The Wiggler

By Mike Rehmus

The Wiggler is a pointer that can be accurately and easily located on the centerline of the longitudinal axis of the spindle to which is attached.

Wigglers are used to indicate the axis of the spindle to which they are temporarily attached. In practice, with the spindle turning at about 1000 rpm, the probe is centered (described later) and then the user visually centers the workpiece under the spindle (or the reverse).

By carefully observing the relationship of the probe and the workpiece, the user can center the workpiece within one or two thousandths of an inch.

Wigglers usually come in a small kit with a body and four or five probes, each of which have a ball on one end that fits into a collet on the body. The collet can be tightened, adjusting the socket/ball fit so that the tool will work properly.

One of the probes is bent, with a relatively large ball on the end. This probe is to hold a dial indicator.

To use, pick a probe with an end appropriate to the indication required. If you want to pick up a scribed center mark on the workpiece, you would use the pointed probe.

Once you have the probe snapped into the body, tighten the collet until a fair amount of friction is felt. Do not lock the robe in the body.

Next mount the body in the spindle and center the probe with your fingers. Then start the spindle at about 1000 rpm (with your hands away from the business end of the Wiggler). You will probably observe that the probe is now spinning nearly horizontal (the collet is too loose) or it is spinning in a near-perfect and small circle along the spindle axis. Using an object like a pencil (ideal), press the pencil on the side of the probe down near the business end. Press in towards the spindle axis and you will observe several phenomena:

The probe will move to absolute center of the spindle.

2. It will be hard to move the probe off center with the pencil.

or

3. If the socket was too loose, the probe is now emulating a helicopter blade. If so, stop the spindle and tighten the collet more, reset the probe in the vertical position, start the spindle again. Repeat the previous alignment procedure.

Now that the probe is running aligned with the spindle, you can use it to align the workpiece or spindle to the proper location.

In practice, when aligning a center point, I find it useful to observe the sharp probe/workpiece relationship with a magnifying glass and from at least two locations 90 degrees apart. Sometimes I try to look at the relationship every 45 degrees or so. Done carefully, you can achieve an alignment within one or two thousandths of an inch.

The Wiggler has a couple of probes with balls on the end. These are used just like you would an edge-finder except these are not self-resetting. That is, when you touch the workpiece with these probles, them start emulating a helicopter blade. Still, they are quite useful and if you have a Wiggler, you don't need to also purchase an Edge Finder too. The smaller ball, at 0.100" diameter can get into smaller places than the other 0.200" ball.

When using the bent probe to hold an indicator, the socket has to be locked rigid.


Email: Mike Rehmus

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Created: 12/08/99
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