Getting Started again

Mostly Printed CNC - MPCNC Troubleshooting
#1

I finally got some time to work on this project again. I’ve never got anything to cut on my MPCNC. I’m still trying to understand the process so let me explain what I’m trying to do.
I created this panel in Blender that I want to cut and etch. It is x=157.9mm, y=108mm, z=3mm.

FLAPS PANEL3
FLAPS PANEL31600×900 195 KB

I exported it as an .stl, opened it in Repetier-Host and sliced it with Cura. I want the bottom left corner of the panel to be at the position on my cnc shown in the picture so I want the router to start there. I’m just drawing it for now.
FLAPS PANEL Start Position
FLAPS PANEL Start Position1920×1440 256 KB

When I start the router it moves way past where the panel should be and the y axis maxes out.
FLAPS PANEL Start Position_2
FLAPS PANEL Start Position_2960×1280 276 KB

I try repositioning the panel in Blender but it doesn’t seem to make any difference. I don’t understand how gcode sets the actual position of the object. I’ve tried moving my endstops to compensate for the difference but the router still moves way off from the position where my panel should be. I know I’m misunderstanding something but I can’t figure out what.

Jerry

#2

You should be using something like Estlcam and not Cura for generating the gcode for the machine. I’d give this and this a read (or reread).

#3

Alex is right, Cura is for additive manufacturing and CAM like Estlcam is for subtractive. Even just etching, or drawing the lines on your model is subtractive (even if you are just using a pen). Estlcam won’t do what you want with an stl though. You should make a sketch on the face you want to machine, and then add in the features you want to tool to follow. Export that sketch as a DXF and open that in estlcam.

But your specific problem is because you haven’t set the origin. Also take a look at this doc: Coordinates - V1 Engineering Documentation

The short answer is you need to set the origin when your pen is where you want the origin. I use G92 X0 Y0 Z0. I use a macro or just type it into the send gcode box. But you can also add it to the top of your gcode file.

And, if you want to just check out your machine to make sure it is working properly, start with the premade gcode file here: test crown. That gcode has been used thousands of times and has the G92 at the top. If you start it with your pen in the lower left, touching the paper, it should draw the whole crown and you can focus on learning CAM.

2 Likes
#4

I’m really tired of struggling with Estlcam and Repetier Host. Sometimes when I import a dxf to Estlcam only part of my object loads. I’m trying to rout circuit boards on a copper clad board. Is there an all-in-one payware program where I can import a file from Adobe Illustrator and it does everything that Estlcam and Repetier-host do including simulating the routing?

Jerry