Thickness Gauge to Measure Center Thickness of Plank

I’ve quickly found several versions of this tool using Google Image Search. None of the vendors says how deep the throat of the gauge is, but it looks shallow to me, unable to reach even the center of a 6” thick plank.

Has anyone seen a device that uses the same overall principles with a 6” deep throat (good for a 1 x 12 plank)?

I am also interested if anyone makes one with where the ‘pointer’ is a second arc that carries a vernier scale, thus allowing a more accurate measurement without much added manufacturing cost? Perhaps nobody teaches students and apprentices how to read a vernier caliper these days?

I know. I could make one myself. Sometimes it is preferable to find that someone is already making the tool. It surprised me that I could not find anything like it in my 1934 Starrett Catalog #25.

http://img442.imageshack.us/img442/3...knessgauge.jpg

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thanks,

baumgrenze

Have you considered bowl-turners calipers? Here's a page full of them...http://www.woodturnerscatalog.com/st...Calipers?Args=

I used a deep throat C-clamp as a micrometer once when I was curious about how accurate my new PM15 planer was. I lightly clamped the center of a 14” wide, freshly planed board and marked the thread/body of the clamp with a fine Sharpie. Then resetting the thread/body of the clamp to line up the marks, I used a small block of wood and feeler gauges to mimic the board’s thickness. It sounds a little complicated but it only took a few minutes.

John,

Are you hand surfacing lumber? I am trying to think of a situation where I would need to know the thickness at the center of a board. I have the pair in the photo. It is not an acurate device. I think it may be helpful when sorting through a pile of lumber of similar thickness. But I much prefer using a tape of pair of calipers.

James

You could make one of these out of plywood like I have done for the price of a dial indicator. This is Stewart Mcdonalds expensive version.
Attachment 235905

I'm not sure I understand what problem you're trying to address but I think you could run a sample piece, rip it, and measure the thickness at the newly ripped edge. Wouldn't that work?


Ken

I just use OD calipers. Not sophisticated, but they work.
Bill

I have the same gizmo as in the picture - not sure why it claimed to be inaccurate - as long as you don't let the bolt that holds the arms together get loose it is accurate to 1/32"

I wanted to use it to check the accuracy of the extended bed I recently described in post 187897. I wanted to be able to check both the edge and the center thickness of the planks as I finished planing them.

The more I think about it, the more I like a device patterned on the image in my original post, but with a deeper throat (bolt to pincers) and with a vernier scale instead of just a pointer. I think it could be made to be quite an accurate tool with just a modest effort.

baumgrenze

The best way to check side to side accuracy on a planer is to run narrow peices through at different points along the width. Run them through individually then compare the thicknessess. That way any problems or movements wont be canceled out by the board affecting the entire head or table at once.