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Old 12-04-2018, 09:33 PM
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Default Edge/Center Finders

Looking at edge/center finders for the new to me mill. There a different styles. I know nothing about them as to which type is best.

Thinking about getting one like this. Comments?????
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Old 12-04-2018, 10:09 PM
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I got a set of those, but often use a thin piece of paper instead.
Something I find far more useful is a co-axial indicator
Pay no attention to ra-ra American made blah blah accuracy nonsense. These things are not for accuracy, they are for centering, and as they rotate you move the cross slides to find the spot where there is the least wiggle of the needle. You don't measure with them.
They are useful on a mill and held in a tailstock chuck are useful in a lathe as well.
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Old 12-04-2018, 10:14 PM
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I use masking tape, close enough for me.
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Old 12-04-2018, 10:38 PM
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Quote:
Originally Posted by Ironman View Post
I got a set of those, but often use a thin piece of paper instead.
Quote:
Originally Posted by digr View Post
I use masking tape, close enough for me.
If you want to be fancy about it you can spend your money on Starrett precision paper or Brown & Sharpe machinist tape.
Stay away from imports like Mitutoyo. Rice paper shreds into dangerous slivers bamboo is too stringy.
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Old 12-04-2018, 10:41 PM
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I use masking tape, close enough for me.
Do you mean instead of a thin piece of paper?
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Old 12-04-2018, 10:50 PM
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Are we all done?
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Old 12-04-2018, 10:58 PM
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I use the tape it sticks to the part
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Old 12-04-2018, 11:58 PM
Rob65 Rob65 is offline
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Chris, for finding punch marks and lines etc I use a pin.

A trick taught to me when an apprentice is put a piece of plasticine, blu tak , chewing gum or whatever on the cutter and stick a taylor’s pin to it. Run the mill at a couple of hundred rpm and true the end of the pin up by pushing it with the back of your thumb nail. Don’t worry about the head of the pin, it’s only the tip that needs to run true.

Once its running true you can use a jewellers eye glass (loop) to line it up with marks. It’s plenty accurate enough for most things quite easy to get within a few thou like this with the right eye glass.

Not sure the health and safety nazi’s would like this in a work place now but this was in the early 1980,s and I still have all my fingers For working at home it’s your risk.

To me it’s easy, quick, accurate & cheep, what’s not to like?

As others have said, use a piece of paper to find edges.

Different papers have different thickness but if you are working to any accuracy you will have callipers or a mic to hand so easy to measure if that degree of accuracy is really necessary.

For me the most important accessory to have for a mill is a sharpie marker pen. Use it for marking out, then scribe lines through it (like dyechem),put a mark on the work piece and touch down until the cutter scratches it to pickup surfaces and also without a DRO use it to mark the dials so you can keep track of where you are relative to the reference faces of the work piece.

Expensive high tech is all well and good but for hobby use the old tricks are usually plenty accurate enough in skilled hands, which I’m sure yours will become with a little practice.

Enjoy your new toy.

Rob


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  #9  
Old 12-06-2018, 12:07 AM
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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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Old 12-06-2018, 04:05 AM
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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.
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