Re: ATM: Regarding new ATMs

[Brad Davy <bdavy@bigdog.fred.net>]

At 02:08 PM 2/24/97 -0800, Akkana wrote:
>All the references I've seen so far, though, assume woodworking
>experience and access to tools like routers.  I've never seen a
>reference which explains for the novice where to get big circular disks
>for alt bearings, or how to cut the alt bearing slots in the rocker
>box if you don't already have a garage full of woodworking tools.

Forget using big circular disks for altitude bearings.  Try using the PVC
Floor flanges for mounting toilets.  Outer diameter is about 5 inches, they
are pre-drilled on the flange, making them very easy to mount on the rocker
box, and they're inexpensive (about $3 US).  They also ride very smoothly on
the "Magic Glide" teflon pads for furniture, available at Wal-Mart and K-Mart.

For the azimuth bearing, again forget circles.  They're only needed for
aesthetics. Squares are easier to cut.  

>This sort of thing turns out to be painful enough that if I have
>to do one more rocker box I'm going to march down to Sears and hope
>I can find someone who will explain to me which tool it is I need
>(router? sabre saw?) to cut big circles even if it means that I have
>to leave the router table rusting outside because I don't have space
>in my garage for something that big.

You can get a small router that will do the job for $60-70.  To cut circles,
you can make a jig from a piece of scrap plywood.  Just use a piece wide
enough to screw the router onto using the screws for the router face.  You
can then drill a hole for the router bit to pass through.  You can get a
1/4" straight bit for the router for under $5 that is 1" deep.  Using the
plywood jig, just measure the distance from either the inside or outside of
the bit, depending on whether you're cutting a disk or a hole.  Then use a
long wood screw through the jig at the center of your circle to screw the
jig to the piece you're cutting.  Take your time and work slowly, and you'll
end up with very nice circles.  

I'm nearly finished with my 8" f8.  I'm convinced I could have built it with
a hand saw and a screw driver, but I wanted to finish it this century.
Handy tools turned out to be the router, as described above, my Dremel
(Thank God for Dremel!!), the cordless drill/screw driver, and a framing
square.  Additional nice to haves were a small table saw and a 2 1/4" hole saw.

I'll be posting a complete description with pictures eventually on my home page.

Regarding the comment on wood working skills, I've had some limited
experience.  Had this been my first project, no amount of reading would have
kept me from tearing my hair out.  In fact, my first wood working project (a
simple set of book shelves) nearly produced that result.  If you ever want
to see some good tips, just keep the TV tuned to PBS on Saturday afternoons.
The New Yankee Work Shop has been a great source of ideas (the router jig
for example).
Brad
bdavy@fred.net               http://www.fred.net/bdavy/home.html
bdavy@nox.cs.du.edu