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goodscrap
12-31-2012, 07:42 AM
I've had a wiggler in my toolbox for about 5 years and today i thought i'd give it a try, so I watched a utube clip or two.

I put the wiggler in my drill chuck on the milling machine moved the table and no surprise it works as expected, however, and here is my question, the drill chuck has quite a bit of run-out, say about 10 thousand's - will this affect the wiggler's accuracy or will it still pick up on the spindle centreline?

excuse me if this sounds a dumb question, i'm having a thick day....

Cheers
Brian

jcon
12-31-2012, 08:07 AM
Brian:

It should work fine, the ball on the shank will run true to the spindal no mater how the shank runs. My experance with wigglers is if you get it too closre to the edge it will jump off and damage the shank.

Jim Connell, DeLand FL.
Daytona Beach is near us.

You haven’t begun learn until to learn until you learn how little you know.

DATo
12-31-2012, 08:17 AM
This assumes you are talking about a wiggler "point" as opposed to edge finder ball end.

I use a wiggler from time to time. If used properly the wiggler "averages out" the error in concentricity of a chuck. To put it another way: When the tip of the wiggler is adjusted such that it is running dead true the point of the wiggler describes the centerline of the shank of the drill chuck, or for that matter the spindle of the machine, without regard to the runout of the chuck. So, to illustrate, if you then took the wiggler out and replaced it in the chuck with a perfectly centered scriber point and brought the scriber point down to the workpiece in theory the point would scribe a circle (in your case with a .010 diameter) around the exact center point of the spindle as a result of the runout. This would be the "true" centerline of the machine.

When used with a vernier height gage to scribe the lines and a magnifying glass one can achieve amazingly accurate results. An example of a situation in which a wiggler would be helpful would be to locate a point previously scribed on an angular or radius surface of a workpiece which could not be accurately located with an edge finder.

Imagine you have a point located with accurately placed scribe lines (vernier height gage). You are doing this because for one reason or another an edge finder is impractical. Then, after getting the wiggler running true and close to the workpiece you sight down the Y axis and adjust the X axis of the mill while looking through a magnifying glass till the wiggler point is directly over the line running north and south, then repeat this for the other axis by sighting down the X axis and adjusting the table along the Y. Once I am convinced that I am very close to center I bring the point of the wiggler down and just barely touch the workpiece. This usually shows a dot centered exactly at the point that the X and Y scribed lines cross.

Hope this is not too confusing and will be of help to you.

goodscrap
12-31-2012, 08:58 AM
Thanks for the replies so far, to clarify, at the moment my use is just finding the edge of the workpiece, using a 0.200" ball type end, though it isn't a true ball, it has a band in the centre about 40 thousandths wide that is parallel at 0.200" diameter.

i just used it in the drill chuck to see how it worked, and was curious if the run-out of the chuck would affect the accuracy of finding the edge of the workpiece.

DATo, I've not progressed to trying to use it to work to scribed lines, i'll bear that possibility in mind.

Brian

gbritnell
12-31-2012, 09:00 AM
I have a couple of the old 'wiggler' sets from Starrrett. They include the point, ball, small disc and indicator holder. When I served my apprenticeship these are what I was taught to use. I have since purchased a couple of the cylindrical type edge finders but in comparing I don't find that they are any more accurate than the old ball or disc type. I was also taught the old chunk of modeling clay/plasticine trick. Take a piece, form it into a cone shape, stick it onto your endmill or chuck, turn on the spindle and insert a small pointed rod. Back in the day the old timers used metal phonograph needles. It works great and takes up less head space than a full sized wiggler.
gbritnell

vpt
12-31-2012, 09:42 AM
Wigglers work great for catching bluegils, perch, and crappies! Way better than waxies.

sasquatch
12-31-2012, 09:50 AM
I thought we were going to have a discussion about "Exotic " dancers!:rolleyes:

Forrest Addy
12-31-2012, 09:51 AM
Yup. Un-reconstructed dinosaur here. Got a touch probe that sits in its box while I noodle around with a wiggler.

