How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

--
Michael Koblic,
Campbell River, BC

In article ,
"Michael Koblic" wrote:

How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

Drill two intersecting holes in a block.

One for the drill (you'd fuss with drill bushings if making lots of
holes).

One for the part - snuggish fit.

Clamping - you can slit to the hole for the part, then clamp the slit
closed. Or you can add a few more cross holes and some setscrews to
clamp it. Choose a faster method if making a lot of parts (some sort of
air powered clamp, perhaps).

--
Cats, coffee, chocolate...vices to live by

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

--
Michael Koblic,
Campbell River, BC

Michael

I do this periodically. I take a block of steel and drill a hole to
hold the piece and drill a hole for a guide to drill the cross hole.
If I am doing a bunch of them or want to do it nice I use a drill
bushing for the cross hole. I clamp the block of steel with whatever.

Bob AZ

"Michael Koblic" wrote in message
...
| How do you drill cross holes in small cylinders (brass or steel). The
| cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
| hole is 1/4"
|
| I am having all sorts of problems with this: The clamping is limited as
the
| clamps often interfere with the drill, especially centre drill. I find it
| impossible to clamp both ends of the cylinder for the same reason. I tried
| drill press vise, v-blocks, side-ways chucks, you name it.
|
| What usually happens is that the part tends to flex somewhat and even if
it
| does not there is horrible chatter.
|
| Some sort of sacrificial v-block? But the part still has to be held in it
| somehow.
|
| --
| Michael Koblic,
| Campbell River, BC
|
|

If you do that process with a 3/8" dia cylinder and 1/4" dia intersecting
cross holes you'd end up having 4 very thin strips of metal bridges (around
0.010") preventing your cylinder from becoming two separate pieces.

What's that drilled piece use for anyway?

On 2009-05-24, Michael Koblic wrote:
How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

Are these solid cylinders, or hollow ones like pipe or tubing?
That can make a big difference.

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

The flex is why I wondered about whether it was hollow.

What I would do, assuming that the workpiece is solid, is to
first part off a piece of the same diameter stock in the lathe after
center drilling it and drilling it to just pass the 1/4" drill bit.
This piece should be perhaps 1/4" to 1/2" long.

Then put the workpiece in the vise parallel to the jaws, place
the drilled piece on top of it with the hole vertical, clamp the vise,
and drill through the workpiece using the hole in the part which you
made to guide the drill bit square into the centerline of the workpiece.

You won't need the center drill -- but if you get the drill bits
with split points, you will probably drill more easily.

If you're going to be doing a lot of this, make the guide from
mild steel, and case harden it so the drill bit does not enlarge the
hole as it is used.

====================

If the part is hollow, what I would be tempted to do is to make
up a special jaw for the vise which has a pin which matches the ID of
the workpiece hole. This pin would stick straight out from the fixed
jaw, and you would slide the workpiece over it, and then clamp it in
place with the vise's movable jaw. Mount the vise to the drill press
table so the hole goes right where you want it -- and be *sure* to use
split point drill bits for this, as you don't have a guide to keep the
bit from walking, and normal chisel-point bits *love* to walk on rounded
surfaces.

If you want to be a bit more stable, make two jaws with short
pins to hold the workpiece properly from both ends.

If the two diameters of workpiece have different through hole
diameters, make two sets of pins on the vise jaws -- one for each size.

It probably would not hurt, if you have a lot of these to make
over time, to make up a separate vise with the modified jaws so you
don't have to be swapping jaws frequently.

Hmm ... you *could* also mill pockets just the right diameter i
the opposing jaws.

Note that I'm assuming that the ends are parted off in a lathe
so they are not at an angle. If you are using a hacksaw, you should at
least pop them in the lathe to clean up the ends before drilling.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

Again -- solid cylinder or hollow?

Good Luck,
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 ---

R T Smith wrote:

"Michael Koblic" wrote in message
...
| How do you drill cross holes in small cylinders (brass or steel). The
| cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
| hole is 1/4"
|
| I am having all sorts of problems with this: The clamping is limited as
the
| clamps often interfere with the drill, especially centre drill. I find it
| impossible to clamp both ends of the cylinder for the same reason. I tried
| drill press vise, v-blocks, side-ways chucks, you name it.
|
| What usually happens is that the part tends to flex somewhat and even if
it
| does not there is horrible chatter.
|
| Some sort of sacrificial v-block? But the part still has to be held in it
| somehow.
|
| --
| Michael Koblic,
| Campbell River, BC
|
|

If you do that process with a 3/8" dia cylinder and 1/4" dia intersecting
cross holes you'd end up having 4 very thin strips of metal bridges (around
0.010") preventing your cylinder from becoming two separate pieces.

What's that drilled piece use for anyway?



I didn't see where the OP wrote anything about "intersecting" holes, did
I miss something? I always thought a "cross hole" defined just one hole
through a part.

A little drill press vise I've had for over 40 years came with a jaw
block which can securely clamp small round parts. It has "V" openings to
clear drills:

http://home.comcast.net/~jwisnia18/t...e/IMG_0209.jpg

Maybe something like that could help the OP.

