I have some circular milling and another project where I have to put
12 evenly spaced holes around a 1 " tube, so am going to pick up a
rotary table, and have a few questions.

This is the one I am looking at:

http://busybeetools.ca/cgi-bin/pictu...22&NTITEM=B061

my question is... how do you mount a chuck to the rotary table? Is
there a special chuck that uses the Tee slots?

second question. They also sell this model, that has additional
accessories, like a tailstock holder, and plates:

http://busybeetools.ca/cgi-bin/pictu...2&NTITEM=B2485

What does the tailstock allow a machinist to do? Is it to support a
longer workpiece?

thanks to all with positive and helpful comments!

my question is... how do you mount a chuck to the rotary table? Is
there a special chuck that uses the Tee slots?

For my RT, I just got a chuck without a backplate. Then made a backplate
about two inch larger diameter. Drill holes on the overhang part and use
this to bolt to T slots in RT.

What does the tailstock allow a machinist to do? Is it to support a
longer workpiece?

Exactly. One common use for me was to make gears. Mount shaft in three jaw
and center on tailstock. gear blank already has bore and key. Put involute
cutter in machine and make a gear. i also use same setup to make timing belt
pulleys.

karl

wrote in
ups.com:


thanks to all with positive and helpful comments!


There are chucks available with mounting holes for a rotary table. The
other option is an adapter plate. Say you have a D style chuck, you can
make/buy an adapter plate, and put 3 csk holes in it to adapt to the rotary
table plate.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

For my RT, I just got a chuck without a backplate. Then made a backplate
about two inch larger diameter. Drill holes on the overhang part and use
this to bolt to T slots in RT.

Couple more points. Bore a hole in the center of your backplate larger than
the hole in your chuck. then make yourself a centering pin. One end exactly
to fit the hole in your rotary table, then long enough to go to the top of
the three jaw at any convenient diameter. Bore a 60 degree hole in the top
end of the centering pin. make a second pin with a 60 degree point and then
a convenient diameter, say 1/2".

Now, after loosely placing chuck on RT, tighten centering pin in three jaw
while end of pin engages RT. Tighten chuck to RT and its centered. Now put
second pin in mill spindle and align entire unit to spindle. Now, everything
is centered under spindle.

Karl

On Nov 4, 2:01 pm, "Karl Townsend"
wrote:
For my RT, I just got a chuck without a backplate. Then made a backplate
about two inch larger diameter. Drill holes on the overhang part and use
this to bolt to T slots in RT.

Couple more points. Bore a hole in the center of your backplate larger than
the hole in your chuck. then make yourself a centering pin. One end exactly
to fit the hole in your rotary table, then long enough to go to the top of
the three jaw at any convenient diameter. Bore a 60 degree hole in the top
end of the centering pin. make a second pin with a 60 degree point and then
a convenient diameter, say 1/2".

Now, after loosely placing chuck on RT, tighten centering pin in three jaw
while end of pin engages RT. Tighten chuck to RT and its centered. Now put
second pin in mill spindle and align entire unit to spindle. Now, everything
is centered under spindle.

Karl


Karl,

Your idea for centering the chuck on a rotary table is truly
ingenious!

Thanks for sharing.

Wolfgang

On Sun, 04 Nov 2007 09:39:34 -0800, wrote:

I have some circular milling and another project where I have to put
12 evenly spaced holes around a 1 " tube, so am going to pick up a
rotary table, and have a few questions.
Unless you have an immediate need for circular milling, consider
a "spindex" with a 1 inch collet. As 12 goes into 360 an even
number of times [a whole number of degrees] the spindex can space
these for you. A 5C collet spindex will allow the pipe/tube to
fit through the spindle so you can work on the ends of long
pieces
click on
http://www.use-enco.com/CGI/INLMKD?S...01=1&SICOUNT=1
and the collet
http://www.use-enco.com/CGI/INSRIT?P...PARTPG=INLMK32
There are many other suppliers.

