Coring Tools

[Frank Kobilsek]

In March I moved up from the Jet 1642 to the PM3520B. My Dad was in my shop so much I had to give him the 1642 so I could get some work done.

I had been coring with a Woodcut system. The 1642 lacked the power to core with much speed but I got by. The toolpost on the Woodcut Sytem is too short for the Powermatic. Therefore I need to make a decision to make a special tool post adapter or replace the coring system. So here are my questions.

McNaughton: I tried the system once in Provo under the supervion of Mike Mahoney. This goes back 3 years but even with Mike at my side the thing just plain scared me. How long does it take to build confidence?

Oneway: It looks like it works similar to the Woodcut except it has the 'Support finger' for the blade. But the support finger is on a separate post and looks like you have to loosen a bolt to advance it under the blade as you go into the bowl. That part just doesn't make sense to me. Someone explain that.

Right now I'm leaning toward the Oneway if I can get over the How it works question, but I welcome getting talked into the McNaughton.

Got my silly stimulus check from the goverment yesterday and I intend to do some stimulating with it.

Frank

 

[Bill Pottorf]

Frank, it doe's not take long to get comfortable with the McNaughton System. I have been using it for at least 4 years and have no qualms about using it. I feel as comfortable with those tools as with any of the other gouges, skews and tools I turn with. You do need some horsepower for the coring operation and the PM3520 will perform well.

I have not tried the Oneway System but have observed one being used. Therefor, I am not going to downplay it. My personal feeling is that you are stuck with a fixed radius coring which I personally would not always want. I prefer the flexibility of the McNaughton, even though I do have a Oneway lathe and lot's of their other tools.

Mike Mahoney is an outstanding teacher of the McNaughton. Mike did come to our club and definitely improved my use of the system drastically and with much more ease. His DVD is well worth the purchase should you decide to get the McNaughton route. His mastery of the tools is just phenomenal. You will be heads and shoulders ahead should you use his mehods right off of the starting line.

Good luck with your decision.

 

[Bernie Weishapl]

Frank you are going to get a hundred different answers I am sure. I watched both the McNaughton and the Oneway being used. I went with the Oneway for ease of use. I am not in a production mode so the little extra time it takes to move the support arm doesn't bother me. As I use it more I am sure setup and use will get faster. If I were going to mass produce these nesting bowls I would probably go with the McNaughton. Yes the cutters come off and mount on a jig for sharpening but you only have to do that maybe every 2nd or 3rd set of bowls and you rotate them from large blade to small blade so they wear evenly when sharpening. When they wear out toss them and put on a new set.

 

[robo hippy]

Frank,
I have all 3 systems (curiosity), and prefer the McNaughton. On the plus side, it is the most versatile of the group. You can core plates and shallow bowls, regular bowls, and deeper bowl/vessels. The down side is that there is a learning curve.

I am surprised that your Woodcut had problems on your 1642, I have used it on 1 hp lathes and had no problems. Sharpening maybe? The down side to is is that it is so small, the big blade is a 5 inch radius, and I turn bowls from about 16 inches down. I also don't use the tailstock, and you need it for this system. It does chatter if you are coring harder woods, and on the larger bowls.

The Oneway is nice and expensive. The support finger is how they deal with the forces of having a cutter that far out past the tool rest (McNaughton has a long handle, and a support bar on the tool rest, Woodcut attaches by a plate that is attached to the tailstock). By advancing the support finger, it gives more support for the blade, and eliminated chatter. This does add to the time spend coring. On a 16 inch bowl, You have to stop the lathe 4 or more times to advance the finger. This tool has a plate that it sets up in rather than fitting onto the banjo. Not too much of a problem. There is some room for moving side to side to make a deeper or shallower cut, but if you go all the way, the support finger binds up in the cut. Sharpening is another down side to this coring system. You have to take the cutter off the blade, and hold it up to the grinding wheel. There is a jig for this. If I used it a lot, I would get a surface grinder of some sort, like a mandril with metal abrasive on it, or a belt sander of some sort.

