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-   -   Edge/Center Finders (https://www.shopfloortalk.com/forums/showthread.php?t=50255)

toprecycler 12-06-2018 12:07 AM

I usually just rip off a piece of paper from the notebook I am working for. My thinking is I check it with the calipers I tend to use, and usually is about .003. And then I can use what ever drill or cutter I have in the mill holder or chuck at the time. If I am trying to find the center of a round shaft to cut a key way, I will add both the cutter diameter and the size of the round stock together, and then decide by 2, to get the distance I have to move the table after I feel the cutter grab the paper. Depends on how much I tore the paper detriments if I add a an extra .001 or two to make up for the paper thickness. I guess if you use cigarettes papers, you need to sneak up more carefully in order it to leave a mark on the work. The .003 paper gives me a little cushion for moving too quickly.

And by using the paper saves time from switching out the edge finder and putting the cutter back in, too.

If you have a lot of runout in your spindle, you could check both sides of the work, to detrimine the true center of the shaft. The drill chuck that I put in the main mill at work has about .007 runout. I think it was crashed a time or two, so I don’t trust that one too much anymore.

Most of the work I do, I have tolerance of +- ,002 anyways, or more as I watch the other guys work.


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GWIZ 12-06-2018 04:05 AM

We have this tip on paper.

https://www.shopfloortalk.com/forums...02&postcount=7

bear in mind if the cutter grabs the paper from your fingers let the cutter have the paper, do not chase the paper with your fingers into the cutter.

Lew Hartswick 12-06-2018 10:46 AM

I've been using a 1/2" double end one for 25 years . Have yet to use the "pointy" end for anything . :-) Whatever you do DON'T get one of those that the moving part is black and the rest is shiny The ones we have at school have a flat on the .2 dia "so-called" click or audible, it is difficult/to/impossible to see the kick and with anything running to hear the click .
...lew...

USMCPOP 12-06-2018 04:30 PM

1 Attachment(s)
Quote:

Originally Posted by Ironman (Post 725967)
Ok, let's kick the football into the herd of cows:D
What is everyone's opinion of the electronic edge finders?

Not sure if a Renishaw probe qualifies as an edge finder or not. But they aren't all that durable on a Monday morning before the coffee kicks in. But they're readily available for $3,500. or so.

Fisher Machine has some nice edge finders. Available from various sources. Made in USA by a family company. I bought one some years ago direct from the company and requested a catalog. It came with a hand-written note from the (second-generation) owner. They also make sine bars and Pee-Dee wires.

http://www.penntoolco.com/fisher-edg...-edge-finders/

The Herman Schmidt edge finders were highly regarded, but the semi-retired guy who made them finally retired some years ago (I called ...). They considered outsourcing them, possibly including Fisher, but stopped selling them. Schmidt makes high $ stuff. They have a nice little machinist vise (Length: 2 7⁄8” x Width: 1 1⁄2” x Height: 1 1⁄4”) for $500 or so. They used to have a matched set of six 1x2x3 blocks for about $900. https://www.hschmidt.com/

rmack898 12-06-2018 05:43 PM

I've had a few different edge finders and they were OK. An old machinist I knew was a really cheap bastard that always looked for a way to save a buck. I was in his shop one day and noticed he had a Herman Schmidt edge finder. I asked him why a cheap SOB like him would spend so much money for an edge finder and he said once you use it, you'll know why.

I don't remember how much I paid for it but I bought a Herman Schmidt edge finder and it was worth it.

I still keep rolling papers in my tool box for use in set ups.

Paychk 12-06-2018 08:12 PM

https://www.youtube.com/watch?v=bga7y4infIo

USMCPOP 12-06-2018 08:14 PM

Quote:

Originally Posted by rmack898 (Post 726018)
... I don't remember how much I paid for it but I bought a Herman Schmidt edge finder and it was worth it....

I like a guy who knows good Schmidt when he sees it.

Farmersamm 12-06-2018 10:11 PM

Coax good if you want rough, fast, center inside or outside tubing/round stock.

Cylindrical very accurate for either an edge, or center of round stock or tubing. Some have a flat for audible use.

Wiggler, if a GOOD one (I spent the bucks for US made Starrett), is also very good for edge, or cylindrical. Reaches into tubing better. Does a very nice job locating center punch marks. Probably one of the best all around tools. A good one doesn't wobble once it's centered with your finger. Should be absolutely straight with no runout.

To find center of circle with edge finder...…….

Set your dial at 0 when you touch the first side (this side can be anywhere inside the circle, or outside the circle). Crank the handle till you hit the other side. Take the total travel, and divide by 2. Crank back to the halfway mark per your calc's. Then repeat for the other axis. Now you're as dead center as your lead screw is accurate.

Solid stock is done same way, just crank the knee down before ya go to the other side, or not :D;):D

MetalWolf 12-06-2018 10:35 PM

I have several okay well a bunch of Starrett indicators and found them to be no more accurate than my cheaply made indicators....
:mad:
:mad:
:eek:
:eek:
:eek:

But then I was shown yesterday that its not my Starrett indicators that are or were the problem.... but the chinezeum holders I was using them on were where the issue lay.... my Starrett wiggler did not come with the accessories so I bought the chinezeum replacement needles/attachments they affected it badly so now I'm in search of used bases, accessories and holders for my Starrett measuring and indicating tools

But heck what the hell do I know about machining tools... Not squat :o :(
although I like to think I know a good price deal when I see one but that might be questionable too... being I've bought a bunch of tooling I'll prolly never use...;)

Although I do have a laser center finder I'm told its not precision but for general purpose drilling it works just fine.... and its not too expensive

milomilo 12-06-2018 10:54 PM

Quote:

Originally Posted by GWIZ (Post 725992)
We have this tip on paper.

https://www.shopfloortalk.com/forums...02&postcount=7

bear in mind if the cutter grabs the paper from your fingers let the cutter have the paper, do not chase the paper with your fingers into the cutter.

I have a few old phone books.:)


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