I have used several hollowing systems in the past few years. I
started out using David Ellsworth’s hollowing set. These are simply
small scrapers on round shaft. Reasonably priced and pretty
effective.

I also own a set of Hamlet hollowing tools. This set uses a ringed
cutter. It can cut a lot of wood in a short time but it sometimes
hard to control. You can get scraping tips for this system as well.
The Hamlet system is more expensive.

Both of these systems, as well as lots of others on the market, allow
you to hollow at various depths depending on the thickness of the
shaft that supports them. The heavier the shaft the deeper that you
can hollow into the wood. Otherwise you will get chatter as you
describe.

Another problem with many systems is that you must turn “blind.” In
other words you cannot see exactly where you are cutting inside the
vessel and as a result it is more difficult to know how thick your
wall is, when to stop so you don’t cut through the wall, you are not
sure how consistent your wall thickness is, etc.

More recently I have purchased a hollowing system sold by Lyle
Jamison. He and others have developed systems that use a laser
pointer to gauge wall thickness as you hollow your vessel. This unit
also has various cutting tips that can be purchased. One of the newer
types of tips for hollowing is a circular carbide cutter. It never
needs sharpening and can be replaced when it finally wares out. The
Jamison system is fairly expensive.

Each system has its own advantages and disadvantages. You have to
find the one that works best for you. To avoid spending lots of money
trying out systems it would be best if you could find turners in your
area that will either demo the system they use or better yet allow you
to turn using their tools. There are also articles to be found on the
internet that describe the pluses and minuses of various hollowing
tools.

You can see several of these systems at www.packardwoodworks.com.
Just click on woodturning tools and browse the list.

Here is an article from the Ohio Valley Woodturners Guild that
compares several hollowing systems and give links to each one that is
discussed.

Stephen Russell has an article on his site about hollowing tools also:
http://www.woodturningvideosplus.com...ing-tools.html

Good Luck,
Ted