On Mon, 14 Jun 2004 04:07:41 +0000, Robert Bonomi wrote:

The bad news -- That tool, and *any* similar one, regardless of manufacturer,
are the WRONG THING for the type of job you propose to undertake.

If there's a finished surface involved, yes. If he's going to cover it
with black carpeting or something, the circle jig that comes with the
rotozip does a reasonable job.

Spiral saws are designed to work in _brittle_ materials -- ones that 'powder'
when 'hit' with a sharp edge. They're _great_ for drywall, and, as long as
you're careful about heat build-up, you can do amazing things on ceramic
tile, too.

I used mine this weekend cutting some 1/8" plexiglass, both straight cuts
against a clamped straightedge, and a circle-cut (freehand for non-critical
circle-ish shape).

For cutting wood, on the other hand, they are 'medium dreadful', to put it
charitably.

Hm, I find it about as usable as a saber saw.

The bits don't have big enough 'flutes' to clear the wood chips, so they
are *very* slow cutting, Like only a few (maybe 5) _inches_ per minute,
in 3/4" stock, *IF* you can keep from breaking the bits.

You're using the wrong bit, then. Lots of options. Sounds like you
were using a tile bit on wood, maybe?

Due to the small diameter, they don't have the structural strength for the
side pressures, and you'll break bits *real* often. Like, if you're lucky,
you'll get 4-6 _inches_ of cut in 3/4" material, per broken 1/8" bit. Don't
even _think_ about using the standard 1/16" ones.

Mine came with 1/8" bits, never saw a 1/16" bit. Sure you're talking
about a RotoZip? Don't get me wrong, I'm not saying that it's high-art
of toolmaking or anything, but what you're describing isn't consistant
with my personal experience.

Tool edge speed aside, for the fwe times I use it, it works great.
Like anything else, using the right bit for the job is critical.

Dave Hinz