Lathe chuck adapter

I'm rebuilding my old wood lathe. It was made by Cant Brothers around 1880 as a standard post & beam lathe.
I've now pushed it to beyond its boundaries, making bowls 30" + in diameter. All are from one piece of wood. Most are pretty unbalanced.



All that has created a fair bit of rocking in the headstock at times.
Hence the new design of steel 2x4's, massive pillow blocks and then filling it all with concrete.

(ok - maybe I should be sane and stick with smaller stuff....but what fun is that?)

As above, I always start with a large faceplate. When the piece is more balanced (and much lighter) I reverse it and use my Oneway Stronghold chuck

A machinist is currently creating the spindle, an adapter for the existing chuck and several faceplates.
The spindle face will be 8" OD. Then faceplates will bolt to it.




My concern is the chuck adapter on page 2 - for my Stronghold.

The adapter will (likely) be a faceplate, with a taper cone for the Stronghold.



1 - My preferred solution would be to take a large 8" dia piece and just turn it down to the cone. But I;ve been told that material cost and time outweigh the benefits.

2 - Hence the modified idea of using a standard Oneway adapter and a large bolt from the back.

I'm just a bit concerned about the strength of this, if the piece is still off-balance.

I'd be grateful for any ideas or suggestions.
Thanks

If you do not want to machine the cone and face plate out of the same piece of material, one can machine those separately (with the cone slightly oversized) and weld the two. After welding the cone and the face plate can be finish machined to size and accuracy.

Makes sense.

The point is to be able to mount large, unbalanced pieces of wood (like 200+ lbs).
So there could be quite a bit of radial load.

Would the following be an improvement?



(Or am I just overthinking things, cuz the chuck jaws would just loose grip first?)

The setup you showing is fine and the weld details can be even simpler. As for working large pieces of wood it is hard to say and all depends on the rotation speed, amount of imbalance and tool pressure. The face-plate and taper are mostly adequate, but(as you have observed) the chuck holding force (and the chuck taper mount) are the weak points. Supporting the work at all times with a live centre on the tail-stock will help even if it means making some special jigs.

At the beginning there is always tailstock support.
If I am hollowing from the end, without the tailstock, then there's usually a steady rest.

However, when doing platters, thats not really an option.
(but then, the weight is usually way down)

Platters - THE ART OF DESIGNING IN WOOD

Thanks for the feedback!

That is some nice work. It is too bad you didn't pick up the lathe I had for sale about a year ago. It had a 3" shaft and easily turned jobs in the 6-8' range. It used to be set up over a pit for turning big jobs and was used to turn up to 16' diameter. I sold it for $500 or so and I question how much the guy who bought it will use it.

Hmmm...want to put me in touch with him?

Hamilton is well within my "poaching" range.

I am a bowl turner who has a 20 inch swing Woodfast and a start of a huge swing lathe made from a lumber mill cut off saw mandrel.

Using a mid 1970s Volvo rear axle with the top hat looking brake disk with internal drum for the parking brake would give you a start. Reverse the disk and you have a face plate. You would also have two spindles, lock one side and work on the other. If the axle is stout enough to hold up 1/4 of a Volvo station wagon, it should hold anything you can hang on it.

My South Bend Heavy 10 metal lathe has a 2 1/4 X 8 TPI spindle thread. Those faceplates are fairly easily available.

I would make your spindle the above thread and then make an adapter with female 2 1/4 X 8 to male thread to fit inside your Oneway Stronghold.

Most turners I have read about use a faceplate and bolt the turning ton that, leaving enough meat at the faceplate to cut off when finishing the bottom, or drilling out where the screws went in and gluing in contrasting dowels.

Ed Moulthrop worked big: Redirect Notice

https://static1.squarespace.com/sta...cdf/t/58135f92ebbd1a7bb4a304be/1477664662980/

About half way down this are couple of home made lathes, one swings a 7 foot turning: Albert LeCoff — Wood, Revisited

Some home made bowl lathes: huge home made bowl lathes - Google Search

Here are some people that work big. Search their names to get details of the lathes: WoodTurning - Top 5 World's Biggest Wooden Bowl - YouTube

Paul

Hi Paul,

We're of the same mindset.
Moulthroupe is the one I've looked at closest and my design is similar:
3" OD spindle, massive pillow blocks, bolted onto a concrete block.
But, I still have a 2 large ways, made of 10" steel I-Beams.

The machinist is working on the spindle now.

Hogbin is in my backyard and I've met him before. Partly retired now, still active in woodworking. He's one of really innovative woodworkers, with a huge variety of designs. But his lathe is VERY different and I dont think would work for me.

Stuart Mortimer is the only one I'd not heard of before. Thanks - he has a really interesting machine, that looks to be totally custom:
Stuart Mortimer - YouTube

Nice, but major effort. Maybe one day....