Reverse cone Live center?

[Prashun Patel]

Apologies if this is a dumb question:

Sometimes I have to remount a stretcher on the lathe after I've trimmed, say 5/8" tenons on both ends.

I have pin jaws on my chuck so I'm good at the headstock. But re-marking the center on the live end doesn't work well. I could mount a second chuck on the tail stock, but that's expensive. The tenon is too large to grab in a drill chuck.

This got me thinking, if there was a live center with a convex cone instead of a point, it would self center the tenon, and would be quick. Does such a thing exist? (I suppose I could make one with a 1/2" tenon that I could then grab in the drill chuck...

Alternate suggestions welcome.

[Michael Mills]

The Nova live center has a stepped exterior but it can also be reversed and is smooth on the inside. Can use with round or square stock; I would have to check to see what the minimum inside diameter is. You could also turn one from a block of hardwood pretty easily.

[David M Peters]

Check out live centers with 3/4"-10 threads, Oneway & Robust both make them. Both sell reversible Al cones which should do what you need.

[Steve Schlumpf]

Prashun, sorry but I do not remember what lathe you are using but if it is a Jet, Powermatic or one that uses a Oneway Live Center or a clone of one, it should work for what you want. Well, that is as long as reversing the cone is what will work for you. https://oneway.ca/2%20MT%20Live%20Ce...=live%20center

[Roger Chandler]

+ 1 on Steve’s recommendation of the Oneway live center. It is configurable with several options, is quality made. I have 2 of them, and it will work well on your Laguna 1836.

[Brice Rogers]

Prashun, I suspect that you could turn a cone center that would slip over and around the tip of your existing live center. It could be turned from a dense hardwood, a plastic or even aluminum. Make it a slight press fit, like you would for a lidded box.

BTW, I'm ignorant on what a "stretcher" is. I presume some sort of spindle? For a chair back?

[John K Jordan]

If you want cheap, make one from wood. If you have a live center with a 3/4"x10 tpi thread and a tap, drill and tap a block, thread the block onto the live center, put a piece of wire or something through the hole in the side of the live center to keep it from rotating, then mount it in the headstock as a drive center and turn a cone on the block of wood. I've made a lot of attachments from wood for live centers like this.

You can also just bore a hole in a block that fits snugly over the threads of the live center instead of having to thread it. Should work as well.

If the tenons on all your stretchers are the same diameter you might just bore a hole in the wood block instead.

That said, I have several reverse cones, one that fits the Nova live center mentioned (arguably the most flexible live center available - I bought two) and the other threaded for the Oneway live center and clones. I can't remember where I got it. A potential problem with the Nova reverse cone is if the tenons on your stretchers are smaller diameter than the center hole in the attachment.

There's an easier way to make various wooden attachments for live centers if you have the Nova center. The Nova has a short #2MT in the end. I turn a short Morse taper (about 3/4-1" long) on a piece of wood held in a chuck or between centers, reverse the wooden piece and fit it directly into the taper in the headstock spindle, turn a jam chuck or what ever desired, then take it out of the headstock and put it into the Nova center. This is the method I use now to make custom attachments for the live center.

This is the Nova center and what comes with it (https://www.amazon.com/gp/product/B0064JIZGC). The attachment in the lower right is the combination step/reverse cone. You can see the #2MT socket on the end of the center.

Nova_live_center.jpg

This shows some short #2 Morse Tapers I turn. These are on the ends of spindles but I turn exactly the same tapers on pieces intended to fit into the Nova canter. (I made a little gauge to size the tapers but you can do the same thing with calipers. I always cut the taper first then relieve a bit in the center so the taper rests on just two rings.) I've made hundreds of these.

morse_taper.jpg

JKJ

[Marvin Hasenak]

If you have 2MT tailstock this will work. https://www.pennstateind.com/store/LTCA18.html

[John K Jordan]

If you have 2MT tailstock this will work. https://www.pennstateind.com/store/LTCA18.html

The only warning I've read about putting one end of a piece in a chuck on the live center is inertia from the mass of a heavy chuck can put a lot of torque on a spindle as it accelerates. A small, lightweight chuck might be better, as perhaps very slowly increasing/decreasing the speed. I have a similar adapter but I haven't tried it for holding a turning.

JKJ

[Peter Christensen]

BTW, I'm ignorant on what a "stretcher" is. I presume some sort of spindle? For a chair back?

A stretcher is one of the turned goodies that go between the legs of chairs and stools to help brace them. You can also find them on small tables.

[Marvin Hasenak]

The only warning I've read about putting one end of a piece in a chuck on the live center is inertia from the mass of a heavy chuck can put a lot of torque on a spindle as it accelerates. A small, lightweight chuck might be better, as perhaps very slowly increasing/decreasing the speed. I have a similar adapter but I haven't tried it for holding a turning.

JKJ

I found the best thing is to make a wood adapters. Drill and tap a blank and then turn to size and for a tenon, drill the correct size. I used to make some native style flutes, I would drill the hole and have a driver plug for the headstock and live center plug to fit the screw on live center from PSI.

[Marvin Hasenak]

Easy and cheap way, cost is a 2x2x6 blank.

This is how I would make chair stretcher turning jig. First I would take a 2x2x6 blank of hard wood, drill and tap for the lathe spindle. Mount and drill from the tailstock end with a bit the size of the stretcher tenons. Turn round and turn the working ends to keep them out of the way. Cut in 2 parts in the middle. One end is the spindle driver, the other end when mounted on the stretcher and the drilled hole is stick up to the live center will keep it all running true.

[Brice Rogers]

Marvin, this is a good idea and is very simple to do. Thanks for posting.

[Leo Van Der Loo]

Apologies if this is a dumb question:

Sometimes I have to remount a stretcher on the lathe after I've trimmed, say 5/8" tenons on both ends.

I have pin jaws on my chuck so I'm good at the headstock. But re-marking the center on the live end doesn't work well. I could mount a second chuck on the tail stock, but that's expensive. The tenon is too large to grab in a drill chuck.

This got me thinking, if there was a live center with a convex cone instead of a point, it would self center the tenon, and would be quick. Does such a thing exist? (I suppose I could make one with a 1/2" tenon that I could then grab in the drill chuck...

Alternate suggestions welcome.

Yes they do exist Prashun, if too expensive for you, you could turn one from some hard dense wood , though that would not last for a lot of use.

Here is the Oneway live center set, it comes with the small inside tip and the knockout bar, also a large solid point that can be screwed onto the threaded end,

plus a larger open cone which can be screwed onto the threaded end of the center in two ways, small end forward or inverse with the large open end forward.

A square spindle stock’s end will automatically be centered in the cone, shown here the Oneway live center set and a picture of the center with the large cone installed,

The red wood outline, to show how that will sit inside the large cone, I know some production spindle turners that use this all the time, no need to find the center of the wood used as spindle stock.

Oneway live senter set.jpg center with large cone.jpg

[Bill Blasic]

I have a Oneway, 2 Powermatic, 2 Nova and a Robust. With prolonged use the Oneway and Powermatic live centers get hot, the Robust and Novas do not. The cone for the Robust is a very hardy size, have it but have not used it.