After coming home from work yesterday, I had a couple of options to spend my time. I chose the Mantis, cause I really wanted to see how it would perform. I had already ordered 2 160×100 mm Copper Clad boards (learning new words all the time) some weeks ago, but…
Neh, the first try was done with pencil and paper; I wanted to see if all went well without the chance of breaking something.
This went well. Next – the real deal! I attached the board to the bed with a screw in each of the four corners (this MDF bed won’t live long cause i need one that’s a bit thicker) and homed the Z-axis with a ‘trick‘: when the cutter touches the copper plate, you could regard this as a “switch” closing, right? So I put the cutter and copper plate in parallel with the Z- end-stop as a 2nd switch! Now I could just move the cutter down to the copper plate and it would stop all by itself. That’s easy.. That’s a good idea for X- and Y- homing too I guess: a vertical metal plate and cutter both connected to the respective end-stop inputs. I’m gonna build something for that soon! The position of the cutter above the board is very important to achieve the right cutting depth; the copper clad board is 1.6 mm thick and cutting to deep would make it too fragile.
Back to the milling! Here’s picture of the milling process after 10 minutes. I chose a feed rate of 50 mm/min cause I had no idea what to expect. On this picture the cutting process looks OK, but you haven’t seen what it looked like after the next pass, and the next… there was a point where I began to doubt if any copper would be left on the board! I’m going to put the result on my flatbed scanner so I can analyze the result better.
Some conclusions and ideas on how I’m going to try to achieve a better result next time:
- The X-axis still needs some adjustment;
- I think I need a better cutter (where to buy?) cause the edges of the cuts are rough;
- The depth of the cut is constant in the area (40 x 60 mm) that has been cut;
- I have to ‘tune’ the Eagle DRC settings to better match the cutter size;
- The same goes for pcb-gcode.
Still lots to do, but the result of this not-so-well-prepared first try is encouraging enough to go on!