Ripsaws have long been a workhorse in the rough mill, ideal for dimensioning and enabling woodworkers to obtain straight, uniform sizes of lumber.

If your machine is not producing quality cuts, here are some possible causes and solutions to the problem.

1. Your material is cut in an irregular manner, with the stock “snaking” through the machine 
Probable causes: (1) The material is not held tightly. (2) The material is being pushed. (3) The feed chains are not tracking correctly.
Solutions:  (1) Check the pressure bar height and set the yield to 1/8 inch; check the pressure rolls for play; check the tops of the feed chain for wear – there should be less than 0.040-inch flat on top of the pyramid; make sure the pressure bar is level and parallel to the feed chains. (2) Check for slivers in the machine and/or check all the pressure rolls for turning. (3) Check for slivers in or under the feed chains; check the feed chains side to side for flat and replace if needed; check for wear or alignment of the front cams of the chain race; check the drive cam for wear or alignment – no more than a 1/16-inch gap should be between the link and cam tooth; and check the feed chain length – the chains should hang the same under the machine

2. There’s a rough cut on the stock.  
Probable causes: (1) The saw blades are not running true. (2) The blade is moving or being deflected.
Solutions:  (1) Check the blade for high teeth – changing the saw blade should change the cut; check for dirt between the saw collars; check for nicks in the saw collars; check the inner saw collar with a dial indicator, a 0.003-inch maximum runout is recommended; check the outer saw collar for dish – there should be 0.005-inch dish in the center of the collar; check for slivers or pitch build up around the saw blade; check the kerf of the saw blade – a 3/16-inch kerf is recommended; check for end play on the inner saw collar – the inner saw collar should not move in or out more than 0.001  inch; check and/or adjust the saw lead – both sides of the material should only show saw marks from the leading side of the blade (no heal marks).

3. Leaves a snipe on the trailing end of the material. 
Probable causes: (1) There is wear in the chain race. Both edges are greater than 90 degrees from the bottom. 
Solutions: (1) Check the feed chains side to side for flat. More than 0.018 inch across chains will cut material unsquare. Replace the feed chains and race.

4. The entire edge of the material is out of square with the bottom. 
Probable causes: (1) There’s wear in the chain race. Both edges are greater than 90 degrees from the bottom. (2) The saw blade is not parallel to the feed chains. (3) The blade is not square with both feed chains; one side is greater than 90 degrees, and the other is less than 90 degrees to the bottom. 
Solutions: (1) Check the feed chains side to side for flat. More than 0.018 inch across chains will cut material unsquare. Replace the feed chains and race. (2) Check and/or adjust the saw lead. (3) Check the blade to both feed chains. Set the angle of the arbor assembly.

5. When sizing the material, one end is cut wider than the other. 
Probable causes:  (1) The stock guide rail is out of adjustment. (2) The material is being pushed sideways.
Solutions: (1) If the leading end is wider than the trailing end, adjust the left end of the guide rail away from the machine. If the leading end is narrower than the trailing end, adjust the right end. (2) Check for slivers in the machine and clean the machine. Check the feed rolls for not turning, and repair or replace. Check the infeed conveyor or roller stand (if used) to ensure it is square to the feed chains; this normally only affects long material. The stock guide may not be locked to the guide rail as the material is fed into the machine. The operator may not be holding the stock against the stock guide when feeding it into the machine.

Source: Mereen-Johnson. For information call 612-529-7791 or visit Mereen-Johnson.com.