drill holes in reflexes, make clamps (photo)

[Emanuel Berg]

I have thought for a long time about being able
to make your own clamps, stays, and so on.
That would be so sweet, as work then wouldn't
have to come off on seemingly simple details
that are nevertheless vital...

Some should not be difficult at all to do if
one possess the right material and tools.
The piece that attach the lower part of the
chain guard to the frame, for example (the top
piece in the photo) - it shouldn't be too
difficult to do!

Incidentally, I used such I piece today doing
a clamp to put the front reflex to the holder.
First I drilled a 5 mm hole thru the reflex,
then put an M5 bolt thru the reflex into
a nylon nut on the other side.

What do you think? I think it is possible to do
and Joe Bike Rider won't ever tell the
difference...

Photo: http://user.it.uu.se/~embe8573/photos/reflex-clamp.jpg

--
underground experts united .... http://user.it.uu.se/~embe8573
Emacs Gnus Blogomatic ......... http://user.it.uu.se/~embe8573/blogomatic
- so far: 55 Blogomatic articles -

[John B.]

On Sat, 25 Jun 2016 00:11:24 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>I have thought for a long time about being able
>to make your own clamps, stays, and so on.
>That would be so sweet, as work then wouldn't
>have to come off on seemingly simple details
>that are nevertheless vital...
>
>Some should not be difficult at all to do if
>one possess the right material and tools.
>The piece that attach the lower part of the
>chain guard to the frame, for example (the top
>piece in the photo) - it shouldn't be too
>difficult to do!
>
>Incidentally, I used such I piece today doing
>a clamp to put the front reflex to the holder.
>First I drilled a 5 mm hole thru the reflex,
>then put an M5 bolt thru the reflex into
>a nylon nut on the other side.
>
>What do you think? I think it is possible to do
>and Joe Bike Rider won't ever tell the
>difference...
>
>Photo: http://user.it.uu.se/~embe8573/photos/reflex-clamp.jpg

With practice you can make almost anything that you want to. The
problem is in your skill level.

I once had a German machinist working for me that had a little "jewel
box" in the top tray of his tool box. One day I asked him what it was
and he showed me. It was a cube of metal about 25mm on a side. He told
me that it was one of the things he had to make to complete his
apprenticeship in Germany. He said that it was accurate to 0.002mm in
all directions. He made it using only hand tools.
--
cheers,

John B.

[Emanuel Berg]

John B. <slocom...@gmail.xyz> writes:

>> Incidentally, I used such I piece today
>> doing a clamp to put the front reflex to the
>> holder. First I drilled a 5 mm hole thru the
>> reflex, then put an M5 bolt thru the reflex

>> into a nylon nut on the other side ...

>>
>> Photo:
>> http://user.it.uu.se/~embe8573/photos/reflex-clamp.jpg
>
> With practice you can make almost anything
> that you want to. The problem is in your
> skill level.

So I suppose you'd start with some metal sheet
which is easy to cut and bend but still has
some stiffness to to it.

I have learned you can put a pipe into a vise
and then hammer the piece around it to get an
even, round shape. Folding can also be done in
a vise but the corners often do not come out
that sharp...

Drilling an tapping, of course. I have learned
you can drill thru a round, soft object (e.g.
fenders) by putting it around around a tree
object first, e.g. mallet, fasten with cord,
and then put the mallet into the vise!

> I once had a German machinist working for me
> that had a little "jewel box" in the top tray
> of his tool box. One day I asked him what it
> was and he showed me. It was a cube of metal
> about 25mm on a side. He told me that it was
> one of the things he had to make to complete
> his apprenticeship in Germany. He said that
> it was accurate to 0.002mm in all directions.
> He made it using only hand tools.

I know how to do that! You use a hacksaw,
a metal file, a micrometer, and then a
try square which you hold to the sun, and if it
is correct, you won't see any light pass by!

That should be pretty easy, right?

:)

[John B.]

Try it. Then come back and tell me how easy it is :-)

Remember that since it is a cube all sides must be perfectly flat and
at 90 degrees to any adjacent flat and that the dimensions between all
sides must be the same, within 0.002mm.
--
cheers,

John B.

[John B.]

