I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??

wrote in message
oups.com...
I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??


I think I'd add a step right after step one; use your cutting tool to locate
(and cut into) the center of the brass stock as far as you safely can. Then
start drilling with your drill bit. I think there will be a little less
'wander' that way.

wrote in message
oups.com...
I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??

First, use a centre drill.
Next, drill from both ends.

Does it start on-centre, then wander, or is it off-centre at the start?

--
Jeff R.

wrote:
I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??


Use a screw machine bit which is shorter and stiffer than a jobber's length
drill bit. Run the machine at its fastest speed and clear the chips often, using
a hunt/peck motion. The idea of drilling starting with a center drill and going
from both ends also has merit. If your hole were larger I'd recommend drilling
undersize and then boring but I can't imagine a boring bar that can bore a 1/8"
hole 1" deep.

This is tricky country, you are boring 800% of the diameter of the drill. Is
there any chance you could get away with using two identical pieces each 1/2" long?

GWE

"Grant Erwin" wrote in message
...
wrote:
I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??


Use a screw machine bit which is shorter and stiffer than a jobber's
length drill bit. Run the machine at its fastest speed and clear the chips
often, using a hunt/peck motion. The idea of drilling starting with a
center drill and going from both ends also has merit. If your hole were
larger I'd recommend drilling undersize and then boring but I can't
imagine a boring bar that can bore a 1/8" hole 1" deep.

This is tricky country, you are boring 800% of the diameter of the drill.
Is there any chance you could get away with using two identical pieces
each 1/2" long?

GWE

As Grant says, you are way beyond the definition of "deep hole drilling".
Deep holes are usu. always difficult to maintain center. Use a center drill
to start, and then a stub length drill (screw machine drill) for the hole.
Good idea to center up and drill from both ends, also. Best results can be
obtained by drilling under size and reaming to finish. Another thought is
to use larger stock, say 5/16; drill, ream and then insert a mandrel of some
sort into the bore and turn the OD down to 1/4.

Bob Swinney

wrote:

I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??

What everyone said and bronze generally
makes a better sleeve bearing than brass.

"Jim Stewart" wrote in message
...
wrote:

I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??

What everyone said and bronze generally
makes a better sleeve bearing than brass.

Bearing bronze; or even oil impregnated bronze, oil lite or something
similar. A good hardware store is your friend.

Bob Swinney

wrote:

I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??



Other replies are good, but have you verified that the lathe chuck is
holding the
1/4" rod on center? If not, then any hope of getting the ID and OD
concentric
will fail. Do you have a dial indicator or dial test indicator? Check
the OD of
the rod as you rotate the chuck by hand. If no change, then you are
fine. If
there is a change in reading, then 1/2 of the max to min reading is the
amount
of eccentricity. Depending on your needs, you can decide if this is too
much
or OK.

To get the most accurately centered hole, you normally have to bore them,
but boring a 1/8" hole would be a major pain. A reamer can make sure it
is straight and free of taper, but it won't do anything for concentricity.

Jon

I would probably try and bore it for the first 1/8", then use a D bit to
drill the rest of the way. Proper gun drills are (in my mind anyway)
basically an outgrowth of the D bit. Lots of pecking: during the drilling
only proceed about 1/16" per cut, then clear chips and add coolant.

Adam Smith
Midland, ON

wrote in message
oups.com...
I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??

wrote in message
oups.com...
I want to make some small brass sleeve bearings with my Smithy 3 in 1
machine. I'm having a difficult time getting a consistent wall
thickness. The material I'm working with is 1/4" brass rod and I'm
trying to get bearings about 1" long and with an ID of about 1/8".
Here's what I'm doing:

1. Insert brass rod into head chuck.
2. Insert a 1/8" drill bit into a chuck that fits the tailstock taper.
3. Start the machine and drive the drill bit into the rotating rod.

I'm not getting perfectly drilled holes in the exact center of the rod.
My machine is aligned correctly but it seems like the drill bit
sometimes wanders a little off course due to flex.

I'd like to improve my technique. Any suggestions on a better setup??


Lots of good sugestions, but as far as keeping your drill bit from
starting off center, put a piece of stock in the tool holder very close to
the brass you are drilling as a brace. Feed this brace against the drill
bit (as close as you can to the tip of the drill bit) to push it just a few
thou off center. Start feeding the drill bit into the brass and slowly back
off the brace. If its not perfect, back the bit off a bit, feed the brace
to deflect the drill bit again, and retry. You can get it so there is no
perceptable wobble. Its quick, works well, and all you need is the standard
drill and a piece of scrap.

Wayne Sippola,
Moose Jaw