This is the one I am looking at:

http://busybeetools.ca/cgi-bin/pictu...22&NTITEM=B061

my question is... how do you mount a chuck to the rotary table? Is
there a special chuck that uses the Tee slots?
In many cases a special backplate is required to mount a small
lathe chuck, frequently 4 jaw independent to allow easy
centering.

Most of the rotary tables currently being sold have a #2 or #3 MT
in the center so it can be easier to use a drill chuck, end mill
holder or ER collet adapter with the proper size shank.

Also you can make a flat plate with slightly oversize holes to
allow some movement to align on center, with either a set-screw
or "pinch" bolt to retain the part. One of the advantages using
a "pinch" bolt plate is that it allows you to hold tapered
pieces.

second question. They also sell this model, that has additional
accessories, like a tailstock holder, and plates:

http://busybeetools.ca/cgi-bin/pictu...2&NTITEM=B2485

What does the tailstock allow a machinist to do? Is it to support a
longer workpiece?
Yes, but more specifically for work between centers. In the case
of your tube/pipe you will have to fabricate plugs with a
centers. Note that work between centers will allow you to flute
tapered pieces such as barrels by offsetting the tail stock
vertically, although it is a PITA to set-up

thanks to all with positive and helpful comments!
If you get the table with the dividing plates, also get some
books on how to use it. click on
http://lindsaybks.com/dgjp/djgbk/series/index.html
see #1153 at bottom of page. Not only tells you how to build a
dividing head but also how it works. Note that the newer rotary
tables have 90 tooth gears while the older dividing heads
typically have 45 or 60 tooth gears.
also see
http://www.atmsite.org/contrib/JSAPP...e/divhead.html

http://www.bevenyoung.com.au/argus.pdf
look at #17 [workshop series books available from US and canadian
suppliers]

http://www.armurerieduroi.com/pages/...ing_heads.html

Let the group know how you make out.


Unka' George [George McDuffee]
============
Merchants have no country.
The mere spot they stand on
does not constitute so strong an attachment
as that from which they draw their gains.

Thomas Jefferson (1743-1826),
U.S. president. Letter, 17 March 1814.

On Nov 4, 9:39 am, wrote:

My 6" Bison 4-jaw chuck uses 4 3/8"-16 SHCS to attach the chuck body
to the threaded backplate, which I simply thread into matching tee
nuts to hold it to my 8" Phase II rotary table.
BTW, you might want to look at Enco (www.use-enco.com) since they have
the same part but I think it's quite a bit cheaper.

Wow, as always thanks very much for all the info!
I will post an update after I figure out which one I will be
purchasing!

I like the idea of buying some books to explain how to use one, since
I am the impatient type for now I will google "how to use a rotary
table" ;-)

On Nov 5, 6:21 pm, wrote:
Wow, as always thanks very much for all the info!
I will post an update after I figure out which one I will be
purchasing!

I like the idea of buying some books to explain how to use one, since
I am the impatient type for now I will google "how to use a rotary
table" ;-)

James A. Harvey's Machine Shop Trade Secrets has an entire chapter
devoted to Rotary Table work, as well as many, many other good tips
and tricks.

I bought the same rotary table and it is an excellent value for the
money. Inspect them carefully because I checked three of them before
I found one that was actually very accurate. The other two were
unacceptable.


On Nov 4, 10:39 am, wrote:
I have some circular milling and another project where I have to put
12 evenly spaced holes around a 1 " tube, so am going to pick up a
rotary table, and have a few questions.

This is the one I am looking at:

http://busybeetools.ca/cgi-bin/pictu...104071608122&N...

Hi Buy_Sell

can you tell me how you tested them for accuracy?

thanks to everyone!

OK, so I was trying to wrap my head around this some more... since
this is a 6" rotary table, and I need to mount a 3 jaw chuck to it....
I would have to use something like a 5" plain back chuck, build an
adapter plate that uses countersunk SHCS to fasten the plate to the
chuck, then have 4 holes located right near the edge to fasten the
plate to the T-Slots? Am I missing something here?

According to :
OK, so I was trying to wrap my head around this some more... since
this is a 6" rotary table, and I need to mount a 3 jaw chuck to it....
I would have to use something like a 5" plain back chuck, build an
adapter plate that uses countersunk SHCS to fasten the plate to the
chuck, then have 4 holes located right near the edge to fasten the
plate to the T-Slots? Am I missing something here?

