Shop Floor Talk

Shop Floor Talk (https://www.shopfloortalk.com/forums/index.php)
-   Machining (https://www.shopfloortalk.com/forums/forumdisplay.php?f=21)
-   -   Edge/Center Finders (https://www.shopfloortalk.com/forums/showthread.php?t=50255)

milomilo 12-05-2018 10:36 AM

Quote:

Originally Posted by Ironman (Post 725918)
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.

I like the coaxial for finding the center of rounds.

Quote:

Originally Posted by GWIZ (Post 725927)
Yes, single end, 3/8" shank, 0.200 tip is what I use all the time.


https://www.shopfloortalk.com/forums...40&postcount=4

Double ended ones do not hold very well in drill chucks so I don't recommend them, (shanks are ground just a little smaller so the chuck clamps on the larger diameter of the tip) .


That is the size I was looking at.

Quote:

Originally Posted by Rob65 (Post 725928)
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


Sent from my iPhone using ShopFloorTalk mobile app


I do use the pin system in my drill press, as well as the sharpie. Think I will make one just for the mill.

Quote:

Originally Posted by LKeithR (Post 725929)
I prefer single ended style but in 1/2" diam., not with the reduced tip diam. The larger diam. seems to wait just a second longer before popping and therefore I think I get a slightly more precise location. Very rarely do I have need of anything else. And if you're using an edgefinder be aware that you can't run them too fast--I usually limit mine to 700-800 rpm. If you go faster the centrifugal force of the tip when it's offset will overcome the strength of the spring that holds it and in an instant the tip is going whackety, whackety, whackety against the vise or the workpiece and it's instant scrap. You'll try to avoid it and most of the time you'll remember to check the speed before powering up the spindle but if you use an edgefinder much you will eventually waste one. I know because I several in a drawer in my toolbox.

As for papers just grab a pack of cigarette paper. They average between .001" to .0015" in thickness which is plenty close enough for most of what I do. If I'm starting from scratch I'll usually use an edgefinder but I occasionally run into a situation where I've already got a tool in the spindle and I need to find an edge--it's real simple to grab a cigarette paper and run the tool up against it--drill, endmill, counter bore; it doesn't matter. I usually turn the speed up a bit; seems to make for a little more precise location.

A co-ax indicator is a great tool but it's no good for finding edges. It is, however, the slickest thing ever for finding the centre of a bore or locating the centre of any round feature on a part. I wouldn't be without one...

I need to remember to look for cigarette papers.

midmosandblasting 12-05-2018 12:06 PM

Your local head shop . Most drive through booze stores ,Even Wally carries them . All for other purpose or rather a different kind of smoke .

threepiece 12-05-2018 12:30 PM

1 Attachment(s)
I have recently started using the one pictured below and I like it. It has a small flat ground on the surface as you can see. It starts to make a clicking sound as it comes in contact with the work, this is a warning that you are about to reach your destination.

It also has better repeatability, that is to say it pops out closer to the same place than the smooth type I used to use. This is a good tool to have for short production of parts that have no means for locating as the clicking sound makes finding the edge faster than the smooth type.

JH35 12-05-2018 02:16 PM

Quote:

Originally Posted by GWIZ (Post 725927)
Yes, single end, 3/8" shank, 0.200 tip is what I use all the time.

https://www.shopfloortalk.com/forums...40&postcount=4

Double ended ones do not hold very well in drill chucks so I don't recommend them, (shanks are ground just a little smaller so the chuck clamps on the larger diameter of the tip) .

Same here. Sometimes a piece of paper, sometimes just touch off on the part depending on what is needed. Indicator to line up on a hole or round part.

1200 RPM or so BTW. they explode at 5000 plus:D I know.

Jeff

edit. May not have been 5000. may have been 10,000. its been a long time and I do not recommend it.

LKeithR 12-05-2018 04:13 PM

Quote:

Originally Posted by threepiece (Post 725956)
...It also has better repeatability, that is to say it pops out closer to the same place than the smooth type I used to use...

That's interesting--never seen one like that before. Guess I'll have to see if I can find one and try it out. I definitely prefer the larger .500" edgefinders to the smaller .200". I've always found them to be more consistent

Quote:

Originally Posted by JH35 (Post 725962)
...1200 RPM or so BTW. they explode at 5000 plus:D I know...

I seriously doubt that you can run one up to that speed without it coming apart. All the ones that I have used come apart at slower speeds than that. I normally run at 700-800 rpm...you don't need any more than that to get accurate readings. The edgefinders with the smaller tips may tolerate higher rpms--I've never run one to destruction.

Chris should buy several and perform a little experiment; just to see how much speed they'll take. It would be good info for the rest of us...:devil:

I think we also need to consider that, in the long run, just about anything will work fine for Chris on this machine. It is just a drill/mill; it's never going to have the accuracy of a decent Bridgeport or clone...

Ironman 12-05-2018 04:30 PM

Ok, let's kick the football into the herd of cows:D
What is everyone's opinion of the electronic edge finders?

LKeithR 12-05-2018 08:24 PM

Quote:

Originally Posted by Ironman (Post 725967)
...What is everyone's opinion of the electronic edge finders?

I don't know--never used one. They may be a little more accurate and a little faster but whether that's an advantage for a little job shop or home shop is a good question. I'd have to say, from my perspective anyway, that they're more gimmick than anything else...

milomilo 12-05-2018 08:37 PM

What about the laser style finders?

digr 12-05-2018 09:09 PM

1 Attachment(s)
I have a two piece set that I some times use, that should be all you need one for edge and one for center finding. Unless you are sub contracting for NASA

milomilo 12-05-2018 11:19 PM

Quote:

Originally Posted by digr (Post 725980)
I have a two piece set that I some times use, that should be all you need one for edge and one for center finding. Unless you are sub contracting for NASA

No NASA stuff in my shop.:D


All times are GMT -5. The time now is 05:51 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.