Tape Measure Surprise

[forrestb]

I have never recognized this problem with tape measures before. This one is (was - it is now gone ) a FastCap Imperial/Metric tape.

I needed a board to be 5 inches wide, so I used my tape measure to set the fence position relative to the blade. I proceeded to make the cut and measured the board with the same tape.

By golly, it was only 4 15/16 wide

I rechecked the fence and it was spot on 5 inches

Of course, it soon dawned on me: the rivets holding the foot had elongated the tape such that when measuring the board it stretched farther than designed and came up with a too short measure.

Checked with another tape the board was actually 5 inches wide

My lesson learned is to periodically checked my tapes for the same failure.

Forrest

[jsburger]

I have never recognized this problem with tape measures before. This one is (was - it is now gone ) a FastCap Imperial/Metric tape.

I needed a board to be 5 inches wide, so I used my tape measure to set the fence position relative to the blade. I proceeded to make the cut and measured the board with the same tape.

By golly, it was only 4 15/16 wide

I rechecked the fence and it was spot on 5 inches

Of course, it soon dawned on me: the rivets holding the foot had elongated the tape such that when measuring the board it stretched farther than designed and came up with a too short measure.

Checked with another tape the board was actually 5 inches wide

My lesson learned is to periodically checked my tapes for the same failure.

Forrest

I never use a tape measure unless I have to measure something longer than 18". I have stainless steel rulers 6, 12 and 18", for all the short stuff.

At least your piece actually came out the right dimension.

[ChrisNeilan]

Nothing wrong with the tape, it's supposed to be that way. It should be able to move by the thickness of the hook (for inside and outside measurements), as gleaned from somewhere on the web:

"The Hook is Supposed to be Loose
I’ve seen many people that want to fix a bad tape measure because the end of it is loose. Well, it’s like that for a reason. When you butt the end of the tape against a wall for an inside measurement, that hook is compressing by the width of the hook itself. Or, conversely, when you hook it onto something for an outside measurement, it’s expanding by the width of the hook. So don’t get fancy and try to fix it, since then your tape would only work for one kind of measurement, at best."

[jsburger]

Nothing wrong with the tape, it's supposed to be that way. It should be able to move by the thickness of the hook (for inside and outside measurements), as gleaned from somewhere on the web:

"The Hook is Supposed to be Loose
I’ve seen many people that want to fix a bad tape measure because the end of it is loose. Well, it’s like that for a reason. When you butt the end of the tape against a wall for an inside measurement, that hook is compressing by the width of the hook itself. Or, conversely, when you hook it onto something for an outside measurement, it’s expanding by the width of the hook. So don’t get fancy and try to fix it, since then your tape would only work for one kind of measurement, at best."

You missed the point completely. Yes the hook is supposed to move. When he set up the saw to 5" the tape was in the inside measurement mode. Then he measured the piece he had just cut with the same tape in the outside measurement mode. It measured 1/16" smaller. It should have measured the same. The movable end of the tape was worn and did not measure the same in both modes. Time for the trash can.

[Gene Howe]

I'm with you Chris. Using a tape measure for almost any measuring is just asking for trouble.
I use story sticks of all descriptions, 123 blocks, key way stock, digital calipers and a great set of etched steel rules.

[dusty]

I use a tape measure for all but the most critical of tasks. But I, like forrest, have learned to check the accuracy of my measuring tools periodically. I learned this simple lesson in much the same way as did forrest except my measurements were off.

When I must make an accurate measurement with a tape measure, I do not use the hook. Instead, I measure from the 1" mark and adjust the result by 1".

[jsburger]

I use a tape measure for all but the most critical of tasks. But I, like forrest, have learned to check the accuracy of my measuring tools periodically. I learned this simple lesson in much the same way as did forrest except my measurements were off.

When I must make an accurate measurement with a tape measure, I do not use the hook. Instead, I measure from the 1" mark and adjust the result by 1".

