SFT48 and SFT49 Feet and Inch Engineering Tools:
SFT48 also runs great on Android Smart Phones using the Droid48 HP Calculator App as well as other HP Graphing Calculator emulators running on various platforms!
The South Fork Technologies Feet and Inch Engineering Tools is an integrated library of programs for calculating in feet and
inches or metric format on a HP48G, HP48G+, HP48GX, HP48GII, HP49G, HP49G+, or HP50G
Calculator. These programs enable you to add, subtract, multiply,
and divide dimensions. You can calculate dimensions using the
trigonometry tools for right triangles, oblique triangles, circular
segments and much more ... all in feet and inches. When working
with the right triangle tools you just set your angle and enter a
side you know and hit the button for the side you want and it is
displayed. Values on the stack from previous calculations are
always preserved so you can flow through a group of triangle
calculations accumulating the results with ease.
Input is entered in feet and inches using just the number keys and
the decimal point. The results of your calculations are displayed
in exactly the same format and the full accuracy of your answers
are retained in the answer value, so you can use the answer in your
next calculation without any loss of accuracy do to the round off
problems associated with converting the answer to feet, inches and
fractions. Sound to good to be true? Please let me explain.
The calculator display is set to display 4 places of accuracy like
this (1.0000). When you enter a dimension, the feet are entered on
the left side of the decimal point, like this (12' = 12.). The
inches are entered in the first 2 digits to the right of the
decimal point, like this (11" = .11) and any number from 00 up to
99 is valid. The fraction is entered in the third and fourth digits
to the right of the decimal point like this (13/16" = .0013) and
again any number from 00 up to 99 is valid. A dimension like 12'-11
13/16" would be entered like this (12.1113).
The software can be set to run in the following fractional modes:
(halves, quarters, eighths, sixteenths, thirty seconds, and sixty
fourths of an inch). The fractional part of a dimension, entered in
the third and fourth places, is just the total number of
denominations in the fraction for the mode that is set. Here is a
table for the sixteenths fractional mode and some examples of
dimensions and how to enter them.
1/16" = 0.0001 | 3/8" = .0006 | 11/16" = .0011
1/8" = 0.0002 | 7/16" = .0007 | 3/4" = .0012
3/16" = 0.0003 | 1/2" = .0008 | 13/16" = .0013
1/4" = 0.0004 | 9/16" = .0009 | 7/8" = .0014
5/16" = 0.0005 | 5/8" = .0010 | 15/16" = .0015
6'-4 1/4" = 6.0404 | 0'-2 1/8" = 0.0202
3'-9 15/16" = 3.0915 | 4'-3" = 4.03
13'-0 7/8" = 13.0014 | 10'-11 15/16" = 10.1115
5'-11 3/16" = 5.1103 | 2'-3 3/4" = 2.0312
You can also enter inches and fractions like this.
79 11/16" = 0.7911
43 1/8" = 0.4302
56 1/2" = 0.5608
Dimension results are read from the display like this:
11.0305 = 11'-3 5/16"
4.0404 = 4'-4 1/4"
16.0205 = 16'-2 5/16"
0.0016 = 1"
Note! (some food for thought)
0.9999 = 99 inches and 99 sixteenths, which is a valid input. If
you add 0'-0" to it, you will get 8.0903 or 8'-9 3/16". You can add
and subtract dimensions in this format with the intrinsic + and -
commands on the calculator as long as a carry does not occur
between the feet, inches, or fraction part of the number. This
makes working with dimensions even faster.
Like this problem:
(1'-5 13/16" + 4'-11 15/16" + 3'-2 7/8") - (5'-7 9/16" + 1'-11 3/16
+ 0'-7 7/16") = ?
