RE: [CAD_CAM_EDM_DRO] Re: Optical mouse for DRO anyone? - not for WIRE!

I would have thought it would be better to measure it under a known tension
where it is consistent.

A set of rollers to keep it taught with measurement in between, or off of
one of the rollers.

The tension rollers could be a simple low power low torque servo so it is
operating at it's torque limit.



It's a bit like the woven cable protectors we use, they are damn awkward to
know how much to cut off the reel since they grow shorter as you fill them
with wires. Always ends up being a wasteful operation.



Dr. Mark Vaughan Ph'D. B.Eng. M0VAU

Managing Director

Vaughan Industries Ltd, reg in UK no 2561068

Water Care Technology Ltd, reg in UK no 4129351

Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH, UK.
Phone/Fax 44 1872 561288

RSGB DRM111(Cornwall)

_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Graham Stabler
Sent: 23 April 2007 10:46
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Optical mouse for DRO anyone? - not for WIRE!




Well you can be sure that the surface texture of a cord will vary
quite a lot over the areas the mouse looks at so I still think that
the mouse will not work for long lengths.

I am not sure how fast you wish to measure the lengths but here is a
solution that might work and could be pretty fast anyway:

what about a two gripper system with one gripper on a pneumatic or
electric actuator, one pulls the cord out by a fixed distance the
other gripper holds it while the first returns to the start position.
With suitable grippers and correct design it would not damage the
cord and would be accurate.

Graham





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