Another coring question

[Brian Brown]

I have never seen this done, and wonder if it can be done. I hope I can describe this so you can understand. I do more shallow bowls than deep, so I am wondering if equal sized bowls can be cored from a blank. Imagine a deepish cylinder mounted on the lathe, and the coring blade entering form the side of the of the cylinder, rather than the face. This would core out multiple bowls the same diameter as the cylinder. Am I smoking wacky weed thinking this can be done? If it can, are any of the systems on the market equipped with blades and mechanisms that can do this?

[Mark Greenbaum]

I saw a video recently of an Oriental man making consecutive bowls on foot or bow powered lathe, from a single log. He used hook gouges to hollow the first, then shape the outside of the first. Thusly he created the inside of the second, and on and on. He made about 15 bowls like that befor breaking them free of each other.

[Bruce Pratt]

In principle yes. For a long cylinder you will either need a really strongly anchored face place or use the tailstock for support, as the cutters will be putting a lot of lateral force on the cylinder, particularly for the first bowls. Otherwise you are talking about the same process that is used for making a set of nested bowls, only done on a different shaped starting blank.

The only problem will be one of grain orientation. If you just mount up a log in the typical orientation for spindle turning, your bowls will all have the grain running vertically in the bowl, which may or may not be desirable. To get the grain running in the usual orientation for bowl, you would need to start with a cylinder of wood which runs from the pith to the sapwood, which would need really big tree, unless you are making very small bowls.

[Jeffrey J Smith]

If it can, are any of the systems on the market equipped with blades and mechanisms that can do this?

Brian: I use the MacNaughton system and routinely slice off blanks for lidded bowls, platters, etc from a prepared blank. I usually use the straight blade, at a slight angle to get a slightly dished blank. it acts like a very large parting tool for this operation. It works great. While I haven't tried coring multiple bowls from a single blank, I wouldn't hesitate to do it (as a matter of fact, I'm thinking I may give it a go as soon as the new shop is up and running. The largest knife in the standard set would allow you to core off shallow bowls the same way. Full disclosure - I use the originl style post/turret with the pins rather than the newer Mark II setup that captures the knife, but I'd think either setup would work as well.

I'd think the biggest challenge would be getting a blank big enough to accommodate the number of bowls you want to wind up with.

As mentioned, tail stock support is needed, and I'd stop short before reaching center and break the blank loose by hand - usually a little bump on the rim does it. I'd start by turning a recess that would allow the blank to be reversed for turning a tenon.

[Reed Gray]

It is possible, but from a time stand point, I think it is much faster to cut out the individual blanks. From a wood saving point, you do save about 1/3. I have a clip up on on You Tube about using the McNaughton where I do that. The clip about the man doing it with the pedal lathe is good, and he does it with the piece mounted end grain ways. As far as being practical (your other post), yes, there are specialized blades for taking mini cores. Valuable if the wood is really special, like rare or highly figures. Not so practical for ordinary wood.

Here's the clip of the pedal lathe, really cool!

https://www.youtube.com/watch?v=zfpo3MasyKQ

robo hippy

[charlie knighton]

thanks Reed....it is cool and very humbling

[Brian Brown]

Really cool video Reed. Working out and turning at the same time, how much better can life get than that? As far as coring goes, I would probably use it almost exclusively for rare burls and figures. I cannot imagine it being practical for run of the mill wood. I have a few burls now that are very expensive, or so exquisite that I cannot imagine wasting most of it. I am just trying to get a feel if coring on a mini is practical enough to look into it more. Thanks for the responses everyone.

[Bill Boehme]

I have never seen this done, and wonder if it can be done. I hope I can describe this so you can understand. I do more shallow bowls than deep, so I am wondering if equal sized bowls can be cored from a blank. Imagine a deepish cylinder mounted on the lathe, and the coring blade entering form the side of the of the cylinder, rather than the face. This would core out multiple bowls the same diameter as the cylinder. Am I smoking wacky weed thinking this can be done? If it can, are any of the systems on the market equipped with blades and mechanisms that can do this?

The purpose of coring, of course, is to make maximum use of the wood that you have. Generally, bowls are turned in face grain rather than end grain. Especially in shallow bowls, the figure in the wood looks far better when you do a face grain bowl. Also, a face grain bowl is much sturdier and less likely to split open. With some wood, an end grain bowl won't hold water ... and that doesn't make it art ... it's just a leaky bowl. Your idea of a long cylinder automatically implies end grain orientation for the bowls and it could be made to work strictly from a technical perspective, but I suspect that very few people would be interested in the results.

[Bill Boehme]

Really cool video Reed. Working out and turning at the same time, how much better can life get than that? As far as coring goes, I would probably use it almost exclusively for rare burls and figures. I cannot imagine it being practical for run of the mill wood. I have a few burls now that are very expensive, or so exquisite that I cannot imagine wasting most of it. I am just trying to get a feel if coring on a mini is practical enough to look into it more. Thanks for the responses everyone.

Given the shape of most burls, the nested bowl method is a lot more efficient use of wood that throwing away wood to make a starting cylinder.

[Bob Bergstrom]

Here's a pic of cutting disks from a large blank. The bowl blank was 8" thick so I used the large MacKnoughton lance to part it off. If the tree were thick enough cylinders could be cut on either side of the pith resulting in cross grain cylinders.

image.jpg

[Reed Gray]

The McNaughton offers the most blade shapes of all the coring systems. The Wood cut is nice, and the large blade is 5 inch diameter. The McNaughton has a learning curve, and best to have hands on, and start with smaller green pieces of some thing like fruit wood. Not too hard, not too soft, just right.

[Hayes Rutherford]

I occasionally turn platter blanks with the McNaughton. Turn the tenon, part off, repeat. Side grain orientation, and a good idea to use the tailstock if only to put a dimple in the center. Angle back toward the tenon dishing the blank out to aid in drying. Once parted off, turn another tenon and repeat.

[Ralph Lindberg]

Very similar to how I do a run of platters.

[Phil St.Germain]

Brian,

I have the woodcut system and have done exactly what you are talking about many times. I typically don;t plan it, but when I am working the bottom of the bowl, sometime things just work out where the blank ends up being taller than usual. Once turned around and in the chuck I will face off the top and then go in from the side very close to the top. If that make sense. When all is said and done I may have two or three same diameter bowls from a single blank.

Phil