On Sun, 26 Jun 2016 01:53:10 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>John B. <slocom...@gmail.xyz> writes:
>
>>> Incidentally, I used such I piece today
>>> doing a clamp to put the front reflex to the
>>> holder. First I drilled a 5 mm hole thru the
>>> reflex, then put an M5 bolt thru the reflex
>>> into a nylon nut on the other side ...
>>>
>>> Photo:
>>> http://user.it.uu.se/~embe8573/photos/reflex-clamp.jpg
>>
>> With practice you can make almost anything
>> that you want to. The problem is in your
>> skill level.
>
>So I suppose you'd start with some metal sheet
>which is easy to cut and bend but still has
>some stiffness to to it.

Actually it is best to start with material that you know will do the
job and then figure out how to cut it :-)

--
cheers,

John B.

[Emanuel Berg]

John B. <slocom...@gmail.xyz> writes:

> Remember that since it is a cube all sides
> must be perfectly flat and at 90 degrees to
> any adjacent flat and that the dimensions
> between all sides must be the same, within
> 0.002mm.

Yeah, but are there really "hand tools"
that accurate?

Or are you not supposed to measure the thing
until final examination?

[Jeff Liebermann]

On Sun, 26 Jun 2016 06:08:11 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>John B. <slocom...@gmail.xyz> writes:
>
>> Remember that since it is a cube all sides
>> must be perfectly flat and at 90 degrees to
>> any adjacent flat and that the dimensions
>> between all sides must be the same, within
>> 0.002mm.
>
>Yeah, but are there really "hand tools"
>that accurate?
>
>Or are you not supposed to measure the thing
>until final examination?

This series of stories might help:
<http://www.practicalmachinist.com/vb/general/ot-old-german-toolmakers-160631/>
I don't recall the required accuracy or exact procedure. Two of my
uncles were machinists in Poland before WWII and had to pass a similar
test. I vaguely recall that the original size of the block of metal
was about 200 mm and that it took a week or more to complete. When I
was about 17 years old, I arrogantly tried to duplicate the feat,
thinking it was easy. I gave up after about 3 days of frustration.

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Emanuel Berg]

Jeff Liebermann <je...@cruzio.com> writes:

> I don't recall the required accuracy or exact
> procedure. Two of my uncles were machinists
> in Poland before WWII and had to pass
> a similar test. I vaguely recall that the
> original size of the block of metal was about
> 200 mm and that it took a week or more to
> complete. When I was about 17 years old,
> I arrogantly tried to duplicate the feat,
> thinking it was easy. I gave up after about 3
> days of frustration.

If the Germans used it as a test of skill, it
sure as hell (Hel) cannot be easy. But I'm
curious about the rules. What does "hand tools"
mean? Is it tools you hold in your hand(s) or
is it tools not fueled by an engine or power?
Are you allowed to build your own tools
and stands?

[Jeff Liebermann]

On Sun, 26 Jun 2016 07:08:46 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>Jeff Liebermann <je...@cruzio.com> writes:
>
>> I don't recall the required accuracy or exact
>> procedure. Two of my uncles were machinists
>> in Poland before WWII and had to pass
>> a similar test. I vaguely recall that the
>> original size of the block of metal was about
>> 200 mm and that it took a week or more to
>> complete. When I was about 17 years old,
>> I arrogantly tried to duplicate the feat,
>> thinking it was easy. I gave up after about 3
>> days of frustration.

>If the Germans used it as a test of skill, it
>sure as hell (Hel) cannot be easy. But I'm
>curious about the rules. What does "hand tools"
>mean? Is it tools you hold in your hand(s) or
>is it tools not fueled by an engine or power?
>Are you allowed to build your own tools
>and stands?

Some of the stories under:
<http://www.practicalmachinist.com/vb/general/ot-old-german-toolmakers-160631/>
(3 pages) explain the details and requirements. As might be expected,
they vary. As I vaguely recall from 40 years ago, hand tools meant
anything without a motor, belt, or drive, that could be wielded in one
or both hands. No power tools. One of the stories in the above URL
mentions, "There were a few files, a hammer, cape chisel, combination
square & vernier caliper". A granite surface plate and dial indicator
would have been nice, but I suspect they weren't available or allowed.
However, even those would not be of any use until after the first
surface of the cube is done and perfectly flat.