The McNaughton for me is by far the fastest to set up and use. There are 2 down sides. There is a learning curve, and it isn't on a fixed pivot point, so you have to do the aiming. This isn't a tool that you can just pick up and use, you need a DVD, and/or some one who can use the tool to show you how. The aiming becomes a problem because you don't know exactly where the point is. There is a laser set up that I really like. I developed the habit of aiming a bit shallow to keep from making lamp shades. That was a waste of wood. With the laser, I can aim for the perfect core every time. The blade also tends to drift to the outside of the cut as you core. This can cause the blade to drift, which in turn will cause some binding. Just come back up to the top, and widen the cut a bit.

You never have to force any of the coring systems. Either the tool is dull, you are drifting, or shavings are pluggin. up the cut.

For the McNaughton, Mike Mahoney has a DVD out, and so do I. We do things a bit differently, and mine shows the laser pointer.

robo hippy

 

[Wipedout]

I have the Oneway and am very happy with it - it actually has more flexibility than you would think

As for how it works - have you watched the video's on Oneways sight?

That will give you a good look at how the support arm operates

but yes it is a seperate post that you move

The Oneway Videos are at http://www.oneway.ca/multi-media/coring_videos.htm

 

[Malcolm Smith]

I have both the Oneway and the McNaughton systems and find that at this point I have settled on the Oneway system though there is a bit of added time involved. In answer to a question about it, one stops the lathe a few times and moves the support farther into the cut. This doesn't seem like a lot of trouble. As the depth of the cut is set, one isn't turning thick bottomed bowls, wasting wood in the process. It's worth having extra cutters so one can sharpen a bunch of them at the same time. If I have a complaint, it's that the smallest cutting tool is not very small. I turn hardwoods and would like to be able to core smaller bowls.

Malcolm Smith.

 

[Steve Worcester]

..As the depth of the cut is set, one isn't turning thick bottomed bowls, wasting wood in the process. Malcolm Smith.

I don't understand what you mean here.

 

[KurtB]

Frank,
Maybe I didn't know enough to be wary of the KM system, but I read the directions and plunged right in (sorry for the pun) and I have now cored green cherry and walnut bowl blanks. It did not seem scary or dangerous. But I can make another suggestion: if you don't mind a little drive, our club is sponsoring Mike Mahoney for a demo on June 7 in NW Arkansas/SW Missouri, and Mike will be showing how the KM system works. Come on down - for the cost of gas and $30, you can see how the whole thing works. Send me a PM, or a phone number if you are interested.

I have not used the Oneway system, and cannot comment on it. However, the KM seems to be fairly simple, so why not stick with that?

Kurt

 

[George Van Beynen]

Does anyone know if the laser guide for the KM Center Saver is available without the laser and upper arm? I already have those parts on my KM hollowing rig and just need the attachment upright for the corer.

 

[Frank Kobilsek]

Thanks

OK guys

I watched the Oneway video, I studied the Crafdts Supply catalog last night. I found my answer on how to sharpen McNaughton bars in another thread.

Summary of what I have learned

1) Oneway is very expensive but would work as well or beter than my Woodcut. Easy to learn, set up and operate.

2) McNaughton may take some practice, but very flexible in the shape and size of cores. If I buy McNaughton the Combo kit from CS gives you the 7 blades of the large and medium sets in one package and probably the best value

3) I could save my Woodcut with a special tool post adapter that I could have made locally for under $100.

Will probably buy the McNaughton. Thanks for the feedback.

Frank

PS: Kurt thanks for the invite to Arkansas. Not likely to make it but I like that part of the world. Old job took me to the rice patty's around Hughes and Weiner quite often back about 10 years ago.

 

[robo hippy]

George,
I don't know if those parts are available separatly or not. It does not come with a pointer, just the mounting bracked, a vertical post, a horizontal post, and a bracket for putting the laser in. I think it would be easy to make a bracket for mounting the vertical post in if you have some metal skills. I did have mine welded to the handle, and if you look at it in the Craft Supplies catalogue, they have it mounted on top of the handle, and it is designed to mount out to the side. I fixed mine so that it is mounted on top. The idea was that with a side mount, you could raise and lower the laser according to the size of bowl you are coring. Not necessary for me.
robo hippy

 

[Malcolm Smith]

'As the depth of the cut is set, one isn't turning thick bottomed bowls, wasting wood in the process. Malcolm Smith.'

