Coring system for PM 3520

[Rob Price]

As I recently came across some neat blanks from Hawaii (see my other post), I was mentioning to my wife how cool it would be if I had a coring system and could get multiple bowls from some of these blanks, and she said, "Happy Birthday- get a coring system..."

So now I'm getting a coring system. I see oneway uses carbide cutters and seems to be viewed as a easy to use but limited in shape/design.

McNaughton may be less user friendly but more versatile. I lean that way, but how steep is the learning curve? Am I looking at tons and tons of practice? I only ask because my turning time is extremely limited. I turned 4 bowls and roughed out another 4 bowls last year. I'm not afraid to learn new tricks but if it's going to be a year before I can use the system proficiently I man lean towards the Oneway...

Thoughts?

[Greg McClurg]

Check out the Woodcut Bowl Saver...great system.

[JohnC Lucas]

I have the McNaughton. I sat through several demos and thought I knew exactly what to do. I immediately cored some bowls very successfully. Was glad I watched the demos so carefully. Then I went to do another set and fought it and fought it. Actually broke one of the knives. Looking back I think the main problem was not staying on center with the cutter. Even though in theory it is more versatile most people don't do anything but cut half circles. That's what the blades do on any coring system. With the McNaughton you can easily enter the wood at a different angle. Your bowls won't be half circles and there will be more waste but yes you can change the shape. I used the Oneway system when a friend was doing a demo and it is so much easier to use it isn't funny. So my recommendation is either the Oneway or the woodcut. The carbide knives stay sharp longer but I had some carbide knives put on my McNaughton and it didn't help the catch problem. It only cut easier.

[John Keeton]

Rob, other than the obvious benefit of maximizing wood usage, I wonder if any coring system is a wise purchase for you given your limited time. I don’t own one and have never used one, but it seems they are more for a production turner that needs to produce volumes of hemispheric bowls. To me, it wouldn’t seem to add to the creative side of turning nor the enjoyment factor. I am sure those that use them do appreciate their utility and I don’t dispute that. It just doesn’t seem to fit your circumstances. Just a random thought...

[Doug W Swanson]

I have both the McNaughton and Woodcut systems. Like the others have said, the McNaughton allows a little more flexibility with the shape of the bowl. The Woodcut is easy to set up and easy to use but the shapes aren't as flexible.

[Jeffrey J Smith]

I use the McNaughton, and have for several years now. There are several things I like about it, and one large thing that needs to be dealt with. The initial cost is relatively low, the setup time is minimal. These are both positive...the learning curve, with the amount of information and resources available today is, in my estimation, not that great.
The big problem (and I think its true for a lot of operations we do as turners) is that it is essentially an operation that relies on muscle memory - unless you use it on a somewhat regular basis you’re condemned to relearning the basics everytime you pickup the tool.
I think that’s a lot of the frustration some feel with the tool, and why the feeling is that the learning curve is too steep. I make it a practice to revisit the basics and even have a sacrificial piece for a practice run when I need to core. Since I don’t pull it out that often, it helps.

[Reed Gray]

Well, as I have said before, any one who has tried to use the McNaughton swears at it. Any one who knows how to use it swears by it. If you get one, best bet is to have some one do a hands on session with you. I have a video up on how to use it and so does Dale Bonertz. It does have a learning curve, and I would practice on some cheaper wood first rather than the Fancy expensive stuff. The Woodcut and Oneway are both fairly simple to use, and again, it really helps to have a hands on session. They both are on fixed radius posts, so almost idiot proof. Woodcut has 3 blades, so a bit more limited than the Oneway, and the Oneway, with 5 blades, or is it 6, can't remember..., is rock solid on the biggest blade all the way out to the end of the cut. Core in the low speed range, and in the 500 and up rpm range, I don't go over about 800, but don't know for sure because I don't have any kind of read out. If you go too slow, none of them work very well...

robo hippy

[Kyle Iwamoto]

You could get get your investment back with a few successes at coring. Some of our wood are pretty "valuable". I have the McN, and I'm still stuck at making 3 perhaps 4 bowls from a blank. Really not a lot of skill to get 3 bowls from just about any good sized blank. Not up to 5 or 6 bowls just yet. I do know people who can get 5 bowls (with the McN) from the same sized blank that I get 3 from. When you get to that level of comfort with the McN, you can make some bucks selling a set of bowls. Good luck!
As Robo says, trying to core less than 500 RPM, you will only get frustrated.

[Rob Price]

Rob, other than the obvious benefit of maximizing wood usage, I wonder if any coring system is a wise purchase for you given your limited time. I don’t own one and have never used one, but it seems they are more for a production turner that needs to produce volumes of hemispheric bowls. To me, it wouldn’t seem to add to the creative side of turning nor the enjoyment factor. I am sure those that use them do appreciate their utility and I don’t dispute that. It just doesn’t seem to fit your circumstances. Just a random thought...

I hear what you are saying- to me the idea of getting more than one bowl out of each blank is attractive. I just turned some big (for me) 16" NE walnut bowls, and part of me really hated having two trashcans full of shavings and only one bowl to show for it. Green wood is few and far between for me, if I could even get two bowls out of that blank I think it would be worth it personally. I see where some folks shape the outer "money bowl" however they want it then core the rest. I guess if you made the cores thick enough you could still get some variations in shape. I wonder if getting proficient with the system would even speed up my hollowing process.