This article offers some more detail:
<http://www.practicalmachinist.com/vb/general/ot-old-german-toolmakers-160631/index2.html#post920091>

I don't know if one was allowed to build their own tools. Since the
test was for beginning machinists, I would not expect them to have
amassed much of a tool and instrument collection at that point.

I recall my father mumbling something about using the stiction from a
gauge block to check for flatness, but I'm not sure. I suspect a
honing stone and abrasive were required to obtain this level of
flatness.

Also, I was wrong on the "week or more to complete". Apparently, it
took much longer to make the cube perfect. The above article mentions
3 months.

[John B.]

On Sun, 26 Jun 2016 06:08:11 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>John B. <slocom...@gmail.xyz> writes:
>
>> Remember that since it is a cube all sides
>> must be perfectly flat and at 90 degrees to
>> any adjacent flat and that the dimensions
>> between all sides must be the same, within
>> 0.002mm.
>
>Yeah, but are there really "hand tools"
>that accurate?
>
>Or are you not supposed to measure the thing
>until final examination?

I don't believe there is any rules about how or when to measure. But
you will be judged on what you do :-)

As for accurate. Well, when I was at the Air Force test center at
Edwards AFB, I saw flat flanges used on the X1 or maybe 2, that were
hand finished to a tolerance that with no gasket - a metal to metal
flat flange joint - were used in a 3,000 PSI system flowing "red
fuming nitric acid" used as an oxidizer for the rocket engine.
--
cheers,

John B.

[John B.]

On Sat, 25 Jun 2016 21:53:58 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>On Sun, 26 Jun 2016 06:08:11 +0200, Emanuel Berg
><embe...@student.uu.se> wrote:
>
>>John B. <slocom...@gmail.xyz> writes:
>>
>>> Remember that since it is a cube all sides
>>> must be perfectly flat and at 90 degrees to
>>> any adjacent flat and that the dimensions
>>> between all sides must be the same, within
>>> 0.002mm.
>>
>>Yeah, but are there really "hand tools"
>>that accurate?
>>
>>Or are you not supposed to measure the thing
>>until final examination?
>
>This series of stories might help:
><http://www.practicalmachinist.com/vb/general/ot-old-german-toolmakers-160631/>
>I don't recall the required accuracy or exact procedure. Two of my
>uncles were machinists in Poland before WWII and had to pass a similar
>test. I vaguely recall that the original size of the block of metal
>was about 200 mm and that it took a week or more to complete. When I
>was about 17 years old, I arrogantly tried to duplicate the feat,
>thinking it was easy. I gave up after about 3 days of frustration.

When I was an apprentice I had to, for some reason, file the end of
piece of one inch round stock flat. I filed on it for a while and got
it pretty good, I thought, and took it to the apprentice master for
approval. He took a "try square" and held it up to the light and say,
"I can see a little light there". Being a brash young smart mouth I
said something like, "I'd like to se someone do better". He picked up
a file, put the piece in a vice and, I swear, hit it three licks with
the file and said. Have a look... No light.

I was than assigned for the next month to "snag" castings. You had a
24" file and a whole stack of cast iron castings and the job was to
file off any seam from the mold joints and the sprues.

I learned two things. Snagging castings is a miserable job and don't
talk back to the boss :-)
--
cheers,

John B.

[John B.]

On Sun, 26 Jun 2016 07:08:46 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>Jeff Liebermann <je...@cruzio.com> writes:
>
>> I don't recall the required accuracy or exact
>> procedure. Two of my uncles were machinists
>> in Poland before WWII and had to pass
>> a similar test. I vaguely recall that the
>> original size of the block of metal was about
>> 200 mm and that it took a week or more to
>> complete. When I was about 17 years old,
>> I arrogantly tried to duplicate the feat,
>> thinking it was easy. I gave up after about 3
>> days of frustration.
>
>If the Germans used it as a test of skill, it
>sure as hell (Hel) cannot be easy. But I'm
>curious about the rules. What does "hand tools"
>mean? Is it tools you hold in your hand(s) or
>is it tools not fueled by an engine or power?
>Are you allowed to build your own tools
>and stands?

Well back in the day, it referred to tools powered by the hands, one
might say. Not engine or motor driven.

The requirement was to make a cube, by hand. The shop would be
equipped with benches, vises, etc.
--
cheers,

John B.

