Custom Tool. Self Centering Caliper

[badluckleather]

I know of only two people of these and they are being stingy with identifying their maker. Anyone know of someone with the skills to make them?

[Art]

What does this do that other tools won't?

Art

[badluckleather]

I guess for example if you needed to make an exact center line all the way down a belt. Essentially a quick accurate "fancy" way of finding center.

[TinkerTailor]

I can't see how it would work, Changing sizes will change the vertical relationship of the outside legs to the center, meaning that the point in the middle will stick out at wide settings and be recessed at narrow ones, unless it also slides in and out. If it slides, i can't see how the linkage would be tight enough to be accurate.

Seams like a tool designed to separate a fool from his money...Any dividers will do what this does. that

Sometimes obscure things are that way for a reason....

[badluckleather]

Touché Tinker. I do know that the mid point will maintain its proper relationship. Point recieved on the linkage. Maybe my Raven mind got the best of me.

I can't see how it would work, Changing sizes will change the vertical relationship of the outside legs to the center, meaning that the point in the middle will stick out at wide settings and be recessed at narrow ones, unless it also slides in and out. If it slides, i can't see how the linkage would be tight enough to be accurate.

Seams like a tool designed to separate a fool from his money...Any dividers will do what this does. that

Sometimes obscure things are that way for a reason....

[TinkerTailor]

I thought about it some, and assuming the points stay inline with each other, and the pivots are tight and accurate, I can see 2 uses for it:

1. On a belt that changes width, but is symmetrical, this tool would allow making a center line on it. A divider can't do this. You need to make a couple center marks with them and then use a ruler for the line. This could be done in one step with this tool as long as the width of the caliper is constantly adjusted to the current belt width as you slide along and the calipers are kept 90 degrees to the edges. Tilting the caliper wouldn't matter here.
2. To find center of anything with straight parallel edges, you can set the tool to any width wider than the strap, and as long as the outside tips are on the sides, the middle is in the center. This will only work if the points are parallel. If you have to tip it to get the center to touch, it throws off the measurement. The caliper can be at an angle to the work in relation to the edges (one side ahead of the other), but it must be vertical. There are other types of tool that do this the same way, and are easy to make. No complex geometry. Timber-framers have been making on site tools for this for centuries.

Edited January 27, 2016 by TinkerTailor

[TinkerTailor]

To make a simple one, take a straight stick of wood, use your dividers to make 3 evenly spaced marks in the stick, and drive a nail into each mark so it sticks out the other side. Make the center one not as deep as the rest so the point is just protruding the other side. Trim the points of the other two and leave them a little longer. Any time you place it on something with parallel sides, and both outside points are against the edge, the middle will be centered provided you drove the nails straight..... Drag it along for a center line.

That is one way it is done for woodwork, the concept is easy to adapt for leather.

[dbusarow]

To make a simple one, take a straight stick of wood, use your dividers to make 3 evenly spaced marks in the stick, and drive a nail into each mark so it sticks out the other side. Make the center one not as deep as the rest so the point is just protruding the other side.

Wow. That is so simple. Thanks,

Dan

[TinkerTailor]

These kind of tricks were so commonplace in workshops and jobsites back in the day. Before computers, draftsmen and craftsmen needed a bit of knowledge in geometry. Machine tools and blueprints have done away with these skills. Back in the day it did not matter how long things were, just that they fit with each other. A compass and a straightedge is all you need to draw most any shape and build most anything if you understand geometry. Look up "story stick" to see how they used to make houses square and level before tape measures. I use this technique for my basic rectangular pattern pieces. I just place all the measurements for all the pieces on one strip, and I can transcribe it to leather with a straightedge and a square. Use coloured pens to differentiate pieces. The pattern for a briefcase then becomes one strip of card 1-1/2" wide with a bunch of lines and measurements on it. Easy to store.

I have just added a story stick patterning tutorial to my list of things to do...

[badluckleather]

That is some great info. Researching story sticks now

[TheModifier]

Do you mean something like THIS?

[TinkerTailor]

Do you mean something like THIS?

That is another way to build one. I was not talking about that exact method, however that is almost as easy to make.

[billybopp]

I made something similar using the Weaver tool using plastruct plastic sheets and chicago screws, and added a few changes and refinements as well. It works great! With the addition of a second tool it's also great for centering letter stamps top to bottom on a belt.

Bill