PCB MILLING WITH BAD RESULTS

[cwiliam]

I have a k2 kt 1414 and tried milling some copper clad but the results are not great.
One side doesn't cut the same as the other even if the depth is set the same .
It seems like the thickness of the board varies from end to end or the something is wrong with my cnc router
what can I do?

[Greolt]

cwiliam

Not sure if this is your problem but because isolation routing on PCB material is typically only done a few thou deep it becomes critical that the surface supporting the material is dead flat in relation to the cutting plane.

What you can do is mill the surface first then fix the PCB material to that surface. This will ensure that the surface of the PCB is perfectly true to the cutting plane.

Hope this helps, Greg

[cwiliam]

I'll try that
thank you
I was looking at denford webpage and their pcb milling machine .It uses a floating head
I was wondering where I can get a floating head for my Cnc Router
does Anyone build these or know where I can get one?

[ivan_j]

http://www.accuratecnc.com/design.html

[Jay C]

It's as simple as using a spoil board of MDF. Skim the top flat and you are good to go. I use carpet tape yo hold my PCBs for milling. Depth of cut is .005", just enough to get through the 1oz copper.

[cwiliam]

appreciate the help Jay C will take it into consideration

ivan_j really impressed with ACCURATE 360 but its out of my price range for now .Bookmarked it just in case things get better

[cwiliam]

http://www.ryobitools.com/catalog/sp...ng_bits/AR2070

Came across this
has anyone used it?
One end is spring loaded
you can see a drill bit in the oval hole it has.
the bit is held by a hex screw close to the shank
thought it could be modified to make spring loaded engraving tool by putting a hex screw flush below the oval hole and reduce tension on the spring

[pminmo]

You don't need the expense of a floating head. http://millpcbs.com/index.php?option...d=17&Itemid=46 For example see this video done without a floating head:

YouTube - Milling a fine trace double sided pcb

YouTube - Milling a fine trace double sided pcb