[Frank Krygowski]

On 6/25/2016 11:28 PM, John B. wrote:
>
>
> Try it. Then come back and tell me how easy it is :-)
>
> Remember that since it is a cube all sides must be perfectly flat and
> at 90 degrees to any adjacent flat and that the dimensions between all
> sides must be the same, within 0.002mm.

Do you know what metal it was made from?



--
- Frank Krygowski

[AMuzi]

A hammer over a cylinder would work.
Making smoother curved shapes:
https://www.youtube.com/results?search_query=english+wheel

Hole in mudguards are usually pierced not drilled:
http://cocosvariety.com/products/copy-of-var-15-fender-punch



--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[AMuzi]

On 6/25/2016 11:08 PM, Emanuel Berg wrote:
> John B. <slocom...@gmail.xyz> writes:
>
>> Remember that since it is a cube all sides
>> must be perfectly flat and at 90 degrees to
>> any adjacent flat and that the dimensions
>> between all sides must be the same, within
>> 0.002mm.
>
> Yeah, but are there really "hand tools"
> that accurate?
>
> Or are you not supposed to measure the thing
> until final examination?
>

It's much more difficult than it may at first seem.

Measurement, judgement and metalworking skill are honed in
that process. It was once a standard test of advanced
machinist skills (at least in Europe; I don't know any
American who made one).

[AMuzi]

Mild steel.

[Emanuel Berg]

AMuzi <a...@yellowjersey.org> writes:

> It's much more difficult than it may at
> first seem.

The 0.002 mm requirement is insane. My
"hand tools" for measurement are not that
accurate by far and I don't have any motor
driven measuring tools either :)

[sms]

On 6/24/2016 3:11 PM, Emanuel Berg wrote:
> I have thought for a long time about being able
> to make your own clamps, stays, and so on.
> That would be so sweet, as work then wouldn't
> have to come off on seemingly simple details
> that are nevertheless vital...

I've fabricated a lot of rear rack stays because often racks come with
stays that are way too short. I've also made clamps, or re-purposed
clamps from other uses, like conduit clamps.

But I'd prefer to purchase professionally manufactured clamps and
brackets when available, and now they are more readily available. It's
easy to order these now, though some have to ordered from outside the U.S..

<https://www.amaincycling.com/search?s=clamp+rack+mount> imports Giant
seat post clamps with rack mounts.
<http://www.bvsportgroup.com/mounts/ibera-bike-black-extended-long-rods-for-ibera-ib-ra5-ib-ra4-carrier-racks-ib-ra5-rods.html>
<http://www.jandd.com/detail.asp?PRODUCT_ID=FEXT>
<http://thetouringstore.com>
<http://www.dx.com/p/92149>
<http://www.dx.com/p/239985>
<http://www.dx.com/p/429654>
<http://www.dx.com/p/69116>

These are on my web site, "37 Useful Items that You Can't Buy at Your
Local Bicycle Shop" at <http://tinyurl.com/notatlbs>

[ERSHC]

On Sun, 26 Jun 2016 08:45:47 -0500, AMuzi <a...@yellowjersey.org> wrote:
> On 6/25/2016 11:08 PM, Emanuel Berg wrote:

.............

>>
>> Yeah, but are there really "hand tools"
>> that accurate?
>>
>> Or are you not supposed to measure the thing
>> until final examination?
>>
>
> It's much more difficult than it may at first seem.
>
> Measurement, judgement and metalworking skill are honed in
> that process. It was once a standard test of advanced
> machinist skills (at least in Europe; I don't know any
> American who made one).
>

I have a 3"x3"x3/8" one made by a friend's father (a tool and die
maker) as his 'test', and somewhere at my folks house is a smaller one
made by my father as a High School test. (He went to a tool and die
tech school).

So I know of two Americans who made them, and I was told that this was
a standard thing to do.

[DATAKOLL MARINE RESEARCH]

zinc

[DATAKOLL MARINE RESEARCH]

waiting a few minutes to re read n edit could help smooth out the rough spots.

