CNC Plate Fabricator Components, Pinch Rolls and Plasma Torch
Plasma Torch
Plasma cutting is today's industrial technology of cutting steel,
preferred over the traditional Oxygen-Acetylene method. It is
defined by "constraining a lightning bolt." A few of the advantages
of using plasma are high volume metal cutting operations, faster
cutting speeds, better edge quality, closer tolerance, efficiency,
weldability of cut parts, dross-free cuts etc... Franklin could not
achieve these advantages on the plate fabricator. Plasma torch
location, ignition, motion, speed, ramp up/down, travel path, and
consistent cut height is commanded by the PIC/PLC. Its proper
function is to lower to material surface (this locates the height)
then rise (depending upon material thickness) to approximately 3/16"
above material surface. Then it is commanded to ignite and travel
through cut path at the predetermined cut height for the entire
part. The Franklin plate fabricating machine never had success in
this area as well. Their machine performance was erratic and
destroyed more material than it could process correctly.
Pinch Rolls
There are two sets of pinch rolls (upper and lower) on each side of
the machine that the steel plate travels between. One set is mounted
on the in-feed side of the machine and one set on the out-feed side.
Their purpose is to clamp, move, and measure distance of travel of
the steel plate. Not dependably successful on fmi machine. At times
these rollers would run out of control again creating a very
dangerous environment for life and limb. The upper rollers are a
little longer than six feet long and about six inches in diameter.
It is a tube mounted on bearing pads that are hydraulically raised
and lowered to clamp the steel plate to the lower roller. The lower
roller (same size) called a drive roller is stationary with motors
attached to drive the steel plate in the "X" axis. At one end of
these upper rollers, there are electronic measuring devices called
encoders. These encoders are supposed to measure the travel of the
material. If they weren't exploding the electrical components they
would simply not function period. To begin a production run, the
steel plate is positioned between the first set of rollers (in feed)
and the upper roller is commanded to lower, clamping the steel
plate. After the bottom (drive) roller is commanded to move the
plate, the upper roller is supposed to measure travel. After the
steel plate moves through the machine and reaches the second set
(out-feed) pinch rollers, they are activated like the first set and
take over the measurement tracking. Again this function could work
or not with no dependability creating a very dangerous environment.