Need Help with math

[harry strasil]

I had a brainstorm and made myself a gauge to determine actual stick out of my plane blades. Its a piece of walnut and a 1/4 inch thick piece of oak, The pointer of oak is 13 inches long from the pivot point (a brass screw) to the end of the pointer, there is a notch in the walnut so the blade can contact the pointer arm. I measured a 64th with a steel ruler at the end of the pointer, how much is my blade sticking out? I don't know if I should divide by 12 or 13?

Thanks in advance

[Nick Laeder]

I had a brainstorm and made myself a gauge to determine actual stick out of my plane blades. Its a piece of walnut and a 1/4 inch thick piece of oak, The pointer of oak is 13 inches long from the pivot point (a brass screw) to the end of the pointer, there is a notch in the walnut so the blade can contact the pointer arm. I measured a 64th with a steel ruler at the end of the pointer, how much is my blade sticking out? I don't know if I should divide by 12 or 13?

Thanks in advance

Not following your description. Can you post a picture? The math shouldn't be too bad, I'm just not following

[Lowell Smith]

I assume you are using two right-similar triangles, the base of one being
this distance along the sole with the height of interest compared to a triangle
of 13 inches with a height of 1/64th.

[Jim Koepke]

Wouldn't it be easier to just put a caliper on the shaving?

jim

[Wes Grass]

If the blade contact is 1" from the screw, then it's 13. And doesn't matter if the blade is making contact on the same side as the pointer, or the opposite. But with a difference of only .0001 between 12 and 13, who really cares ;-)

Makes a difference with a larger protrusion though.

[harry strasil]

Wouldn't it be easier to just put a caliper on the shaving?

jim

with Woodies there is no knob and if you set the blade stickout first, you don't mess anything up.

[harry strasil]

Sorry, I get lots of Brain F---s. LOL Luckily most of them work well or with just a bit of modification. I spent most of my life as a Blacksmith, Welder and Machinist solving other peoples problems, sometimes in rather unorthodox ways.

[Jim Koepke]

I know about the Brain ----s.

I am not picturing what you are doing without an image to see.

I can see that just because people have been doing it one way for a long time that is not a reason to avoid looking for a better way.

jim

[harry strasil]

with gauge blade open to show notch.

http://img.photobucket.com/albums/v81/irnsrgn/wood/planegauge001.jpg

With plane blade set pretty rank to show how end of gauge shows protrusion, blade is flush with bottom of walnut piece when no protusion, measure distance at narrow end and divide by 13 to find blade stick out, there is a mark at 1 inch for the blade to touch.

http://img.photobucket.com/albums/v81/irnsrgn/wood/planegauge002.jpg

[Pedro Reyes]

Harry,


You divide by 13 (if that was the distance from where you measure the height to the pivot point), and assuming the blade measurement is 1" from the pivot point. I guess another assumption is that the pivot point is exactly where the oak line intersects the sole.

In other words:

height at end/13 = height at blade/1, or in this case just blade protrusion.

/p

[Leon Jester]

I had a brainstorm and made myself a gauge to determine actual stick out of my plane blades. Its a piece of walnut and a 1/4 inch thick piece of oak, The pointer of oak is 13 inches long from the pivot point (a brass screw) to the end of the pointer, there is a notch in the walnut so the blade can contact the pointer arm. I measured a 64th with a steel ruler at the end of the pointer, how much is my blade sticking out? I don't know if I should divide by 12 or 13?

Thanks in advance

Divide by the distance from point-of-contact to the pivot point.

Why not just put the butt end of a dial caliper on it?

My B&S 6-inch will allow depth measurement that way.

file:///C:/DOCUME%7E1/User/LOCALS%7E1/Temp/moz-screenshot-3.pnghttp://ecx.images-amazon.com/images/I/21WB2TN33GL._SL500_AA208_.jpg