I do that too.

[ChrisNeilan]

Nothing wrong with the tape, it's supposed to be that way. It should be able to move by the thickness of the hook (for inside and outside measurements), as gleaned from somewhere on the web:

"The Hook is Supposed to be Loose
I’ve seen many people that want to fix a bad tape measure because the end of it is loose. Well, it’s like that for a reason. When you butt the end of the tape against a wall for an inside measurement, that hook is compressing by the width of the hook itself. Or, conversely, when you hook it onto something for an outside measurement, it’s expanding by the width of the hook. So don’t get fancy and try to fix it, since then your tape would only work for one kind of measurement, at best."

You missed the point completely. Yes the hook is supposed to move. When he set up the saw to 5" the tape was in the inside measurement mode. Then he measured the piece he had just cut with the same tape in the outside measurement mode. It measured 1/16" smaller. It should have measured the same. The movable end of the tape was worn and did not measure the same in both modes. Time for the trash can.

Well, we are assuming some things here. If he held the hook to the blade and pulled the tape to the fence those measurements will be skewed by 1/16 inch....
if pushed to the blade, a different story...

From what I have read from Forrest's posting , I'd be inclined to think the tape might be bad... even though Fast Cap has a great reputation...

[jsburger]

Nothing wrong with the tape, it's supposed to be that way. It should be able to move by the thickness of the hook (for inside and outside measurements), as gleaned from somewhere on the web:

"The Hook is Supposed to be Loose
I’ve seen many people that want to fix a bad tape measure because the end of it is loose. Well, it’s like that for a reason. When you butt the end of the tape against a wall for an inside measurement, that hook is compressing by the width of the hook itself. Or, conversely, when you hook it onto something for an outside measurement, it’s expanding by the width of the hook. So don’t get fancy and try to fix it, since then your tape would only work for one kind of measurement, at best."

You missed the point completely. Yes the hook is supposed to move. When he set up the saw to 5" the tape was in the inside measurement mode. Then he measured the piece he had just cut with the same tape in the outside measurement mode. It measured 1/16" smaller. It should have measured the same. The movable end of the tape was worn and did not measure the same in both modes. Time for the trash can.

Well, we are assuming some things here. If he held the hook to the blade and pulled the tape to the fence those measurements will be skewed by 1/16 inch....
if pushed to the blade, a different story...

From what I have read from Forrest's posting , I'd be inclined to think the tape might be bad... even though Fast Cap has a great reputation...

WHAT??? You are assuming things here. I doubt anyone else is. When you cut a piece of stock to width the dimension is the distance from the fence to the side of the blade next to the FENCE. That is an inside measurement. If you hook the tape on the blade and measure to the fence you are measuring to the outside of the blade and your cut would be 1/8" off if you are using a standard kerf blade. Let alone you would be measuring at an angle unless the top of the saw blade was the same height as the top of the fence, unlikely.

Does ANYONE out there set a table saw fence by measuring from the blade to the fence? If so how do you do it?

[reible]

Been there and done that with tapes as the wear. Yes they should only move the amount equal to the thickness of the end but sometimes they go past that.

The other thing I ran into was tapes are not all the same and you get different readings because of that. I long ago learned to use the same tape to measure and cut with and to check with as if you don't you can get it to trouble.

In case you don't believe me take out several tapes and hook them on to a spot then go out to say 10 feet and see if they all read the same..... I've seen tapes from the same manufacturer be different and some might read the same at 10 feet but not at 5 feet.

Some years ago, I think before this forum existed I had a picture of different rules and showed how different they were. Others didn't believe me until they tried it them selves, then they did.

For putting a house together a tape is fine, doing fine woodworking you are better off with other tools, or be prepared to adjust.

I'm thinking I must have at least a dozen tape measures, hey maybe even more cause I have them in many locations but once I pick one I try to use it for the whole job.

Ed