Hollowing tools?

[Kaptan J.W. Meek]

I have never really done a true "hollow form".. I have a "Sorby" 24" swan neck hollowing tool and it's just not cutting like I think it should.. I've got it sharp, and have tried several different angles and I'm getting LOTS of chatter... I'm deep enough, but just can't get the walls thinner than an inch.. I can't get a scraper in that far, and since I'm going through a hole about 2-1/2", bowl gouge and spindle gouges just scare the hell out of me.. The outside of this piece of cherry turned so smooth it was really nice, but the inside is just giving me a really tough time.. Either I don't have the right tool, or I'm using the tool I have wrong. Any ideas?.. Thanks for all comments.

[Scott Hubl]

Have you watched the Vids on Sorby's web site?
http://www.robert-sorby.co.uk/

Click on "Movie Clips"

[Steve Schlumpf]

Kaptan - hollowing is fun but can be challenging! You didn't mention how deep you were into the hollow form when having all the problems. You say the cutters are sharp and have tried several different angles - but are you cutting at the center line within the hollow form? If you are either to high or low you will get lots of catches. Other thing is - what bit or cutter are you using? Want to use something fairly narrow to rough out the interior and then switch to a rounded cutter to clean up any ridges. If you start out with a large surface cutter - chances are it will grab (catch) as it is offering way to much cutting surface to the inside of the form. That's a lot of torque you have to counteract! Using a narrow cutter is easier to control when roughing out and then you can go back and use a round or oval cutter to clean everything up. Remember to use light cuts and try to keep your movements as smooth as possible to help eliminate tear-out.

It's a challenge but once you have the hollow form in hand it's worth it! Have fun with it and if you still have problems get back to us and we'll figure something out!

[Kaptan J.W. Meek]

Ok, Thanks so much to everyone that has offered advice so far. 1) Yes I've seen the videos but he doesn't use the "swan neck" hollower, that I have in the videos.. The only one I've seen is the "hollowmaster" and it has a nice flat on the bottom of the shaft that keeps the tool stable on the tool rest. 2) I have turned plenty of bowls where I can get a nice little scraping bit in there, but this hollow form is different.. It's only about 5" deep, and say 8" wide.. so 4" from center. I'm using the smallest cutter that came with the tool.. it's an oval cutter, the edge touching the wood couldn't be more than say 3/16ths at any one time.. still too much?.. If I could get a too rest inside the thing, THAT would make it so much easier.. but perhaps thats the whole thing about a hollow form... You can't just shove a tool rest in the hole!.. I dunno, maybe I'm just trying to go too fast?.. I figured a piece thats 5"x7" I should be able to hog out in about 6 hours.. too fast?...

[David Walser]

Kaptan,

What is the relationship of your tool to the toolrest? With a swan-neck tool, it's important that all of the swan-neck be in front of the tool rest. If the curved portion of the shaft is on the tool rest bad things will happen -- the tool will be almost impossible to control, you'll have problems with excessive vibration, and your favorite baseball team will fail to make the playoffs.

You're probably avoiding this mistake already. In which case, I've got no idea what to suggest.:o