Wigglers

[mklotz]

Wigglers are used to assist in the centering of work held in the 4jaw or faceplate. Typically, a long rod pivots off-center on a pivot point held in the tool holder. The short end of the rod goes in a hole-to-be-centered in the work. The long end points at a center held in the tailstock. As the work is rotated by hand its offset center makes the short end of the rod describe a circle. Because of the lever effect the long end then describes a much magnified circle around the TS center. Adjustments are made to null out the circling of the long end and this centers the work.

If you've just finished building a lathe ball turner, the top one is for you. The brass ball can be slid along the rod to change the magnification. The ball seats in a conical dpression in the hexagonal ring.

The bottom one is a somewhat different design but easier to build since no ball turning is required. Same principle but the magnification factor is fixed.

The one in the middle is my personal favorite. It's called a "pump" center. The male end goes in the work and the spring-loaded female end is supported by the tailstock center. A DI held in the tool holder bears on the portion of the rod close to the work and makes it trivial to center the work if you use my centering technique documented elsewhere.

[kbalch]

Thanks Marv! I've added your Wigglers to our Lathe Accessories category, as well as to your builder page: mklotz's Homemade Tools. Your receipt:

Wigglers by mklotz

tags: lathe, centering

[Toolmaker51]

Only 1 year, 8 months, 22 days [908,630 minutes] past-post. But good work doesn't disappear.

The pump center is an easy build, user friendly, and stores in a minimal space.
Also not particular to precise overall straightness as a gimbal or orbiting pointer.
Long as center drill on part and point of rod mate correctly, length negates relative error at tailstock. Closeness of indicator to part will generate nearly 100% of available sensitivity.

Certain indicating methods should be utilized for practice and a sense of "oh yeah, this works too".
Back in the day [waaay pre me even] wigglers, simple lever indicators
and toolmaker buttons were THE standards of precision setup.
Even center to center work evolved this way...long before the milling machine, jig bore. or anything with means to orientate a fully independent 3 axis coordinate.

And for readers, Marv's ball & socket wiggler corresponds to pictured lever indicator in what way...? Click the jpeg for a hint.

[mklotz]

I have a set of toolmaker's buttons inherited from the father of a (late) good friend. I think I set up one job with them just to demonstrate to myself the procedure, which, in retrospect, said procedure was a galloping PIA. Accurate, sure, but brings a new meaning to "fiddly".

I don't and probably never will do anything that requires accuracy beyond what I can get with an edge finder and DIs. Still, they make a great "bet you can't guess what these are for" display when folks tour my shop.

[Toolmaker51]

Yep, they can be fiddly. Mentor clued me in with depth mics, Jo blocks, and sometimes good magnets,
I use them rather often, when a pattern extends beyond axis of mill movement. Instead of losing travel indicating last hole, I tap for a button and dial it in after swinging or extending ram. The trick is a bent shim 'spring washer' under the hold-down screw. .010-.015 stainless is perfect.
Reminds me to post on tooling balls. Manner of projecting a position that way gives me a thrill.
I looked at your photo-bucket, wow...I ever get back home [Compton born, grew up in Lakewood/ Buena Park] I'd love tour of Garage Mahal.
Also need a clever more distinguished name for my 'cave'.