[DATAKOLL MARINE RESEARCH]

pierce then drill

needa flat table n a square angle iron

cut cube with saw

file

grind on flat table against moving or stationary square angle

one would use precision jigs nt hold the expletive deleted in your hand ..

anyway those German's bought the cubes from a shop in Geneva for $5

metal flanges n nitric acid...... pphhooop

Journey In The Dark/Flavin 1944.....deep south land owner turned aircraft machinist loses pilot son to Japanese but comes home with stainless steel dice.

more Sherman ,,,,,

[Emanuel Berg]

sms <scharf...@geemail.com> writes:

> I've fabricated a lot of rear rack stays
> because often racks come with stays that are
> way too short. I've also made clamps, or
> re-purposed clamps from other uses, like
> conduit clamps.

Indeed, re-purposed is the word. However every
time I do that it is not a 100% good feeling
because you suspect the other day the now
re-purposed clamp would be just it! Better to
have a sheet of raw material for those
occasions...

[sms]

On 6/26/2016 12:51 PM, Emanuel Berg wrote:
> sms <scharf...@geemail.com> writes:
>
>> I've fabricated a lot of rear rack stays
>> because often racks come with stays that are
>> way too short. I've also made clamps, or
>> re-purposed clamps from other uses, like
>> conduit clamps.
>
> Indeed, re-purposed is the word. However every
> time I do that it is not a 100% good feeling
> because you suspect the other day the now
> re-purposed clamp would be just it! Better to
> have a sheet of raw material for those
> occasions...

That's great if you have your own mill.

[Emanuel Berg]

sms <scharf...@geemail.com> writes:

>> Indeed, re-purposed is the word.
>> However every time I do that it is not
>> a 100% good feeling because you suspect the
>> other day the now re-purposed clamp would be
>> just it! Better to have a sheet of raw
>> material for those occasions...
>
> That's great if you have your own mill.

Your own mill! That's a great idea! But it's
more of a long term thing - right now we have
to focus on more immediate goals.

[DATAKOLL MARINE RESEARCH]

urenglish improves.

http://www.countryliving.com/real-estate/news/g2403/8-historic-grist-mills-you-could-actually-live-in/

[John B.]

The one the German fellow had was made from common mild steel, he
said, out of the crap barrel, and gold plated.
I asked him about the gold plating and he said that it took so much
time and effort and he was so proud of it that he had it gold plated.
From his conversation I believe that he made it over a period of
months, in his spare time.

Over a couple of years I made a 2" machine vise, in my spare time,
that was square in all directions,using a "try square", and accurate
to with in 1/10,000 of an inch. But I used every machine tool
available :-)

A fellow I worked with was into steam engines and had several in his
tool box. When I knew him he was making a single cylinder engine with
a 1/4" bore. He said, if the ever finished it he was thinking of a
turbine :-)

By the way, Walter Chrysler's tool box with a number of tools that he
had made himself used to be on display in the Chrysler Building.
--
cheers,

John B.

[John B.]

On Sun, 26 Jun 2016 17:30:07 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>AMuzi <a...@yellowjersey.org> writes:
>
>> It's much more difficult than it may at
>> first seem.
>
>The 0.002 mm requirement is insane. My
>"hand tools" for measurement are not that
>accurate by far and I don't have any motor
>driven measuring tools either :)

No, not really. It equates to 1/10,000 of an inch and you can measure
that with a "vernier micrometer" and I've seen work drawings with
tolerances in that range. When I worked at the Test Center at Edwards
AFB a guy there had made some 1/1000" drill bits for a project. I have
seen them... well looking through a tool makers microscope.
--
cheers,

John B.

[John B.]

On Mon, 27 Jun 2016 00:28:55 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>sms <scharf...@geemail.com> writes:
>
>>> Indeed, re-purposed is the word.
>>> However every time I do that it is not
>>> a 100% good feeling because you suspect the
>>> other day the now re-purposed clamp would be
>>> just it! Better to have a sheet of raw
>>> material for those occasions...
>>
>> That's great if you have your own mill.
>
>Your own mill! That's a great idea! But it's
>more of a long term thing - right now we have
>to focus on more immediate goals.

While I am not recommending it you can use end mills in a drill press
with a Chinese made "milling vise" http://tinyurl.com/zwegmdx
bolted to the drill press table for light milling.

I've got a friend that does it successfully for certain jobs. Very
light cuts and very slow travel :-)
--
cheers,

John B.

