I hope this will be enough info.

1, This is my original chuck jaw. 1/4" deep.

2, This is the new jaw. 1/2" deep.

3 & 4, this is the wood I am trying to turn.

5$6, here is the wood in the chuck.

 

 

Sorry I left a few things out. I have tried using a bowl gouge, spindle gouge, square carbide tool and round carbide tool. I am turning around 1650 rpm. Nothing seems to work.

End grain can be tough/hard but still turnable. When I turn something like this, I do what Gerald mentioned and use a forstner bit to remove the bulk of the material. With a large hole drilled to the depth of the hollowed portion, the forces used to finish the opening will be primarily directed toward the headstock/chuck down the side of the opening. This should help prevent the piece from coming loose. 

 

My choice of turning tool for this would be primarily the round carbide cutter . Then the square carbide cutter to sharpen up the side wall/bottom transition.

 

As for the speed, I usually go pretty slow- but that's a personal choice.

In you picture of the jaws in contact with the wood it looks like is a small gap between the jaws and the wood? May just be the angle of the picture. That surface must be clean and contact the face of the jaws squarely. I can't think of anything else that might be happening.

 

Steve

Here is a video by the late Bob Hamilton.  You can drill a say 3/8" hole to depth in the center and not have to worry about moving the gouge the way Bob does after plunging in the middle.  A bowl gouge or a spindle gouge can be used with this method.

 

 

53 minutes ago, HandyDan said:

Here is a video by the late Bob Hamilton.  You can drill a say 3/8" hole to depth in the center and not have to worry about moving the gouge the way Bob does after plunging in the middle.  A bowl gouge or a spindle gouge can be used with this method.

 

 

 

 

One of the best youtube authors ever, only my opinion but I learned a ton watching him.

Steve

53 minutes ago, Steve Krumanaker said:

 

 

One of the best youtube authors ever, only my opinion but I learned a ton watching him.

Steve

 

Me too!  He can get boring at times but I believe the slow pace makes for better learning.

Edited May 18, 20178 yr by HandyDan

3 hours ago, Steve Krumanaker said:

In you picture of the jaws in contact with the wood it looks like is a small gap between the jaws and the wood? May just be the angle of the picture. That surface must be clean and contact the face of the jaws squarely. I can't think of anything else that might be happening.

 

Steve

It must be the angle. I had a small gap between the jaws and wood to begin with and then trimmed it down a bit so it would set tight to the jaws.

 

Thanks everybody for you replies and links I appreciate it very much. I will watch that link tonight and check for more of his on youtube.

On a turning this size the spindle gouge works very well after drilling . May be in the video but with the spindle gouge flute up or to a 10 o'clock position you can hollow the inside. This method is used by a lot of European turners. By the way the jaw depth is measured inside the jaw and I have never seen a nova jaw less than 1/2 inch.

Something I just thought of. I do believe that there is something about your tenon the chuck doesn't like. I don't know what exactly but I do know the length of the tenon is not your issue. The strength comes from a good bearing surface where the jaws meet the wood, that is critical. A tenon doesn't have to be very long at all for this to work. As an example here is another plate I just took off the lathe. It is soft maple about 12" diameter. I only had 4/4 stock to start with so I didn't have much room for a tenon. The tenon on this piece is just over 1/8" long. The jaws need only just enough to clamp on. I did keep tailstock support for as long as possible but also relied on the chuck only a good bit.

 

Steve

I drilled out the center with a 1 inch forstner bit. I slowed down the lathe from 1600 rpm to around 850 rpm. It made a world of difference. No problems now. I guess I will cut slow and speed up to sand.

Just now, RustyFN said:

speed up to sand.

Sand slow! It helps lessen sandpaper burning.

34 minutes ago, lew said:

Sand slow! It helps lessen sandpaper burning.

 Lew is exactly right, the paper needs time work.

 

 

Steve

I don't think that anybody mentioned that when hollowing, the point where the tool contacts the wood needs to be above center.  The other important thing to avoid catches is that the the cutting edge needs to be oriented so that there is tool rest support directly beneath it.  In other words, you don't want a situation where cutting the wood is causing a force that is trying to twist the tool and you are fighting against the tool being twisted.

A half rest might help at times....