Is the torque release clutch there to make sure it is impossible to strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force is
the area where grime/gummy lubricant etc would give inconsistent results if
measurement was by feel of "first" touch.

N_Cook wrote:
Is the torque release clutch there to make sure it is impossible to strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force is
the area where grime/gummy lubricant etc would give inconsistent results if
measurement was by feel of "first" touch.


Both

The former in the hands of idiots, and the later for all others.

CarlBoyd

"CarlBoyd" wrote in message
...
N_Cook wrote:
Is the torque release clutch there to make sure it is impossible to
strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force
is
the area where grime/gummy lubricant etc would give inconsistent results
if
measurement was by feel of "first" touch.


Both

The former in the hands of idiots, and the later for all others.

CarlBoyd

Well said. I was taught at school to do three "clicks". When I got to work
and watched a machinist, I thought about it. After many years of practice, I
now know for sure who was right.

I recently measured a couple of hundred used pins from a large industrial
chain. These had some witness marks at the contact sites, but you couldn't
reliably estimate the wear from individual measurements across the worn and
unworn diameters. However by measuring everything (diameters in two planes
and four axial positions) and then doing the stats I was able to show that
the worn pins (only pins from some parts of the chain were worn) had on
average two tenths of wear on them. The diametral tolerance was about a
thou, and some of them had half a thou of taper.

"N_Cook" wrote:

Is the torque release clutch there to make sure it is impossible to strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force is
the area where grime/gummy lubricant etc would give inconsistent results if
measurement was by feel of "first" touch.

It is never impossible, heck, they can drop it. It is an attempt to mechanically put
'feel' into the mic.

I haven't checked but if the user spins the mic closed on part being measured, I'm sure
they can get a different reading regardless of any ratchet or friction system. Inertia
you know.

Wes

Wes wrote:
"N_Cook" wrote:

Is the torque release clutch there to make sure it is impossible to strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force is
the area where grime/gummy lubricant etc would give inconsistent results if
measurement was by feel of "first" touch.

It is never impossible, heck, they can drop it. It is an attempt to mechanically put
'feel' into the mic.

I haven't checked but if the user spins the mic closed on part being measured, I'm sure
they can get a different reading regardless of any ratchet or friction system. Inertia
you know.

Wes

My set of Starrett 1" to 6" 436 mikes have the ratchet because when I
bought them, the ratchetless model was out of stock. I wouldn't buy
the friction thimble design because I've seen too many of them with
frozen thimbles. I don't use the ratchet, and I wouldn't use the
thimble. I trust my feel to .0001" which has been good enough so far.

David

My set of Starrett 1" to 6" 436 mikes have the ratchet because when I
bought them, the ratchetless model was out of stock. I wouldn't buy the
friction thimble design because I've seen too many of them with frozen
thimbles. I don't use the ratchet, and I wouldn't use the thimble. I trust
my feel to .0001" which has been good enough so far.

David

A frozen thimble on a Starrett 436?? Mine will be 40 years old this coming
Jan 7. Never had a problem with the thimble.

"Wes" wrote in message
news
"N_Cook" wrote:

Is the torque release clutch there to make sure it is impossible to strain
the mechanism by over tightening or is it to give results that are
repeatable if used by different people. ie below the torque release force
is
the area where grime/gummy lubricant etc would give inconsistent results
if
measurement was by feel of "first" touch.

It is never impossible, heck, they can drop it. It is an attempt to
mechanically put
'feel' into the mic.

I haven't checked but if the user spins the mic closed on part being
measured, I'm sure
they can get a different reading regardless of any ratchet or friction
system. Inertia
you know.

Wes

A couple of the old timers I knew in the business, at Mitutoyo and Starrett,
didn't disguise their disdain for relying on ratchet thimbles. The general
opinion was that three different inexperienced users, all using the same
ratchet mike, would get three different readings off of the same part.

You still need some practice with the things to get consistent results.

--
Ed Huntress

Rick Samuel wrote:
My set of Starrett 1" to 6" 436 mikes have the ratchet because when I
bought them, the ratchetless model was out of stock. I wouldn't buy the
friction thimble design because I've seen too many of them with frozen
thimbles. I don't use the ratchet, and I wouldn't use the thimble. I trust
my feel to .0001" which has been good enough so far.

David

A frozen thimble on a Starrett 436?? Mine will be 40 years old this coming
Jan 7. Never had a problem with the thimble.

Neither have I, don't use them, as I said. The frozen ones weren't mine.

David

Ed Huntress wrote:

A couple of the old timers I knew in the business, at Mitutoyo and Starrett,
didn't disguise their disdain for relying on ratchet thimbles. The general
opinion was that three different inexperienced users, all using the same
ratchet mike, would get three different readings off of the same part.

You still need some practice with the things to get consistent results.

--
Ed Huntress

Is there a measuring system where that isn't true? :^)

David