[Jeff Liebermann]

On Mon, 27 Jun 2016 08:57:38 +0700, John B. <slocom...@gmail.xyz>
wrote:

>By the way, Walter Chrysler's tool box with a number of tools that he
>had made himself used to be on display in the Chrysler Building.

Walter P Chrysler's Toolbox
<https://www.flickr.com/photos/stuffbyxtine/3796829392>

I like the Henry O. Studley Tool chest:
<https://blog.lostartpress.com/2014/08/10/studley-tool-chest-exhibit-faqs/>
<https://lostartpress.files.wordpress.com/2014/08/studley_overall_img_0132-2.jpg>
<https://www.google.com/search?q=studley+tool+chest&tbm=isch>

When I was young and stupid, I decided to build a tool box for my
growing collection of tools. For some forgotten reason, I built it in
wood, not metal. I also didn't bother weighing all my tools. When I
loaded the box and lifted it (with help), the bottom fell out.

[Emanuel Berg]

John B. <slocom...@gmail.xyz> writes:

>> The 0.002 mm requirement is insane. My "hand
>> tools" for measurement are not that accurate
>> by far and I don't have any motor driven
>> measuring tools either :)
>
> No, not really. It equates to 1/10,000 of an
> inch and you can measure that with a "vernier
> micrometer" and I've seen work drawings with
> tolerances in that range.

1/10 000 inch is 0.00254 mm so yes, that is
close to the guy's cube.

But my caliper is +/-0.03 mm and my micrometer
+/-0.01 mm so nowhere close!

[Frank Krygowski]

On 6/26/2016 11:12 PM, Jeff Liebermann wrote:
> On Mon, 27 Jun 2016 08:57:38 +0700, John B. <slocom...@gmail.xyz>
> wrote:
>
>> By the way, Walter Chrysler's tool box with a number of tools that he
>> had made himself used to be on display in the Chrysler Building.
>
> Walter P Chrysler's Toolbox
> <https://www.flickr.com/photos/stuffbyxtine/3796829392>
>
> I like the Henry O. Studley Tool chest:
> <https://blog.lostartpress.com/2014/08/10/studley-tool-chest-exhibit-faqs/>
> <https://lostartpress.files.wordpress.com/2014/08/studley_overall_img_0132-2.jpg>
> <https://www.google.com/search?q=studley+tool+chest&tbm=isch>

That's an example of what people can accomplish when they don't have a
TV to distract them.


--
- Frank Krygowski

[John B.]

On Mon, 27 Jun 2016 06:20:47 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>John B. <slocom...@gmail.xyz> writes:
>
>>> The 0.002 mm requirement is insane. My "hand
>>> tools" for measurement are not that accurate
>>> by far and I don't have any motor driven
>>> measuring tools either :)
>>
>> No, not really. It equates to 1/10,000 of an
>> inch and you can measure that with a "vernier
>> micrometer" and I've seen work drawings with
>> tolerances in that range.
>
>1/10 000 inch is 0.00254 mm so yes, that is
>close to the guy's cube.
>
>But my caliper is +/-0.03 mm and my micrometer
>+/-0.01 mm so nowhere close!

I've never used a mm mike, but your description sounds very close to
what inch mikes, common and vernier, are.

But in many cases ultra small tolerances are not really necessary. I
hear people talking about "umpteenth of an inch tolerance" but my
guess is that even on a bicycle (High tech machinery) they aren't
really important. Back when I was in the trade a tolerance of +.001
-.000 was very rare, indeed.


--
cheers,

John B.

[Emanuel Berg]

John B. <slocom...@gmail.xyz> writes:

>> 1/10 000 inch is 0.00254 mm so yes, that is
>> close to the guy's cube.
>>
>> But my caliper is +/-0.03 mm and my
>> micrometer +/-0.01 mm so nowhere close!
>
> I've never used a mm mike, but your
> description sounds very close to what inch
> mikes, common and vernier, are.
>
> But in many cases ultra small tolerances are
> not really necessary. I hear people talking
> about "umpteenth of an inch tolerance" but my
> guess is that even on a bicycle (High tech
> machinery) they aren't really important.
> Back when I was in the trade a tolerance of
> +.001 -.000 was very rare, indeed.

