core removal

[Gregg Feldstone]

I have attempted to get two bowls out of this cherry. The outer is about 7". I did this with a skew gouge and parting tool........never again!!! What's the best coring system to get?
The bottom is now only about 1/4" to 3/8" thick.
A crack developed across one edge of the bottom when I attempted to knock and pry the core out. I applied CA immediately. There is still about a 2" diameter attachment at the bottom. I really want to save this bowl and maybe still get the core out intact. My plan is to get more room by going after the sides (of the outer bowl) with my gouge and see what happens. Has anyone ever tried a "string saw" held by a couple needle noose plyers or hemastats and running the lathe at lowest speed (50 rpm for me)? What might I use for the saw? Suggestions welcome.

[Gregg Feldstone]

Correction...I used a skew. Don't know what a "skew gouge" would be.

[Gregg Feldstone]

help tonight pls.

[Scott Hubl]

I chose the Kel McNaughton system.

I looked at several systems talked to alot of Turners and decided it was the one for me.

I bought the "standard" system that Woodcraft sells.
http://i125.photobucket.com/albums/p59/AmericanAndProud/Shopping%20Spree%20Woodcraft/center-saver-2-upc.jpg

http://i125.photobucket.com/albums/p59/AmericanAndProud/Shopping%20Spree%20Woodcraft/center-saver-1.jpg

[Bob Hamilton]

The fellow that does the demo for Oneway's coring system (Dave Lancaster??) put the tool rest against the side of the bowl where he was prying to break the core loose to support the side and keep it from flexing. That was while the piece was still mounted on the lathe, of course.

Just a thought
Bob

[Gregg Feldstone]

How do you like it so far? What made you decide on it over the others?

[Nathan Hawkes]

I don't know if I can provide any help for you, but I've used what you're describing as a "string saw". There are wire saws available for cutting PVC pipe. A braided wire is attatched to two loops on either end; you just pull back & forth. I have no idea how it would work on wood; it would certainly get hot enough to burn it pretty quick. You may actually melt the wire eventually. I just got a McNaughton coring system, but have yet to use it. I just haven't had time yet.

[Scott Hubl]

BIG difference in using the Oneway coring system and coring with just a skew.;)

The Oneway has a curved piece that rides in the cut kerf that the blade rides on.

Or any of the coring systems out there.

A skew is NOT designed to be used as a bowl corer. IMHO.

I sure would'nt attempt it.
I have the Don Pencil Scorpion and Stinger tools and I'd rather use a dedicated coring system for coring.

[Scott Hubl]

I liked it over the Oneway system because you can core different shapes and sizes by how you aim and work the tool.

Your kinda stuck with the swivel point in shape with the Oneway.

I watched Demos of those 2 systems and one other I forgot the name of.
I bought Mike Mahoneys DVD on the McNaughton system and watched it a few times, its more versatile compared to the Oneway. IMHO.

[Bernie Weishapl]

Gregg first let me say you have more guts than I do using a skew to core a bowl. Whew. I have the oneway system and love it. I got to watch both in use and decided on the oneway. I am not that worried about one being more versatile than the other. What I like about the oneway is the ease of use. It does not take hardy any pressure at all to core with it. It just seemed like to me that using the other it just took a lot of work to core with it. Just my humble opinion in watching both being used. Besides I am not in production mode and not in a big hurry.

[Gordon Seto]

Do a search on posts by Reed Gray regarding this subject. He is a production turner. He is a member here. He has a new DVD about different bowl coring systems. I hope he might chime in and correct if what I understand was wrong.

The Oneway has less learning curve, but it lacks the flexibility of the McNaughton. The Oneway cutter is also difficult to sharpen.

In his DVD, he also introduce the laser attachment for the McNaughton which would help where to aim the coring knife.

[Reed Gray]

I got an e-mail about this thread, and since I core a lot, I have to chime in.

First of all, with the project you have going, it isn't easy doing it that way. Best if you have a long deep parting tool, and make a couple of cuts down inside to open it up enough to get the tool all the way down. You need to get the tenon inside down to about an inch for fairly easy break out unless it is crotchwood, or a burl, then you need to cut it all the way off. Usually, I will tap the edge of the core with my hand, or the handle of a big gouge or scraper. A sharp tap, not like you are splitting wood, and driving the maul all the way through.

For the 3 coring systems out there, I prefer the McNaughton. It is the fastest, most versatile, and reasonably priced. The down side is that there is a learning curve. You have to aim, and without the laser, you seem to end up too shallow, or too deep; can you say lamp shade? Start with the medium set of blades. I also use the mini, and on occasion, the large set. The large set maxes out the tool rest, and I don't think you can get bigger with any of the systems. It is just too far out off the tool rest. Most of the time I use the medium curved blade. It works great for the standard bowl. The other blades can be used to core plates and flat bowls, or deeper vessels. The straight blade makes a great deep parting tool.

