Joseph Herbert on thu 8 oct 98
June Perry wrote: "and have been terrified to drill the holes for fear of
getting them mis-aligned and really botching it!"
You shouldn t have too great a fear of this operation. If you get the holes
the correct distance apart, the worst that can happen is your bats will only
go onto the pins one way after a pot is thrown.
Tools required: Needle tool, center punch, hammer, metal straight edge, scale
accurate to one thirty second inch, compass or divider, bullseye level, square
or torpedo level, dowel, one eighth inch drill bit, nine thirty-seconds inch
drill bit, electric drill.
On the other hand, the operation can be accurately completed with a few simple
tools (listed above) and some care. First locate the center of the wheelhead.
This can be done by holding a pointed tool, like an awl of needle tool,
vertically on the surface of the slowly turning wheel head. Move the point
toward the center of the wheel until the point no longer moves in a circle.
This point is the center of the wheelhead. Mark it by tapping on the tool so
the point makes a small prick in the wheel head. Take a center punch and
strike the pin prick to define the center.
Inspect the underside of the wheel head to find an appropriate hole location.
Some wheelheads have strengthening ridges on the underside and you should
locate the diameter line to miss these ridges. Using a metal straight edge,
scribe a line that includes the center pin prick across the wheel head. This
is a diameter line across the wheel head. This line can be easily made by
placing the point of the needle tool in the center pin prick and sliding the
straight edge against the tool. Hold the straight edge down on the wheel head
so it cannot move and scribe along the edge with the needle tool. If you keep
the tool in the same vertical position throughout the operation, the line
should be exactly a diameter line. If you hold the tool vertically when you
place the straight edge and then slant it when you scribe the line, the
resulting line will not pass through the center of the wheel head - the object
of our desire.
Locate the bat pin hole centers with a compass or divider. Set the compass
for half the desired diameter of the pin circle. Put the point of the compass
in the center pin prick and scribe the intersection of the diameter line and
the bat pin circle. Mark each pin location with the center punch. Inspect
the center punched locations with a magnifying glass and an accurate rule.
The center punched marks should be right on the diameter line and within one
thirty-second inch of the pin circle mark. Check the separation of the center
punch marks to assure the separation of the holes will be within one thirty-
second inch of the desired separation.
Drilling the holes requires two drill bits, one for a pilot hole, one for the
final hole. Do not skimp on the pilot hole. This hole increases the accuracy
of the hole location. The pilot hole should be smaller than one eighth inch
in diameter. The final hole size is a clearance hole for what ever size bat
pins you choose to use. If you are using socket head screws, the screw size
is one fourth inch and the proper drill size is nine thirty-seconds inch.
The holes should be as parallel to the wheel axis as possible. This can be
accomplished as follows: Purchase a Bullseye level - a round device filled
with fluid, and a bubble, having a curved upper face that is marked with a
bubble sized circle in the center. When the bubble is exactly in the circle,
the surface the level is sitting on is level. Make sure the wheel head is
level using this device. Once the wheel head is level. Chuck a long drill
bit or dowel in the chuck of your electric drill. Using a square or level,
orient the drill so the dowel is exactly vertical. When the dowel in the
drill is exactly vertical, attach the bullseye level to the back of the drill
so it shows exactly level. You can do this with clay and tape, chewing gum,
hose clamps, whatever.
Now you are ready to drill the holes. With the pilot bit in your electric
drill, carefully locate the drill point in one of the bat pin circle pin
pricks. Orient the drill to vertical using the bullseye level and drill
through the wheel head. Repeat the operation on the second bat pin circle pin
prick. Change to the clearance drill bit. Orient the drill exactly
vertically using the bullseye level and drill the clearance holes by letting
the drill bit follow the pilot holes.
If you don t like the holes, fill with epoxy and try again on a different
diameter. Or you can take the wheel head to a machine shop and let them do
it.
Joseph Herbert
JJHerb@aol.com
Richard Gralnik on fri 9 oct 98
Joseph,
This is a great set of instructions. I had the same fear of screwing up
my wheelhead, but I found a neat tool at Harbor Freight that basically
holds different diameter drill bits square to a flat surface. Just put the
guide on the wheelhead, slip the drill bit through the guide and drill.
To make sure the drillbit drills on your punched marks, try using
brad tip bits. These have a small point that will catch in your punch
and help make sure the hole goes where you intended it.
Also, if you screw up, there is an aluminum putty you can buy to fill
in the oops hole. Epoxy putty is another good way to patch the mistake.
Richard
At 09:35 AM 10/8/98 EDT, you wrote:
>----------------------------Original message----------------------------
>June Perry wrote: "and have been terrified to drill the holes for fear of
>getting them mis-aligned and really botching it!"
>
>You shouldn t have too great a fear of this operation. If you get the holes
>the correct distance apart, the worst that can happen is your bats will only
>go onto the pins one way after a pot is thrown.
>
>Tools required: Needle tool, center punch, hammer, metal straight edge, scale
>accurate to one thirty second inch, compass or divider, bullseye level,
square
>or torpedo level, dowel, one eighth inch drill bit, nine thirty-seconds inch
>drill bit, electric drill.
>
>On the other hand, the operation can be accurately completed with a few
simple
>tools (listed above) and some care. First locate the center of the
wheelhead.
>This can be done by holding a pointed tool, like an awl of needle tool,
>vertically on the surface of the slowly turning wheel head. Move the point
>toward the center of the wheel until the point no longer moves in a circle.
>This point is the center of the wheelhead. Mark it by tapping on the tool so
>the point makes a small prick in the wheel head. Take a center punch and
>strike the pin prick to define the center.
>
>Inspect the underside of the wheel head to find an appropriate hole location.
