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 12-04-2018 09:33 PM

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?????

Ironman 12-04-2018 10:09 PM

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.

digr 12-04-2018 10:14 PM

I use masking tape, close enough for me.

cutter 12-04-2018 10:38 PM

Quote:

Originally Posted by Ironman (Post 725918)
I got a set of those, but often use a thin piece of paper instead.

Quote:

Originally Posted by digr (Post 725920)
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.

milomilo 12-04-2018 10:41 PM

Quote:

Originally Posted by digr (Post 725920)
I use masking tape, close enough for me.

Do you mean instead of a thin piece of paper?

milomilo 12-04-2018 10:50 PM

Are we all done?

digr 12-04-2018 10:58 PM

I use the tape it sticks to the part

GWIZ 12-04-2018 11:43 PM

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) .

Rob65 12-04-2018 11:58 PM

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

LKeithR 12-05-2018 12:15 AM

Quote:

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

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) .

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...

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

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.


Sent from my iPhone using ShopFloorTalk mobile app

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.:)

Farmersamm 12-07-2018 10:07 AM

https://www.grainger.com/product/STA...nder-Set-5UAR7

Actually :D , deflection, and lead screw inaccuracy, will mostly make all your precision edge finding an exercise in futility :D

One way around it is to have a DRO, or use the poor man's DRO.....pancake dial indicator, or something equivalent.

I've always maintained that welding fabrication takes skill.....machining just takes a bottomless wallet :D:p:devil:

milomilo 12-07-2018 09:36 PM

Speaking of the wallet, I just got a 20 piece set of 1/8" parallels at HF today. Used my 25% coupon so ended up paying $26. I expect the bleeding will not stop in the near future.:(

terry lingle 12-07-2018 09:51 PM

No it will only get worse until you have enough mill bling that you realize you need a ....... better mill. Then the cycle starts again :devil:

milomilo 12-07-2018 10:05 PM

Quote:

Originally Posted by terry lingle (Post 726118)
No it will only get worse until you have enough mill bling that you realize you need a ....... better mill. Then the cycle starts again :devil:

So what mill are eyeing for the future?

LKeithR 12-07-2018 10:09 PM

Quote:

Originally Posted by terry lingle (Post 726118)
No it will only get worse until you have enough mill bling that you realize you need a ....... better mill. Then the cycle starts again :devil:

Yeah, my thoughts exactly. A drill/mill is better than nothing but it's a far cry from a real mill. The upside is that there's very little tooling that you'd buy for the drill/mill that you wouldn't be able to use on a proper one so not a lot of waste.

Chris should allocate so much money from his monthly tooling budget to a fund he sets aside for the purchase of a real one. It's inevitable...:devil:

LKeithR 12-07-2018 10:20 PM

Quote:

Originally Posted by milomilo (Post 726120)
So what mill are eyeing for the future?

For us? Or for you? :D I have a First LC 18; a Taiwanese built Bridgeport clone that weighs about 1000 lbs. more than a real Bridgeport. Terry has a really nice, clean clone--probably Taiwanese but I'm not sure--that I helped him find about 5-6 years ago and Gerry has his (relatively) new to him Lagun FTV-3 which is also an awesome machine. We're all livin' the dream--and paying the price :eek:--but it's worth it in every way.

You bein' a proud and patriotic American and all the only machine for you is a prime condition genyouwine Bridgeport. I don't think you'd be happy with anything else. Time to pony up Chris...:D:D

terry lingle 12-07-2018 10:50 PM

Well every once in a while my thoughts stray to that new CNC mill we had a look at :D

milomilo 12-07-2018 11:25 PM

Quote:

Originally Posted by LKeithR (Post 726122)
For us? Or for you? :D I have a First LC 18; a Taiwanese built Bridgeport clone that weighs about 1000 lbs. more than a real Bridgeport. Terry has a really nice, clean clone--probably Taiwanese but I'm not sure--that I helped him find about 5-6 years ago and Gerry has his (relatively) new to him Lagun FTV-3 which is also an awesome machine. We're all livin' the dream--and paying the price :eek:--but it's worth it in every way.

You bein' a proud and patriotic American and all the only machine for you is a prime condition genyouwine Bridgeport. I don't think you'd be happy with anything else. Time to pony up Chris...:D:D

That was intended for Terry. I know you do not need another mill since you are retiring.:D

terry lingle 12-08-2018 01:29 AM

Truth is my shop has a 7ft 6 inch ceiling in it which puts a pretty hard limit on machine size.
I have had to get creative a couple of times to get enough travel range but a little thought and i get things done. If I was a full time machine shop the mill would definitely be larger.
All my machines and tooling have paid there bills and I am happy.

The first job I got for the mii put it in the black.
It was making arbors for an adjust on the fly edger. the shafts were about as long as I could cut in one pass and needed key ways 180 degrees apart. I made 5 of them along with the mounting to allow the entire saw set to be swapped out in about 5 minuets when they got dull. The edger was fast enough that it would easily catch up with the head saw if it needed to stop for a blade change.

69Z28Nut 12-08-2018 08:57 PM

Quote:

Originally Posted by milomilo (Post 725914)
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?????

I prefer this one by Starrett because one side can edge find on flat & round stock while the other end can center on punch marks.

https://www.grainger.com/product/STA...er_Also_Viewed

Your also going to need this one too because larger round stoch will limit the use of the other Edge Finder.

Edge Finder, Single, Cylindrical End Type, 0.5 Tip Dia. (In.)
Brand MITUTOYO
Item # 1ZRN6
Mfr. Model #050109


All times are GMT -5. The time now is 01:55 PM.

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