The Oneway is nice, and expensive, and the cutter is difficult to sharpen. You have to take it off the blade, and hold it up to the grinder. If I was to use this most of the time, I would have a surface grinder of some sort, metal abrasive on a mandril or a belt sander. The major down side to it for me is that it is slower than the McNaughton. On a bigger bowl you have to turn off the lathe 3 or 4 times to advance the support finger. It is predictable because it is on a pivoting center. The support finger does make for less chattering on deep coring.

The Woodcut is a nice small system, the big blade is a 5 inch radius, so you can remove a core slightly bigger than than. There is some chatter with it, especially on bigger cores, and harder woods.

As far as pressure, there will be pressure if your cutters are dull, just like regular tools. Otherwise, little pressure is required to work any of them. With the McNaughton, it tends to drift off course. This can make the blade bind in the cut. Come back to the top, and widen the cut a little. If you are having to force the tool, then some thing is wrong.

Mike Mahoney has a DVD out on using the McNaughton, and so do I. We do things a bit differently. If you get the McNaughton, you probably can't figure out how to use it yourself, you at least need a DVD, or some one who can walk you through it.

Robust robo hippy

[Gregg Feldstone]

Thanks for the advice Reed. Since I do plan to do large bowls on my 3520B I'm thinking of getting the McNaughton standard/large combo set....I might not use all of it for a while, but when I do it seems cheaper to buy all the tools together now than pay more later if purchased separately.
Does the handle supplied work for any other tools?

[Rasmus Petersen]

Reed do you have a site with info on the video and laser system ??

[curtis rosche]

to get his one off, i would say get a cheep parting tool and bend it so that its curved

[Reed Gray]

Gregg,
The handle is a 13/16 opening, and you can put all sorts of 3/4 inch and smaller cutting accessories in it if you have the adapters.

Curtis,
Actually, that isn't safe. If you have hollowed with one of the goose neck tools, you have to have the curve off the tool rest, otherwise the tool will twist out of your hand. The McNaughton has vertical support fingers for the blades to go into to keep this twisting from happening.

Rasmus, I will sent you a PM

robo hippy

[Don Orr]

to get his one off, i would say get a cheep parting tool and bend it so that its curved



DON'T !!!

I tried just that and will never do it again. No support or control = dangerous! Sounded good at the time though:eek:. Beat me up pretty bad and I stopped.

[Bernie Weishapl]

Curtis ditto what Don said. My brother who is to cheap to buy the proper tools tried just that. It cracked his wrist. Now he is a firm believer that you use the proper tool or don't do it. Short cuts usually never work. Think.

[curtis rosche]

ok, the saw method sounds like it would work though, right? alot cheaper

[Gordon Seto]

to get his one off, i would say get a cheep parting tool and bend it so that its curved
Curtis,
Have to rub in to defend those 51 - 61 and above.
Here are couple pictures of demonstrators using the straight parting tool. When you have so much overhanging over the tool rest as in coring, that takes a lot of leverage to counter the force. If you bent a tool and cutting edge is not in line with the handle, the twisting torque would be so great, someone is going to get hurt. If you look at most full size bent tool, they have double bent.

http://i118.photobucket.com/albums/o83/gbseto/KeltonHollower.jpg
This is the picture of Doug Thompson coring the inside of the hat. I don't know how much the undercut was. I took the core out home and made a thin wall bowl. I know I max out on the bowl size, it is only 6½" dia. by 3½" tall. The core was already sticking out before the coring, the depth of the parting tool cut was not that deep. Doug was tucking the X-long handle under his arm and using his body weight as leverage.

http://i118.photobucket.com/albums/o83/gbseto/b38d0853.jpg

This was JoHannes Michelsen doing a hat demo as well. He was coring the outside rim. The core is no more than 3~4" deep. He connected two full size steel handles. He was using the leverage from 1½ handle length.

http://i118.photobucket.com/albums/o83/gbseto/8-18-2007017.jpg

In both cases, the straight parting tools were top of the line, not just any parting tool. If they are using so much weight and long leverage on the handle side, You can imagine the kind of stress the blade is subject to.

In the matter of safety, there is NO substitute for experience. Joking aside , my primary intention is let other aware of the safety issue here. Coring is serious stuff. If the parting tool can be bent easily, I want to avoid it. No wood is worth cored if I have to risk getting hurt.