Payback to this group

QEs are nothing more than 2 bit Gray code (only one bit changes) connected to a counter.

Nick

That is an intresting "observation". I never thought of that. :-) ...lew... (retired electronics engineer)

I meant: looking at the signal.

Of course QEs and Gray-code are two different things.

Nick

Thanks for that link/hint!

Nick

If you ship US Post Office Priority mail, you can get boxes for free.

Here is a link to triangular "tubes":

-- Jim

Welcome.

Interestingly, the inventor is a Swede (by the name) living in Seattle. Wonder what the story is. Does Mitutoyo have an R&D facility there?

Joe Gwinn

Okay, had one taker and mailed a 360° layout for a 5" chuck this morning. I put three copies on a strip of Mylar, gives him three chances to cut and paste on to his chuck. Surprisingly with a 5"x9" soft pack envelope and toilet paper tube, the whole thing weighed in at a little over 1/2 of an ounce. Very cheap to ship. Thanks to everybody for their shipping advice. Will change to film canisters as soon as I can scrounge up some more.

Anybody else want a 5" diameter scale? Any other scales? Let me know.

Ivan Vegvary

No - maybe a field office supporting a local customer. Like I used to do in Austin.

Mitutoyo Institute of Metrology is in Aurora, Ill. US offices : Michigan (motor cars maybe?) Illinois (three sites) California (city of Industry)

Martin - using his Handbook of Metrology version 1.1 :-)

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

Joseph Gw> >

Just go to the US patent website and look it up. Karl

That works, but doesn't yield a pdf file.

For the record, the US patent website is at .

Joe Gwinn

A once-per-rev index pulse is still ambiguous if the encoder goes thru more than one revolution in the travel range of the moving part, not an uncommon situation. A rotary encoder might well be geared up for higher resolution and accuracy.

"Absolute" generally connotes being able to sense absolute position even after a power outage during which movement occurred one way or another. The absolute encoder knows immediately where it is without having to hunt for an index, a fiducial mark or a limit sense condition.

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I would even go so far as to "always" . If it's not Absolute then it's only relative. :-) ...lew...

According to Don Foreman :

That may be so -- but I think that he may have been referring to the linear glass scales, which have one index pulse at one end, and quadrature encoding throughout the range.

I agree. And this makes it easy to recover from an interrupted CNC machining run.

Enjoy, DoN.

Yet many machine tools use incremental encoders with an index along with limit switches. To recover from lost position the machine will move each axis to the limit switch and then reverse direction until it senses the index. It works, but is slow. Looking at the price difference between absolute and incremental encoders it's easy to see why machine tool builders like the incremental encoders. ERS