Hole detection and avoid them she probing

[itzalak2]

Dear all,

I was looking for a software to auto-level the Z axis of my CNC to improve the PCB milling and I found this incredible useful software but, after several time looking for info I didn't find anything about if there is any way to avoid the drills when the system makes the leveling process.

Any info about it?


Thanks a lot.

[Country_Bubba]

I etch before drilling. I also believe that is the way most people do it.

[kcassella]

Yes, this happens when doing doublesided boards. The alignment pin holes get in the way when flipping the board around to etch the other side. There needs to be a way to avoid the holes?

[daedelus]

I think we are talking about 2 different things here, i.e. holes drilled for through hole mounting and holes drilled for alignment pins when doing double sided boards?

I make Art right. I think most people etch before drilling. However, as of v.0.8 you can persist the probing results to a file and generate drill or etch files from this probing results file in any order. Therefore, it would be easy, using this technique, to drill before etching. Probe -> Drill -> Etch. You would only need to probe 1 time too. What you can't do is probe after drilling, with any version, i.e. Drill -> Probe -> Etch, because, yes, you will need a clean board in order to probe.

Regarding alignment pins... I use a jig fixture myself so I dont use this technique for double sided boards, but surely its possible to arrange your work so that the alignment pins are no-where near your probe and work areas?

[kcassella]

I also etch before drilling. I use Flatcam to produce my G-Code files. I use Autoleveller to probe the board and then I etch the bottom first but before flipping the board over to etch the top layer, the alignment pin holes (4 of them) must be drilled. Once the board is flipped to the top layer, I use autoleveller to probe and hope it will miss the alignment holes.
I guess I don't understand how you can change out the tool with only doing a height one time on the board.

Thanks

[daedelus]

I presume you have this sort of arrangment http://3.bp.blogspot.com/-QV3vahlpamE/T ... _small.jpg from http://woodworkerbcncrouterproject.blog ... lling.html?

If you 'touch off' the Y axis by 1/2" for example then your work area will be clear of the pins whilst still being able to align everything correctly when you flip. Is this correct / possible?

[kcassella]

The alignment holes that I use are drilled in each board that I etch.

Why couldn't I change the XY coordinates under probe settings in Autoleveller to miss the alignment holes?

Thanks

[Zig]

I too use tooling posts.

I use only two posts outside the work area but inside the machine envelope.

The posts are located along X = midle value of the axis range.
I position my design in the centre of the working range and then extract the milling info so that the machine bed and tooling posts match the extracted data. lipping along the mid value of the axis then simply flips data in machine space as well and this takes care of alignment.

As for probing and crashing into posts.. if they are outside the PCB area then the probe ought not even come close to them.

[daedelus]

As for probing and crashing into posts.. if they are outside the PCB area then the probe ought not even come close to them.

Thanks Zig. Thats exactly what I imagined.

If, for some reason, you cannot get your posts outside the PCB area. You can adjust the extents of the probing area and probe spacing in the Autoleveller settings to try and avoid specific points.

[renix]

what if I need to make drill holes before etching? in order to make electroplatting vias (and other platting holes), and then... make the scanning process before etching... this is a desirable feature... with drill file as input... pcb-gcode does it in a special version present in the yahoo group files but is a very old version compared with the official version that does not include hole avoiding...