I am not much familiar with all the things that can be done with and cautions
about using the spiral saw.
Is there a discussion which specializes in using this tool for home woodworking?
I'm interested in the sorts of routing that can be done with the tool and
bits and jig adapters for rabbetting and circle cutting.
My main application is doing the final trim work on audio speaker cabinets:
driver cutouts, terminal cutouts and finish work for flush mounting drivers and
edge trimming (roundover) of 3/4 birch plywood on small surfaces with other
larger projects to come. No veneering at this time, but that is another
Any help or how to articles also appreciated.
My unit is made by Tool Shop. It is 30,000 rpm with an accessory kit.
Weeeellll that tool is Great at cutting sheet rock, that is what it was
designed to do.
After that, its like a lawn mower salesman showing you how this particular
lawn mower can also power your car, pump the water in your well.
Why do we need such a specific group? It's not like we have
alt.tablesaw or rec.jointer!
Post some specific questions.
Roto-Zips and their clones were originally developed for drywall
cutouts. I'm sure others have developed other uses for them.
The tool should be able to do what most other light duty routers can
do, check out <http://www.patwarner.com for 1router info, or visit
your local library for some good router books.
Ping "Trent", he's really into his Roto-Zip.
AH ha! Got it at Menards, I betcha. Their house-brand special.
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.
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
For cutting wood, on the other hand, they are 'medium dreadful', to put it
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.
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.
For any sort of a powered cutting edge, you want more-or-less the same
lineal speed at the cutting edge, regardless of the size of the cutter
being used. What the 'correct' lineal speed is, does depend on the material,
but the speed can be regarded as a constant for any specific material.
_Standard_ setting on a router will spin a 3/4" diameter bit at around
22,000 RPM. This is equivalent to about 17,000 RPM for a 1" dia. bit.
To get an equivalent 'cutting edge speed' from a 1/8" diameter bit, you have
to spin it 8 times faster than that 1" bit -- or around 135,000 RPM. More
than _four_times_ what your tool is capable of.
A reasonable light-duty router can be had for under $100. See the Skil
1815, for one example. It has an 'edge guide' option -- which includes
circle-cutter capability -- that sells for about $15.
For less than double the money (i.e. under $200) you can get a "good"
router. And under $300 will get a top notch 'commercial grade' unit.
On Mon, 14 Jun 2004 04:07:41 +0000, firstname.lastname@example.org (Robert Bonomi) wrote:
Aha!, Yest I did, but I didn't use it yet until I post a few more questions or take
it back or a combination of both.
Well, here's the lowdown. I manage to do my little projects in an apartment
on a single small worktable. I'm also asthmatic and so the use of the spin
drill sends the waste mostly down instead of into the air.
I've played with a a hand drill and drill guide plus RotoZip bits and had
a few break.
The point is that I need a low profile, non-industrial or non-"shop solution"...
not the proverbial "More Power!" from Tool Time. Before I made the purchase,
I studied a project from a Canadian gent who had his flatpack (pieces to be
glued together) cut buy a shop and then did the trim work including roundover
of baltic birch ply in his shop. I do not recall what sort of bits he was using.
His completed project looked fine.
I believe I have tried to have this discussion in the past and there were no
takers, now there are. The timing was just a bit wrong for my purpose.
And yes, I like the feel of the fixed base Skil model at Menard's and was
hoping for a deal on it for Father's Day and I would set up a small
Workmate (tm) outdoors to use it.
Before using the Spin Saw, if it is going to be totally uselss even under the
described conditions, I could exchange it for the Skil router but with
no discount. I'm aware also that a Jasper Circle cutting jig is the tool
to use for this type of hobby work.
--> But as stated I was looking for a lightweight solution and minimal waste
material flying about. Given that criteria but not wanting to go through
another package of bits is the device a waste of time?
If you are working in THIN materials, these are acceptable, under the
circumstances you describe.
Having used one to cut a sink cutout in 3/4 plywood, my jigsaw having taken
a hike, it is not a task I would plan on asking of the tool more than once
But light duty hobby work might succeed. As with any tool, take it at the
appropriate pace. And if your cutter sounds like mine, you'll want some
hearing protection. It's still loud.
Here is the Canadian project. Note the flute size in the spin drill.
On Mon, 14 Jun 2004 04:07:41 +0000, email@example.com (Robert Bonomi) wrote:
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.
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
Hm, I find it about as usable as a saber saw.
You're using the wrong bit, then. Lots of options. Sounds like you
were using a tile bit on wood, maybe?
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 and All,
thanks for continuing the discussion.
For those of you who are doing some of these things like Dave and Patriarch,
can you see from the photo link up there at the other post if the roundover
bit used is something off the shelf or maybe supplied with my Canadian
friend's spin saw kit? Mine is not the same. I have sent a mail to the guy
but didn't get any replies yet... it's vacation season.
