I'm working on a mould that has a platen with nine cavities. They're simple
holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch taper, top
to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would interfere
with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be in
service two or three months before its replacement machine is finished.

Any suggestions are darned welcome!

LLoyd

Buy a Wolhaupter boring head on ebay? Those things can bore a taper, I believe.

GWE

Lloyd E. Sponenburgh wrote:

I'm working on a mould that has a platen with nine cavities. They're simple
holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch taper, top
to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would interfere
with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be in
service two or three months before its replacement machine is finished.

Any suggestions are darned welcome!

LLoyd

"Grant Erwin" wrote in message
...
Buy a Wolhaupter boring head on ebay? Those things can bore a taper, I
believe.

GWE
I looked one up, and unless it's to be used like a circle cutter in some
configurations, I don't see how it could. It tilts, it expands, it follows
a pilot, but I can't see how it would change its diameter as it cut. Never
used one, so I certainly may be wrong.

One thing, though... it's big. These are only 1.75" holes.

LLoyd

"Lloyd E. Sponenburgh" wrote in message
...
I'm working on a mould that has a platen with nine cavities. They're
simple
holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch taper, top
to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would
interfere
with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the
platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be in
service two or three months before its replacement machine is finished.

Any suggestions are darned welcome!

LLoyd



Make a single flute cutter on the grinder with the proper taper. Or, 3D
machine on a cnc, or, ram burn on an edm.

Hey Lloyd,

Any possibility of using plugs. Make the 9 cavity holes say 3",
straight sided. Turn 9 "plug" inserts 3"OD on the lathe with the
proper diameter and draft angle ID, then weld them in place into the
tool.

Just a thought.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXXXXXXXX

On Wed, 11 Jan 2006 19:09:18 GMT, "Lloyd E. Sponenburgh"
wrote:

I'm working on a mould that has a platen with nine cavities. They're simple
holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch taper, top
to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would interfere
with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be in
service two or three months before its replacement machine is finished.

Any suggestions are darned welcome!

LLoyd

"Brian Lawson" wrote in message
...
Hey Lloyd,

Any possibility of using plugs. Make the 9 cavity holes say 3",
straight sided. Turn 9 "plug" inserts 3"OD on the lathe with the
proper diameter and draft angle ID, then weld them in place into the
tool.

Well, yeah... so far that's my only option. But the tool is (almost) a
throw-away, so I'd hate to do the extra 9-up machining if I can machine the
taper directly into the cavities during the boring cycle.

LLoyd

In article ,
says...
I'm working on a mould that has a platen with nine cavities. They're simple
holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch taper, top
to bottom (increasing).


Shopmade D-reamer. Or for a hole that big you could make a single flute
reamer with an inserted tooth. Use a square tool bit for the insert and
grind the appropriate rake and relief on the edge.

Ned Simmons

Used end mills are cheap. You might buy one and have a
tool & cutter grinder grind the taper on it. There is one on Ebay 7578883449
with a buy it now price of $1.25 and
$8. shipping. And seller says he has more sizes.
I don't think it would cost too much to grind.
Jim

"Lloyd E. Sponenburgh" wrote in message
...
I'm working on a mould that has a platen with nine cavities. They're
simple holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch
taper, top to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would
interfere with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the
platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be in
service two or three months before its replacement machine is finished.

Any suggestions are darned welcome!

LLoyd

Lloyd E. Sponenburgh wrote:

I looked one up, and unless it's to be used like a circle cutter in some
configurations, I don't see how it could. It tilts, it expands, it follows
a pilot, but I can't see how it would change its diameter as it cut. Never
used one, so I certainly may be wrong.

I have a Wolhaupter (I'm from of Wohlhaupter-land) and it can make
tapers.

BUT:
This works only if you can adjust the RPM of the spinde and the feed of
the table (Z-axis I guess) in a way that fits the taper. Wohlhaupters
have buttons you press (4?) and each pressed button either increases or
decreases the diameter of the hole by 1/100 mm per revolution of the
spindle. Now if feed and RMP match the taper you can get what you want,
or even conical threads.


One thing, though... it's big. These are only 1.75" holes.

No problem with that. I did made holes (cylindrical) of about 10mm.
Depending on the bit, you can make 4mm to 200mm (or so) diameter.

Very nice tool!


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO - YADRO - Eigenbau-Digitalanzeige

You are probably thinking of the Tree boring head, which does tapers. So
far as I know the UPA series of Wohlhaupters does not. They are things of
beauty, though.

"Grant Erwin" wrote in message
...
Buy a Wolhaupter boring head on ebay? Those things can bore a taper, I
believe.

GWE

Lloyd E. Sponenburgh wrote:

I'm working on a mould that has a platen with nine cavities. They're
simple holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch
taper, top to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would
interfere with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the
platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be
in service two or three months before its replacement machine is
finished.

Any suggestions are darned welcome!

