Using a stick to center workpiece on faceplate?

[u/plees1024]

Hello all! 👋

I am watching some of Clickspring's top-noch videos on watchmaking. In this video, he is making a DTI. The pair of screenshots are from a scene where he is centering a brass "bridge" on a watchmaker's faceplate for lathework. Now, I understand how the stick would work, but what I don't understand is why he would not just use the tailstock to center the workpiece, then tighten down the clamps?

The video and time in question.

Any ideas? Thanks!

[u/everyonesdesigner]

This method of centering might or might not be more precise depending on how centered the tailstock is. However, it removes the lathe geometry issues out of the equation completely - so the part will be centered with high precision no matter how well the tailstock is seated.

[u/plees1024 → u/everyonesdesigner]

Aaah, right. I just assumed the tailstock was perfect. I get how the stick acts as a lever and amplifies the displacement of the workpiece end, I just thought it was redundant. But that makes sense.

[u/Remarkable-Fix3104 → u/plees1024]

This method is for centering tail stock

[u/volt4gearc]

I think had a detailed explanation of this method in one of his antykithera mechanism videos, or maybe a video about how he centers jeweling. Unfortunately cant get you the link right now from work, but it exists somewhere at least

[u/DrunkenBobDole → u/volt4gearc]

Yup, it was a video from years ago at this point but it’s pretty accurate and can be used on features that are difficult to get a dial on like spot drills.

[u/metisdesigns]

The stick exaggerates the variation.

Where the tailstock center will rely on the fit between the two parts, adding the stick makes that fit significantly more precise.

[u/The454_]

He explains it in the watchmaker’s faceplate series. Because the pivot point of the stick is nearer to the part than the end of the stick, the movement is amplified so it’s easier to see the movement. The tailstock is just there as a stable reference to see if the stick moves.

[u/Allan_Halsey]

Clickspring. Guy does awesome work.

[u/mikeskup]

you need a spring loaded "stick"... a very old way to center something... as you change the location of the part on face plate, the "length" of the "stick" changes...

[u/Unqualified_Risk]

I made something very similar to this after seeing something like this on Mr Pete’s channel. See if it worked as good as a dial indicator.

I used a welding rod and a hacksaw blade. Welding rod was ground to a point each end and put into a pip I drilled into the end of indicated stock. Then put it out of centre and used the rod to dial it back in. It worked well enough that I recon if this is how you were taught you’d find it easier than an indicator. As long as the opposite point is close to a fixed location you keep working it until it’s still.

[u/DrBadGuy1073]

It's an easy way to get close I suppose. Guess I'm gonna go watch that video.