Only that I would try a 4" chuck, or maybe a 4-1/2" one if you
can find it not a 5" one, because a 5" one would leave you only 1/2"
clear for the heads of the screws which go into the T-nuts in the slots.

Also -- some rotary tables have three slots instead of four, or
six slots, so while what you described would work with *your* rotary
table, it might not work with another -- and certainly others will read
this later.

You will also want a centering slug to hold it properly centered
while you clamp down the backplate. (For quick-and-dirty, you might be
able to mount keys on the back of the plate to engage the T-slots
inboard from where your T-nuts will be used. That will get things close
enough for many uses, but you will still need the centering slug (which
you will probably have to make) for precision work.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:
According to :

OK, so I was trying to wrap my head around this some more... since
this is a 6" rotary table, and I need to mount a 3 jaw chuck to it....
I would have to use something like a 5" plain back chuck, build an
adapter plate that uses countersunk SHCS to fasten the plate to the
chuck, then have 4 holes located right near the edge to fasten the
plate to the T-Slots? Am I missing something here?


Only that I would try a 4" chuck, or maybe a 4-1/2" one if you
can find it not a 5" one, because a 5" one would leave you only 1/2"
clear for the heads of the screws which go into the T-nuts in the slots.

Also -- some rotary tables have three slots instead of four, or
six slots, so while what you described would work with *your* rotary
table, it might not work with another -- and certainly others will read
this later.

You will also want a centering slug to hold it properly centered
while you clamp down the backplate. (For quick-and-dirty, you might be
able to mount keys on the back of the plate to engage the T-slots
inboard from where your T-nuts will be used. That will get things close
enough for many uses, but you will still need the centering slug (which
you will probably have to make) for precision work.

Enjoy,
DoN.


There ARE chucks available, meant to be mounted on a R/T or faceplate,
that have mounting bolts that come through the chuck from the front face.

Such as that may be what you need to look at.

Called a front mounting chuck.

Cheers
Trevor Jones

OK, so I was trying to wrap my head around this some more... since
this is a 6" rotary table, and I need to mount a 3 jaw chuck to it....
I would have to use something like a 5" plain back chuck, build an
adapter plate that uses countersunk SHCS to fasten the plate to the
chuck, then have 4 holes located right near the edge to fasten the
plate to the T-Slots? Am I missing something here?

First of all, you do not need to spend all that money to do your job.
Since you only want to drill 12 holes( 1 hole every 30 degrees) get your
self a spin fixture. I have a cheap one and you can index to an accuracy of
1 degree. My cheap $40 job has sufficed for lots of projects like yours.
These devices accept 5C collets which screw into the fixture. The cheapest
collet is about $15 from Enco.
I do not know the length of your piece but if quite long, just support the
other end somehow (v -blocks, machinists jacks, or the tailstock you
mentioned)
I started out with a spin fixture, but as you gain experience a rotary
table is nice to have. A horizontal/vertical is a good choice over one that
can only be used in one plane.
Your question as to how a chuck is mounted on the table is a good one and
had me thinking when I encountered this. I searched the newsgroups and found
a good way to do it, although it required you to have a lathe to make a
centering part. The chuck is mounted to the rotary table using the T slots
on the table. Get yourself a clamping kit for about $60. these typically use
T nuts and 3/8 inch bolts to which strap clamps are attached and tightened
down on the chuck. Make sure you get T nuts that fit the rotary table. Most
tables come with a set. They can be purchased separately in different sizes
too. The trick is to center the rotary table with the chuck.
The hole in the center of the rotary table is generally one that has a
Morse Taper. Usually, a #2 MT. Buy a cheap adapter that has a male MT of the
same taper as the hole in the rotary table to some male other taper like a
Jacobs taper. (cost about $4; mine was a Jacobs #3 taper to MT2). You make
a cylindrical part on the lathe that has a matching bored female Jacobs
taper on one end, and a bored hole in the other end to which a 1/2 inch say
drill rod is pressed into. This usually requires you to have a tapering
attachment for the lathe, but it can be done without one by setting over the
tailstock by the correct amount of the taper. make the cylinder long
enough to protrude through the body of the chuck and a little above the
jaws. I made my diameter very close to a slip fit the chuck's hole so it is
very closely aligned already.