LLoyd

"Lloyd E. Sponenburgh" wrote in message
...
I'm working on a mould that has a platen with nine cavities. They're
simple holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch
taper, top to bottom (increasing).

INCREASING?!?!?! Larger at the bottom than at the top? On a manual mill?
Wow.

If the holes were to have normal draft--smaller at the bottom--I can think
of a couple of
ways to do it without breaking the bank. But larger at the bottom? What
the heck is it
that the platen does? What kind of mould uses a hole with reverse draft?

"Bill Marrs" wrote in message
...

"Lloyd E. Sponenburgh" wrote in message
...
I'm working on a mould that has a platen with nine cavities. They're
simple holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch
taper, top to bottom (increasing).

INCREASING?!?!?! Larger at the bottom than at the top? On a manual
mill? Wow.

If the holes were to have normal draft--smaller at the bottom--I can think
of a couple of
ways to do it without breaking the bank. But larger at the bottom? What
the heck is it
that the platen does? What kind of mould uses a hole with reverse draft?

Heh, heh! I wondered if anyone would catch that. Actually, with a bit of
oddleg fixturing, I can invert the platen during machining... it's just got
a bunch of 'interference' all over the top.

This mould has material applied from the top, then pressed out by ejectors
through the bottom. That's the 'why' of the inverse taper.

LLoyd

"Ned Simmons" wrote in message
...
In article ,
says...
I'm working on a mould that has a platen with nine cavities. They're
simple
holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch taper,
top
to bottom (increasing).


Shopmade D-reamer. Or for a hole that big you could make a single flute
reamer with an inserted tooth. Use a square tool bit for the insert and
grind the appropriate rake and relief on the edge.


I think this may be my best solution... Somehow it never occurred to me that
I could do it with a single flute... but I guess I don't see why not.

LLoyd

Heh, heh! I wondered if anyone would catch that. Actually, with a bit of
oddleg fixturing, I can invert the platen during machining... it's just
got a bunch of 'interference' all over the top.

This mould has material applied from the top, then pressed out by ejectors
through the bottom. That's the 'why' of the inverse taper.

OK--I agree with the D reamer concept. I've used them myself for oddball
tapers. Also
made a few fluted reamers over the years.

Here is one more possible method, assuming you have DROs on your mill:
Purchase a tapered endmill in the appropriate taper. Get one with a little
size/stiffness to it. I use a 3/4" x 3" long 2 degree for a lot of draft
work on thermoforming moulds.

Rough in you holes to the minor diameter. Figure your "toolpath" as a bolt
circle, the more
points the better. Circle diameter is minor diameter minus tip diameter of
cutter. Machine
then hand blend as needed. If you use a large cutter, very little blending
is required.

I did some tapered bores in a billet aluminum intake manifold I made
for a Jaguar engine with a Wohlhaupter. I boring head I used had
several radial feed rates one of which when combined with the vertical
feed on the mill happened to give the taper I needed. Not ideal, but
it worked. I just reversed the mill motor at the end of each pass.

Mike Henry wrote:
You are probably thinking of the Tree boring head, which does tapers. So
far as I know the UPA series of Wohlhaupters does not. They are things of
beauty, though.

"Grant Erwin" wrote in message
...
Buy a Wolhaupter boring head on ebay? Those things can bore a taper, I
believe.

GWE

Lloyd E. Sponenburgh wrote:

I'm working on a mould that has a platen with nine cavities. They're
simple holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch
taper, top to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would
interfere with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the
platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be
in service two or three months before its replacement machine is
finished.

Any suggestions are darned welcome!

LLoyd

I did some tapered bores in a billet aluminum intake manifold I made
for a Jaguar engine with a Wohlhaupter. I boring head I used had
several radial feed rates one of which when combined with the vertical
feed on the mill happened to give the taper I needed. Not ideal, but
it worked. I just reversed the mill motor at the end of each pass.

Mike Henry wrote:
You are probably thinking of the Tree boring head, which does tapers. So
far as I know the UPA series of Wohlhaupters does not. They are things of
beauty, though.

"Grant Erwin" wrote in message
...
Buy a Wolhaupter boring head on ebay? Those things can bore a taper, I
believe.

GWE

Lloyd E. Sponenburgh wrote:

I'm working on a mould that has a platen with nine cavities. They're
simple holes 2" deep and 1-3/4" i.d., but need to have 5-thou per inch
taper, top to bottom (increasing).

I can buy a taper reamer -- OOF! $300 bucks; but this is a one-off job.

The platen plate is too large to put on my rotary table, and mill the
cavities to a taper. I could reach some of them, but others would
interfere with parts of the mill.

I don't know anyone locally who has a lathe big enough to swing the
platen.

I can, but would hate to, make tapered sleeves and press them into the
platen on what amounts to a disposable device. It'll probably only be
in service two or three months before its replacement machine is
finished.

Any suggestions are darned welcome!

LLoyd