Howdy racers and race fans! I'm Jerry Gordon (Maverick on the net)
Crew Chief for Al Miles and the FFR PRO DRAGSTER race team out of
Edmonton Alberta Canada. I have been riding and racing motorcycles
since I was 11 years old. When I started racing Fred Flintstone
was my crew chief. Over a 25 year period I have built and raced
a 890cc RC Eng. Honda Street bike, a double engine 2200cc RC Eng.
Honda, a Kawasaki 1200cc Pro Stock, a blown and injected Top Fuel
1100cc Honda, a Kawasaki 1200cc turbo NOS Funny Bike, a 1385cc injected
Nitro Suzuki, plus a bunch of road race stuff in the late 70ds.Over
the years I have fabricated about 25 complete drag racing chassis
complete with motor plates and some body work. I was the fastest
man in Canada for over 10 years and held the record for the longest
wheel stand with a Honda CBX. I was the first man in Canada to run
a nitro-powered motorcycle and learned a lot of what I know about
nitro from Bernie Fedderly one of Force's crew chiefs.
Anyway...enough about the past. Let's talk about the future. The
future of machining components for all types of racing machines
2 or 4 wheel, straight line or roundy round. The future is CNC machining
coupled with CAD CAM systems. CNC stands for computer numerical
control. Basically this means that the machine movements are controlled
by a code of letters and numbers. The letters and numbers in the
code tell the machine to perform a specific function, for example
drill a hole. Then another set of numbers with an X,Y,Z letter in
front tell the machine where to drill that hole and how deep. If
you were to take a map of your hometown and lay it on the table
of a milling machine then give the machine the address of your house
the machine would go to your house and drill a hole right in the
middle of it. That code would look something like this.
G81 X-0.418 Y-1.765 Z-0.113 R0.1 F1.5
T1 (Tool number for the drill)
M6 (change the tool)
M3 (turn the spindle on)
S1500 (RPM for the spindle)
M8 (turn the coolant on)
G81 (drill a hole)
X-0.418 Y-1.765 (move the table to this position)
Z-1.00 (drill the hole 1inch deep)
F1.5 (feed the drill into the material at 1.5 inches per minute)
R0.1 (return the drill to .100 above the part)
This type of code is called G code and about 90 percent of the
CNC machines in the world use it.
Now lets move on to CAD CAM programs. CAD stands for Computer Aided
Design or Drafting.
Basically this is a computer program that allows
you via a keyboard and mouse to draw on your computer screen. The
nice thing about this type of drafting is that you never need a
protractor or an eraser. This system is great for doing things like
conceptual design and engineering. Parts and components can be drawn
to scale on the screen and the easily multiplied, or manipulated
into completed assembles. Nowadays with 3D graphics and solid modeling
one can see exactly what a part or assemble will look and fit like
before it is ever made.
CAM stands for Computer Aided Machining. This computer program
links to the CAD program and is really the heart and soul of the
system. What it does is allows you to click on different elements
of you part drawing on the CAD screen and apply tool paths (machine
moves) to your drawing.
For example drilling holes or machining
the shape of your part. Then you can do a graphic animation of what
the machine will cut and see what your part will look like. As you
are doing this, the program is writing the G Code that the machine
understands in the background. The code produced may be thousands
of lines long but the computer generates it in a mater of seconds.
This code can then be transferred to the machine on the shop floor
and the parts can be made.
So as you can see the basic principles of CNC CAD CAM are fairly
simple. CNC machines have been around for many years but it was
not until the development of CAD CAM software that they became practical
for doing one off or small run jobs. In the early days of CNC the
operator had to write the code line by line on the computer in the
machine. This was a long and arduous process and was not very practical
for complex parts or small runs.
So now your thinking well what good is that to me as the average
racer? From what I have seen over the years is that the average
racer always has some part or gismo that he or she would like to
make or needs to be remade because you cant get it any more. Here's
the deal the largest part in most cases, of producing CNC parts
is the drawing of that part. If the part is drawn accurately and
to scale then it is a relatively easy process to have a local CNC
machine shop with a CAD CAM system program the code and make the
CAD systems are relatively inexpensive to purchase and fairly
easy to learn. CAD CAM systems on the other hand cost thousands
of dollars and require a good general knowledge of machining.
There is currently a post running on the stipbike.com bulletin
board under V-Twin Racing called CAD CAM if you are interested come
over and have a look. There should be some very interesting tips