Cup Chuck

[Perry Hilbert Jr]

2 years ago, I saw a fellow using what I learned is a cup chuck. He was at a craft fair making turning small Christmas tree decorations. His stock was all 2 x 2 Bass and he just used a mallet to pound the stock into the hollow steel cup on the head stock. When the work was finished and parted off, he he extracted the stump of the wood using a knock out rod. I was not then back into turning, and I was quite unfamiliar with technical advances in turning in the 40 years since I was turning. It got me hankering to do some turning so I bought a lathe and started again. But I could find no reference to the kind of tooling he used to fasten the stock to the head stock. Even in catalogs, not on ebay, no where. Then I found a You tube video of a guy turning parts and he seemed to use an identical system. He pounded in the stock with a small hammer and turned without a face plate or tail stock.

This is a video about making music boxes, but the chuck I am talking about is shown starting at 56 seconds.

https://www.youtube.com/watch?v=hDUUqIVxn5c



Two days ago, I was reading Raffan's book about turning and he described a "cup chuck" for use when several items are made using the same size stock. In fact there is even a picture of a piece of wood just hammered into the morse taper of the head stock and to be turned that way. However, I can find no such chucks for sale, although in the UK, they are offerred by Sealey and in Australia by Hercus Ltd.

https://www.grizzly.com/products/Cup-Chuck/G1525?utm_campaign=zPage&utm_source=grizzly.com

http://www.fwhercus.com.au/jrdebay/ebay/Spares/Cup_ChuckA.htm

It would seem that if I was going to turn out several nearly identical items using uniform stock, such a "cup chuck" would save alot of time

Does anyone have experience with such a thing?

[John K Jordan]

They used to be used a lot but I haven't seen one lately. It would be easy enough to machine a cup chuck from scratch if you really wanted one.

Some people do hammer wood into the morse taper but two issues - one, I don't want to apply any hammered force to my headstock bearings, and two, the taper doesn't hold very well and generally needs tailstock support. I often turn a short morse taper on the end of stock to hold long thin spindle work but again, this needs tailstock support (and is not a fast technique) although it has several compelling advantages.

I think one reason you can't find cup chucks now is the near universal use of scroll chucks.

Any scroll chuck will hold the turning square (or round) much more securely with no tailstock support needed for moderate extensions. I often grip stock at least 6 times the diameter to turn multiple short things or one finial or thin spindle.

For the Nova chucks their pin jaws or 25mm jaws are perfect. I turn small things so often I keep 3 or 4 chucks with just these jaws.

For larger stock bigger jaws like the 35mm, 45mm, or long spigot jaws hold very securely. I typically hold an 8" piece of say 1.5" stock and turn several finger tops in a row, no tailstock support needed.

JKJ

[Marvin Hasenak]

I am not familiar with the term "cup" chuck, but it sounds like it is a version of a jam chuck using the headstock. Some of the Japanese folk art turners use a similar system. When I was in Japan at the Army Hospital in 1969, a Japanese national showed me some of his tricks at the Camp Drake hobby shop. If you can show me an example of what you want to turn, I might be able to come up with some sort of system.

I will need to know the brand of lathe you are using and what current chucks tooling etc., you have, along with a picture of the turnings you want to do. Today so many people are so used to buying chucks to fit their needs, that the "art" of turning without chucks is being lost inside of us "old" people, I would rather share it.

[Leo Van Der Loo]

Perry here is what I have on Cup chucks, I never used one, but it seems a very solid holding of pieces of wood, and the bearings are certainly capable of withstanding wedging the wood into them, though they are probably a good size.

file:///Users/leovdl/Desktop/www.youtube.com:watch%3Fv=VhR9ALVd0Js.webloc

file:///Users/leovdl/Desktop/www.youtube.com:watch%3Fv=Cc4mD8t-xOs.webloc


file:///Users/leovdl/Desktop/cup%20chuck.webloc

[John K Jordan]

...and the bearings are certainly capable of withstanding wedging the wood into them,

Wedging? Perhaps. But to use force to pound wood towards the headstock, with a hammer or mallet might ignore the recommendations of the smart people who designed the lathe. Lathe manufacturers are often very clear about this for good reason - it takes special bearings to withstand forces in that direction. I suspect those who care about their tools have read the manual and know this.