I had the same question when I was an apprentice fresh caught to the mills. Don Herman, one of my old mentors, set up a wiggler in a drill chuck with a popsicle stick under one jaw. The wiggler wobbled like crazy but it located edges as reliably as if it was held in a collet.

The disk or ball end of the wiggler is in a universe of its own centered on the spindle AXIS. Chuck or tooling run-out plays no part if the wiggler is first centered properly. The wiggler body can gyrate around like it's slinging hula-hoops but the contact end will still reliably "kick" if over-centered a few tenths of a thousandths.

Trust it. A wiggler is reliable as hell for edge location to +/- 0.0002" maybe closer.

goodscrap
12-31-2012, 10:05 AM
Brilliant, thanks all

forrest thanks for the detail, i had though about trying to proove it to myself, but putting the shank in a boring head, some way off centre to see if i ended up getting the same result on the machine dials, but you've answered my question in a nut shell

Cheers
Brian

loply
12-31-2012, 10:57 AM
I have both a Starrett wiggler and one of the 'center finder' probes with a cone on one end and a straight shank on the other end, what's the consensus on which is best for edge finding?

I tend to use the 'center finder' type for edge finding as the wiggler invariably seizes up it's little ball joint chuck, requiring pliers to release it and change out the tip. Tried oiling it.

loose nut
12-31-2012, 11:23 AM
Trust it. A wiggler is reliable as hell for edge location to +/- 0.0002" maybe closer.

That depends on the individual doesn't it.

I have machinist friends that say they can't be trusted to more them 1 or 2 thou. I figure that the wiggler can do it but some people don't have the reaction time to stop turning the handle fast enough to get tenths accuracy.

bborr01
12-31-2012, 11:40 AM
Yup. Un-reconstructed dinosaur here. Got a touch probe that sits in its box while I noodle around with a wiggler.

I had the same question when I was an apprentice fresh caught to the mills. Don Herman, one of my old mentors, set up a wiggler in a drill chuck with a popsicle stick under one jaw. The wiggler wobbled like crazy but it located edges as reliably as if it was held in a collet.

The disk or ball end of the wiggler is in a universe of its own centered on the spindle AXIS. Chuck or tooling run-out plays no part if the wiggler is first centered properly. The wiggler body can gyrate around like it's slinging hula-hoops but the contact end will still reliably "kick" if over-centered a few tenths of a thousandths.

Trust it. A wiggler is reliable as hell for edge location to +/- 0.0002" maybe closer.

Forrest,

I have read lots of your posts and respect your opinion but I do have to question the +/- .0002 with a wiggler. Did you mean .002. That would seem a lot more realistic.

Brian

Stu
12-31-2012, 01:22 PM
Just a quick question, how tight should the shaft be held in the body of the wiggler? Mine is set pretty loose, but still seems to work. fine

Stu

Forrest Addy
12-31-2012, 02:54 PM
I figured challenges would follow as soon as I wrote all those zeros. 0.0002" sensitivity on a wiggler? Do-able if you exercise due diligence but you can't do it right out of the box. You have to practice a little and experiment with your tooling.

Exercise the wiggler first. Apply a little oil to the socket and ball, adjust the tension, chuck it up, spin the wiggler to 500 RPM or so, deflect the wiggler with a hooked finger and hold it until the friction smooths up - say a minute or so.

RPM is important. 200 to 1000 maybe but YMMV. Too slow and you over-run the wiggler's sensitivity. Too fast and and the first motion is over in an instant.

OK Use the wiggler in normal fashion but learn its readings. When you set it for edge-finding adjust it imperfectly so the little ball or disk has 1/64 runout. When this runout steadies you are close to "kicking". Watch cosely as you move the axis. The wiggler will show "contact" where your deliberate run-out disappears then "first motion" where the wiggler begins to kick sideways but is stable more or less. A few "tenths" more and the wiggler kicks out sideways and has to be re-set.

The first motion may be smooth or jerky depending on surface of the work, presence of a little lube, beards of magnetic swarf (the wiggler is steel and the last few magentic flinders are hard to elimnate) the material, etc.