Anyway, today from the added messages I feel a little bit better about
keeping the thing. But still I'm hoping for more discussion.
And yes, what I'm doing is very casual: what I have is a flat pack of
baltic birch plywood to make 2 desktop speakers for computer use. The
longest length is 16 inches for roundover. The cutouts for this project
will be made with a 3" fly cutter (hole saw) and I am wanting to do a rabbet
to flush mount the driver plus a chamfer on the back side for relief of the
So what are the chances of significant kickback from the tool?
As you can see from the picture the guy used the roundover for a lot
of pieces. I re-read the whole thing and no mention is made of
the job being really slow.
I use a 1/4" shank, 45 degree chamfer bit, or a 3/32" radius roundover bit
in my Porter Cable trim router quite a lot. I'm a lot more comfortable
with that tool, than with the Dremel cutter. I don't know that I would
attempt it with the Dremel. YMMV.
In fact, of my 5 router type tools, the PC trimmer gets the most frequest
use, lately. My son, OTOH, uses his Dremel for almost everything. Prolly
just using whatcha got...
Same here, only mine's a Bosch.
I find the little guy GREAT for cleaning waste from dovetails
(especially half blind), small hinge mortises, many roundover and
chamfer operations, etc...
I find almost any non-plunging, non-table routing is better with the
small, light machine.
Using it for long saw runs would not be the objective. I'd prefer having the
flexibility of a fixed base router and router base mount for shaping. But I'm
still pretty tentative about the jobs I can tackle.
The consensus seems to be that it'll work for small jobs with the right
bits and will take (with the right collet) standard router bits for chamfer
and rabbet and roundover.
Thanks to all who answered.
First thing--if you're looking primarily for a cutting tool then get a good
saber saw--Bosch isn't cheap but they're worth the money. You can use a
drill to start the cut for inside cuts. While a rotary tool will cut wood
and with the right bit even gives a fairly clean cut there's a lot of
waste, a lot of chips produced, and they're hard to guide freehand--while
with much practice you may be able to follow a line a moments inattention
can make a big mess (you can do that with a saber saw too but it doesn't
tend to hare off at right angles to the cut line and pull itself along by
brute force). The saber saw will actually produce fewer chips than the
rotary saw and the ones it produces will tend to be a bit larger, so
despite it moving the chips up instead of down I would expect it to be more
friendly to your asthma--I'd get a good dust mask anyway.
Next, a rotary saw is a small router or a big hand grinder, depending on how
you want to look at it. It can with the right accessories do some of what
either does but except for the one task of cutting drywall and plaster it
doesn't do any task as well as the purpose-made tool--it's too bulky to be
a good hand-grinder and it's very low-powered for a router, not to mention
that by the time you have it fitted out to do what a router does you've
pretty much paid for a decent router.
The "wood cutting" spiral bits cut very slowly and not very cleanly.
There's a reason for the slow cut--it gives you enough control to be able
to actually cut wood with the thing hand-held. It's still going to be
trying to wander all over the place but it will do it slowly enough that
you have a chance of catching it. Put a real router bit in the thing and
it will cut a lot faster and a lot cleaner, but if you try to use it
handheld odds are that until you get a _lot_ of practice with it it's going
to ruin a lot of work for you and it's always going to be a lot happier
with a guide or template or fence. This is why a standard router would be
a bad choice for you--while there are small diameter bits for them they
have a short cutting depth and so can't be used for sawing anything but
relatively thin stock, and the smallest shank most routers will take is
1/4" so you can't use the rotary-saw bits in them.
If right now you can afford only the one tool then the rotary saw is the
only one that will do everything you say you need, albeit poorly. Two
things to look for--the ability to take 1/4" shank bits and the
availability of a plunge base--if those are not available for the tool you
have take it back and trade it in on one that does--the Dremel Advantage is
not horribly expensive, and the variable speed should give you a bit more
control. The Rotozips have a wider range of accessories available and the
low end fixed speed model is under $60 so if you're on a super tight budget
that would be the way to go--if you can afford a bit more then the RZ10 or
RZ20 would be a good choice. You're going to need the plunge base--the
standard base that comes on rotary saws is fine for sawing but it's not
wide enough to give you good stability when routing edges and the like and
the depth adjustment is not very precise or convenient either--you'll find
that that's important later--being able to take several small cuts and
reliably return to the same final depth setting is the way you work around
the relatively limited power of the tool when doing such things as rounding
For cutting with a fence or guide get yourself a 1/4" diamater downcut
spiral router bit (Amana 46202 for example)--it will make a lot of chips
but you'll find that it cuts cleaner and faster than the "rotary saw" bits,
but it's going to be hard to control without a rigid guide. Like the
rotary saw bits it will send the chips down instead of up.
Reply to jclarke at ae tee tee global dot net
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