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Some of my upcoming projects will require me to turn a taper. So I have been looking into lathe taper attachments. Everyone that I found requires you to make a contraption that hangs off the back side of the lathe except for one which uses a wheel attached to the crossslide turned by a taunt wire. Don't know if it is kosher to include a link to another site so I copied the post that describes this taper attachment.
Here's a simple taper attachment that is easy to make. It uses a taut wire wrapped around a
specified wheel which is attached to the cross-slide lead screw. The wire is attached to the
lathe bed by means of two stand-offs. This, of course, works for inside, outside, long, or
short taper turning.
Plans for this taper attachment were published by the Home shop Machinist:
Title: An Accurate Taper Attachment for Under $5.00.
Author: J.O. Barbour, Jr.
Issue: March-April 1986 Page 20
How it works: A wheel is machined to an exact diameter needed for a certain taper. This
wheel is attached to the cross slide lead screw. Then a taut wire is wrapped once around
this wheel and fastened parallel to the lathe bed by stand-offs (see photo below).
When the carriage moves it will automatically turn the cross slide in proportion to the
machined wheel...thereby giving the correct taper. The wire doesn't have to be very strong
since most of the stresses are on the cross slide lead screw or carriage. The main thing is
that the wire wrapped around the wheel must not slip...which one wrap should accomplish when
wire is drawn taut.
I think this works great, especially for tapers that need to be made over and over again.
Set up time would only involve the time necessary to attach the wheel and pull the wire
taut.
All parts don't need to be made with any particular accuracy with the exception of the
wheel. This wheel needs to machined very accurately (minus one wire diameter less than
calculated diameter). This is very easily accomplished using the lathe and micrometer. Of
course, the stand-offs need to be strong - but that's not a problem!
Here's an example: Lets say a 1/8" taper per foot is desired and the wire being used is
0.020" music wire. Since the taper is being cut on both sides, the cross slide only needs go
1/16" per foot of carriage travel. If the lathe has a 10 TPI lead screw then the wheel needs
to turn 62.5 percent of a revolution in 12". This means that the circumference needs to be
0.625 X 12 = 7.500" then divide by pi to get a diameter of 2.387". So the final diameter of
the wheel will need to be 2.387 - 0.020 = 2.367".
As one can see, this is very handy as it doesn't depend on the length of material the taper
is to be cut on, as it would be on a tailstock offset, just the taper per foot.
One additional note:
For the wire "clamp" on the stand-offs (which is not part of the article) a small drill
chuck was used. This chuck sells for about $8.00 and can be obtained at most hardware
stores. The chuck comes threaded for a standard size and the bolt used is threaded for about
three inches. Flats were also machined on each side of the bolt so one can use a wrench to
hold the chuck from turning when tightening the wire. In addition, the bolt has a small hole
drilled thru its entire length for excess wire to pass. This setup works great to achieve
the proper tautness of the wire so it will not slip on the precision machined wheel.
Have any of you guys used this type of taper attachment? What do you think?
Here's a simple taper attachment that is easy to make. It uses a taut wire wrapped around a
specified wheel which is attached to the cross-slide lead screw. The wire is attached to the
lathe bed by means of two stand-offs. This, of course, works for inside, outside, long, or
short taper turning.
Plans for this taper attachment were published by the Home shop Machinist:
Title: An Accurate Taper Attachment for Under $5.00.
Author: J.O. Barbour, Jr.
Issue: March-April 1986 Page 20
How it works: A wheel is machined to an exact diameter needed for a certain taper. This
wheel is attached to the cross slide lead screw. Then a taut wire is wrapped once around
this wheel and fastened parallel to the lathe bed by stand-offs (see photo below).
When the carriage moves it will automatically turn the cross slide in proportion to the
machined wheel...thereby giving the correct taper. The wire doesn't have to be very strong
since most of the stresses are on the cross slide lead screw or carriage. The main thing is
that the wire wrapped around the wheel must not slip...which one wrap should accomplish when
wire is drawn taut.
I think this works great, especially for tapers that need to be made over and over again.
Set up time would only involve the time necessary to attach the wheel and pull the wire
taut.
All parts don't need to be made with any particular accuracy with the exception of the
wheel. This wheel needs to machined very accurately (minus one wire diameter less than
calculated diameter). This is very easily accomplished using the lathe and micrometer. Of
course, the stand-offs need to be strong - but that's not a problem!
Here's an example: Lets say a 1/8" taper per foot is desired and the wire being used is
0.020" music wire. Since the taper is being cut on both sides, the cross slide only needs go
1/16" per foot of carriage travel. If the lathe has a 10 TPI lead screw then the wheel needs
to turn 62.5 percent of a revolution in 12". This means that the circumference needs to be
0.625 X 12 = 7.500" then divide by pi to get a diameter of 2.387". So the final diameter of
the wheel will need to be 2.387 - 0.020 = 2.367".
As one can see, this is very handy as it doesn't depend on the length of material the taper
is to be cut on, as it would be on a tailstock offset, just the taper per foot.
One additional note:
For the wire "clamp" on the stand-offs (which is not part of the article) a small drill
chuck was used. This chuck sells for about $8.00 and can be obtained at most hardware
stores. The chuck comes threaded for a standard size and the bolt used is threaded for about
three inches. Flats were also machined on each side of the bolt so one can use a wrench to
hold the chuck from turning when tightening the wire. In addition, the bolt has a small hole
drilled thru its entire length for excess wire to pass. This setup works great to achieve
the proper tautness of the wire so it will not slip on the precision machined wheel.
Have any of you guys used this type of taper attachment? What do you think?
