On Tue, 12 Dec 2017 17:23:04 -0500, Ed Huntress
wrote:

On Tue, 12 Dec 2017 14:57:53 -0700, Bob La Londe
wrote:

On 12/12/2017 2:31 PM, DoN. Nichols wrote:
On 2017-12-11, Bob La Londe wrote:

I watched one the other day that was a sort of interesting trick for
turning tapers "between centers." You put a boring head in the tail
stock. For low angle tapers you can just put a center in the boring
head, and for sharper angles you can use a cup with a ball bearing in
the chuck and the boring head. I get all of that and it makes sense.
What got me and the guy makign the video didn't show (or I missed it) is:

How do you make sure the center or ball bearing cup in the boring head
is on center vertically?

Perhaps put a level on the dovetail with it extended a bit?

Since I don't have to turn a lot of tapers I thought this might be a
nice stop gap technique instead of making a taper attachment for my lathe.

Many (though not all) lathes have provisions for offsetting the
tailstock to do taper turning between centers. You loosen the tailstock
clamp to the bed, loosen a screw in the middle of the back side of the
tailstock, and tighten the one in the front side to move the tailstock
ram back. (Or the other way around, to move it towards you, depending
on whether you want the big end of the taper towards the tailstock or
the headstock.) With this, there is no question as to whether the
height of the center is correct.

However, you need to come up with a way to set the tailstock
back on horizontal center when you are done. There are various tricks
for this.

The two lathes which I have had which do not have this feature
are the Unimat SL-1000 (on that, you rotate the headstock to shift the
tip back or forward), and the Emco-Maier Compact-5/CNC, which being a CNC
lathe, can do tapers without the trick. However, the same tailstock is
used on the manual Compact-5, so there such a trick would be useful.

Enjoy,
DoN.


Yeah, a couple folks have said, "Just offset the tail stock BOY!!!" LOL.

I donwanna. LOL.

On the same work piece I need to have the tail stock in line, and
separately I need to be able to turn the longish taper. I might have
mentioned I might need to do a few of them down the road. I had already
resigned myself to building a guide rod style taper attachment when I
ran across the other offset adapter ideas like the boring head idea.
Then somebody pointed out the purpose built adapter that's dead cheap.
I reckon I can level that faster than I can put a guide rod taper
attachment on the lathe.

I tend to spend way to much time thinking about these things looking for
the easiest way to get a satisfactory result.


That is not a bad thing. It will save you from doing a lot of
time-consuming or expensive things that you'll want to kick yourself
for when you finally *do* realize what the easy or cheap way was. g

These days, I just sit and think about little jobs before tackling
them, if it's something I haven't done before. Fortunately, nobody is
watching me or paying me to do it.

In the Air Force shops there used to be a joke - maybe it actually
happened. The inspector comes in the shop and one guy is just sitting
there staring off into space and a second guy is frantically turning
pages in the Machinery's Handbook and scribbling numbers on a piece of
paper.

The Inspector marks the guy staring off into space as "Not Working"
and the guy with the book as "Working" when in actual fact the guy
staring off into space was calculating the number and sequence of "set
ups" he would use to machine the part and the guy with the book was
trying to figure out how to cut threads :-)
--
Cheers,

John B.