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Subject: Re: Setting drill collars to length

From: "Bob_xyz" <bob_barr@...>
Date: 2005-10-02

--- In Homebrew_PCBs@yahoogroups.com, "Andrew Mawson" <andrew@m...>
wrote:
<snip>
>
> The top HAS to be the reference as in fact it rests against a
> shoulder
> on the collet to set the position in the spindle. Settting the Z
> height
> for each tool isn't an option as I'm using a Heidenhain controller
on
> a
> Bridgeport Interact 1 CNC mill, and although tool lengths can be
set
> individually when called this is not the case in the event of a
> breakage. Variation in collar thickness isn't much - maybe 0.1mm
max
> but enough to spoil your day if you are isolation milling pcbs !
If
> it were just drilling holes it could be ignored and allowed for in
> the sacrificial underpad.
>
> AWEM

My thought was that, as long as the collars were all the same
thickness, there's a fixed distance from the bottom face of the
collar to the top of it. That fixed distance could be taken into
account in your collar setting device.

Regards, Bob