Oval Turning today

[waltben]

I'd been trying to locate an oval turning chuck or lathe that could handle 5 pound and up blocks of wood for over five years, and finally was able to purchase one from Craft Supplies last December. Vicmarc had finally released thier oval turning chuck based on[font=Trebuchet MS, Arial, Helvetica] Prof. Johannes Volmer's design (http://www.volmer---ovaldrehen.de/englisch.htm) with counterbalance weights. This is significantly different than either the DaVinci sliding plate or the Rose engine designs, in that I can turn at much higher speeds without my 700 pound lathe walking across the floor!

Why did I want to turn big oval blocks of wood? I originally started turning to make my wife hat blocks that she uses to hand make ladies hats. I would turn them round, and then have to belt sand them oval - very time consuming, and the crown tops never came out the same. Thus far, I've completed three hat blocks for my wife and have paying orders for three more. After one aborted start, I've got a pecan bowl about half finished. Oval turning is actual turning, but I've found the methods to be quite different.

I'm wondering if anyone else out there has had any experience with the VOD, or with any other oval turning devices.[/font]

 

[Ken Grunke]

Walt, congratulations on your new toy.
You are likely familiar with Dan Bollinger's project:
http://www.claycritters.com/lathe/

 

[Brodie Brickey]

Walt,

What's the part number? I can't find the chuck on Craft Supplies' website.

Thanks.

 

[GA Darling]

Interesting

I'm going to have to look into this oval turning chuck a bit more.

How come I manage to turn ovals without this type of chuck???

GA Darling

 

[waltben]

A few answers . . .

Yes, I know of Dan's oval turning lathe. He built it based on Volmer's design but I'm not any where near as mechanically competent as he is. I can fix broken things very well, but making them from solid hunks of metal isn't my thing.

Now, as to a part number - this thing is the "VOD 300", and you'll have to talk to Rex Burningham himself. I can't say enough positive things about him and Craft Supplies in making the one I have a very usable device (and no, they aren't paying me anything). Be prepared to put a dent in your plastic card though, it isn't cheap and here's a couple more photos to show the insides.

 

[waltben]

A bit more . . .

I'd like to clarify a few things. This chuck lets you to TURN oval objects, but one could also MILL them if it were attached to the right lathe. I believe every turner knows that to turn something means having a rotating piece of wood that the turner applies a stationary tool to. Any machinist will agree that milling is applying a rotating tool to a moving piece. A Rose Engine can be used for either, depending on the kind of tool used (stationary or rotating). Oval turning is not necessarily ornamental turning, and vice versa, but milling is never turning (and vice versa).

 

[sass]

Price

How much did it cost? I can't find it on Craft Supplies web page. Your VOD 300 looks like a lot of fun.... sass

I'd been trying to locate an oval turning chuck or lathe that could handle 5 pound and up blocks of wood for over five years, and finally was able to purchase one from Craft Supplies last December. Vicmarc had finally released thier oval turning chuck based on[font=Trebuchet MS, Arial, Helvetica] Prof. Johannes Volmer's design (http://www.volmer---ovaldrehen.de/englisch.htm) with counterbalance weights. This is significantly different than either the DaVinci sliding plate or the Rose engine designs, in that I can turn at much higher speeds without my 700 pound lathe walking across the floor!

Why did I want to turn big oval blocks of wood? I originally started turning to make my wife hat blocks that she uses to hand make ladies hats. I would turn them round, and then have to belt sand them oval - very time consuming, and the crown tops never came out the same. Thus far, I've completed three hat blocks for my wife and have paying orders for three more. After one aborted start, I've got a pecan bowl about half finished. Oval turning is actual turning, but I've found the methods to be quite different.

I'm wondering if anyone else out there has had any experience with the VOD, or with any other oval turning devices.[/font]

 

[waltben]

Craft Supplies contact

To find out availability and price, call Craft Supplies customer service - 1-800-551-8876, Monday - Friday, 7am-6pm, MST, or email them at service@woodturnerscatalog.com, and ask for Rex. It's not listed in their catalogue yet, but Rex should be able to answer your questions.

 

[waltben]

Here's what it looks like finished

I turned this completely freehand, including the rim treatment. Only problem came when trying to clean off the foot on a small vacuum chuck - the spalted wood had left too much of a surface variation and it came off. My wife said not to worry because it was hers, and I couldn't try to sell it anyway.

 

[seafoam]

[font=Trebuchet MS, Arial, Helvetica]This is significantly different than either the DaVinci sliding plate or the Rose engine designs, in that I can turn at much higher speeds without my 700 pound lathe walking across the floor! [/font]

So how fast can you spin the wood? Is the limit down to the chuck mechanism, lathe bearings or weight of lathe?