The Oneway has a set up process where one determines what the diameter of the bowl will be and how far from the chuck the curved cut be. As this is the path the cutting tool will take, one doesn't need to be cautious by allowing some extra thickness to avoid removing too much wood as one does with the McNaughton system.

The Oneway system is more reliable for turners who don't frequently use it. The McNaughton system, as stated, does require less set up time and gives one more choice in the path that is cut.

I have both systems.

Malcolm Smith.

 

[Myron Smith]

Hey, I have a quick followup question regarding the McNaughton. Frank mentioned getting the standard and the large set of blades. How big of a diameter have you guys gone with the standard blades? How big of a chunk of wood do I need to really require the large blades? Does the larger cross section of the large blades help even on medium-size coring jobs?

Thanks,
Myron

(With more questions than answers.)

 

[Bill Pottorf]

Myron, my experience is that the standard blades are used easily and safely on everything up to about 15". Diameters greater than that will have to be cored with the larger set. The problem is the length of the blades on the standard are not long enough to completely core out a bowl above 15" diameter. Likewise the larger blades are much too large and long for coring anything smaller than 15". The large blade crossection is not necessary for the smaller diameter corings. The 15" is only an estimate from my head right now. You may find that you have to switch around 14" or so. 15" is somewhere in the ballpark.

The important thing is to keep the cutting path clear enough to eject shavings and keeping the blade from binding generating heat and a possible catch. This is done by backing out and enlarging the cut slightly towards the rear of the cut. This all comes with experience in use of the KM system.

Hope this answers your question.

 

[George Van Beynen]

I did have mine welded to the handle, and if you look at it in the Craft Supplies catalogue, they have it mounted on top of the handle, and it is designed to mount out to the side. I fixed mine so that it is mounted on top. The idea was that with a side mount, you could raise and lower the laser according to the size of bowl you are coring. Not necessary for me.
robo hippy

Thanks, I guess I will have to do some trials on a setup in the shop, should be doable.

 

[Frank Kobilsek]

Bill

Follow up on Malcolm's follow-up. Based on your 15" for the standard blades I might not need to order the large blades to core any piece that would fit on my 3520B. Math (blank round on lathe is at most 19", 10% of diameter for wall thickness 2", times two leaves me with a 15" core, did I think that out right) So the combo pack might not be the best value for me.

You are about to save me a hundred bucks so you be my buddy.

Frank

 

[Bill Pottorf]

Frank, I would go ahead and get the combo set. You will not be using it too much, but will on a 15" diameter cored bowl. The standard blade length will not be long enough to get to the bottom. You will push the envelope with a 19.75" bowl blank at sometime when you really discover the ease at which the corings can be done. There will be that one piece of wood that you just need to turn. You know what I mean. The savings on the combo is worth it. Sorry to not be your buddy but go ahead and get the combo.

Bill

PS: I forgot to say that when you put that 19.75" blank on the lathe, you will need a 2nd banjo behind and one in front of the blank to do the turning. You will not be able to run the banjo underneath the blank. Just remember that turning turns out to be an expensive hobby, particularly for those of us that are retired.

 

[Frank Kobilsek]

Thanks Bill, I'll get the combo

Expenses come in two forms - You have time and watch the $s, I am still making $s but can't make time. There are only two true resources in the world, time or money. Few of us can muster both simultaniously.

Frank

 

[Malcolm Smith]

Using the Oneway system, If one is coring a very deep bowl, one can use a larger tool than one would normally use. As long as the end of the cut meets at the bottom without being too close to the chuck the result will be good. This can be determined during the set up with everything positioned for the blank but with the blank removed. The Oneway system does offer some flexibility though not as much as the McNaughton.

Malcolm Smith.

 

[robo hippy]

As far as which blades, I recomend the standard set to start. I figure they are good for bowls up to 14 inches with the medium curve blade. This may be stretching it a bit. For bowls bigger than that, use the big set. The cutters are the same size, but with the large blades you are reaching farther out past the tool rest. When using the big blades, you do need to open up the cut wider than one blade width. On the medium set, some times I can get away with one cut all the way to the bottom, but this is the exception rather than the rule.
robo hippy