Automatic Centering Device

[Bob Swenson]

Automatic centering device.

Recently while preparing a piece of  wood to turn on the lathe for a handle
for a  tote box I am making (Per calls it my High School project) I was confronted
with the age old problem of marking a perfect center. This has always bugged  me.
So in the middle of the night I came up with this concept based on an old principal
with a new twist.
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My prototype worked perfectly but lacks  ease of use and sophistication,  so back
to the drawing board.

Once I am happy with the design I will jig up and make a bunch. Should be a handy
for a lot centering needs.

When the next model is made I will tell you what I don't like about this one.

Who knows., maybe you will like It.

Bob

 

[woodshopdemos]

Bob,
  It looks to be a neat little jig. If you can teach Per to use it, then it will be easy for the rest of us.

 

[Matthew Schenker]

Bob,
That's excellent!  Pretty good for a "prototype" (you're too modest).  Please post on your progress as you enhance this tool.
Thanks for sharing that idea here.
Matthew

 

[Bill Wyko]

Great Idea Bob. Keep us posted.

 

[b_m_hart]

For those that remember Jr. High geometry class:

Plot two separate lines tangent to the outside of a circle, then take a perpendicular line where the tangents meet the circle.  Where those two perpendicular lines meet will be the exact center of the circle.

So, to translate into non geometry-ese: take a straight piece of wood (or any other material).  Put two pegs sticking out of the bottom, one on each end.  In the exact middle, extend another piece of material such that one edge is on the exact mid-point between the two posts.  That will allow you to draw a straight line down through the circle.

So, take your jig, hold the two pegs up to the a circle, and draw your line through the middle of the circle.  Lift it up, move it to any other spot around the circle, and draw another line.  Where they meet is dead center.

Here's a way of seeing how this would work: http://www.instructables.com/id/How-to-find-the-center-of-a-circle/

 

[Bob Swenson]

B-M-Hart

Thats why they make this.

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Bob

 

[b_m_hart]

cool toy!