4 jaw chuck for taig lathe

timothy thorpe · Post by **timothy thorpe** » Wed Jul 18, 2007 2:07 pm

hi, i just exchanged my 3 jaw for a 4 jaw self-centering like i was directed.
now i tryed to chuck a pre-formed stem in the 3 jaw, so i hope it is easier in the 4 jaw? most of the time i will be turning stems for a rod. i jsut have about 40 pre-formed lucite stem to use

thanks

staffwalker · Post by **staffwalker** » Wed Jul 18, 2007 7:07 pm

The system I have come up with to turn a preformed stem on my Taig works very well and I suspect others do something much like it. From the tenon end, I start a short (2.5 inch) 5/32 bit by hand into the small hole the preformed stems come with. I then use a power drill to drill into the stem until the flutes on the bit are buried. I then leave the bit embedded in the stem. I then chuck up the protruding part of the bit in either my 3 jaw or 4 jaw chuck on the Taig leaving about one inch between chuck and the tenon end of the stem. I use a left hand cutter to cut the tenon starting from the chuck toward the stem. If I run the Taig at lowest or second lowest speed I never have any problem. The bit in the stem is so tight it never slips. On short stems I don't need a tailstock but on long stems where there tends to be wobble I place a live center in the center of the button opening which stops any wobble. This system works every time, just remember not to remove the bit from the stem until completely finished. If you take the bit out of the stem you will never be able to get it to hold when you reinsert it.

For Churchwarden stems I do the same and then use a steady rest instead of the tailstock. When I determine where the rest will sit to steady the stem I then wrap the stem at that point with several layers of duc tape so the steady rest doesn't mar the stem.

I have only done this on vulcanite stems and don't know if it will work on lucite.

bob gilbert

kbadkar · Post by **kbadkar** » Wed Jul 18, 2007 7:10 pm

I'm confused by your post.

Anyway chucking a round pre-formed stem in a 3 or 4 jaw won't be any easier or harder one way or another. Trying to chuck a square into a 3 jaw would be a challenge. Why are you chucking preformed stems anyway? Are you try to turn down the tenon to fit a mortise? If so, make sure you have your tenon with the airhole in the live center on the tailstock, then tighten your chuck, and spin to see if it's turning true to center. This method will most likely marr the pre-formed stem. Or, turn it around and put a snug drill bit in the tenon airhole and chuck the bit in a jacobs (drill) chuck.

kbadkar · Post by **kbadkar** » Wed Jul 18, 2007 7:12 pm

Darn, beat again to basically the same post response!

RadDavis · Post by **RadDavis** » Wed Jul 18, 2007 7:52 pm

It's amazing that there are so many different methods for cutting a tenon on a molded stem!

The thing about round molded stems is that they are never really round. They will be much easier to chuck up to spin true in a four jaw chuck. I have used both, and the 4 jaw is much easier.

Bob, I have never heard of anyne doing it the way you do, but if it works, that's great.

What I used to do was put that pointy thing that comes with the lathe in the tail stock and move the tail stock up close enough to the chuck that you can put the smoke hole in the tenon end of the stem onto the point while chucking the stem up. Just leave enough of the stem sticking out that you have the molded tenon part and about 1/4 inch of stem exposed. Move the tail stock back out of the way.

After the stem is chucked, turn on the lathe. If the hole is all wobbly while spinning, then stop the lathe and try again. You should be able to get it to spin pretty true within a few tries.

Cut your tenon with a good and sharp HSS tool, and there's no need for any support at the smoke hole. Just cut away until you get it the right size.

Rad

staffwalker · Post by **staffwalker** » Wed Jul 18, 2007 9:19 pm

Rad wrote.

<<<<<Bob, I have never heard of anyne doing it the way you do, but if it works, that's great. Smile
What I used to do was put that pointy thing that comes with the lathe in the tail stock and move the tail stock up close enough to the chuck that you can put the smoke hole in the tenon end of the stem onto the point while chucking the stem up. Just leave enough of the stem sticking out that you have the molded tenon part and about 1/4 inch of stem exposed. Move the tail stock back out of the way. >>>>>

Rad, I tried the method you describe early on. The problem with the Taig chucks I have, the center is too small to allow the button to pass. Even churchwardens, whose buttons tend to be smaller than other preformed stems, won't pass through the center of my three or four jaw chucks. I wish they would it would be a heck of a lot easier.

bob gilbert

RadDavis · Post by **RadDavis** » Wed Jul 18, 2007 11:34 pm

Hi Bob,

I'm not familiar with the Taig, and I didn't realize that a stem button wouldn't pass through the chuck. That would definitely limit your options.

Rad

timothy thorpe · Post by **timothy thorpe** » Thu Jul 19, 2007 6:44 am

kbadkar wrote:Darn, beat again to basically the same post response!

thanks guys, and yes. i will be turning pre-formed tenons to fit the mortise. only because i have 38 pre-formed stems!!!!! most of them are real thick so i can alter them is the shaping at least.

staffwalker · Post by **staffwalker** » Thu Jul 19, 2007 5:43 pm

<<<Hi Bob,

I'm not familiar with the Taig, and I didn't realize that a stem button wouldn't pass through the chuck. That would definitely limit your options.

Rad>>>

In my exuberance to explain why I was doing things differently than others it appears I goofed. I said the button end would not pass through the Taig chuck but it isn't the chuck. It's the headstock and pulley. The chucks open to about an 1 1/2 inch but the hole through the headstock and pulley is only about 5/16 or so. I have never measured but almost nothing will pass. It is, in my opinion, a major failing on the geeks at Taig not to have engineered around this a long time ago.

bob gilbert

ckr · Post by **ckr** » Sat Jul 21, 2007 10:31 am

I realize that plug tricks are not at the top of the list around here and one should probably be squarely placed in my mouth. BUT

When I used to do molded's I used a rubber plug cut in half with a bevel cut in it.

Line it up while chucked on a drill as previously recommended and make sure each jaw is squarely on the plug

and tighten the jaws down till they squish the heck out of the plug till it budges from the pressure, remove the drill and chuck, and replace it with a the center.

Now this is hard to believe, but this shot is it spinning, true as can be and the stem is protected from getting marked up from the jaws. Too bad the eye of a camera is that fast, I shutter just thinking about it.

Fume in pace, ckr

staffwalker · Post by **staffwalker** » Mon Jul 23, 2007 8:44 pm

Thanks for the plug pics. Why didn't I think of that?

bob gilbert

ckr · Post by **ckr** » Mon Jul 23, 2007 9:06 pm

Bob, if you had 10,000 shares of United Rubber, you'd be pluggin' it every chance you had too.

BUY plugs, ckr

Frank · Post by **Frank** » Tue Jul 24, 2007 2:19 am

ckr wrote:BUY plugs, ckr

I think I'll leave my assorted orifices(orifi?) unplugged for the present, thank you very much!

hazmat · Post by **hazmat** » Thu Jul 26, 2007 11:14 am

When I turn pre-formed stems on my Taig, I always use a live center in the tail stock. I do as Rad suggests, using the center to make sure it's spinning true, but I leave it there and tighten it down into place once it is. I then use a right hand cutting tool and go to work. You have to make sure your stem is tight in the headstock chuck and, yes, it will leave marks. These, however, disappear quickly when you're filing/sanding your stem out. The problem I've always run into with round tapers and the like is the headstock chuck can't hold them well because of the taper. The stem wants to squirt out of the jaws if you don't steady it with the tailstock. This can be interesting or frightening when it happens, depending on your perspective.