Electronic edge finders

[kmanuele]

I see these for sale in various places. How do they work?

Are they any better than the traditional wobbly ones?

thx

K

 

[RJSakowski]

The "wobbly" edge finders and the wiggler edge finders both are independent of spindle runout. Most of the inexpensive electronic edge finders are not.

The taster type electronic edge finders usually have an adjustment for aligning with the spindle axis but they must be clocked to the spindle in order to retain that alignment. They should be directly mounted in the spindle using an end mill holder rather than using a drill chuck or a collet for best accuracy.

I use the wobbly kind and can quickly and repeatably locate an edge to +/= .0001".

 

[alloy]

Where I used to work the boss bought all of us the electronic edge finders. Withing a few days all 6 of us switched bck to wobbly edge finders.

 

[snoopdog]

6 to one, half dozen to the other.

 

[Inferno]

I have a wobbly and I have electronics. I use the electronic and have as goo repeatability as possible on my machine.
They work by just completing a circuit between the part and the finder. The shank on the finder is insulated from the ball so when the circuit completes you hear a tone and see a light.

 

[BGHansen]

The electronic ones need a material that's conductive; aluminum, steel, brass, copper, etc. (won't work on plastic or wood). The ones I have are metric with a 20 mm shaft, 10 mm ball. I bought a couple of 20 mm R8 collets that are dedicated to the electronic finders. I have DRO's on both mills and usually work in English units, but it's easy to switch to metric if using the electronic ones (or try to remember that 5 mm is 0.19685").

I use a mechanical edge finder 99% of the time. Not because I'm deathly afraid of spindle runout (if it's greater than 0.002" I've got other issues), it's what I'm used to. My mill work is done on a Bridgeport with an ER collet chuck. Most of my work involves using either a 3/8" or 1/2" collet. Out of laziness, I have edge finders in both diameters to save me from changing ER collets.

I use an electronic probe most of the time on my Tormach CNC mill, but also have a 3D taster (Haimer). The Tormach's original owner had an electronic edge finder, but I've never used it.

Bruce

 

[Boswell]

On my PM45M-CNC, I use an electronic LED touch thing to set the Z when I change tools as Bruce says, it will not work on non-conductive material. I also use an electronic PROBE to find edges. Seems to work very well. Other than the time that I crashed it and bent the feeler . Fortunately it was easy to replace.

 

[kmanuele]

I have a wobbly and I have electronics. I use the electronic and have as goo repeatability as possible on my machine.
They work by just completing a circuit between the part and the finder. The shank on the finder is insulated from the ball so when the circuit completes you hear a tone and see a light.

Ok, completing a circuit. Got it.

You can over-travel a wobbly quite a bit without damage. Is there some play at the ball end on these things?

 

[Inferno]

Ok, completing a circuit. Got it.

You can over-travel a wobbly quite a bit without damage. Is there some play at the ball end on these things?

Yes, the ball is attached with a spring. It resets into a beveled tube by itself.