Now take a 1/2 inch collet and stick it in your mill, place the 1/2 inch
drill rod into it. the other end of the alignment jig has the MT male end
sticking out which fits into the hole into the rotary table. Now tighten
the bolts on the rotary table to the T slots on the mill. Your RT is
aligned with spindle on the mill. Next step is to clamp the chuck to the
RT using the strap clamps. tighten the bolts finger tight.
Assuming a 3 jaw self centering chuck is used, tighten the jaws up to the
cylindrical part of the alignment jig. Be very careful as this is
tricky-tighten up on the clamping bolts sequentially, and in several stages
like tightening the bolts on an engine cylinder head. If you try and tighten
each one fully and go around, the chuck will be pulled off center when you
remove the alignment jig. It took me a while to realize this after checking
with a dial indicator and finding concentricity way off.
Your concentricity should be checked. Remove the alignment jig, use a dial
indicator. Spin the rotary table around and check the dial indicator which
is attached to the edge of the chuck.
When you are satisfied with this, remove the bolts from the RT and place
the RT vertically and clamp in a position where the pipe is centered over
the drill.
Use a support of some kind like a machinist jack or the like if tubing is
real long. You are right, the tailstock serves the same purpose as the one
on a lathe- to keep long work from springing and thus aligning it with the
turning axis.
The time spent in making your alignment jig will be well worth it. It will
take some practice to get things right also, but that is part of the fun of
learning.

--
don paolino
wrote in message
ups.com...
I have some circular milling and another project where I have to put
12 evenly spaced holes around a 1 " tube, so am going to pick up a
rotary table, and have a few questions.

This is the one I am looking at:


http://busybeetools.ca/cgi-bin/pictu...22&NTITEM=B061

my question is... how do you mount a chuck to the rotary table? Is
there a special chuck that uses the Tee slots?

second question. They also sell this model, that has additional
accessories, like a tailstock holder, and plates:


http://busybeetools.ca/cgi-bin/pictu...2&NTITEM=B2485

What does the tailstock allow a machinist to do? Is it to support a
longer workpiece?

thanks to all with positive and helpful comments!

as a postscript to my previous reply, I just remembered another technique to
center a rotary table on a mill using a dial indicator and an edge finder.
It is called Osbornes maneuver and is fully described in the Machinist
Bedside Reader #2 by Guy Lautard. It is very interesting and dates from
about 1900 machine shop practice.
There still remains the problem of centering the chuck to the table but
chucking a cylindrical part in the mill after the table is centered and
drawing the 3 jaw up to it gently and then clamping as I previously
indicated would work.

--
don paolino
"desperado" wrote in message
.. .
First of all, you do not need to spend all that money to do your job.
Since you only want to drill 12 holes( 1 hole every 30 degrees) get your
self a spin fixture. I have a cheap one and you can index to an accuracy
of
1 degree. My cheap $40 job has sufficed for lots of projects like yours.
These devices accept 5C collets which screw into the fixture. The cheapest
collet is about $15 from Enco.
I do not know the length of your piece but if quite long, just support
the
other end somehow (v -blocks, machinists jacks, or the tailstock you
mentioned)
I started out with a spin fixture, but as you gain experience a rotary
table is nice to have. A horizontal/vertical is a good choice over one
that
can only be used in one plane.
Your question as to how a chuck is mounted on the table is a good one
and
had me thinking when I encountered this. I searched the newsgroups and
found
a good way to do it, although it required you to have a lathe to make a
centering part. The chuck is mounted to the rotary table using the T slots
on the table. Get yourself a clamping kit for about $60. these typically
use
T nuts and 3/8 inch bolts to which strap clamps are attached and tightened
down on the chuck. Make sure you get T nuts that fit the rotary table.
Most
tables come with a set. They can be purchased separately in different
sizes
too. The trick is to center the rotary table with the chuck.
The hole in the center of the rotary table is generally one that has a
Morse Taper. Usually, a #2 MT. Buy a cheap adapter that has a male MT of
the
same taper as the hole in the rotary table to some male other taper like
a
Jacobs taper. (cost about $4; mine was a Jacobs #3 taper to MT2). You
make
a cylindrical part on the lathe that has a matching bored female Jacobs
taper on one end, and a bored hole in the other end to which a 1/2 inch
say
drill rod is pressed into. This usually requires you to have a tapering
attachment for the lathe, but it can be done without one by setting over
the
tailstock by the correct amount of the taper. make the cylinder long
enough to protrude through the body of the chuck and a little above the
jaws. I made my diameter very close to a slip fit the chuck's hole so it
is
very closely aligned already.

