Bridge saw

[Ken Barnes <barnestrav@zzzzzzzzz>]

I would love to see Clive's setup in person or by photo.  Although it
is not a bridge saw, it sounds like it functions better than a bridge
saw in many respects and is cheap.

I have a rudimentary bridge saw that would be relatively simple to put
together, if you are mechinically inclined.  The operating guts of the
saw are a GDM Walcutt hydraulic wall saw used in the concrete cutting
business.  Typically the concrete cutter will bolt track onto a
concrete section to be sliced, power up the hydraulic powerpack for the
saw (by either internal combustion engine or electric motor) and then
use the hydraulic controls to move the saw back and forth on the track.
 The operator gets a step cut by hand cranking the saw body down into
the cut at each step.

If you instead bolt the tracks to a rectangular steel tube (say 2
inches by 8 inches) that is 10 feet long, you have the bridge of your
saw.  You can have this bridge be stationary, move back and forth
horizontally on a secondary rail, or even have the bridge move up and
down.  If you have a hydraulic table that can provide the up and down
for step cutting.  My bridge is mounted on hydraulic cylinders so that
I can move it up and down.  I also have a hydraulic table that moves up
and down and back and forth horizontally, so that is overkill.

As an additional feature, I mounted the bridge to the hydraulic
cylinders by way of stainless steel rods through pillow blocks (a type
of bearing system), so that I can get rotation of the bridge for bevel
cuts.  You need to have a way to move the head of the saw to and from
the axis of bridge in order to get step cuts on a bevel, and the wall
saw has that ability (manual crank).

The GDM wall saw can accomodate up to a 4 foot blade, although I mostly
use the 3 foot blade.  One day I will get their flush mount attachment,
but for now I use the normal blade attachment.  I bought my saw already
assembled in this fashion, but then tore it down and rebuilt it to
match my needs.

I spent about US$6,000 to buy all the various parts used and hire a
little time from the local welding pro.  I did the light duty welding
and fabrication myself, and got almost all of the steel for free.  I
have hundreds of hours into this project, but I knew absolutely nothing
about it when I started.  I could do it today in a couple weeks or
less.  Now that it is running I am overjoyed.  Two years ago I was
wishing I had never set eyes on the damned thing.

Over the last year I have seen all of the separate components of this
listed on eBay used for a total cost of US$5,500, but you would have to
ship them and buy steel and hydraulic cylinders and some controls.

You could also consider modification of some of the demolition wire
saws that are out there, depending upon your needs.  Let me know if you
want me to send some photos off-line.

Ken Barnes