Guys,
I got a wanted ad from Machinetools.com and someone is looking for
a CNC lathe with a taper attachemnt??? This makes no sense to me at
all. With a CNC control you can progam in any taper you want.

What am I missing? Is there a real use for a taper attachment on a
CNC lathe?

Randy
Remove 333 to reply.
Randy

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On Wed, 04 Jan 2017 10:39:49 -0500, Randy333
wrote:

Guys,
I got a wanted ad from Machinetools.com and someone is looking for
a CNC lathe with a taper attachemnt??? This makes no sense to me at
all. With a CNC control you can progam in any taper you want.

What am I missing? Is there a real use for a taper attachment on a
CNC lathe?

Randy
Remove 333 to reply.
Randy

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I can't imagine why a CNC lathe would have a taper attachment. I
regularly program and then cut tapers that have very small angles.
When checked on the surface plate with .00005" (half a tenth)
resolution indicators there is no discernable stepping or waviness in
the tapers. When checked with blued gauges there is also no sign of
the taper not being a straight surface. Maybe the person asking
doesn't realize that the taper can just be programmed.
Eric

wrote in message
...
On Wed, 04 Jan 2017 10:39:49 -0500, Randy333
wrote:

Guys,
I got a wanted ad from Machinetools.com and someone is looking
for
a CNC lathe with a taper attachemnt??? This makes no sense to me
at
all. With a CNC control you can progam in any taper you want.

What am I missing? Is there a real use for a taper attachment on a
CNC lathe?

Randy
Remove 333 to reply.
Randy

---
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https://www.avast.com/antivirus
I can't imagine why a CNC lathe would have a taper attachment. I
regularly program and then cut tapers that have very small angles.
When checked on the surface plate with .00005" (half a tenth)
resolution indicators there is no discernable stepping or waviness
in
the tapers. When checked with blued gauges there is also no sign of
the taper not being a straight surface. Maybe the person asking
doesn't realize that the taper can just be programmed.
Eric

Perhaps they never learned trigonometry and want the attachment to
compare / measure / duplicate the tapers on existing parts?

-jsw

On 2017-01-04, wrote:
On Wed, 04 Jan 2017 10:39:49 -0500, Randy333
wrote:

Guys,
I got a wanted ad from Machinetools.com and someone is looking for
a CNC lathe with a taper attachemnt??? This makes no sense to me at
all. With a CNC control you can progam in any taper you want.

What am I missing? Is there a real use for a taper attachment on a
CNC lathe?

This depends on what kind of motors are on the axes, and what
resolution they are capable of. I've got an Emco-Maier Compact-5/CNC
which has stepper motors capable of either 0.01mm or 0.001" resolution
is pretty coarse when asked to cut a Morse taper. I tried a Morse No. 2
taper with it, and it was visibly stepped -- no need to even measure it.
(Remember, 0.001" cutter steps mean 0.002" diameter steps. And since
the machine's native steps were metric, some conversions are off enough
so a 0.002" step actually works out to be 0.003".

So -- yes, *that* machine could benefit from a taper attachment.

However, ones capable of significantly more resolution can
happily cut tapers with the program. This would likely include
machines doing micro-stepping, or machines with servos instead of
steppers.

So -- it all depends, but a better CNC lathe would be preferred
to one with a taper attachment.

Enjoy,
DoN.

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On Wed, 04 Jan 2017 23:58:56 +0000, DoN. Nichols wrote:

On 2017-01-04, wrote:
On Wed, 04 Jan 2017 10:39:49 -0500, Randy333
wrote:

Guys,
I got a wanted ad from Machinetools.com and someone is looking for
a CNC lathe with a taper attachemnt??? This makes no sense to me at
all. With a CNC control you can progam in any taper you want.

What am I missing? Is there a real use for a taper attachment on a CNC
lathe?

This depends on what kind of motors are on the axes, and what
resolution they are capable of. I've got an Emco-Maier Compact-5/CNC
which has stepper motors capable of either 0.01mm or 0.001" resolution
is pretty coarse when asked to cut a Morse taper. I tried a Morse No. 2
taper with it, and it was visibly stepped -- no need to even measure it.
(Remember, 0.001" cutter steps mean 0.002" diameter steps. And since
the machine's native steps were metric, some conversions are off enough
so a 0.002" step actually works out to be 0.003".

