Foley United 633 Operator's Manual page 32

OPERATION
ORIGINAL INSTRUCTIONS
NOTE: SETUP PROCEDURE FOR SPIN DRIVE RPM
SPIN DRIVE RPM DURING SPIN GRINDING IS VERY IMPORTANT IN ACHIEVING A QUALITY GRIND. THE
DIAMETER OF THE REEL AND THE NUMBER OF BLADES ON THE CUTTING UNIT YOU ARE GRINDING
DETERMINE THE INITIAL SPIN SPEED.
Generally, the SPIN DRIVE RPM for spin grinding will be between 180 RPM and 380 RPM. For all reels, there
is an optimum SPIN SPEED where there is an AGGRESSIVE, yet smooth grind.
It is recommended to start grinding each reel at the spin speed of 180 RPM and then evaluating the RPM by
adjusting higher and lower to optimize the SPIN SPEED for that reel.
INCORRECT SPIN SPEED can cause two problems: grinding wheel dressing or grinding wheel resonance.
For some reels, especially small diameter high blade count reels, if the SPIN SPEED RPM is set too high, the
reel can act as a dresser to the grinding wheel. There can develop what appears to be a very aggressive grind
(as if the infeed has self-infed) and then a sudden stop of grinding with no grinding wheel to reel contact. If
this occurs, your SPIN SPEED was set too high and you have dressed your grinding wheel.
Some reels have a resonant RPM where the reel goes into harmonics with the grinding wheel and the
resonance vibrates the grinder which results in a very bad grind. By changing the SPIN SPEED to a higher or
lower RPM you will move out of the resonant range. After determining the best SPIN SPEED RPM for a reel,
write the setting in the REEL SETUP CHART.
Spin grinding is complete when enough material has been removed and full contact is made across the entire
length of the reel and the entire width of all blades. Spark-out the reel to complete grinding the outside
diameter to a true diameter. To Spark-out the reel, infeed the grinding head approximately .002" and let the
grinding wheel continue to traverse for at least 20 passes or until there is a 99% reduction in grinding sparks
compared to normal spin grinding.
NOTE: Set traverse at slow speed on the TRAVERSE SPEED KNOB. The slower the traverse speed, the better
the finish. Approximately 8 feet per minute or slower is recommended, but adjust the speed to your finish
requirements for final grinding sparkout. After sparkout, adjust the TRAVERSE SPEED KNOB to 0 and then
switch all motors to OFF.
Open the doors and inspect the reel. If it is sharp, go to the relief grind process. If not, repeat the spin
process, as required. If you wish to inspect the reel in the middle of a grind program, turn off all switches
when the grinding head is in the HOME position. You can then open the doors and check the reel. If you
wish to continue, close the doors and turn all the motor switches back to ON.
NOTE: At this point your reel has been sharpened with the SPIN GRIND process. If you do not want to RELIEF
GRIND, simply remove the reel and SPIN GRIND the next reel. If you want to RELIEF GRIND your reel, go to the
RELIEF GRINDING section of this manual on the next page.
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