I'm using this version AutolevellerAE-0.9.5u2.
can you show me your settings so I can tntar and see if it works with my STB5100 Chinese controller?

Gerry, Chuck, Reuelt: Thanks so Much!!

Just opened basically the same issue looking for an Auto Tool Zero answer for China made boards (I have the infamous USB STB5100 Controller Board).

Luckily I stumbled on this topic and thanks to your work my problem is gone!

If you happen to go through Windsor, Can, PM me - buying a beer!

Autoleveller is a great piece of software but when milling PCBs I prefer to hold the workpiece flat, eliminating the need for profile correcting software.  Simple vacuum chucks can do this extremely well.  I have made several for different size boards.  Here is a 20 minute video showing the smallest one,  the second half of the video shows measurements which illustrate just how flat the boards are held.
https://www.youtube.com/watch?v=Xn7rKm1RwYM

Hi,
my mill is flat to within 4um over its XY surface but the problem is the PCB blank material is not perfectly flat,
even with good name brand board you can expect up to 10um over 100mm deviation from flat.

A good vacuum chuck should 'pull' a PCB blank flat to within the flatness of the chuck.

I find that Autoleveller allows Z axis placement within 6um over the entire PCB blank despite the blank
having as much as 0.1mm warp/bow. Thus when I isolation route boards I command a Z axis depth of 0.05mm (50um)
( using 1oz or 35um copper PCB) and that results in perfect isolation WITHOUT undue cutting of the underlying fibreglass.

I have used vacuum but disliked the fact that if drilling through holes in your PCB then you lose vacuum. You can of course
drill holes last and retain the PCB with tape, after all the hole drilling is not especially sensitive to placement in Z but of course
is critical in XY. Additionally I found that having to make a different vacuum chuck for different sized boards tedious.

I use double sided tape to hold the board down onto a sacrificial polycarbonate carrier that fits into my mill vice. The polycarbonate
gets replaced every 50 boards or so. The double sided tape does a good job of holding the blank, it does not 'pull' it flat with anything
like the surety of vacuum, but still not bad. Then its probed using AutolevellerAE. For an 80x100mm the probing takes about four minutes.
Thereafter the isolation routing takes place in an identical fashion be it vacuum chuck or doublesided tape/Autoleveller.

All-in-all I find the doublsided tape/Autoleveller combination to be effective and fast, especially as almost ALL my boards are one offs,
without the overhead of the vacuum plant and vacuum tooling.

Craig

I do not drill into the vacuum plate, that would be real dumb and after a few holes you would lose the vacuum anyway.

Hi,

I do not drill into the vacuum plate, that would be real dumb and after a few holes you would lose the vacuum anyway.

Yes, that is the point. Thus in order to do a PCB you have to remove it from the vacuum chuck after being isolation routed then
set it up on a spoil board with EXACT registration before you can drill the through holes. Considerable messing around.

I use 1/2 polycarbonate because I was given a whole bunch, as a spoil board. I anticipate that when I drill through holes the
underlying spoil board will get drilled a wee bit as well. Also when I run around the periphery of the board will an endmill to
cut/machine to final size likewise a groove will be machined into the spoil board. Because the blank is double sided taped to the
spoil board it does not shift and so I do not have to do ANY mid-process alignment/registration.

If I have to flip the board (two sided) I use registration pins, actually short lengths of 1.6mm welding wire, into holes drilled
while the board in in the upright position. Too easy!!!

Craig