If you're looking for 0.0002" wiggler indication you will have to be careful of variables (wiggler constancy and operational cleanliness) and your sneak-up technique. Also remember a wiggler takes a little force to operate and because it's made of metal it acts like rubber - the force of operation deflects it an important trifle making the contact dia apparently larger.

If you are looking for accurate edge finding you will have to "calibrate" your technique - that is wiggle an edge then tram it with a DTI and slip. The error should be consistant within a couple tenths but you will have to determine the "fudge factor" - the amount to add or subtract from the wiggler setting to center the spindle axis on the edge you are addressing. The correction may not be precisely the current DRO reading plus (or minus) half the wiggler tip dia.

chucketn
12-31-2012, 03:35 PM
How about a video demonstrating the finer points and maybe a few no-nos?
I have a wiggler set but only use the needle point and then only to find a punch mark or scribed intersection. Never have used it to find an edge.

Chuck

bborr01
12-31-2012, 06:11 PM
Forrest,

My misunderstanding. I was getting a vision of someone trying to pick up a scribed line within .0002 using a pointed wiggler. I have the other type of wiggler like you talk about and have never used it. I still do think that .0002 is a stretch but I haven't tried it so I don't know for sure.

Brian

Ron of Va
12-31-2012, 07:04 PM
I have both a Starrett wiggler and one of the 'center finder' probes with a cone on one end and a straight shank on the other end, what's the consensus on which is best for edge finding?

I tend to use the 'center finder' type for edge finding as the wiggler invariably seizes up it's little ball joint chuck, requiring pliers to release it and change out the tip. Tried oiling it.

Not completely sure what you are saying, but if you are using the pointy one to find an edge, that one is used for finding the center of a punch mark and is used when the machine is not running. You are supposed to feel the alignment with your fingers.

The one with straight shaft is for edge finding with the machine running.

uncle pete
12-31-2012, 07:52 PM
And maybe a couple of more points? I'd never question Forrest's posts as he's forgotten more than I'll ever learn. But I started out with a couple of cheap wigglers. For at least myself, I couldn't make them work consistently enough to trust them. I found out the the two surfaces of the movable tip and the shanks end that the tip slides on have to be very well made and lapped ultra smooth. Any roughness at all and they just won't work as well or be at all as consistent as they should. And I also figured out they need to be lubed once in awhile with some instrument oil. Even 3n1 works fine.

While I haven't tested it yet, I'd almost bet I could get within half a thou or less with some Zig-Zag cigarette rolling papers used for edge finding. I still use those sometimes since there's no need to pull a tool out of a collet and their dirt cheap, and they also work with the tooling in a lathe.

Pete

willmac
01-01-2013, 07:32 AM
I'm getting a bit confused. That's not hard to do, but it could be that I'm not alone. A wiggler to me is different to an edge finder. Certainly you can edge find with a wiggler, but why would you when an edge finder does it much better (for me anyway). You should be able to find edges reliably and consistently with an edge finder easily to less than a thou

Ron of Va
01-01-2013, 08:18 AM
I'm getting a bit confused. That's not hard to do, but it could be that I'm not alone. A wiggler to me is different to an edge finder. Certainly you can edge find with a wiggler, but why would you when an edge finder does it much better (for me anyway). You should be able to find edges reliably and consistently with an edge finder easily to less than a thou
Now that you mention it, it can be confusing. I am

A wiggler/center finder can be used to either find an edge or the center of a punch mark depending on which tip you use.
http://www.youtube.com/watch?v=RhtBdar4iVg and is used in either a static or dynamic state.

An edge finder can be used to find an edge while the machine is running (dynamic) and you watch for the kick out. Some of them come with a center finder end (cone) which is to be used in a static state.
http://www.starrett.com/metrology/metrology-products/precision-measuring-tools/machinists-precision-shop-tools/Edge-And-Center-Finders#itemsPerPage=24&currentPage=1&displayMode=grid&sortBy=none/asc