Re: [CAD_CAM_EDM_DRO] Digitizers, Renishaw

From Peter Meinhard

>Hi Bill
>Of course I don´t mind. It´s interesting stuff .
>>I wondered how the VAST-Head of neu ZEISS Prismo is working.
>Do ou know that.? ( Sure it is not Your company, but when I was at AUDI in
>their research center I saw lots of Mercedes, BMW, even Jaguars in there).

No sorry, Zeiss are a competitor but also a customer. They use our products
and we use theirs. I just design interfaces and only get to play on the
machines when something has gone wrong that our customer support people
can't fix.

>But two things:
>>>quite simple and there ist no need for high accuracy .
>
>>You are at least partly right but I think you will find it is much simpler
>>to calibrate if the stylus is on the same axis as the mounting screw.
>For home-shop digitizing I usualy don´t need calibration. At work I use the
>Renishaw for example to mashine the valve-seats guides of Mercedes racing
>motors exactly fitting to the valve guides Compensating temperature-failures
>and position-failures. I would not use a home-made probe for that.
>
>>Sounds like you have one of the big ones. I just measured a probe I have in
>>the workshop and it is only 13mm external diameter. The bigger ones are
>>normally used on the big machine tools and are designed to cope with long
>>stylus with large balls on the end. You may find that it is rather stiff
>>for digitising especially on soft materials.
>
>The spring is adjustable, and because I use it only vertical I adjusted it
>very soft.

Sounds like you've been reading the manual!

>( By the way , I saw a small Renishaw on ebay about 6 month ago. It was sold
>for 90$)

A bargain, maybe. These probes have a long but finite life. If you wish to
retain the stated accuracy they need servicing and calibrating. Could be
the one for sale was a high mileage example. No way of telling from the
outside. If yours still has the serial number on it you can get a rough
idea of its year of manufacture. Current ones start with an R I think. D
gets you back to say 1990. Very few that old will still be in circulation.
Accidents are frequent, and normally terminal. We have quite a chuckle at
some of the units returned for 'repair'.

>
>Thanks for the answer
>
>Peter
>