Bessey K Body Clamps - Parallel jaws ??

Hi,

I bought a bunch of Bessey K Body REVO clamps recently and decided to see if the fixed jaw was perpendicular to the bar. All of them were less than 90 degrees, somewhere between 1/3 and 2/3 of a degree off - 89:20 - 89:40. I took a look at my old (10+ y.o.) K Body clamps and they were similar.

Are these designed to first apply pressure at the end of the jaw and then, as you tighte the inner portion applies slightly less? Or is this a manufacturing flaw?

Thanks

I expect it's to compensate for the bending of the aluminum bar when you tighten the clamp. The bar will bend upwards in the middle.

I like those K body Revo clamps.

Mike

Same reason we angle our vise chops, they parallel under load.

Quote:

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Originally Posted by Mike Henderson

I expect it's to compensate for the bending of the aluminum bar when you tighten the clamp. The bar will bend upwards in the middle.

I like those K body Revo clamps.

Mike

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My old ones all have steel bars, I know because I drilled them all for the black plastic end pieces.

My new ones also have steel bars. In fact I was thinking of adding some Jr's to the mix depending on if they are noticeably lighter.

They may have a small allowance in there for the teeth to wear in as well.

try clamping a stick of hardwood, tighten it down and then see what degree you get . . . .

What are you using to measure the degree?

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Originally Posted by Patrick McCarthy

try clamping a stick of hardwood, tighten it down and then see what degree you get . . . .

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That's a good idea. I can only place the hardwood at the end of the jaws (to have room to measure). When I do that, I see 90.5 degrees. So almost a whole degree deflection with reasonable hand tightness - not really cranking down.

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Originally Posted by Mike Heidrick

What are you using to measure the degree?

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I have a vernier protractor.

There is no reason to control that to 90 degrees with any precision. It could be off by 3-5 degrees and it would not really matter. All that maters is if the two faces are parallel under load.
Bil lD

Quote:

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Originally Posted by Bill Dufour

There is no reason to control that to 90 degrees with any precision. It could be off by 3-5 degrees and it would not really matter. All that maters is if the two faces are parallel under load.
Bil lD

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Which they never can be because the bars bend. If they have to be straight, and I'm not sure they do if you stagger them, you've got to have support on both sides like the Plano press.

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Originally Posted by Alex Zeller

In fact I was thinking of adding some Jr's to the mix depending on if they are noticeably lighter.

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I have 10 of the revo jr's, Alex. Mine are 18" and they work well. I cant speak for longer ones.
Fred