So -- yes, *that* machine could benefit from a taper attachment.

However, ones capable of significantly more resolution can
happily cut tapers with the program. This would likely include machines
doing micro-stepping, or machines with servos instead of steppers.

So -- it all depends, but a better CNC lathe would be preferred
to one with a taper attachment.

Interesting. It's a good argument for always building your control
systems with a resolution that's better than the precision of the
device. Had they done that their tapers may not have been _accurate_,
but they certainly would have had better surface finish.

So, I wonder if it would have been worthwhile to turn your taper, and
then run a whetstone over it to smooth it out on the lathe? It's kinda
redneck, but might work out well if you had a good touch (and a flat
whetstone).

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!

"Tim Wescott" wrote in message
...
On Wed, 04 Jan 2017 23:58:56 +0000, DoN. Nichols wrote:


So, I wonder if it would have been worthwhile to turn your taper,
and
then run a whetstone over it to smooth it out on the lathe? It's
kinda
redneck, but might work out well if you had a good touch (and a flat
whetstone).

Tim Wescott

I turned two cast iron spheres (with stems) by cutting steps according
to a spreadsheet calculation and smoothing then with a file. The
spheres are the balls in ball-and-socket joints, running in plywood
sockets so they don't have to be perfect.

It was easy to file until the steps almost disappeared. They
contrasted well enough with the filed surface and their remaining
width was a good guide.

I roughed it out quickly by setting the step size large and ball
radius oversized, then reduced both for the finish pass. The same
spreadsheet defined the sockets.

-jsw

On 2017-01-05, Tim Wescott wrote:
On Wed, 04 Jan 2017 23:58:56 +0000, DoN. Nichols wrote:

On 2017-01-04, wrote:
On Wed, 04 Jan 2017 10:39:49 -0500, Randy333
wrote:

[ ... ]

What am I missing? Is there a real use for a taper attachment on a CNC
lathe?

This depends on what kind of motors are on the axes, and what
resolution they are capable of. I've got an Emco-Maier Compact-5/CNC
which has stepper motors capable of either 0.01mm or 0.001" resolution
is pretty coarse when asked to cut a Morse taper. I tried a Morse No. 2
taper with it, and it was visibly stepped -- no need to even measure it.
(Remember, 0.001" cutter steps mean 0.002" diameter steps. And since
the machine's native steps were metric, some conversions are off enough
so a 0.002" step actually works out to be 0.003".

So -- yes, *that* machine could benefit from a taper attachment.

However, ones capable of significantly more resolution can
happily cut tapers with the program. This would likely include machines
doing micro-stepping, or machines with servos instead of steppers.

So -- it all depends, but a better CNC lathe would be preferred
to one with a taper attachment.

Interesting. It's a good argument for always building your control
systems with a resolution that's better than the precision of the
device. Had they done that their tapers may not have been _accurate_,
but they certainly would have had better surface finish.

Agreed. Granted, this machine was intended as a training
device, not a production machine. As such, it had accessories like a
tool turret, but was fairly small (5" swing, or 2.5" by UK standards.)
I guess that it was small to minimize the damage to people from a crash. :-)

So, I wonder if it would have been worthwhile to turn your taper, and
then run a whetstone over it to smooth it out on the lathe? It's kinda
redneck, but might work out well if you had a good touch (and a flat
whetstone).

Hmm ... maybe, with lots of protection for the ways before
getting something like that near it. I did not trust my ability to
do that precisely enough -- and at the time did not have female and male
taper gauges for a proper blueing check. So instead, I ordered some
blanks with the MT2 on one end, and about an inch and a half of 1"
cylinder soft to turn to needed shape on the other. Using those, I made
a pair of adaptors for some TapMatic heads to my drill press. (Both
required a threaded adaptor (two different sizes), which the CNC lathe
did do fine. And it is my go-to for metric threading, rather than
rebuild the geartrain of the 12x24" Clausing. :-)

Enjoy,
DoN.

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