I know how to find the center of a pipe, using a vee block, but my
question is how do you scribe a line from one end to the other , so the
first hole is in perfect alignment with the last hole .. take for
example a 20 foot pipe , or tubing . If we had a 20 foot layout table
fine , clamp pipe down and use a height gauge to scrib a line the length
of the pipe. if you do not have a line you could get a twist(miss
alignment) but what can a person due that does not have a 20 foot layout
table . Maybe I am being to critical

JB MacDonald wrote:
I know how to find the center of a pipe, using a vee block, but my
question is how do you scribe a line from one end to the other , so the
first hole is in perfect alignment with the last hole .. take for
example a 20 foot pipe , or tubing . If we had a 20 foot layout table
fine , clamp pipe down and use a height gauge to scrib a line the length
of the pipe. if you do not have a line you could get a twist(miss
alignment) but what can a person due that does not have a 20 foot layout
table . Maybe I am being to critical

Two methods I have use:

1) "Chalk line", available at any hardware store. Stretch line tight
down the center of the top of the boom (as viewed from above) snap!

2) Lay a 20 ft board, which is 1/2 dia of boom, next to boom and scribe
line down the top of the board on the boom.

I am sure there are other ways ...

JS

Tnx for the reply The chalk line, securing one end and guessing at the
other , a little off on the other end ( guess)at center of pipe at
best could through line off. 2. Great idea but you have to have a
perfect flat level surface to start with.great idea for small lengths
though. JB

John Smith I wrote:
JB MacDonald wrote:
I know how to find the center of a pipe, using a vee block, but my
question is how do you scribe a line from one end to the other , so
the first hole is in perfect alignment with the last hole .. take for
example a 20 foot pipe , or tubing . If we had a 20 foot layout table
fine , clamp pipe down and use a height gauge to scrib a line the length
of the pipe. if you do not have a line you could get a twist(miss
alignment) but what can a person due that does not have a 20 foot
layout table . Maybe I am being to critical

Two methods I have use:

1) "Chalk line", available at any hardware store. Stretch line tight
down the center of the top of the boom (as viewed from above) snap!

2) Lay a 20 ft board, which is 1/2 dia of boom, next to boom and scribe
line down the top of the board on the boom.

I am sure there are other ways ...

JS

JB MacDonald wrote:
I know how to find the center of a pipe, using a vee block, but my
question is how do you scribe a line from one end to the other , so the
first hole is in perfect alignment with the last hole .. take for
example a 20 foot pipe , or tubing . If we had a 20 foot layout table
fine , clamp pipe down and use a height gauge to scrib a line the length
of the pipe. if you do not have a line you could get a twist(miss
alignment) but what can a person due that does not have a 20 foot
layout table . Maybe I am being to critical

Forget the scribed line - what you really need is for all the holes
through the boom to be parallel. A spirit level clamped at 90deg to the
boom will achieve that.


--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

snip


Forget the scribed line - snip.




--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)http://www.ifwtech.co.uk/g3sek




What is so aweful about a scribed line that leads you give an
instruction to' forget it' ?
I've never seen a 'spirit level' being used in a tool room for
accuracy nor could I specify from what you said as to why it should be
used from now on instead of conventional means.

On 18 Apr 2007 14:17:27 -0700, art wrote:

I've never seen a 'spirit level' being used in a tool room for
accuracy nor could I specify from what you said as to why it should be
used from now on instead of conventional means.

Well, I guess you haven't had much experience in the tool room.
Otherwise you would have been aware of how precession levels used to
set up machinery. They are used often. How do you think those long bed
lathes are adjusted so they are straight, level and parallel? Yes, my
poor misinformed person they use precession levels.

Danny, K6MHE

On 18 Apr, 17:09, Danny Richardson wrote:
On 18 Apr 2007 14:17:27 -0700, art wrote:

I've never seen a 'spirit level' being used in a tool room for
accuracy nor could I specify from what you said as to why it should be
used from now on instead of conventional means.

Well, I guess you haven't had much experience in the tool room.
Otherwise you would have been aware of how precession levels used to
set up machinery. They are used often. How do you think those long bed
lathes are adjusted so they are straight, level and parallel? Yes, my
poor misinformed person they use precession levels.

Danny, K6MHE

Danny,
don't be silly, you obviously have not spent a lot of time in a tool
room.
A tool room machine is not in any way used as a reference level. What
is used as a reference level is the machine slide with reference to
the cutting plane. An installation of a machine is subject to settling
but it does not affect the accuracy of the product.
Use of a spirit level over the use of a straight piece of angle as a
reference plane is rather stupid and impracticable.

On 18 Apr 2007 19:30:01 -0700, art wrote:

On 18 Apr, 17:09, Danny Richardson wrote:
On 18 Apr 2007 14:17:27 -0700, art wrote:

I've never seen a 'spirit level' being used in a tool room for
accuracy nor could I specify from what you said as to why it should be
used from now on instead of conventional means.

Well, I guess you haven't had much experience in the tool room.
Otherwise you would have been aware of how precession levels used to
set up machinery. They are used often. How do you think those long bed
lathes are adjusted so they are straight, level and parallel? Yes, my
poor misinformed person they use precession levels.

Danny, K6MHE

Danny,
don't be silly, you obviously have not spent a lot of time in a tool
room.

Only forty years plus. In that time I've moved and/or installed many
lathes, mills, planners, surface plates and etc... Each time using a
precession level. Just as I had been taught by a master millwright
back in my apprentice days.

A tool room machine is not in any way used as a reference level. What
is used as a reference level is the machine slide with reference to
the cutting plane. An installation of a machine is subject to settling
but it does not affect the accuracy of the product.

Yea sure a twisted lathe bed does accurate work....BS

I see your knowledge of shop practices is exceeded only by your
knowledge of antenna theory.

Danny, K6MHE

"art" wrote in message
oups.com...
On 18 Apr, 17:09, Danny Richardson wrote:
On 18 Apr 2007 14:17:27 -0700, art wrote:

I've never seen a 'spirit level' being used in a tool room for
accuracy nor could I specify from what you said as to why it should be
used from now on instead of conventional means.

Well, I guess you haven't had much experience in the tool room.
Otherwise you would have been aware of how precession levels used to
set up machinery. They are used often. How do you think those long bed
lathes are adjusted so they are straight, level and parallel? Yes, my
poor misinformed person they use precession levels.

Danny, K6MHE

Danny,
don't be silly, you obviously have not spent a lot of time in a tool
room.
A tool room machine is not in any way used as a reference level. What
is used as a reference level is the machine slide with reference to
the cutting plane. An installation of a machine is subject to settling
but it does not affect the accuracy of the product.
Use of a spirit level over the use of a straight piece of angle as a
reference plane is rather stupid and impracticable.


What a pompous jerk. You have finally stooped so low to try to make your
ownself sound intelligent as to insult others.

On Apr 18, 2:17 pm, art wrote:
snip

Forget the scribed line - snip.

--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)http://www.ifwtech.co.uk/g3sek

What is so aweful about a scribed line that leads you give an
instruction to' forget it' ?
I've never seen a 'spirit level' being used in a tool room for
accuracy nor could I specify from what you said as to why it should be
used from now on instead of conventional means.

That's funny. My dad was a machinist before me and I still have one
of these in the tool chest he left me. (In the original box no less)

http://catalog.starrett.com/catalog/...sp?GroupID=487