When a straight line rip saw stops producing consistent cuts, the root cause is almost always mechanical — worn feed chains, misaligned pressure bars, deflected blades, or a stock guide that’s drifted out of adjustment. This guide walks through the four most common symptoms we see on rip saws in the field, with a diagnostic table for each one covering the probable cause and step-by-step corrections.
Before working through the checks below, confirm that your machine is on a current general rip saw maintenance schedule — many of the issues outlined here are accelerated by skipped lubrication intervals or deferred chain replacement.
Erratic Cuts
Erratic cutting is the most frequently reported issue on straight line rip saws, and it typically shows up as material “snaking” through the machine or producing a rough, inconsistent edge. Because the feed chains, pressure bar, pressure rolls, and saw blade all work together to hold and track stock through the cut, a problem in any one of those systems can produce the same symptom. Work through the probable causes below in order — start with the quickest visual and cleanliness checks before committing to parts replacement.
| Description | Probable Cause | How to Correct |
| Material is cut in an irregular manner. Stock “snakes” through the machine. | Material is not held tightly. | Check the pressure bar height. Set the yield to 1/8″. |
| Check the pressure rolls for play. Repair or replace. | ||
| Check the tops of the feed chain for wear. There should be less than .040″ flat on top of Pyramid. | ||
| Check the pressure bar for level. The pressure bar should be parallel to the feed chains. | ||
| Material is being pushed. | Check for slivers in the machine. Clean the machine. | |
| Check all pressure rolls for turning. Repair or replace. | ||
| Feed chains are not tracking correctly. | Check for slivers in or under the feed chains. Clean the machine. | |
| Check the feed chains side to side for flat. Replace the feed chains and race. | ||
| Check for wear or alignment of the front cams of the chain race. Replace the feed chains and race. | ||
| Check the drive cam for wear or alignment. No more than a 1/16″ gap should be between the link and cam tooth. Align or replace. | ||
| Check the feed chain length. The chains should hang the same under the machine. Replace the feed chains and race. | ||
| Rough cut on stock. | Saw blades not running true. | Check blade for high teeth. Changing the saw blade should change the cut. |
| Check for dirt between the saw collars. Clean the saw collars and the saw blade. | ||
| Check for nicks in the saw collars. Repair or replace. | ||
| Check the inner saw collar with a dial indicator, a . 003″ maximum run out is recommended. Repair or replace the collar and bearings. | ||
| Check the outer saw collar for dish. There should be .005″ dish in the center of the collar. | ||
| Saw blade moving or being deflected. | Check for slivers or pitch build up around the saw blade. Clean the machine. | |
| Check the kerf of the saw blade. A 3/16″ kerf is recommended. Thinner blades can be deflected by the material. | ||
| Check for end play on the inner saw collar. The inner saw collar should not move in or out more than .001″. Replace arbor bearings. | ||
| Check the saw lead. Both sides of the material should only show saw marks from the leading side of the blade (no heal marks). Adjust the saw lead. |
No Glue Joint
A proper glue joint cut produces two edges that, when placed together, form a slight concave gap (.003″ to .006″ for standard applications, less for RF gluing). If your saw is producing convex or uneven cuts that won’t clamp cleanly, the cause is almost always either stress in the material itself, worn feed chains that have lost their flat, or a misaligned blade. Material stress is often overlooked — always edge stock after it has been busted down to size rather than trying to edge wide material in one pass.
When checking chain race adjustment, use two pieces of material 6″ wide and 4′ to 6′ long, edge both on the same chain, and put the cut edges together to measure the gap. Do not lock the stock guide during this check.
