Defective Festool tape measure / looking for suggestions on options
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jimmylittle
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If my tape measure is more accurate than my pencil lead, I'm OK with that.
festnoob
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bkharman said:
Bro, when I'm all over the place getting a project done I have a few tapes lying around. I'll think twice about grabbing for the "dark blue" and green. I wouldn't grab an ikea one either, just saying it's more accurate. I'll stick to my fastcap(s)
jimmylittle
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On the subject of accuracy--- I have a shop in Brooklyn, NY. It has recently become spring here, with temperatures rising about 15-20º F in the last couple weeks.
A panel for a half-finished project I finally got back around to is about 1.5mm bigger than it was 2 weeks ago because the heat in the warehouse is now off and natural airflow and humidity is back.
Wood movement is a known issue just about everywhere, so is a half a millimeter really that big of a deal if the wood is going to change size on it's own anyway?
A panel for a half-finished project I finally got back around to is about 1.5mm bigger than it was 2 weeks ago because the heat in the warehouse is now off and natural airflow and humidity is back.
Wood movement is a known issue just about everywhere, so is a half a millimeter really that big of a deal if the wood is going to change size on it's own anyway?
NYC Tiny Shop
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jimmylittle said:
I assume that all the boards expanded equally? But, then how can you tell if it was really 1.5mm, if your measurement tool is defective. Read your signature quote, Jimmy.
I've followed this thread. Interesting. Tape measures are always a problem. The Fastcap Flatback tapes appear to be very accurate, but they are difficult to use in some applications because they aren't stiff. If you are working on projects in a shop and you want accurate measurements on a board laid down flat (like on an MFT) the Flatback tape has appeared always be much more accurate than others I've tried. In other situations, where I need to do measurements to fit in a certain length opening or where I have to match a length accurately, using a story stick works great. I recently bought a Woodpecker Pro Story Stick set but don't have any experience with it yet. Before that, though, many times I just used a handy straight piece of wood to mark opening sizes, etc. Even that works great and then exact measurements don't matter. You are merely fitting it to the opening or exact size marked on the stick. I am distressed by the problems noted with Starrett squares and even Woodpeckers. Machinists or Engineers squares seem to be very accurate but, to be honest, I am now going to try to check mine after reading this thread.
I have a BMI tape, and it has the same problems - on the upper face of the tape. I had assumed the error was a rounding error in calculating the mm scale from the inch scale (which appears OK). However the scale on the bottom (used when you view through the window) seems fine. Am I missing something?
Finally, to those that say "Just stick with one measure through the whole project" are missing a key point. If you are making an assembly where say 5 pieces stack together, and each is out by 0.5mm, then the assembly will be out by 2.5mm. If the error is a single jog in the scale, then the total will still be out by 2mm against the same tape measure.
At least I now have something to blame those gaps on ;-)
Andrew
Finally, to those that say "Just stick with one measure through the whole project" are missing a key point. If you are making an assembly where say 5 pieces stack together, and each is out by 0.5mm, then the assembly will be out by 2.5mm. If the error is a single jog in the scale, then the total will still be out by 2mm against the same tape measure.
At least I now have something to blame those gaps on ;-)
Andrew
NYC Tiny Shop
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Yes, agreed.
Also, if you are utilizing other tools with different measuring tools, for your project, such as a table saw, router table, thickness planer, drill press, jointer, other measuring tools, etc...then there will be more error introduced. I think a part of keeping it simple is keeping it as accurate as possible across all tools. Hence, why we pay good money for accuracy.
Also, if you are utilizing other tools with different measuring tools, for your project, such as a table saw, router table, thickness planer, drill press, jointer, other measuring tools, etc...then there will be more error introduced. I think a part of keeping it simple is keeping it as accurate as possible across all tools. Hence, why we pay good money for accuracy.
jimmylittle
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NYC Tiny Shop said:
That's exactly my point. Wood has a mind of its own. We can be as accurate as we can be, but in the big picture, wood will do what it wants. We can control it by surfacing it, gluing up panels the correct way, getting high-quality air dried lumber, etc., but in the end, it's a tree. Trees don't care about micro measurements.
I'm not saying we should just build stuff "close enough". If I had that mindset, I wouldn't be neck deep in the Green. But if we spend our days worrying that a flexible tape measure might be off a half a mm over a meter or two, we're not spending our days building beautiful and functional things.
I build in Imperial and Metric, depending on the project. I use FastCap and Stanley tapes. My Stanley Powerlock 5m/16ft mixed marking tape is accurate to my FastCap 32mm layout tape within .5mm at 3m. I'm a cabinetmaker, not a machinist. That's good enough for what I do. If others need more accuracy, that's up to them. But, one shouldn't expect micrometer accuracy from a flexible metal tape of any price.
Roseland said:
Cumulative error is most likely to raise its ugly head when we give it no respect, or thought. If we are building in situations where we can fall prey to it we should take measures (pun intended) to mitigate it. That may mean taking the first 5 components, in your case, that will reflect the total cum and checking what the end result will be before committing to building each component assembly. There are probably a number of good ways to avoid cum error but the main issue is to be aware of it so you can pick a technique to mitigate it early rather than be surprised by it after everything is cut, assembled, and onsight. I guess this is why we have all learned various techniques to scribe filler strips. [scratch chin]
Greg, you're right - if you can measure the overall dimension of the sub-assemblies and them make the outer that works. But imagine you're trying to make five boxes to exactly fit a shelf. You measure the shelf, divide by five and start building; you're still going to get caught out.
To be fair this is somewhat hypothetical; the error seems to be small and at least in part, corrected further along the scale. And I've never actually been caught out by it. But I'm still surprised BMI (and Festool) allow this obvious issue, if only because of the poor quality image.
Andrew
To be fair this is somewhat hypothetical; the error seems to be small and at least in part, corrected further along the scale. And I've never actually been caught out by it. But I'm still surprised BMI (and Festool) allow this obvious issue, if only because of the poor quality image.
Andrew
There are many reasons as to why there are so many different types of measuring devices. It is up to the use the chose the appropriate measuring tool.
Hopefully many will realize why older carpenters carry both a measuring tape and a folding rule.
I am sure the BMI tape measure can be used accurately but is certainly cannot be use precisely.
As to why the measuring tape when reading inside measurements form the top is correct and when reading on the face is wrong, try looking at the backside and observe what is there. It is not the scale on the front.
Many wood workers would cut outside the line providing for joining processing and to allow a cut to final width after a test fit. And that might be enough to just make up the error.
The converse of Norm Abram's "Measure twice and cut once":
"I have cut it twice and it is still too short!"
When this happens, check your head space!
Hopefully many will realize why older carpenters carry both a measuring tape and a folding rule.
I am sure the BMI tape measure can be used accurately but is certainly cannot be use precisely.
As to why the measuring tape when reading inside measurements form the top is correct and when reading on the face is wrong, try looking at the backside and observe what is there. It is not the scale on the front.
Many wood workers would cut outside the line providing for joining processing and to allow a cut to final width after a test fit. And that might be enough to just make up the error.
The converse of Norm Abram's "Measure twice and cut once":
"I have cut it twice and it is still too short!"
When this happens, check your head space!
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