That vise also came with another jaw block which can clamp tapered
parts, and if used with the first block can let me clamp tapered shafts,
It has a stub on its lower side which fits in the vise slot and keeps it
from ssliding out sideways:

http://home.comcast.net/~jwisnia18/t...e/IMG_0210.jpg

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

"DoN. Nichols" wrote in message
...

Thank you and all the others.

Are these solid cylinders, or hollow ones like pipe or tubing?
That can make a big difference.

Solid. Sometimes there is a much smaller axial hole (1/8") as well. The
purposes vary. Most frequently they are used to attach gnomons to the
sundial armature.

The flex is why I wondered about whether it was hollow.

I think it is a function of a short piece being held in a v-groove of a
drill press by its end and bending under pressure (that has been the only
way to get near it with a centre drill).

What I would do, assuming that the workpiece is solid, is to
first part off a piece of the same diameter stock in the lathe after
center drilling it and drilling it to just pass the 1/4" drill bit.
This piece should be perhaps 1/4" to 1/2" long.

Then put the workpiece in the vise parallel to the jaws, place
the drilled piece on top of it with the hole vertical, clamp the vise,
and drill through the workpiece using the hole in the part which you
made to guide the drill bit square into the centerline of the workpiece.

You won't need the center drill -- but if you get the drill bits
with split points, you will probably drill more easily.

If you're going to be doing a lot of this, make the guide from
mild steel, and case harden it so the drill bit does not enlarge the
hole as it is used.

Right. I can see myself making a jig along those lines. I have just seen a
nice one on YouTube also. I think the frequency of doing this will justify
it.

====================

If the part is hollow, what I would be tempted to do is to make
up a special jaw for the vise which has a pin which matches the ID of
the workpiece hole. This pin would stick straight out from the fixed
jaw, and you would slide the workpiece over it, and then clamp it in
place with the vise's movable jaw. Mount the vise to the drill press
table so the hole goes right where you want it -- and be *sure* to use
split point drill bits for this, as you don't have a guide to keep the
bit from walking, and normal chisel-point bits *love* to walk on rounded
surfaces.

If you want to be a bit more stable, make two jaws with short
pins to hold the workpiece properly from both ends.

If the two diameters of workpiece have different through hole
diameters, make two sets of pins on the vise jaws -- one for each size.

It probably would not hurt, if you have a lot of these to make
over time, to make up a separate vise with the modified jaws so you
don't have to be swapping jaws frequently.

Hmm ... you *could* also mill pockets just the right diameter i
the opposing jaws.

Note that I'm assuming that the ends are parted off in a lathe
so they are not at an angle. If you are using a hacksaw, you should at
least pop them in the lathe to clean up the ends before drilling.

No doubt the time will come I shall be drilling hollow cylinders and this
will be very useful.

--
Michael Koblic,
Campbell River, BC

Michael Koblic writes:

How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length.
The hole is 1/4"

5C collet in a 5C collet vise.

http://www.use-enco.com/CGI/INSRIT?PMAKA=235-6085

On May 23, 6:06*pm, "Michael Koblic" wrote:
How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

--
Michael Koblic,
Campbell River, BC

A perennial project in The Model Engineer magazine was the cross-
drilling jig. Most consisted of an upside down "V" with some manner
of drill bushing and a clamping mechanism for the part. If you want
to spend some bucks, Heinrich makes them and MSC catalogs them. You
need the drill bushing for accuracy, just going at it on a curved
surface leads to wandering and breakage. I have used a crotch center
in the lathe tailstock to do cross-drilling. I had a Jacobs headstock
chuck to hold the bit, I used a center bit to start with and
progressed from there. The work was long enough to hand-hold. Drilled
the hole first, then cut and faced to length and hole position. It was
low-accuracy, but got the job done. Crotch centers seem to have
vanished from the catalogs, I got mine from Sears waaay back.
Basically a round v-block on a Morse taper shank. One could be made
up easily enough.

Stan

wrote in message
...


snipped

A perennial project in The Model Engineer magazine was the cross-
drilling jig. Most consisted of an upside down "V" with some manner
of drill bushing and a clamping mechanism for the part. If you want
to spend some bucks, Heinrich makes them and MSC catalogs them. You
need the drill bushing for accuracy, just going at it on a curved
surface leads to wandering and breakage. I have used a crotch center
in the lathe tailstock to do cross-drilling. I had a Jacobs headstock
chuck to hold the bit, I used a center bit to start with and
progressed from there. The work was long enough to hand-hold. Drilled
the hole first, then cut and faced to length and hole position. It was
low-accuracy, but got the job done. Crotch centers seem to have
vanished from the catalogs, I got mine from Sears waaay back.
Basically a round v-block on a Morse taper shank. One could be made
up easily enough.