 

[waltben]

Turning speed

I don't have an true rpm readout and the chuck gives one rpm out for every two rpm from the lathe headstock. I can tell you I've been turning at about the same speed as I would be without the VOD though. I've had to slow it down for power sanding due to the surface orientation changes away from the centerline.

 

[Claude]

I am sure you enjoyed it very much
The Vicmarc Oval turning device is really fantastic.
In addition it's the less combersome of all such devices to install and use.
As you say, father Xmas does not give it to any body But it sure is a fantastic item.

 

[waltben]

More Woodturning

I submitted an introductory review of the VOD to Fred Holder and he was kind enough to publish it in the current issue of his magazine. Johannes Volmer also has a review of a small German made oval turning lathe in it. I'm attempting to finish my second installment on turning a bowl with the VOD, but keep getting side tracked with things like working to make money. Bummer!

Walt

 

[Paul Rohrbacher]

Oval Chuck

I am making an Oval Chuck that should handle 5#'s.
The slides are 5/8" round bar stock that slide in bronze bushings. The Ring offset is up to 1".

To balance the system, a counter weight chuck runs on the same shaft except that the offset is opposite to the primary chuck. The balance chuck is heavy with provisions to add more weight and to slide it in or out for balance.

The first Oval Chuck I made worked perfectly except for lubrication. I used "V" ways and found that the oil was thrown out and the chuck locked up after 5 min. of run. BUT, I could run at 450 rpm with the lathe not weighted. The lathe ran smooth as if I was turning round.

The Bearers must be adjusted vertically to exactly center on the Ring. Everything on my chuck is adjustable and can be locked in place.

I use a Articulated Hollower that I made. It uses 3/16 Cobalt metal lathe bits. I also have some half round scraper bits.

I have a Laser set up on center. The tool rest is set so the cutting edge of the bit is exactly on center. I don't get a horizontal ridge in the center of the work piece because I am on center. If a ridge appears the Bearers have loosened and need to be readjusted. I now have positive locks to hold the Bearers in place.

All work must be done on the Point of Tranquility, the only place where everything is constant. Every other place on the work piece is a blur.

 

[Sergio Villa]

Vicmarc oval turning attachment is on stock at Woodworkers Emporium. I wanted to buy one but was afraid of the learning curve! Is it a difficult turning to learn?

 

[Gerald Lawrence]

Could this also be done by eccentric turning?

 

[hockenbery]

Could this also be done by eccentric turning?

Short answer is no!
The oval chucks move the piece as it turns so that a fixed spot on the tool rest traces and oval on the work.

In theory you could turn an outside oval with lots of centers. Each center cuts an arc on the outside surfaces. Change it enough and the outside could look oval.
A long time ago, I turned a couple of almost oval lamps. Used two centers to cut arcs on opposite sides of a cylinder and blended the corners with sanding. Result was an oval appearance.

Hollowing an oval bowl requires and oval chuck, although I suppose in theory you could do lots of eccentric plunge cuts if some sort.
Dale Larson has been turning some terrific oval bowls.

Al

 

[Charlie Knighton]

when Alan Lacer demoed at Virginia Symposium in '10, he displayed an oval oak bowl that was way undercut, at the rotation he demoed how to make the cutters to undercut with drill rod, but the oval part not a whisper, i thought at the time he somehow had turned it green and it warped without cracking....... how naive we can be.....an oval chuck......over 3 years later i finally understand

hehehehe....good one Alan....

actually there were 2 turnings, one not undercut

 

[Bill Boehme]

Several years ago (2009) when Alan Lacer was in Fort Worth for a week of hands on training for our club, he brought along an oval chuck and demonstrated its use during our monthly meeting. The oval chuck definitely does have a learning curve and some of the stuff that Alan Lacer demonstrated, "they" said couldn't be done -- maybe not by everybody, but then Alan is not your average turner to say the least.

The first image is a typical oval bowl that was made by Alan and the second is an oval hollow form that he made. I daresay that the oval hollow form isn't something for the beginner.

 

[R Henrickson]

See David Springett's book Adventures in Woodturning on how to build (almost entirely from wood) and use a chuck for oval/elliptical turning. He also has done a DVD on the topic.

 

[n7bsn]

Vicmarc oval turning attachment is on stock at Woodworkers Emporium. I wanted to buy one but was afraid of the learning curve! Is it a difficult turning to learn?

Not terribly, there are enough on-line helps that basic oval turning is, well, no tougher then simple box making.

If you ever want to see tough, there are oval-turned boxes, made in the 16th century that will just blow your mind.

Just showing, that there is very little "new" in the world.

 

[Sergio Villa]

Thank you. I agree with the nothing new. In fact the biggest masterpieces in any kind of art were done before the electronic/computer age...

