- Joined
- Jul 29, 2014
- Messages
- 2,728
I normally use the cylindrical type of edge finder that kicks off center at some kind of fuzzy point. I have always been suspicious of this device, without evidence however. Every time i’ve checked for repeatability, it does ok, so I use it. If I did not have a DRO I am pretty sure I would not like the 0.100” offset compensation. And my eyeballs have to get closer to metal parts than I like.
But Joe Pie on Youtube showed a really clever device (see the photo). It has a 3/4” shank, and one face is exactly on the shank centerline.
The other three faces are exactly 0.500 away from center. This allows a few features, but mainly I like that you can move the work up to this, feel the self alignment, and get a good feeling that this is actually the edge. I made an attachment awhile ago for my vise that makes it easy to align on the fixed jaw with this tool, rotate it 90 degrees and pick up the x axis as well.
However, in the making of this, some inexplicable tragedy occurred and the main face was exactly 0.020 too deep. Rather than scrap and start over. I bored out and pressed in a 0.75” diameter plug and machined that off to the, this time, correct depth. Trying it out, I was either spot on with the rotary edge finder, or at most 0.001 off. I have more confidence in this new one I think.
The picture makes it look like a poor finish, but it is quite smooth really. Really.
Or, Joe sells them for around $40.
But Joe Pie on Youtube showed a really clever device (see the photo). It has a 3/4” shank, and one face is exactly on the shank centerline.
The other three faces are exactly 0.500 away from center. This allows a few features, but mainly I like that you can move the work up to this, feel the self alignment, and get a good feeling that this is actually the edge. I made an attachment awhile ago for my vise that makes it easy to align on the fixed jaw with this tool, rotate it 90 degrees and pick up the x axis as well.
However, in the making of this, some inexplicable tragedy occurred and the main face was exactly 0.020 too deep. Rather than scrap and start over. I bored out and pressed in a 0.75” diameter plug and machined that off to the, this time, correct depth. Trying it out, I was either spot on with the rotary edge finder, or at most 0.001 off. I have more confidence in this new one I think.
The picture makes it look like a poor finish, but it is quite smooth really. Really.
Or, Joe sells them for around $40.