[BentRods]

Hi,
I've been digging around looking for edge finder's and touch probes for my gantry/mill and I came across this and the claim 1um accuracy Thebestedgefinder.com - Home

The spec's say there's an output for DRO's and probes this would be handy if 1um accuracy was needed,

I have no connection with these guys, just sharing what I thought was a neat affordable tool.

Bentrods

[aarggh]

For what is essentially a continuity tester with no mechanics or moving parts, in effect quite a simple device, I'd consider the price outrageously high. So far as the claimed 1um accuracy, using some wire and a metal connector you would get the exact same result. This video below is a very good example of a well implemented and almost free auto-zero setup, there's really not much too them as you can see:

Mach3 2010 Screenset Tool Change - YouTube

Another thing to note, as it's a simple continuity tester with a relay output for DRO's (which has a degree of latency and bounce I might add, a digital output using level shifted schottky circuitry would be much better and give nice clean signals!), think LED with two probes in series with the LED and battery, touching a conductive surface completes the circuit and the LED lights up, accuracy is only as good as your machine is rigid, and the level of machining quality of the cutter your using to set zero, and the precise repeatable positioning of the steppers. If you have 1um out of round on the cutter, that at the very least will be the error amount, although for practical reasons unless you have a fairly high quality machine, in practice it will quite likely be in the order of a thou or so (1 thou hopefully at most) generally.

I'm not saying it's bad or good, just in my opinion it's a very overpriced continuity tester.

cheers, Ian