shop/home-made taper attachment

[S.L.Schroder]

I would like to see some plans or pictures of a shop/home-made taper attachment that you all may have built. I have a Jet 12x40 PY from about 1983 (not that is matters, I will probably have to adapt any plan to this lathe). I was hoping somebody could point me in the right direction. I tried a search, but I am never very successful with those. Thanks in advance for any help you can give. S.L. Schroder in Wyoming

[EdK]

In the recent issues of "The Home Shop Machinist" there has been a series of articles about making a taper attachment. I think the author was making one for a South Bend lathe but I'm sure it could be scaled up or down to fit just about any lathe. It looks like a challenging project I wouldn't mind tackling some day.

Ed

[S.L.Schroder]

Thank you EdK. Challenging wasn't what I was really hoping for. I will try to find it. I don't subscribe, but maybe I can find it somewhere. I hope I don't let it become a 10 year project.

I would appreciate other ideas as well. S.L.

[Russ Hanscom]

Check the Chaski threads under General discussion - there were several articles within the past year. In several cases, a NOS Jet taper attachment was used; they seem to be quality units and relatively inexpensive. I put one on a Harrison lathe with good results. Taper attachments can also be scratch built.

[DICKEYBIRD]

A simple but effective one is here: http://www.gadgetbuilder.com/Taper.html

I use a boring head in the tailstock to set that end over without disturbing the tailstock alignment.

[DICKEYBIRD]

Here's some instructions I ran across on the web somewhere for using a ball bearing at the headstock & tailstock when using the tailstock set-over method of taper turning. It eliminates the live center galling problem when cutting steeper tapers.

Quote:
"When offsetting the tailstock for taper turning, or using a special
tailstock fixture for the same purpose, the 60 degree center points don't
fit well in the centerholes of the work being taper turned.

This method needs custom-made lathe centers for both headstock and tailstock.
The sharp point is turned off for a short distance, and centerdrilled just
as is done for the work being turned.

Hardened steel balls are captured in the centerholes between the lathe
centers and the work, at each end.

The correct centerhole size is important in relation to the bearing ball diameter.

For a standard 60 degree centerdrill, the opening of the hole at the ends
should ideally be between 88% and 90% of the diameter of the ball. (.389” for my .4325” ball)

If larger, there may not be enough clearance between the lathe center
and work to allow any offset.
If the hole's opening is smaller than 87% of the ball's diameter, only
the corner of the hole's opening will contact the ball and the whole
thing may come loose under heavy cutting pressure.

In practical experience, I've had very good results with this technique
while turning morse taper shanks.

For the purpose of accurately setting the tailstock setover, the effective
length of the workpiece is measured between the centers of each ball.

Just mike the workpiece with the balls in place, and subtract the total of
one half the diameter of each ball.

Be sure to use your favorite tailstock center lube on that end
(I use white lithium grease)." End Quote

Here's a pic of one I made up using a .4375" ball out of an auto front hub bearing.

[S.L.Schroder]

Well thanks again everybody. I will try the boring head and bearings trick. I will also keep thinking about a taper attachment.

[eeengineer]

Here is one approach, made by Jim Sehr, and shown some time ago on the NewJersey Logan Lathe, Yahoo Group.
Its a taper attachment that fits on the cross slide in place of the compound and offers more travel.

I have full details of the construction if you want them.

[aametalmaster]

Here is one i made for my SB 10K lathe. I used a round sine bar and round radiused followers but a square bar and square cut out followers can be used. I used what i had on hand. I remove the cross slide screw co the compound just floats on the cross slide and follows the sine bar. Simple to make and works well. Any more questions just ask. I do have some more pics...Bob aametalmaster@yahoo.com

[BadDog]

Here is one approach, made by Jim Sehr, ...

Its a taper attachment that fits on the cross slide in place of the compound and offers more travel.

Or just get a compound from a larger lathe. Mine has 5" of travel, and I just used it today (and last weekend) to cut a taper just under 5" long. The only real problem is difficulty in consistent feed with the standard handle, but I use a "speed handle" to both keep my hands away from the chips, and provide a smooth and even feed.

Or, get a tracer. A tracer can not only produce tapers, but arbitrary shapes. I got a tracer some time ago, but got as far as the template holder, and just never followed through. I recently got some CNC linear rails which will form the basis of my template holder, so hopefully back on that soon (after my current paying job, which will put my lathe in the clear!).