| Description | Probable Cause | How to Correct |
| Cuts do not provide a concave cut down the length of the material. When setting the cut of the ripsaw, adjust each chain independently. Use two pieces of material 6″ wide and 4′ to 6′ long for setting chain race. Do not lock the stock guide when feeding material into the saw when checking the adjustment of the chain race. Edge both pieces on the same chain, and put the cut edges together. There should be .003″ to .006″ between the two pieces. Less for RF gluing applications. | Stress in the material. | Edge the material after it has been “busted down” to size. |
| Cut wide material into smaller sizes before edging. | ||
| Material not tracking on chains. | Check the machine for slivers. Clean the machine. | |
| Check the pressure rolls for play or not turning. Repair or replace. | ||
| See erratic cuts section. | ||
| Machine is worn. | Check the feed chains for wear (side to side and even length). Replace the feed chains and chain race. | |
| Check the front idle cams. Are the inside edges of the cams touching. Replace the feed chains and chain race. | ||
| Material being deflected. | Check sharpness of saw blade. Replace. | |
| Machine misaligned. | Check saw blade setting (lead). Adjust arbor. | |
| Check the adjustment of the front idle cams. Adjust front idle cams. |
Edges Not Square
Out-of-square edges almost always trace back to one of three causes: wear in the chain race that’s allowed the chains to sit unevenly side-to-side, a saw blade that’s lost parallel alignment with the feed chains, or — less commonly — the arbor assembly itself being out of square. More than .018″ variation across the chains will produce noticeably un-square cuts and indicates the feed chains and race need to be replaced.
If you’re only seeing a snipe on the trailing end of the material, the root cause is the same chain race wear issue — the machine cuts square at the start of the piece but drifts as the stock exits the chains.
| Description | Probable Cause | How to Correct |
| Entire edge of the material is out of square with the bottom. | Wear in the chain race. Both edges greater than 90 degrees from the bottom. | Check the feed chains side to side for flat. More than .018″ across chains will cut material un-square. Replace feed chains and race. |
| Saw blade is not parallel to feed chains. | Check saw lead. Adjust saw lead. | |
| Blade is not square with both feed chains. One side greater than 90 degrees, the other is less than 90 degrees, to the bottom. | Check the blade to both feed chains. Set the angle of the arbor assembly. Be certain of the need for this. This is an uncommon adjustment. | |
| Leaves a snipe on the trailing end of the material. | Wear in the chain race. Both edges greater than 90 degrees from the bottom. | Check the feed chains side to side for flat. More than .018″ across chains will cut material un-square. Replace feed chains and race. |
Wedges
Wedging — where one end of the ripped piece is wider than the other — is almost always a stock guide or feed issue rather than a problem with the blade or arbor. The first thing to check is the stock guide rail adjustment, followed by whether the operator is holding stock firmly against the guide through the entire cut. Material pushed sideways by slivers, non-turning feed rolls, or an out-of-square infeed conveyor can also produce wedging, particularly on longer pieces.
| Description | Probable Cause | How to Correct |
| When sizing the material, the saw cuts one end wider than the other. | The stock guide rail is out of adjustment. | Leading end is wider than the trailing end. Adjust the left end of the guide rail away from the machine. |
| Leading end is narrower than the trailing end. Adjust the right end of the guide rail away from the machine. | ||
| Material is being pushed sideways. | Check for slivers in the machine. Clean the machine. | |
| Check the feed rolls for not turning. Repair or replace. | ||
| Check the infeed conveyor or roller stand (if used) for square to the feed chains. Normally only affects long material. | ||
| Stock guide is not locked to the guide rail as material is fed into the machine. | ||
| Operator is not holding stock against the stock guide when feeding it into the machine. |
Related Maintenance and Reference Guides
Troubleshooting is most effective when paired with regular preventive maintenance. For additional support on your straight line rip saw, review these related resources:
- General rip saw maintenance
- General troubleshooting guide
- Straight line rip maintenance
- General saw safety guide
- Choosing the best rip saw
Still Can’t Resolve the Issue?
If you’ve worked through the probable causes above and your rip saw still isn’t producing consistent, glue-line quality cuts, our factory service team can help. Mereen-Johnson technicians have the original manufacturing records and decades of field experience on every machine we’ve built, which means we can diagnose issues other service providers can’t.
Contact Mereen-Johnson service or call (612) 529-7791 to speak with a factory technician about your straight line rip saw.