From my Powermatic 3520b manual, not generally considered a light weight:

Drive the spur center about 1/4” into the
workpiece, using a wood mallet or dead
blow hammer as shown in Figure ... never
drive the workpiece onto the spur center
while it is mounted in the Lathe spindle.

From a Grizzly manual:

WARNING Do not press the workpiece too firmly with
the tailstock or the bearings will bind and
overheat. ...

From a Nova 1624 manual:

17. DO NOT POUND WORK PIECE into headstock
drive (spur) center when turning between centers.
Pound the drive center into the work piece with a soft
mallet before installing it between centers in the
lathe.
18. DO NOT USE TAILSTOCK to drive work piece into
the drive (spur) center when turning between
centers. Secure work between centers with light
pressure from the tailstock quill action.
and
Warning!
Do not pound work piece into
headstock drive center when
turning between centers or you
may damage the headstock.

From my Jet 1642 manual:

Note: Never drive
stock onto spur while it is mounted in the lathe
spindle.

Anyone is, of course, free to pound anything on his own lathe - I'm certain anecdotal "evidence" abounds from long term pounders that this has not been a problem on their lathe and some of those might even respond to this.

A recent comment on one of the forums I read indicated understanding or experience that lathe spindle bearings normally needed to be replaced every few years. Not true. I wondered if that misunderstand came from applying too much axial force to the headstock bearings, either from constantly overtightening the tailstock or from the common method of seating a blank into a spur center while it is mounted on the lathe. (or from another known cause of bearing problems: over-tightening a drive belt, also warned against in the manuals)

JKJ

[Leo Van Der Loo]

Notwithstanding all the above, the people in these videos have some impressive experience, and a manner of use that to me shows they have done this day in day out for years, seems all the above does not apply in real life with high quality and apropriate size bearings.

[David Delo]

Don't have any experience with cup chucks but did consider it at one time. Was wanting to do offset splits into spheres that had already been formed and was researching ways to do it. Considered vacuum chucking and also looked at a cup chucks system that the Escoulan employs. Was about to pull the trigger on buying one but decided that spending that much money on a new toy that didn't do exactly what I wanted to do wasn't the best investment. However, it does do a few things that are on my bucket list and might try it out in the future. If a cup chuck can take the "shock" of offset turning like this one can, might be a nice addition to the tool addiction toolbox. Here's an older link to a demo.
https://www.youtube.com/watch?v=Jni6Qnth844

[John K Jordan]

Wow, I've seen a number of offset chucks but never that one - it sure has a lot of nice features. I've seen his ball and socket chuck for angling cuts - I wonder if can be fit to the offset chuck. The possibilities with that are mind boggling.

I've done a variety of off axis turning with a standard Nova scroll chuck. It almost hurts my brain to imagine ahead of time the effect of a given axis. I don't have any good photos but this one shows a aluminum "golf tee" turned held only with pin jaws on a scroll chuck, turned with a spindle gouge:

367713

Combine angles and offset and I would have an excuse for insanity!

JKJ

[David Delo]

I'm really not sure if this exact set-up is still available or not, maybe someone with more knowledge will chime in. The video is from 2007 and I think (don't know) he sold out at some point after that so now Vermec has their own Vermec Escoulan chuck. I was looking for something like this but also had vacuum capability. Since it doesn't, I came up with my own home brew that fit a specific application.

