Bad Finish on your Valves? “Chatter”?
A wavy finish, often called “chatter,” on the valve face is typically due to some form of vibration. Most people suspect the grinding motor or the grinding wheel itself, but these are just the most obvious potential sources.
For more information, please visit valve grinder machines.
Here are several steps to follow if your valves are not achieving an ideal finish. Regular maintenance of the machine is crucial and is often overlooked.
Grinding Motor Slide and Gibs
Test this by dressing your grinding stone. After the final sweep, move the stone so the diamond is in the middle of the stone with the motor running. There should be no scraping sound. If pushing on the center of the motor housing makes the diamond contact the stone, then the Slide Gibs are out of adjustment. Refer to the manual for adjustment procedures for the Motor Slide Gibs.
Chuck Movement
Movement in the chuck can lead to an out-of-round finish or chatter (rough-lined look) on the valve. Adjustments are necessary if these issues occur. If the valve face is okay but the finish is out of round, the Chuck likely has lateral movement and requires the spline pulley to be re-seated (refer to Chuck Pulley Adjustment below).
To test chuck runout, insert a known straight shaft into the chuck, place a dial indicator an inch from the face of the chuck on the shaft, and check for correct tolerance while running the chuck. If off, possible causes include loose Chuck Slide Gibs, a worn chuck bearing, or an overly tight chuck belt. If tolerance is correct, check for lateral movement and oil squeeze from the Chuck Slide Gibs by pushing and lightly pulling the slide crank wheel side to side.
Making the adjustments
ALL ADJUSTMENTS SHOULD BE MADE WITH THE MACHINE UNPLUGGED FROM POWER.
Start Easy
If a new grinding stone was recently installed, try rotating it 180 degrees to see if that resolves the issue. Remember to re-dress the stone after remounting it.
Grinding Motor Slide Gibs
To check the Grinding Motor Slide Gibs, power off the machine and move the Traverse Handle to the 12 o'clock position. Twist the grinding motor unit by placing hands on the aluminum end covers. Any movement indicates that the gibs need adjustment. Follow manual instructions for adjusting, and be mindful that thread locks are used, which may make adjustment screws stiff.
Chuck Saddle Bearing Adjustment
Remove the chuck belt. Adjust the saddle nearest the valve side of the chuck first while turning the chuck shaft. Stop adjusting when you feel drag and back off slightly, then repeat for the other saddle bearing.
Saddle bearings only consist of the chuck shaft and saddle surface, both ground to precise tolerances and hardened for durability. Ensure they are frequently oiled and free of debris.
For more valve grinding equipment info, please contact us for professional assistance.
Chuck Pulley Adjustment
For lateral chuck movement, place your palm on the face of the chuck and push towards the back. If a gap forms between the pulley and the saddle bearing, loosen the pulley set screw and adjust the pulley until there is no gap. This ensures lateral movement is properly controlled.
Chuck Belt Adjustment
The Chuck Motor Belt is often to blame for chatter on the valve face due to over-tightening. Contrary to general beliefs, the Chuck Motor Belt should be loose enough to avoid motor vibration transfer while remaining tight enough to prevent slipping during grinding.
Chuck Gib Adjustment
Out of roundness generally stems from loose Chuck Slide Gibs. Start with the gib screw nearest the valve and tighten until you feel a drag, then back off slightly. Repeat for center and outer screws.
Sticky Chuck
If the Chuck operation sticks or fails to engage fully, likely causes are dirt or residue. Avoid residues by not using WD-40 or brake cleaner. Instead, soak the chuck in automatic transmission fluid (ATF) overnight. If issues persist, disassemble and clean with Denatured Alcohol, then reassemble using ATF.
During disassembly, inspect the Chuck Balls for flat spots and ramps for wear. Replace worn parts to avoid short-term fixes that deteriorate quickly.
Poor Valve Finish Frustration
Problems often arise at the worst times, but a subpar valve finish is 99.9% caused by inappropriate movement somewhere in the machine. Thorough adjustments typically reveal and rectify the cause.
For further assistance with chuck performance or replacement chucks, contact Kwik-Way Tech Services or Sales at 800-553-5953.
Interested in learning more about valve grinding equipments? Contact us today for expert consultation!
Comments
0