A recent thread on using tape measures in the shop got me to thinking
about this.

I went on Starrett's website and found that the most that they will
write up a Certificate for on a tape is +/- 1/32". They also say on
that website that whatever tool you use to measure with should be
capable of measuring to 1/10 of what your tolerance is. So, if their
best tape is only capable of +/- 1/32", then my tolerances can't be
any tighter than 5/16", which seems a tad generous to me for cabinet
work.

I have some Starrett and Rabone-Chesterman metal rules that will
measure to 1/64", which would allow me to have tolerances of a little
heavier than 1/8". I guess I could use these rules for framing houses
- but they still aren't accurate enough for building cabinets.

I have a Starrett dial caliper that will measure to 1/1000" - now that
will let me have tolerances of about 1/100", which is heading in the
right direction but when I think about it, a piece of newsprint is
about 4/1000", or 1/250" and I know that my joints are tight enough,
when they are cut properly, that I can't fit a piece of newspaper into
them.

And yet, that can't be possible because the best measuring instrument
that I have in my shop will only allow me to have tolerances of
1/100".

It makes you wonder why framing carpenters and masons even bother to
own measuring devices at all and, it has been my suspicion for some
time that many of them don't.

It is gratifying to me that I am capable of doing the impossible but
it makes me a bit squeamish, if you follow me. A man needs to know
where he stands in this world and how can you do that if you can't
measure anything proper like?

When I had my first philosophy course in college we studied this old
boy named Zeno the Eleatic and his paradoxes. Now, Zeno said that you
can never get from one place to another because, first you have to
cover half the distance from A to B, then you have to cover half of
the remaining distance and then half of that remaining distance, and
so on for ever and ever. So, there's no sense in trying to measure
anything because it just ain't gonna work out.

Zeno may have been the first framing carpenter, although I am not
entirely sure about that - nor anything else, it seems.



Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Sun, 10 Aug 2008 17:54:29 -0400, Tom Watson
wrote:

They also say on
that website that whatever tool you use to measure with should be
capable of measuring to 1/10 of what your tolerance is.

I wonder what's their justification for that statement. Seems to me
that a measuring capability smaller than the tolerance is simply
unnecessary, unused precision.

Tom Veatch
Wichita, KS
USA

Zeno may have been the first framing carpenter, although I am not
entirely sure about that - nor anything else, it seems.

Zeno might be an optimist.

Anyways, any measuring tool is a best guess in my mind. I
was told by a friend to make sure I always use the same measuring
tape, rule, etc for a job. In that the differences between tapes from
the same manufacturer is sufficient to cause your measurements
to be off.

Within a tape there could be differences as well, right? Isn't that
a reason for test cuts?

MJM

Tom Veatch wrote:

On Sun, 10 Aug 2008 17:54:29 -0400, Tom Watson
wrote:

They also say on
that website that whatever tool you use to measure with should be
capable of measuring to 1/10 of what your tolerance is.

I wonder what's their justification for that statement. Seems to me
that a measuring capability smaller than the tolerance is simply
unnecessary, unused precision.


That is a typical rule of thumb for test equipment in a factory
environment, particularly for electronic equipment. Not sure that such a
rule of thumb would be applicable to cabinet making.


--
If you're going to be dumb, you better be tough

I wonder what's their justification for that statement. Seems to me
that a measuring capability smaller than the tolerance is simply
unnecessary, unused precision.

In a production environment, that capability is important. It allows small
adjustments of equipment as the process goes forward. With a go/no go
gauge, you don't know if anything needs adjustment. You just know it's in
tolerance. When it gets out of tol. the process must stop, make
adjustments, and then rework that item(s) . Many engineers forget about
tol. stack up, or worse, have no idea what is is.

Tom Watson wrote,on my timestamp of 11/08/2008 7:54 AM:


It makes you wonder why framing carpenters and masons even bother to
own measuring devices at all and, it has been my suspicion for some
time that many of them don't.

If they are anything like me, they just grab a story stick
and mark away, then read off the marks for that project
and the next one along same. Much more precise than
any tape measure.

Zeno may have been the first framing carpenter, although I am not
entirely sure about that - nor anything else, it seems.

join the club...

On Aug 11, 4:46*am, Noons wrote:
Tom Watson wrote,on my timestamp of 11/08/2008 7:54 AM:



It makes you wonder why framing carpenters and masons even bother to
own measuring devices at all and, it has been my suspicion for some
time that many of them don't.

If they are anything like me, they just grab a story stick
and mark away, then read off the marks for that project
and the next one along same. *Much more precise than
any tape measure.

Zeno may have been the first framing carpenter, although I am not
entirely sure about that - nor anything else, it seems.

join the club...

I'm just barely a journeyman wood smasher, but measurements using a
tape are just to get the board to the rough size. I never trust the
little metal clip on the end, but use the painted marks after that. I
CHECK the overall measurement using the metal clip, to make sure I
have the right number of inches. I do use metal rules, 6 or 12 inch,
for most things without problems, but even with a steel rule in 100th
of an inch markings, I don't think you get the needed repeatability.
With my limited experience, I try and plan my cuts so that all like
boards get cut exactly the same. For example, if I need some boards
5/8" thick, I plane them all at the same time, checking with a dial
caliper. Once the first board is correct, I can do a last pass on the
rest, and they will be close enough to each other. Then, the actual
size can be 5/8" +/- whatever, and they will all be the same.
I have not learned how to fit boards together well enough to just
saw and glue. I have to fine tune each joint as I go to get a fit
that is visually "invisible". Takes a while longer, but the
embarrassment of having friends and family see a poor joint on
furniture lasts much longer.

rich wrote:
Takes a while longer, but the
embarrassment of having friends and family see a poor joint on
furniture lasts much longer.