Now take a 1/2 inch collet and stick it in your mill, place the 1/2 inch
drill rod into it. the other end of the alignment jig has the MT male end
sticking out which fits into the hole into the rotary table. Now tighten
the bolts on the rotary table to the T slots on the mill. Your RT is
aligned with spindle on the mill. Next step is to clamp the chuck to
the
RT using the strap clamps. tighten the bolts finger tight.
Assuming a 3 jaw self centering chuck is used, tighten the jaws up to the
cylindrical part of the alignment jig. Be very careful as this is
tricky-tighten up on the clamping bolts sequentially, and in several
stages
like tightening the bolts on an engine cylinder head. If you try and
tighten
each one fully and go around, the chuck will be pulled off center when you
remove the alignment jig. It took me a while to realize this after
checking
with a dial indicator and finding concentricity way off.
Your concentricity should be checked. Remove the alignment jig, use a
dial
indicator. Spin the rotary table around and check the dial indicator which
is attached to the edge of the chuck.
When you are satisfied with this, remove the bolts from the RT and place
the RT vertically and clamp in a position where the pipe is centered over
the drill.
Use a support of some kind like a machinist jack or the like if tubing is
real long. You are right, the tailstock serves the same purpose as the one
on a lathe- to keep long work from springing and thus aligning it with
the
turning axis.
The time spent in making your alignment jig will be well worth it. It
will
take some practice to get things right also, but that is part of the fun
of
learning.

--
don paolino
wrote in message
ups.com...
I have some circular milling and another project where I have to put
12 evenly spaced holes around a 1 " tube, so am going to pick up a
rotary table, and have a few questions.

This is the one I am looking at:



http://busybeetools.ca/cgi-bin/pictu...22&NTITEM=B061

my question is... how do you mount a chuck to the rotary table? Is
there a special chuck that uses the Tee slots?

second question. They also sell this model, that has additional
accessories, like a tailstock holder, and plates:



http://busybeetools.ca/cgi-bin/pictu...2&NTITEM=B2485

What does the tailstock allow a machinist to do? Is it to support a
longer workpiece?

thanks to all with positive and helpful comments!

I just remembered another way out of the centering process for the rotary
table.
In case you do not want to go through the process of making a centering
jig as I described, you can center the table using an edge finder only.
The process is described fully in "The Machinists Bedside Reader #2" and is
known as Osbourn's Maneuver. Probably would take about 3 passes of the
technique to get a reasonable centering. They recommend a 4th pass to be
sure.
Basically the procedure is to start with an arbitrary edge of the table;
pick up the edge with the edge finder. Zero the dial on the longitudinal
axis, and move along the axis a distance equal to the radius of the RT plus
the radius of the edge finder. Move out with the cross feed and pick up the
edge of the RT again and zero the cross feed dial. move along the cross feed
in the same distance as the first move. Now repeat the process with the
longitudinal feed. Makes no difference whether you start with longitudinal
or cross feed.
You still need the dial indicator to check how well the table is centered
to the spindle and to center the chuck prior to clamping along the lines I
described previously.
The Machinists Bedside reader series of books are quite interesting and
have many tips and useful info. There are 3 books so far in the series and
are well worth the money.