[Marvin Hasenak]

I found a reference to a cup chuck in this book. Woodwork Theory by PF Lye. There is a Google book of it, but it doesn't show the appropriate pages of the chuck and some of the description. You will note that pages 54 ad 55 are not shown. It will cost you $10 on Amazon to see the missing pages. https://books.google.com/books?id=RWg30Lf99MEC&pg=PA50&lpg=PA50&dq=cup+chuck+for+wood+lathe&source=bl&ots=JUS4cJhoj5&sig=mqJWCIZNlhZ0SHCkzV_njzqn3ZY&hl=en&sa=X&ved=0ahUKEwjXtd6t8Z7WAhVh0YMKHR8OBqI4FBDoAQhVMAM#v =onepage&q=cup%20chuck%20for%20wood%20lathe&f=false

[Marvin Hasenak]

I'm really not sure if this exact set-up is still available or not, maybe someone with more knowledge will chime in. The video is from 2007 and I think (don't know) he sold out at some point after that so now Vermec has their own Vermec Escoulan chuck. I was looking for something like this but also had vacuum capability. Since it doesn't, I came up with my own home brew that fit a specific application.
Penn State Industries had an offset chuck, cost about $90, but currently on Amazon it is shown as not available, and there is no listing on the PSI website. I have one, it is fun to play with, but not the chuck that is in the video. https://www.amazon.com/gp/product/B00AO01JRY/ref=od_aui_detailpages00?ie=UTF8&psc=1

[Michael Schneider]

JKJ,

Look at the vicmarc offset turning jaws. It does what you say and it is pretty cool.

https://vicmarc.com/index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id=100&virtuemart_category_id=14&Itemid=526

it combines the orig eccentric chuck with offset.

You can do either or both. Woodworker's emporium sells them in the US

One more tool for your pile.....
Michael

[John K Jordan]

JKJ,
Look at the vicmarc offset turning jaws. It does what you say and it is pretty cool.
https://vicmarc.com/index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id=100&virtuemart_category_id=14&Itemid=526
it combines the orig eccentric chuck with offset.
You can do either or both. Woodworker's emporium sells them in the US
One more tool for your pile.....
Michael

Thanks, that looks perfect. The Woodworker's Emporium makes it hard to know what options to buy (or maybe I'm just dense.)

Oh, just searched for a manual and found this: https://vicmarc.com/files/Vicmarc-Escoulen-Manual.pdf Maybe it will provide a clue.

JKJ

[Michael Schneider]

JKJ

Did you see the guide on the Woodworker's Emporium site http://www.woodworkersemporium.com/Vicmarc_V00295-3/ That and the pdf you have may be helpful

Michael

[John K Jordan]

JKJ
Did you see the guide on the Woodworker's Emporium site http://www.woodworkersemporium.com/Vicmarc_V00295-3/ That and the pdf you have may be helpful
Michael

No, I didn't find that yet but I printed and read the manual. All is clear now - I see how the pieces fit together and what is standard, and what options make sense. The combination of the offset and swivel should be powerful. I require one of these. :)

I notice that the tenon must be turned fairly precisely to the right diameter and with with 1-deg taper. That makes sense and explains how it holds so securely. The instructions are to hammer the workpiece into the cup chuck while it is resting on a board or workbench, then mount it into the eccentric chuck on the lathe.

JKJ

[Len Mullin]

If you want an offset chuck, why not build one? Allan Stratton build his own, it seems to work pretty good. You could check it out on his site, it's title is As Wood Turns. I don't know if anyone would be interested in building one, but I thought it was worth mentioning.
Len

[Perry Hilbert Jr]

I found a video of a russian fellow making a cup chuck and then using it. https://www.youtube.com/watch?v=sxm9K3dbTV4

[John K Jordan]

I found a video of a russian fellow making a cup chuck and then using it. https://www.youtube.com/watch?v=sxm9K3dbTV4

Interesting lathe that converts from a wood lathe to metal lathe. Wonder if that is a shop-made conversion. I like the built-in tray that collect the metal chips.

Interesting wood insert for cup chuck. He did roughly round the wood before inserting.

Interesting tool at 8:40 and beyond.

Resulting turning was kind of crude. But not understanding the language, perhaps it was just a quick demo instead of a finished piece.

[Bernie Kopfer]

Thank you John for the well put together reminder to be nice to our headstock bearings. Of course I read those warnings when I first got the lathe but with time and memory loss it was good to be reminded.

[John K Jordan]

Thank you John for the well put together reminder to be nice to our headstock bearings. Of course I read those warnings when I first got the lathe but with time and memory loss it was good to be reminded.

Thank you for the kind remark! I see I wrote that note over 3 years ago. My opinion today is the same. :)