Fowler edge finder

[macardoso]

From where I was instructed by and old Journeyman machinist the youtube video above leaves a whole lot to be desired.

I'd love to learn more. That video was the first time I had ever seen a truly precision edge finding. Is the goal of the "chair" to hit both edges with the indicator until the reading is the same?

 

[higgite]

I got a Fisher audible edge finder last year and have been using it since.

I trust that it’s audible, but I can’t hear it with the mill running, so I rely on my eyeballs to tell me when it has found the edge. The DTI method in the video intrigued me, so I ran my own experiment on my bench mill with my edge finder vs my Mitutoyo DTI. The two readings were different by about the width of a tick mark on the X-axis dial, maybe .0002”. And it was repeatable. That’s closer than my machine can machine anyway and I don’t do production work, so I’m sticking with the Fisher edge finder until something cheaper, easier and faster comes along. Plus, I felt like the guy with two watches… which one is right? ymmv

Tom

Edit: Sorry for the large size of the pic. Maybe a moderator could shrink it a little?

 

[GunsOfNavarone]

So I didn't realize there were replies here. I knew 23a wouldn't work just by how much room was in the edge finder and it wasn't evenly divided by the length of the 23a...but that's the only 12v I could find. 2 batteries leave about 1/2 of space, 3 batteries won't fit. Reading thread now....

 

[GunsOfNavarone]

I've got 2 of them. Both use 12V 23A batteries (same unit purchased yrs apart that came in different style cases) & both of mine came with batteries. They use only one. 23A batteries were commonly used in older automotive keyless entry & alarm remotes. Newer ones don't use 23A batteries anymore so not sure what else uses 23A batteries.

I'm surprised you are having trouble with the Mitutoyo. Although I use the Folwer one more often I have PEC conventional edge finders & I trust them more. The Fowler one I use a lot cause they're quick & good enough (accuracy) but mainly when I don't want to mar the finish of a finished part. Useless for non-conductive parts or when I'm using something to protect the parts when clamped. But a jumper takes care of the latter, I'll just use a scale to complete the circuit cause it's always around. I'll use a conventional anytime the accuracy is more important, they're more accurate than the Fowler/SPI.

There's 2 models that Fowler/SPI offer though. The other one is the break away ball tip type that costs more than double than the standard one. Not sure what battery those use though.


View attachment 308045

Mine is like this one....what is that piece with the resistor? Mine doesn't have that piece

 

[GunsOfNavarone]

GunsOfNavaron -
Though I can sympathize with you for having trouble with a traditional (spinning) edge finder, I gotta say that I still prefer it over any of the ones (like the electronic type) that don't involve spindle rotation. If the collet or chuck is a bit off, a non-rotating edge finder will be off by whatever error there is in the holding device. Suburban Tool has a neat video that demonstrates how accurately a spinning edge finder works, even when deliberately placed way off center:

Yeah the Mitutoyo just slowly move slowly to the side as I slowly turn the the x axis wheel. I was under the impression they just to side when edge is found. If it was when it centered itself.....that would be MUCH easier. I'm running about 780 rpm.

 

[darkzero]

Mine is like this one....what is that piece with the resistor? Mine doesn't have that piece

That is the "electronic" part of the edge finder. It's the module that contains the LED that lights up on contact. If your's doesn't have that you should return it for another.

 

[darkzero]

Mine is like this one....what is that piece with the resistor? Mine doesn't have that piece

Is it missing for sure or possibly just stuck inside the unit? No reason really for it to come out but mine does. Like can you see the red LED through the holes near the tip?

Edit: Well since you say a 23A battery is too short I suppose it really is missing on yours?

 

[Tinkertoy1941]

The rotating edge finders with an experienced Journeyman machinist can guarantee an accuracy of plus/minus of .0015 and that is not close enough for gage work. The small rotating diameter is on the edge just as the small diameter just moves off center and that depends on the skill of the operator!

The spindle being tramed "swept with an indicator to read .0000 in four directions) to the table is required to qualify to even get close to the +/- .0015 tolerance!

The chair method of finding an edge takes all the guess work out of finding an accurate edge!

 

[GunsOfNavarone]

Is it missing for sure or possibly just stuck inside the unit? No reason really for it to come out but mine does. Like can you see the red LED through the holes near the tip?

Edit: Well since you say a 23A battery is too short I suppose it really is missing on yours?

so yeah.....Mine is a hollow shell...nothing inside. I had Amazon credit the sale. Guess I'm gonna look for something else. Since the side kick version doesn't work for me, what would you all recommend that is easy to distinguish that you have found the edge of a work piece?

 

[darkzero]

so yeah.....Mine is a hollow shell...nothing inside. I had Amazon credit the sale. Guess I'm gonna look for something else. Since the side kick version doesn't work for me, what would you all recommend that is easy to distinguish that you have found the edge of a work piece?

Ah that sucks but at least Amazon took care of it. Sorry, if I may ask, did Amazon ask you to return it? If not, wanna sell me the empty shell?

Aside from a conventional edge finder & the chair method, another option is a wiggler. If your conventional is kicking out to the side, sounds like it's working fine. That's what they are supposed to do. Although some cheaper ones don't work that well if the sliding surfaces aren't lapped well (not expected from Mitutoyo) or is gummed up from old oil.

There are other options & methods for edge finding but are much more expensive (like a 3D- edge finder) or take longer (like a good ol DTI).