/ circuit/ environment problem.