--
don paolino
"desperado" wrote in message
.. .
First of all, you do not need to spend all that money to do your job.
Since you only want to drill 12 holes( 1 hole every 30 degrees) get your
self a spin fixture. I have a cheap one and you can index to an accuracy
of
1 degree. My cheap $40 job has sufficed for lots of projects like yours.
These devices accept 5C collets which screw into the fixture. The cheapest
collet is about $15 from Enco.
I do not know the length of your piece but if quite long, just support
the
other end somehow (v -blocks, machinists jacks, or the tailstock you
mentioned)
I started out with a spin fixture, but as you gain experience a rotary
table is nice to have. A horizontal/vertical is a good choice over one
that
can only be used in one plane.
Your question as to how a chuck is mounted on the table is a good one
and
had me thinking when I encountered this. I searched the newsgroups and
found
a good way to do it, although it required you to have a lathe to make a
centering part. The chuck is mounted to the rotary table using the T slots
on the table. Get yourself a clamping kit for about $60. these typically
use
T nuts and 3/8 inch bolts to which strap clamps are attached and tightened
down on the chuck. Make sure you get T nuts that fit the rotary table.
Most
tables come with a set. They can be purchased separately in different
sizes
too. The trick is to center the rotary table with the chuck.
The hole in the center of the rotary table is generally one that has a
Morse Taper. Usually, a #2 MT. Buy a cheap adapter that has a male MT of
the
same taper as the hole in the rotary table to some male other taper like
a
Jacobs taper. (cost about $4; mine was a Jacobs #3 taper to MT2). You
make
a cylindrical part on the lathe that has a matching bored female Jacobs
taper on one end, and a bored hole in the other end to which a 1/2 inch
say
drill rod is pressed into. This usually requires you to have a tapering
attachment for the lathe, but it can be done without one by setting over
the
tailstock by the correct amount of the taper. make the cylinder long
enough to protrude through the body of the chuck and a little above the
jaws. I made my diameter very close to a slip fit the chuck's hole so it
is
very closely aligned already.

Now take a 1/2 inch collet and stick it in your mill, place the 1/2 inch
drill rod into it. the other end of the alignment jig has the MT male end
sticking out which fits into the hole into the rotary table. Now tighten
the bolts on the rotary table to the T slots on the mill. Your RT is
aligned with spindle on the mill. Next step is to clamp the chuck to
the
RT using the strap clamps. tighten the bolts finger tight.
Assuming a 3 jaw self centering chuck is used, tighten the jaws up to the
cylindrical part of the alignment jig. Be very careful as this is
tricky-tighten up on the clamping bolts sequentially, and in several
stages
like tightening the bolts on an engine cylinder head. If you try and
tighten
each one fully and go around, the chuck will be pulled off center when you
remove the alignment jig. It took me a while to realize this after
checking
with a dial indicator and finding concentricity way off.
Your concentricity should be checked. Remove the alignment jig, use a
dial
indicator. Spin the rotary table around and check the dial indicator which
is attached to the edge of the chuck.
When you are satisfied with this, remove the bolts from the RT and place
the RT vertically and clamp in a position where the pipe is centered over
the drill.
Use a support of some kind like a machinist jack or the like if tubing is
real long. You are right, the tailstock serves the same purpose as the one
on a lathe- to keep long work from springing and thus aligning it with
the
turning axis.
The time spent in making your alignment jig will be well worth it. It
will
take some practice to get things right also, but that is part of the fun
of
learning.

--
don paolino
wrote in message
ups.com...
I have some circular milling and another project where I have to put
12 evenly spaced holes around a 1 " tube, so am going to pick up a
rotary table, and have a few questions.

This is the one I am looking at:



http://busybeetools.ca/cgi-bin/pictu...22&NTITEM=B061

my question is... how do you mount a chuck to the rotary table? Is
there a special chuck that uses the Tee slots?

second question. They also sell this model, that has additional
accessories, like a tailstock holder, and plates:



http://busybeetools.ca/cgi-bin/pictu...2&NTITEM=B2485

What does the tailstock allow a machinist to do? Is it to support a
longer workpiece?

thanks to all with positive and helpful comments!