Realistically, most people probably wouldn't notice unless you pointed
it out to them. As a hobbiest, really high quality joinery is for the
benefit of the maker, not the viewer.

Chris

"Chris Friesen" wrote in message
...

As a hobbiest, really high quality joinery is for the benefit of the
maker, not the viewer.


That's reason enough.

{Snip}
Anyways, any measuring tool is a best guess in my mind. I was told by a
friend to make sure I always use the same measuring tape, rule, etc for
a job. In that the differences between tapes from the same manufacturer
is sufficient to cause your measurements to be off.

Within a tape there could be differences as well, right? Isn't that a
reason for test cuts?


Yes!

It has to do with how steel measuring tapes are made and the marks
printed on the steel. Plus the steel measuring tapes are affected by
temperature.

The error noted by Starrett of +/- 1/32 is the error of their marks
(indications on the tape) being "true", nothing to do with user's error
to transfer marks to working stock. Error is Starrett's not your
craftsmanship.

Sorry, but this is all basic Prof. Deming process control stuff that the
Japanese beat up the USA over back in the 1970s and 80's; AKA Quality
Control. And are now being use to great success by the Chinese.

Again, it has to do with how steel tape measures are made, not your
craftsmanship. White dot / Red Dot your Yo-Yo tapes. Use only one per
project. Just turn your dotted tape into a modified story stick, and
stop thinking that an inch is an inch by any other stick.

Just IMHO.

Phil

Phil Again wrote:
Just turn your dotted tape into a modified story stick, and
stop thinking that an inch is an inch by any other stick.

While this is true, I do try to get my tapes close to "true"... I test
them against an accurate steel rule when in the store, and only buy ones
that match the rule. This ensures that the first foot or so is accurate.

So far I've had pretty decent results, but I still generally stay with a
single tape for a given project.

Chris

Chris Friesen wrote:
Phil Again wrote:
Just turn your dotted tape into a modified story stick, and
stop thinking that an inch is an inch by any other stick.

While this is true, I do try to get my tapes close to "true"... I
test
them against an accurate steel rule when in the store, and only buy
ones that match the rule. This ensures that the first foot or so is
accurate.

So far I've had pretty decent results, but I still generally stay
with a single tape for a given project.

FWIW, Fastcap has a couple of tapes
http://www.woodcraft.com/family.aspx?FamilyID=5829 that are designed
to be used as story sticks, with inch marks on one edge and the other
edge blank write-on. One is the one that says "Story Pole" and the
other is the "Flatback".

Won't swear to their accuracy (really, if you want accurate bite the
bullet and get a Starrett) but the story pole feature can be damned
handy, especially seeing as you can carry 16 feet of it in your
pocket.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Phil Again wrote:
Just turn your dotted tape into a modified story stick, and
stop thinking that an inch is an inch by any other stick.

My tape IS a story stick!

It's the PS-SP:
http://www.fastcap.com/products.aspx?id=346

It's got a pencil sharpener and note pad, too.

If your tongue is planted firmly in your cheek for too long a time -
can it go into spasms?



Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Mon, 11 Aug 2008 20:46:04 +1000, Noons
wrote:

join the club...


Are you still here?

If you are you and you are still here - good on you brother and did
you ever get a solid piece of land to live on?

Did you ever even get to unpack all your gear?



Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

Tom Watson wrote,on my timestamp of 12/08/2008 11:52 AM:

On Mon, 11 Aug 2008 20:46:04 +1000, Noons
wrote:

join the club...


Are you still here?

hope so!


If you are you and you are still here - good on you brother and did
you ever get a solid piece of land to live on?

Yup. after 4 years of sheer pure hell with a
dishonest builder. All sorted out now, we won all
the battles. Lost a lot of moolah in the process and
it's taken us a while to get back to normal. Plus the
usual family troubles from very old relatives. But it's
all under control now, almost back to normal.


Did you ever even get to unpack all your gear?


Er........
(next question?)
LOL!

Actually, yes. I'm in the process of finalizing
the gar^H^H^Hworkshop with all the stuff I had
before - and a lot more. Another 3 or 4 months
and it should all be sorted out and working like
a charm. Mind you: I'm still a galoot at heart,
so "working" is probably not the best word choice...

The kids are now old enough to give me a hand as well
so that makes things a lot easier.


Regards, Tom.

Good to hear from you, Tom. Anyone else from the
old gang still around? I've followed the porch
all these years although no time to participate.
But here I totally lost contact until a coupla
months ago.

Tom Watson wrote:

If your tongue is planted firmly in your cheek for too long a time -
can it go into spasms?

Go ahead, tell us.

"Tom Watson" wrote in message
...


If your tongue is planted firmly in your cheek for too long a time -
can it go into spasms?



Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

A charley horse is within the realm of plausible!
Tom

Waddabout marking out accuracy?

oblique blunt crayon works fine for me,


--Zeno the Elastic