>Some wheelheads have strengthening ridges on the underside and you should
>locate the diameter line to miss these ridges. Using a metal straight edge,
>scribe a line that includes the center pin prick across the wheel head. This
>is a diameter line across the wheel head. This line can be easily made by
>placing the point of the needle tool in the center pin prick and sliding the
>straight edge against the tool. Hold the straight edge down on the wheel
head
>so it cannot move and scribe along the edge with the needle tool. If you
keep
>the tool in the same vertical position throughout the operation, the line
>should be exactly a diameter line. If you hold the tool vertically when you
>place the straight edge and then slant it when you scribe the line, the
>resulting line will not pass through the center of the wheel head - the
object
>of our desire.
>
>Locate the bat pin hole centers with a compass or divider. Set the compass
>for half the desired diameter of the pin circle. Put the point of the
compass
>in the center pin prick and scribe the intersection of the diameter line and
>the bat pin circle. Mark each pin location with the center punch. Inspect
>the center punched locations with a magnifying glass and an accurate rule.
>The center punched marks should be right on the diameter line and within one
>thirty-second inch of the pin circle mark. Check the separation of the
center
>punch marks to assure the separation of the holes will be within one thirty-
>second inch of the desired separation.
>
>Drilling the holes requires two drill bits, one for a pilot hole, one for the
>final hole. Do not skimp on the pilot hole. This hole increases the
accuracy
>of the hole location. The pilot hole should be smaller than one eighth inch
>in diameter. The final hole size is a clearance hole for what ever size bat
>pins you choose to use. If you are using socket head screws, the screw size
>is one fourth inch and the proper drill size is nine thirty-seconds inch.
>
>The holes should be as parallel to the wheel axis as possible. This can be
>accomplished as follows: Purchase a Bullseye level - a round device filled
>with fluid, and a bubble, having a curved upper face that is marked with a
>bubble sized circle in the center. When the bubble is exactly in the circle,
>the surface the level is sitting on is level. Make sure the wheel head is
>level using this device. Once the wheel head is level. Chuck a long drill
>bit or dowel in the chuck of your electric drill. Using a square or level,
>orient the drill so the dowel is exactly vertical. When the dowel in the
>drill is exactly vertical, attach the bullseye level to the back of the drill
>so it shows exactly level. You can do this with clay and tape, chewing gum,
>hose clamps, whatever.
>
>Now you are ready to drill the holes. With the pilot bit in your electric
>drill, carefully locate the drill point in one of the bat pin circle pin
>pricks. Orient the drill to vertical using the bullseye level and drill
>through the wheel head. Repeat the operation on the second bat pin circle
pin
>prick. Change to the clearance drill bit. Orient the drill exactly
>vertically using the bullseye level and drill the clearance holes by letting
>the drill bit follow the pilot holes.
>
>If you don t like the holes, fill with epoxy and try again on a different
>diameter. Or you can take the wheel head to a machine shop and let them do
>it.
>
>Joseph Herbert
>JJHerb@aol.com
>
>
June Perry on fri 9 oct 98
Wow! Thanks for those good instructions! I didn't think about a pilot hole and
that somehow gives me a feeling of security about doing that job.
I'm an old hand with the drill, but have never attempted drilling through a
chunk of metal. I already figured I'd center one of my bats on there with clay
and then take the pin tool or a metal scribe and outline the holes. My biggest
concern was being able to hold the drill perfectly upright and keep it stable
during the drilling. The pilot hole suggestion if great and eliminates that
worry.
Hopefully, in the next couple of days I'll be able to get into the studio and
tackle that chore! I did too much lifting yesterday, thinking my back was out
of the woods, and I got a clear message via pain, that I'm rushing things. :-(
Thanks again for all the help. What a great group this is!
Warmest regards,
June
Bill Amsterlaw on sun 11 oct 98
Hi Clayart:
<< terrified to drill the holes for fear of getting them mis-aligned and
really botching it! >>
Rather than answering the question of how to drill bat pin holes, I would
ask the question: Why use pins?
I have been trying to do as much throwing as possible right on the
wheelhead. I think that the asymmetry and/or marks introduced by removing
the pot from the wheelhead is a good thing.... I removed the pins from my
wheelhead.
But if I want to use a bat, it sure is easy to just throw a flat patty of
clay onto the wheelhead to stick bats to. You put a spiral groove into it
to prevent trapping air bubbles under the bat. In use, you wet the patty,
put on a bat, tap to center, press it on. No fiddling to match up the holes
with the pins. To remove the bat, gently pry it with a big screwdriver to
break the suction. You can do this with bats of varying sizes ... and even
use square bats. The bats don't need to be drilled with holes. You can
use the same patty all day because you re-wet it before you stick on a bat.
You might prefer pins for huge bats, but the patty system should work fine
for bats up to 20" diameter or so.
- Bill Amsterlaw (wamster@slic.com)
Plattsburgh, NY
June Perry on mon 12 oct 98
Bill, I find it a lot faster to use bats. I throw with very soft clay and
often throw quite thin and sometimes like to take a partly throw npot off and
let it firm up a bit before I do more work on it. Recenter a bat with a pot
on it, on a clay patty is not as fast as just putting the bat back on the
pins. I do use the clay patty method if I'm doing a whole bunch of mugs that
I'm going to throw and trim all at once, but for plates where I use really
soft clay, and then come back later and flatten the rim, or for two part
pieces that I want to firm up, it's much easier and less time consuming to use
the pins.
I remember my professor showing us how to slide the pots off the wheel head,
using a pool of water to help the pot along, but that doesn't work too well
when I use such soft clay and am throwing thin; but it does work well
otherwise.
Warm regards,
June
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