READMEH.TXT for TUBEFITH 9/9/2008

STRAIGHT IN and STRAIGHT ACROSS refer to how the cut tube is cut, and 
therefore how it fits against the uncut tube.

STRAIGHT IN means that you should keep your saw or file pointed straight
toward the center of the tube. In most cases you would use the solid
line. Where the dotted line goes below (or to the right of in the
printout) the solid line, the OD of the cut tube will interfere and you
should remove metal in that area. You can file straight in or at an
angle. This will make sense when you are actually doing it!

You can also use the dotted line of STRAIGHT IN to cut in the direction
of the axis of the uncut tube to make a fit where there is no gap.
That is where the whole end of the cut tube touches the uncut tube. The
dotted line is the projected OD of where the cut tube touches the uncut
tube. Cutting this way could be used for gluing PVC pipe together.
This gives you two options for using STRAIGHT IN.

STRAIGHT ACROSS was the original intent of TUBEFIT. This type of cut is
the most efficient cut for welding tubing together in most cases -- at
least for tubing up to about 2 inches diameter. The cut can be done
with a manual hacksaw or a power hacksaw. For small tubing like in
aircraft work it is convenient to use a bench grinder for fitting. 
Just mark the tube from the template with a felt tip marker, and make a
saw cut in from each side. The cuts are almost straight lines, but not
quite. Cut far enough that the cuts intersect. This will leave two
sharp ends that can be trimmed off. The whole ID of the cut tube will
then fit against the uncut tube, and there will be a sort of bevel
between the ID and OD which is just right for welding.

TUBEFITH now labels the angles 0, 90, 180 and 270, as well as labeling 3 
reference lines 2 inches apart which show how far it is to the 
intersection of the uncut tube. The purpose of these 3 lines is to
allow you to control the length of a cut tube if both ends have to be
cut to fit a certain length.

This version (TUBEFITH) is capable of generating postscript files for
very large templates. By manually editing (by using the DOS type edit
command in WindowsXP, for example) the "1 1 translate" command near the
beginning of the file the template can be printed on multiple pages.

To show increasing angles (0 degrees is at the top of the page) change
the x variable in the negative direction. For example: "-6 1 translate"
will offset the image upward on the page so that what was not printed
because of being off the bottom of the page on the original printout
will be printed. Similarly, changing the y variable will allow what
was off page to the right to be printed. For example: "1 -5 translate."
Combinations of offsets will allow you to print out as many pages as
it takes for templates up to 9999 inches in circumference, and up to a
similar dimension for low angles of fit.

This technique works using my LaserJet 4mPlus. It simply ignores
commands to print off page. Hopefully it will work for you the same
way. Yes, I know the program should do this automatically, but this
is as far as the TUBEFIT program has evolved so far.

Dan Hopper
Walton, IN