PDA

View Full Version : Woodcut bowl saver question



Terry Quiram
06-22-2008, 6:49 PM
For those of you that use the Woodcut bowl saver have you left the cutter in its original shape? I was using mine today and it worked pretty well on 3 bowls and a clear failure on the fourth. I was talking with a friend after he witnessed the failure and he suggested that I regrind the cutter to have a vee point. I know the Keltons and the Oneway cutters have been reshaped to have vee points. I am open to suggestions.

Reed Gray
06-23-2008, 12:10 PM
Sorry, I was distracted yesterday and missed this one.

The point on the Oneway serves as a chip breaker. It breaks the fibers and then the blade to the sides of it cuts away the fibers. You get fewer shavings this way, and more saw dust, or in my case with green wood, smaller chips. Generally this means less clogging of the kerf while coring.

The McNaughton Spear point was an idea of Mike Mahoney. It is particularly useful for cutting a core all the way off. If you are coring crotch wood, at the bottom of the cut, the fiber is going in several directions at once, and if you try to break out the core, you can rip out the bottom of your bowl, even if it is over 1/2 inch thick. I have done this. It is similar to burl. Burl has little grain orientation, and if you don't cut it almost all the way off, you can again rip out the bottom of your bowl. Same thing if you are coring end grain.

If you are cutting flat grain (standard bowl orientation), when you get close to the bottom, with a spigot of about 3/4 to 1/2 inch (less than 1/2 inch and it starts to wobble on its own), it is easy to break out with a tap of the heel of your palm, or a tap with a gouge handle. The core should wiggle a bit on its own before you do this.

Now, as to the different profiles. Keep the shape of your cutter the way it is. I have ground the spear points off my McNaughtons. When I told Kel I had done this, he was a bit shocked. With my early McNaughton blades, I tried a lot of different profiles to see if it improved the tracking of the blade. It had no effect that I could see or feel. I settled on square because it presents a smaller cutter to the wood, but keeps the same width of cut. I can cut the core all the way out with a square tip. It is a bit easier with a spear point though, but not enough to make any real difference to me.

I got one cutter from Oneway, that they hadn't ground to shape with the point, and used it. I did prefer it to the pointes ones because it cut better (more agressivly which is why they don't sell it that way to the general public: professional driver on closed course, do not attempt!). I also don't have to remove it from the blade to sharpen it.

The Wood Cut works very nicely as is, and you need to keep it sharp. I believe that you sharpen the face of the tool, and not the top which is slightly concave. I don't really remember. I just went out and checked, and the concave on my 8 inch wheel is flatter than the grind on the cutter. I had some one tell me that the concave profile on the top of the blade is to help with chip ejection. I don't know if that is true or not.

You didn't say what the failure was. Did you have a catch? Was the coring tool not cutting well? Were you getting a lot of chatter (this is a small problem with this tool, especially if you are coring some thing hard like locust, or osage)?

robo hippy

Bob Hallowell
06-23-2008, 12:26 PM
Sorry Terry nothing to add to your woodcut but Robo I finally got to watch my fathers day gift you made for the McNaughton corer. It was very good thank you. Now all I have to do is buy the tool:D.

Bob

curtis rosche
06-23-2008, 12:28 PM
just buy a whole new cutter:D:D

Terry Quiram
06-23-2008, 6:43 PM
Reed

The Woodcut is a new tool and it was freshly sharpened. I believe my failures were a combination of 3 things. The bowl was about 5 inches tall with a smallish tenon and the blank was shot through with some wicked curl. I actually tore the tenon off twice before I gave up trying to core that blank.

Thanks for your reply. I will leave things as they are.

Terry

Reed Gray
06-23-2008, 7:02 PM
The size of the tenon most probably was the biggest problem. If you are coring a 12 inch bowl, you want at least a 3 inch tenon. It is a leverage thing, and if it isn't wide enough, then the pressure of coring and turning can twist it right off. You can also over tighten the chuck where you crush the fibers, making it weaker. Get it good and snug, but not white knuckle tight. I prefer a recess myself. You also need the fit to be as close as possible between the jaws and the tenon. If your jaws close down to 2 inches, and your tenon is 4 inches, you will get a decent hold, but not as good as if your tenon was 3 1/4 inches, and your jaws close down to 3 inches. You get more metal on the wood.

robo hippy

Jerry Rhoads
06-24-2008, 8:17 AM
Terry I have the woodcut and have had good luck with it. I do not sharpen the top face.
The cutter tooth is not that deep. Grinding to an angle may go past the cutter tip. also an angle will give more contact to the wood, I keep the cutter exactly at center hieght.
I have broke off the tennon before, For large bowls I use the Vicmarc VL120 with the large jaws down nearly as small as it will allow.
I like the woodcut coring tool. But some times wish I had a larger coring tool.

Jerry

Frank Kobilsek
06-24-2008, 8:48 AM
Terry

Like the others, I have given up on coring with 2" jaws and my Woodcut. Unless it is very soft wood and I am very patience I'll spin the blank in the 2" jaws. 4" jaws no troubles.

I have a new post being made so my Woodcut will fit my 3520. Hopefuly by the holiday weekend I'll be coring all this maple I picked up from the Mothers Day storm.
Frank