Just got my replacement Printrboard after my original had the USB port break off and I'm pretty close to printing now, but I'm hitting some snags in getting the firmware right. I've updated the #define MANUAL_Z_HOME_POS (in my case it is near 223.0), but when I start to print the distance between the glass and the nozzle changes pretty significantly (+/- 5mm between the towers). I've read through the RichRap firmware post (http://richrap.blogspot.com/2013/12/3dr-build-tutorial-part4-firmware.html) and through the Delta calibration post linked in the blog (http://minow.blogspot.com/index.html#4918805519571907051) and it seems that I'm able to identify different distances as described in this routine:
When I do this sequence I get the following nozzle to glass distances:
A - 0mm
B - 5mm
C - 10mm
D - 1mm
That blog post then mentions adjusting the end-stop screws, but there are no end-stop screws in this design nor are the endstops themselves adjustable. How do I account for this alignment issue?
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2- Calibrate the towers to the actual build surface.
An important trick here. Set up four scripts in RepetierHost, or four user defined buttons in Pronterface, to move the carriage to four specific measurement locations on your build surface. Three locations are on a circle centered on the center of your build surface immediately in front of each of the three towers. The fourth is the actual center of your build surface. And each of the four locations is at height Z=0.
Let’s call the three tower locations A, B, and C, and the center D. The script code for each is:
Button Script
A g28 g0 f8000 x-77.94 y-45 z0
B g28 g0 f8000 x77.94 y-45 z0
C g28 g0 f8000 x0 y90 z0
D g28 g0 f8000 x0 y0 z0
When I do this sequence I get the following nozzle to glass distances:
A - 0mm
B - 5mm
C - 10mm
D - 1mm
That blog post then mentions adjusting the end-stop screws, but there are no end-stop screws in this design nor are the endstops themselves adjustable. How do I account for this alignment issue?
