Re: [CAD_CAM_EDM_DRO] Cnc PCB drilling machines z axis linear pot

In a message dated 09-Dec-01 08:31:18 Central Standard Time,
byron@... writes:

> Is there any advantage of using this potentiometer. . . .
>
> Look forward to the groups views on this

Byron: Advantage? It's electrically simpler than just about any other kind
of encoder, and as ALL PCB holes are "THRU-holes", depth-precision is not a
factor.

MY home-brew machine uses only "Microswitches" for "fully-down" and
"fully-UP, again", and they are perfectly fine for the purpose.

One detail: I have only seen "professional, 4-quill CNC PCB
drilling-machines" from four feet away, and I didn't stay to get FR-4 dust in
my face, so I have no clue how those machines "tell" how deep to "chuck up"
bits, when they change bits, automatically (that's sumpin to see!). Wonder
how "accurate" (repeatable) that is, and how "indexed"???

Anyone reading this know????? Jan Rowland


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