I never used one for fixing a bike - tho that
would be cool if such precision was needed -
but here I mention it because doing the metal
cube to a degree of perfection that cannot be
measured, at least not with the tools in my
possession - or put it this way, how would the
master verify the work of the apprentice when
he hands over the cube? Are there micrometers
and verniers that are more expensive that
carries more precision?

[John B.]

There are all kind of things that reach a higher level of accuracy
than a micrometer. "Gauge Blocks come in several classes".

Class (AAA): small tolerance (ą0.05 um) used to establish standards
(AA): (tolerance +0.10 um to be used to calibrate inspection blocks
and very high precision gauging
(A): (tolerance +0.15 um to be used as toolroom standards for setting
other gauging tools
(B): large tolerance (tolerance 0.25 um to um20.15 \u03bcm) used as
shop standards for precision measurement

That "um" means micro meter. This computer won't make the "micro"
designation character.

I once saw an imaging device used to determine the accuracy of a gear.
You drew the outline of the gear, as accurately as possible, at, say
10 times the size of the actual gear on some sort of stabilized paper.
Then projected an image of the actual gear through an optical device
at a magnification of 10 times, onto the paper and the imperfections
were readily identifiable.

I've also seen a electronic "dial indicator" that read in increments
of 0.000001 inch.
--
cheers,

John B.

[Frank Krygowski]

On 6/28/2016 9:53 PM, John B. wrote:
>
> I once saw an imaging device used to determine the accuracy of a gear.
> You drew the outline of the gear, as accurately as possible, at, say
> 10 times the size of the actual gear on some sort of stabilized paper.
> Then projected an image of the actual gear through an optical device
> at a magnification of 10 times, onto the paper and the imperfections
> were readily identifiable.

Sounds like you're describing an optical comparator.
https://en.wikipedia.org/wiki/Optical_comparator


--
- Frank Krygowski

[Emanuel Berg]

John B. <slocom...@gmail.xyz> writes:

> There are all kind of things that reach
> a higher level of accuracy than a micrometer.
> "Gauge Blocks come in several classes".
>

> Class (AAA): small tolerance (±0.05 um) used

> to establish standards (AA): (tolerance +0.10
> um to be used to calibrate inspection blocks
> and very high precision gauging (A):
> (tolerance +0.15 um to be used as toolroom
> standards for setting other gauging tools
> (B): large tolerance (tolerance 0.25 um to
> um20.15 \u03bcm) used as shop standards for
> precision measurement
>
> That "um" means micro meter. This computer
> won't make the "micro" designation character.
>
> I once saw an imaging device used to
> determine the accuracy of a gear. You drew
> the outline of the gear, as accurately as
> possible, at, say 10 times the size of the
> actual gear on some sort of stabilized paper.
> Then projected an image of the actual gear
> through an optical device at a magnification
> of 10 times, onto the paper and the
> imperfections were readily identifiable.
>
> I've also seen a electronic "dial indicator"
> that read in increments of 0.000001 inch.

Ha ha, this sounds like some industrial complex
in East Germany! "Dial indicator" you say,
yeah, I should get one of those...

[John B.]

Yes, but I thought I should explain it a bit. It was at Fellows Gear
Shaper in Springfield, Vermont. I was told that it was the first
company to "generate" a gear.
--
cheers,

John B.

[John B.]

On Wed, 29 Jun 2016 06:03:02 +0200, Emanuel Berg
<embe...@student.uu.se> wrote:

>John B. <slocom...@gmail.xyz> writes:
>
>> There are all kind of things that reach
>> a higher level of accuracy than a micrometer.
>>

>> I've also seen a electronic "dial indicator"
>> that read in increments of 0.000001 inch.

<much previous material deleted >

>Ha ha, this sounds like some industrial complex
>in East Germany! "Dial indicator" you say,
>yeah, I should get one of those...

Well, it had the finger that rested on the work and a round gauge but
everything else was electronic :-)
--
cheers,

John B.

[AMuzi]

A verier or dial expands the reading between two marks to a
finer increment than can be readily seen. Modern digital
readout models can go to extremes in that regard, very
useful for jet engine manufacturing, more information than
you need for most bicycle work.

Derailleur chain length for example, runs in one inch
increments so even if you determine an 'ideal length' at
112.3864 links you'll have to choose either 112 or 114 links.