 

[Paul Rohrbacher]

Oval Chuck/Oval Turning

I have designed an Oval Chuck made of aluminum and steel. The chuck operates like David Springett's with one major exception. I was able to balance the chuck so at 330 to 400 rpm vibration is nil. Using round steel sliders running in bronze bushings, the slider lubrication problem was solved. The Ring Cam and sliders needs a drop of oil every 15-20 min. of run time.

The chuck is totally adjustable to center everything and to take up any looseness. When hollowing I found it beneficial to place a steady rest roller at the Point of Tranquility.

Could anyone doing Oval Turning please contact me to discuss turning tools and techniques.

 

[Mike Stephens]

I have designed an Oval Chuck made of aluminum and steel. The chuck operates like David Springett's with one major exception. I was able to balance the chuck so at 330 to 400 rpm vibration is nil. Using round steel sliders running in bronze bushings, the slider lubrication problem was solved. The Ring Cam and sliders needs a drop of oil every 15-20 min. of run time.

The chuck is totally adjustable to center everything and to take up any looseness. When hollowing I found it beneficial to place a steady rest roller at the Point of Tranquility.

Could anyone doing Oval Turning please contact me to discuss turning tools and techniques.

Id really like to see some pics of your chuck.

 

[Andy Chen]

I have designed an Oval Chuck made of aluminum and steel. The chuck operates like David Springett's with one major exception. I was able to balance the chuck so at 330 to 400 rpm vibration is nil. Using round steel sliders running in bronze bushings, the slider lubrication problem was solved. The Ring Cam and sliders needs a drop of oil every 15-20 min. of run time.

I designed an elliptical turning chuck about 15 years ago after reading a chapter of John Jacob Holtzapffel’s book, The Principles & Practice of Ornamental or Complex Turning. To reduce the machining expenses I used oil-impregnated bronze bushings (similar to Paul’s) and rubbing blocks (no oiling needed). The chuck can be adjusted so the differential of the long and short axes can be anywhere between 0” and 2”. The first picture shows the anatomy of the chuck. The upper left picture shows the setup at 0” offset for turning round and the upper right picture shows 2” offset. The lower left picture shows the back side of the sliding assembly. The lower right picture shows the assembled oval chuck without the mounting plate. A weed pot in the next picture shows the range of the axis variation. The next picture shows a set of nested platters turned with the oval chuck. The last picture shows an oval box with a matching lid which is a challenge to accomplish.

 

[Charlie Knighton]

thanks for sharing, Andy

those are fantastic, no favorite, like them all

 

[n7bsn]

..... A weed pot in the next picture shows the range of the axis variation. The next picture shows a set of nested platters turned with the oval chuck. The last picture shows an oval box with a matching lid which is a challenge to accomplish.

Andy
Amazing.
The transition in the weed pot is impressive, slowly decreasing the offset, smoothly, is difficult.
Not as difficult as as set of nested, assuming you cored them. If you did I am amazingly impressed.
I've been "thought probleming" my way through an oval box with lid, as it's one my list of "things to learn to do"

Ralph

 

[Paul Rohrbacher]

jWonderful World of Oval Wood Turning

The Oval Chuck you made 15 years ago speaks of simplicity and function. The Weed Pot, nesting platters and cocobolo box are wonderful testimonials of how well your chuck functions.

How did you handle the inherent out of balance operation of the Oval Chuck? I would guess that the mass of your lathe was sufficient to dampen the vibrations.

So far, the big problem I have experienced is turning the inside of a wood form. The relief angles on the cutting tools in the interior are constantly changing like experienced on the exterior. But, the interior turning in a deep vessel is blind.

All turning must be done on the Point of Tranquility. Draw an oval line on the Oval Chuck's Faceplate, it will be a blur except at the zero axis, the Point of Tranquility. You will see a shallow "X" formed at this point.

My Oval Chuck is independent of the lathe. The chuck's spindle is driven from the lathe's #2 MT spindle. The chuck can be mounted on the bed of any lathe 12", 14" or 16". By adding the Balance Chuck, the chuck's Ring Cam's are off set opposite to the Working Chuck, which cancels most vibrations caused by the out of balance workings of the Oval Chuck.

I have Emailed Johannes Volmer for his comments on my chuck design. He was disappointed that I had used a 150 year old solution to cancel the balance problem. He is the designer behind Vicmarc ODM and VOD systems. Johannes wrote, Ovalturning dated Aug. 2006, which details his system. The PDF details how the Oval chuck works, in great detail along with his approach to balance the Oval Chuck. Vicmarc also has a PDF instruction manual for their VOD Oval Chuck which is a must read for anyone interested in Oval Turning.