Plus the wife already said yes so I'm not sure where the debate is ;)

I have a buddy who's in the woodworking business- he presents at the woodworking shows across the country- he doesn't sell bowls but turns a bunch and rubs shoulders with pros and he recommended the Oneway as well. I think the added time investment vs benefits of the McNaughton don't make sense at this point.

EDIT: found this, very helpful: https://www.youtube.com/watch?v=TFpZ8Ta7cWw

[daryl moses]

I have the Oneway and really like it. I just purchased the #2 &#3 knives. Anything that the #1 can core is too small to fool with IMO and I seldom get a blank large enough for the #4.
I usually only try to get two bowls out of a blank as I prefer to leave them a bit thick so I can shape them the way I want.
I can still get three bowls if I want to even though I only have two knife sets if you count the "baby" bowl.
The Oneway really shines when making natural edge bowls.

[Bruce Schoenleber]

...
EDIT: found this, very helpful: https://www.youtube.com/watch?v=TFpZ8Ta7cWw

Watching that video convinced me that Mr Keeton's viewpoint wins. Looks like a whole lot of bother to get one extra bowl out of a 1/2 log.

[JohnC Lucas]

It really depends on the wood. The reason I bought the McNaughton was a lady brought me 3 really nice large Box Elder logs and wanted 3 bowls. she asked if I would do it and how much. Beautiful wood. If I made the 3 bowls all the good shavings would be on the floor. I looked up the price of the McNaughton and then quoted that price as my price for turning the bowls. I cored 3 bowls out of each piece. Got 3 for her and 6 for me plus the tool. The learning curve wasn't that difficult after my first mistakes however I still think the Oneway offers and easy alternative for most people. Very few that I know of use the McNaughton to carve out anything other than semi circular bowls which is what the Oneway does and does it much easier.

[Reed Gray]

It has been a while since I used the Oneway. Interesting approach of using a laser to determine depth of the cut. I had a set of plywood spacers to put between the headstock and the knife/support finger base. I think that is more simple than the laser, but both would work.

robo hippy

[David M Peters]

I'm a hobbyist turner that owns the McNaughton set and am glad to have it as an option. Here is a YouTube playlist (https://www.youtube.com/playlist?list=PLx-U1SrKSjzr75ENqCVhPZI0UKUdnoHQm) including Reed's and Dale's videos, they were very useful.

I didn't find the system to be tremendously difficult to learn but I've yet to perfect its usage, my cores are always a bit off but are usable.

My advice would be to get the OneWay or Woodcut systems and sell it in a year or two if you find hemispherical bowls limiting.

[Kyle Iwamoto]

Plus the wife already said yes so I'm not sure where the debate is ;)



There you have it! Seems the Oneway is the ticket. The boss says OK, I'd drop the big bucks.
Just another tidbit, the McN has straight blades, and a gentle curve. Useful in "coring" plates and vases. You could get 3 or 4 plates from a nice sized chunk of wood. I think the wood loss is much much less than making a bunch of blanks with a chainsaw, and mounting each one. Time saver too. I reverse and jam chuck the plates as they come off, turn the tenon/recess and you can start the next plate.

[Rob Price]

Success! Tried on an 11” Milo bowl. Not huge but hard to come by.
Outside bowl calabash style bowl. Cored an 8” bowl out of the middle as a bonus. I gave myself lots of wiggle room.
Used the laser jig I saw in the video above. I really don’t think it would have been any quicker just to hollow it the regular way.

[Alex Zeller]

How many knives did you get. I assume that's the 9" in your picture. I think the 13 1/4" would make a nice compliment that would allow you 2" thick wall on the middle bowl that would give you plenty to reshape it.

[Rob Price]

I bought the smaller two sizes. I’ll orobably get the third at some point.

[Ralph Lindberg]

Kyle, I frequently use the straight blades for either plates or taking the front off a bowl blank to make a lid for the bowl.
A matching plate set has proven popular...

[John Spitters]

With the OneWay easy core system there is a much easier setup method than what Mike Guyre shows in the video.
On the back side of each of my knives I’ve written down what I refer to as the zero measurement for each knife.
This is the measurement from the outside tip of the cutter to the inside face of the knife baseplate when the tip of the knife is aligned with the Center point of the lathe spindle.
With your knives marked as such you can now draw a registration line on your lathe bed that is in line with the outside face of the jaws on the chuck you will be using for coring your bowl block.
If you want the bottom of your cored out bowl to be 1” thick simply add this to the zero measurement written on your knife, then from the line drawn on your lathe bed set the knife baseplate this accumulated distance back from the line.

If you are looking to get multiple roughout cores from a block, first setup the largest cutter using this method. Now without moving the baseplate install your smallest knife, set up its corresponding support finger and take out the smallest core. Then again without moving the baseplate install the next largest knife and its corresponding support finger and remove that core, continue on to the next knife once again without moving the baseplate.

It’s just that easy.