Those Heinrich cross drilling jigs look very neat.

http://www.heinrichco.com/drilljig.htm






Stan

On May 24, 8:06*am, "Michael Koblic" wrote:
How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

--
Michael Koblic,
Campbell River, BC

In article ,
"Michael Koblic" wrote:

How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

If you are doing only a few, what I do is to mill a small flat, and then
spot drill and then through drill with a screw-machine length bit, all
without removing the workpiece from the mill vice. With the milled
flat, it's easy to find the center of the flat, which is where the hole
is drilled. I've used this method to drill diametrical holes in
spherical parts.

If you are making a lot of parts, I'd make something like the
intersecting-holes jig that others have discussed.

Joe Gwinn

On May 24, 9:42*am, Joseph Gwinn wrote:
In article ,
*"Michael Koblic" wrote:

How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

If you are doing only a few, what I do is to mill a small flat, and then
spot drill and then through drill with a screw-machine length bit, all
without removing the workpiece from the mill vice. *With the milled
flat, it's easy to find the center of the flat, which is where the hole
is drilled. *I've used this method to drill diametrical holes in
spherical parts.

If you are making a lot of parts, I'd make something like the
intersecting-holes jig that others have discussed.

Joe Gwinn

A small, motorized, cross drilling spindle that fits the QCTP and is
automatically located on the lathe centre line is an ideal tool for
second operations such as described in the foregoing posts.

Wolfgang

"Michael Koblic" wrote in message
...
How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as
the clamps often interfere with the drill, especially centre drill. I find
it impossible to clamp both ends of the cylinder for the same reason. I
tried drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if
it does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

Ceramics clay and let dry to hold part, end mill to create flat spot, then
drill???

Some variation thereof.

The most helpful step for me, is to make a flat spot on a round surface, as
Joe mentioned.
A small, center-cutting endmill will do a good job, but a file an do just as
well at making a small flat spot.

Many vises don't hold a single small part well, beause the moving jaw often
has some play in it.
Making plates that can be temporarily fixed to the vise jaws (even
double-sided tape), with 2 sets of holes in the plates will allow 2 dowel
sections to be held at the same time (perpendicular to the jaw faces),
ensuring that any vise jaw movement will be canceled.

Drilling 2 sets of holes that are the diameter of the dowel sections, and at
the same horizontal height, should make easy work of creating the small
flats with a narrow file (or the edge of a wider file), since each workpiece
will act as a guide for the file.

The holes in the temporary jaw plates could be blind (thick plates) or thru
holes (thin plates), and it probably won't matter if the workpiees aren't
exactly the same length, as many vises will tolerate less than perfectly
parallel jaws.

The drilling steps could begin with a center drill, but a short, stiff
split-point drill, as DoN suggested (chucked as close to the drill point as
practical) should be adequate, eliminating the need for a center drill.

If for some reason the drill walks, using an automatic center punch or a
slight tap on a prick punch should allow the hole location to be
predictable.

For long workpieces, a set of soft jaws could possibly be machined along the
jaw joining line with a ball endmill (deeper than the workpiece radius), I
suppose (haven't tried it). The resulting trough would hold a round section
at any point for cross drilling at any point along the length.
This holding method would require a fairly well-made precision vise so the
moving jaw wouldn't creep up as the vise is tightened.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Michael Koblic" wrote in message
...
How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as
the clamps often interfere with the drill, especially centre drill. I find
it impossible to clamp both ends of the cylinder for the same reason. I
tried drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if
it does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

--
Michael Koblic,
Campbell River, BC

On Sat, 23 May 2009 23:45:59-0600, Michael Koblic wrote:
On Sat, 23 May 2009, 21:13:11-0600, DoN. Nichols wrote:

Are these solid cylinders, or hollow ones like pipe or tubing? That can
make a big difference.

Solid. [...]

The flex is why I wondered about whether it was hollow.

I think it is a function of a short piece being held in a v-groove of a
drill press by its end and bending under pressure (that has been the
only way to get near it with a centre drill).

You apparently are cutting short lengths and then drilling cross
holes; it might be better to drill first and then cut. That is,
you could drill all the cross-holes in the long piece of stock,
before cutting short pieces to length, on the basis that work
holding for the drill step is more demanding than for the
end-finishing step.

--
jiw

On Sat, 23 May 2009 17:06:05 -0700, "Michael Koblic"
wrote:

How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

Clamp the part in the mill vise with a parallel under it; pick the
height parallel so the top of the cylinder is slightly below the top
of the jaws. Pull the parallel out. Use an edgefinder on the jaws to
center the part under the spindle. Spot with a center or spotting
drill. (Double check to make sure you removed the parallel. g) Drill
to size.

If you're doing this on a drillpress, in place of using an edgfinder,
chuck a piece of the same diameter as the workpiece and lower it
between the jaws to center things up before clamping the vise.

--
Ned Simmons

On Sat, 23 May 2009 17:06:05 -0700, Michael Koblic wrote:

How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length.
The hole is 1/4"

- turn a hardwood dowel to fit inside?
- turn two conical mandrels and clamp them and the piece axially?

--
Przemek Klosowski, Ph.D. przemek.klosowski at gmail