Re: update copylathe with Siemens 802c and Newall Microsyn readout

Ray wrote:. I've watched some installers put the latest versions of
electronic flow

> control valves in several lumber mills around and these things are a
> real b**** to tune and require frequent resetting to maintain the 1/32
> accuracy that the mills use.
>
> I'd replace the hydraulics with some other kind of drive.

Dear Ray ,

That sound sounds like a horror story, in german we would say you get
out of the rain and enter the gutters (You get out of the frying pan
into the fire).
Were these machines equipped with an accurate readout system for
back feed? I remember a step motor (toy) mill from technics without
back feed that lost 0.020" to 0.050" per piece we had to mill.
Some when we changed to an grandfather Index mill.
In studies some 14 years ago we were told that it wouldn't be a big
deal to change the pattern follower against a proportional valve
as long as you use a closed loop system. But as you say dimensioning
and synchronization seem to be a headache.
I would like to ask a Traub maintenance man about his experience,
because Traub built before pretty famous hydraulic lathes.

Thank you very much for the answer.

Sven Peter

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