Horn builders tool - diy rip fence/guide

[quadtech]

So I got the ply for building my pair of Sachikos and ran into the problem of
rippling the 8x4 sheets into precise 11 3/4" strips. All I have is a cheap
circular saw and no access to a table saw or CNC and other niceties.

I rigged up a cheap rip fence or guide which might interest some of
the folks here.
I cut about 4 strips of ply so far and all are absolutely precise at 11 3/4" width.

You need a couple of lengths of threaded rod (the kind you
get in Home Depot), 8 pairs of nuts and washers and a flat metal strip of
about 1/2" width and 8" to 12" length.
I used two lengths of 20" of 8mm threaded rods.

I cut two strips of about 1.5" , drilled holes for the threaded rod, and
welded them to the base of the circular saw. Welded two such strips
to the long metal strip.

The pics here should be self explanatory.

http://picasaweb.google.com/prasadb/RipFence#

- Prasad

[pjanda1]

How precise were your cuts? I've thought of building a rip fence. I don't have a table saw either, but even if I did, I don't have room for enough table to handle big sheets (like you need for the big boxes). I've always clamped straight edges as guides. When I built the BIB's, I cut a strip to the distance I needed for the guide (required board width + distance from saw edge to blade edge). That was quick, but not as quick as a fence would have been.

pj

[quadtech]

How precise were your cuts?

There is no measurable (with a tape/scale) variation from top to bottom of the
sheet. I stacked up the cut sheets against a wall, and as far as I
can see, they are all the same width all the way. I guess the error is of
the order of a millimeter.
Any errors will become evident as the build progresses.

Prasad

[thosuk]

Try this
Simple and minimises splintering

[Mr Evil]

I use some "guide clamps". They make great straight edges for marking long lines too.

[quadtech]

What I was trying to solve was a way to adjust/set once and get the
same dimension for every subsequent cut. Repeatability.

In a design like the Sachiko, to get a tight air seal at the joint with the sides,
the width of all the internal pieces must be within close tolerance.

I do use a guide like the Popular Mechanics one for smaller or one-off cuts.

[EEatKSU]

Try something like this, they do work well.

http://www.amazon.com/All-Clamp-9-In...1719550&sr=1-4

[gpsmithii]

I made one similar to this several years ago. It is specific to your individual saw. You mark your points, line up each end, and get very square cuts.

http://www.lowes.com/lowes/lkn?actio...d/RipCirc.html

[gychang]

I have tried most of above... Most have one problem in common that narrower stock can not be cut accurately.

For example one needs to cut 10" width of long plywood, and u have 12"..., can be done but I find it difficult... I manage to get by with the circular saw.

gychang

[quadtech]

GY, I ran into the same scenario where you need to trim a little bit off
along the whole length.

The rip fence I made works fine to cut narrow pieces
by simply fixing the threaded rod towards the cutting wheel , instead of
the other side as shown in my original pic.
(It needed a small mod to my fence, so the saw handle does not obstruct the
threaded rod.)

So the vertical guide piece is on the same side as the
cutting wheel and I can adjust the cut size down to about 20 mm.
It could probably do even smaller, but the saw safety casing on my saw hinders
further travel of the guide. I didn't need better than this, so I left it there.