i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

Anybody here could do that within 5 tenths

wrote in message
oups.com...
i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

wrote in message
oups.com...
i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

I don't know about the accuracy but as long as the tool/toolholder length is
at least six inches, using the quill is not necessary. Unless I'm missing
something, it could be chucked in a rotary table and turned, raising the
knee or lowering the quill after each pass is taken.

Tom Gardner wrote:
Anybody here could do that within 5 tenths


Yeah, I could probably do it within 5 tenths of an inch..

wrote in message
oups.com...

i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

wrote:
i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

A Bridgeport EZ Track could do this nicely, but I doubt your friend has
one in his garage. If he does he's a lucky guy!

Chris

On Tue, 21 Jun 2005 11:54:22 +0000 (UTC), Christopher Tidy wrote:

wrote:
i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

A Bridgeport EZ Track could do this nicely, but I doubt your friend has
one in his garage. If he does he's a lucky guy!

Chris.



I'm confused. Do you mean that you want the EZ Trak to interpolate a 4.250"
+/-.001 hole that is 6 inches deep? Sorry, ain't gonna happen that way.
Your interpolated hole will not be round to the tolerance specified.

I think the quill travel on an EZ Trak is even less than a regular B'Port
due to the readers, drive...

I think on a knee mill, the reasonable way to assure success may be to ue a
boring head with a rigid boring bar installed at 90°, lower the quill all
the way and bore by raising the knee. You'll get your extra one inch of
effective travel because the boring head head will extend below the quill.

--
Skuke
Reverse the domain name to send email

skuke wrote:
On Tue, 21 Jun 2005 11:54:22 +0000 (UTC), Christopher Tidy wrote:


wrote:

i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

A Bridgeport EZ Track could do this nicely, but I doubt your friend has
one in his garage. If he does he's a lucky guy!

Chris.




I'm confused. Do you mean that you want the EZ Trak to interpolate a 4.250"
+/-.001 hole that is 6 inches deep? Sorry, ain't gonna happen that way.
Your interpolated hole will not be round to the tolerance specified.

Maybe not. Reading quickly I had missed the "6 inches long" bit. I used
an EZ Track for making recesses maybe 1/2" deep (can't remember exactly)
for bronze bushes and it worked nicely.

Chris

wrote in message
oups.com...
i have a cast iron tube that is about 6 inches long with a id of 4
inches. i need to enlarge the id by about a quater inch . my friend who
has been a machinist for fifteen years says that he can do it on his
mill in his garage as he does not have a lathe. he says that he can jig
it up to make it work without much trouble eventhough the quill travel
is only five inches. he is a good friend and all but he is well known
for overstating sometimes.i need the final id to be within 1000th of a
inch. what do you think?

I *think* you're tolerance is probably incorrect, or at least incorrectly
stated.

Indeed, actaully nailing a +/-.001" tolerance on a 6" long bore would be
difficult using a very rigid lathe, let alone a flimbsy knee mill.

Do you actually need the diameter to be within +/-.001" for its entire
length? What about the straightness of the hole in relation to either the
round faces of the tube, or the outside diameter of the tube (or both?)

Your friend may tell you he can make the part you need correctly because he
understands its appliction. If you actually need +/-.001" over 6", you'll
probably have to pay a *lot* more than your friend is charging you...

Regards,

Robin