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From: Bruce Lehmann
Categories: Saw cracks
Date: 08 Oct 1999
Remote Name: 126.96.36.199
I once ran across a bandmill where the wheels weren't round. I guess there were hard spots in the rim and no one checked the rim with a dial indicator. I clued in to the problem when I was told that a 1.5 pound balancing weight was put on the last time the balance was checked. Saws were only lasting 2 hours, then exploding.
Other things to check: 1. How course are the grind marks on the bottom of the gullets? The scratches are perfect places for cracks to start. 2. Is there any burning from the grinding? Burnt steel is very brittle. 3. Is the actual strain what you think it is? 4. Is the gullet shape "smooth" at the bottom of the gullet? A small radius at the bottom of the gullet intensifies the stresses.
What plate thickness are you using? Thicker plates crack sooner.
Good Luck Bruce
I'VE BEEN WORKING ON THIS PATICULAR MILL FOR 3 YEARS AND HAVEN'T BEEN ABLE TO STOP THE CRACKING .I THINK I'VE DONE EVERY THING I COULD POSS -IBLE DO. I'VE GROUND THE WHEELS ,CHECK BEARINGS( NEW MACHINE MACDOUNAH 6FT. HORIZONTAL )REDID THE DUST SHOOT SO THAT THE DUST WOULD FALL STRAIGHT DOWN INSTEAD OF GOING BACK AROUND THE WHEEL AND CAUSING HEAT. IT HELPED THE HEAT SOME BUT WERE STILL GETTING IT FROM SOMEWHERE. GUIDES ARE IN LINE AND GUIDE PRESSURE IS FINE .NO CROSS ALIGHNMENT IN MILL.SCRAPERS AND CHIP BREAKERS ARE IN LINE,LUBRACATION-USING DIESEL ON THE OIL WICK.CHANGING SAWS EVERY 4 1/2 HOURS ,LUBRACATING MACHINE REGULARY , NOT WITH ANYTHING THAT WOULD CAUSE HEAT .IN THE FILING ROOM WEVE GOT OUR GRINDERS ALIGHNED AND BENCHING IS LEVEL AND TENTION IS NOT TO HEAVY OR TO LOW (40 TENTION AND TIRE LINE IS 1/2 INCH FROM GULLET)THEY MAY BE MORE THAT ICAN'T REMEMBER .BUT IF ANY ONE CAN HELP PLEASE E-MAIL ME AT DIMMOK2@AOL.COM OR ILL JUST SEE IT HERE.IF NOT DOES ANYONE KNOW OF ANOTHER JOB ANYWHERE! HA!HA! THANK YOU WAYNE BUSBY ( HORIZONTAL FILER) 1 (205)752 -4051
From: WAYNE BUSBY SAWFILER LINDEN LUMBER CO.SAWDOCTOR@ALTAVISTA.COM
Date: 04 Feb 2000
Remote Name: 188.8.131.52
WAYNE IF IM SEEING WHAT YOUR SAYING RIGHT ,IT MAY HELP TO GO TO A NEGATIVE HOOK.THE SAW WILL NOT SNATCH OR THROW AS LIKELY.5 DEGREE NEG. WAYNE BUSBY,