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Been looking at electronic edge finders that light up when they touch the edge of the workpiece, but don't see how they work. Is it that touching the workpiece completes a circuit through the mill - this seems a tad tenuous, or does the contact close a switch in the finder.. in which case how sensitive is that if these are good to .02mm or better! Thoughts?
Well have you seen the edge finder a guy posted on the zone ? i also read about a guy who took the mouse from an old laptop and turned it into a edge finder.
Is that the kind of thing you mean or ?
I mean this sort of thing:Quote:
Originally Posted by Lee Roberts
The tip is insulated and when it touches the workpiece, the circuit is completed and the LED lights.
Too bad if you're machining plastic. :thumbdown:
that means the circuit is tip, workpiece, table, column, head, chuck... surely not... a tad tenuous at best...Quote:
Originally Posted by tumutbound
Only as tenious as power station, sub station, machine tool and neutral,Quote:
Originally Posted by irving2008
is 36,000 miles a second or whatever good enough ?
not speed John, connectivity... surely relying on all those having a good or any electrical connection to each other is tenuous?Quote:
Originally Posted by John S
Especially if the spindle has ceramic bearings no ?
Yep, that how those ones work (I have a Sony probe for my magnescale DRO that works exactly the same)Quote:
that means the circuit is tip, workpiece, table, column, head, chuck... surely not... a tad tenuous at best...
You can get touch probes that are effectively sensitive normally-closed switches (usually three switches in series at 120' to each other) relying on movement of the probe to open the switches and the closed position of the switch as a position reference.
Nice home-brew design here:
http://tmonnot.free.fr/Fraisage/Palpeur3D.htm
Just found the pics i was looking for irving:
Lee, is that an IBM 'niipple' (touch mouse) being used as a touch sensor?
Any idea how accurate it is? (ie. repeatability etc.)
not huge I'd imagine..., although the long probe improves. my concern would be how consistent the 4 switches are relative to each other...Quote:
Originally Posted by BillTodd
Yes it is, ill need to have a dig on the zone to find the Thread the guy started about using it. Cant remember all the details but i think he did get it going and was using it..
Hi guys, here is the link to the guys thread on the zone: http://www.cnczone.com/forums/showthread.php?t=51079
What i also liked about this setup was that you could use it on wood and so on, gaging on presure rather then a "completed cicuit".