Z-Axis depth guide sensor ?

[deleteallusers]

No matter what I do, I can’t get my work area exact level enough to have the proper depth when milling my PCB on my DIY CNC machine, (I’m always cutting to deep some areas and to shallow others). always around 0.0050 off

(I’m going to try routing the work area level again).

However,
Is there any general sensor method I could hookup that would act as a
depth guide ?

Example:

If I mounted something similar to a spring loaded thin metal ball point pen
To the base of my spindle, so that it would complete a circuit (similar to a touch off plate) When ever it touched the copper PCB, then I could use it as a depth guage to control How deep past the pen’s contact point I drilled.

I would always adjust the Z position relative to the contact point of the pen.

Has anyone done this ?
Is there anything like this, How can I do it ?

Thanks,

[samco]

How are you holding the circuit board down?

sam

[deleteallusers]

A vacuum table, Plus I have a 0.0060 deep aluminum rail system around
the boundry with a small lip that overhangs the PCB about 1/32.

I just slide the PCB into the pocket and turn the vacuum table on.

It's verry flat, and stays in place, but the PCB is unlevel some how because
of the workarea, It's MDF, I have 4 bolts on the edges that I use to adjust
each cornner of the work area, I also have two bolts in the center that
screw down and can actually pull the workarea down for fine adjustment.

No matter what I do, I'm always off around 0.0050 across the 6x4inch PCB.

and thas two much, some of my pcb stock is not even that thick !

[samco]

How are you facing the work area? If you machine it flat - then suck a vacumm - it isn't most likely going to be flat.

My table is actually plywood - I machined it flat under vaccum then drilled the holes for the vacumm to come thru. That way - when vacumm is applied - the table is flat.

My next table will probably be mdf. (bit more stable for me)
http://www.electronicsam.com/images/KandT/vactop.JPG
http://www.electronicsam.com/images/KandT/vacback.JPG

[rayan]

any one can tell me about wcs in maastercam x complete video

[rayan]

i am a beginner in cnc programming and masterrcam is there a good video that an explain 3d design and toolpath ,construction plane thruogh wcs yr response will be higly appreciated thanks