On the calculator:
1.0513 "ENTER" 4.1115 "+" 3.0214 "+" 5.0709 "ENTER" 1.1103 "+"
0.0707 "+" "MINUS" = 1.0607
Right before you run the MINUS program you see
8.1842 in level 2 and
6.2519 in level 1
After running the MINUS program you will get 1.0607 or 1'-6 7/16"
which is the answer to the problem. You only had to find and run
one program to solve this whole problem!
When a decimal dimension is converted into this feet and inch
format, you see the numbers to the left of the decimal point and
the four digits to the right of the decimal point. The full
precision of the dimension is stored in the digits beyond the
fourth decimal place which you do not see, but are used when you
feed the value into your next calculation. Because of this feature,
your answers are never rounded off to the even fraction and they
always maintain their full precision.
You may need a chart for a day or two, but after learning the
simple number system of the mode you use most often, you will
appreciate the speed at which you can key-in, read, and manipulate
dimensional data. Any other entry/display system sacrifices too
much power and speed on these calculators to be usable in a program
like this, designed for high speed production work.
You can solve all your design or dimensional problems without
working with the decimal equivalents. Using the software to
calculate bracing and gusset plates is a breeze. You can calculate
building geometry, the running dimensions for a complex beam or
column, or check the dimensions for a stair stringer, faster and
with greater accuracy, than any other system available today. A
comprehensive user manual is provided to quickly bring you up to
speed with this powerful software package.
A very important feature of this software is a set of 3 commands
that allow you to save your critical angles and dimensions in a
special storage area that is accessed with an index number. This
allows you to label angles and dimensions on your drawings with
numbers and then recall the data in its full precision when you
need to use it in a calculation. This feature is integrated with
the trigonometry commands and allows you to keep all the angles and
dimensions used in your project readily available. The storage area
data is all stored in one variable. This makes it easy to backup
your data to port memory or a PC for future use.
Commands are provided for calculating the weight of, quantities of
cubic units, quantities of lineal units, and quantities of square
units using feet and inch or metric input.When running in feet and
inches mode the weight in pounds, of one cubic foot of steel (490
lbs.) is provided as a default input for the per cubic unit input.
When running in metric mode the weight in kilograms of one cubic
millimeter of steel (0.00000784905 kg.) is provided as a default
input for the per cubic unit input. You can use these or enter your
own values. This allows you to easily calculate the weight of steel
or any other material.
There are conversion commands used to convert to and from metric
and to convert or display a dimension in any of the available
fraction denominators. This library of commands provides the power
and speed you need to get the job done fast and accurately.
Simple Trigonometry Example:
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In this example we are calculating the overall length, end cut
dimensions, and bevel on 12" of a sloping member. The Feet and Inch
Engineering Tools quickly calculates the dimensions "A" through "G"
with the following command sequence.
1.11 [Enter] .0612 
1.0404
Dimension "A" = 1'-4 1/4"
6.0210 [Enter] .0710 .1108 4.0708
Dimension "B" = 4'-7 1/2"
0.0308, 4.0913, 16.3197
Bevel "C" = 3 1/2"
Angle "D" = 16.3197 deg.
Dimension "E" = 4'-9 13/16"
Note! The angle is now stored in the angle variable for subsequent
operations.
Leave 4.0913 in level 1 and delete the bevel and angle result.
1.04 
0.0411
Dimension "F" = 4 11/16"
5.0208
Dimension "G" = 5'-2 1/2"
This example shows you how to flow through a very simple problem. A
problem with many trigonometry calculations like a stair stringer
or gusset plate is just as easy to calculate using this software.
Using the feet and inch trigonometry commands, and the feet and
inch plus and minus commands, you can quickly string together
triangles and dimensions as needed to solve a problem with no
re-entry of results, no round-off errors, and no decimal
equivalents. With The Feet and Inch Engineering Tools, you too can
be the fastest most accurate dimension guru in your office.
The library file that is to be copied to your calculator is stored
in the program folder with the manual. You will need a serial cable
to connect your calculator to your computer and the PC Connectivity
Kit software.