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General Rip Saw Maintenance Guide

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General Rip Saw Maintenance Guide

A disciplined rip saw preventive maintenance program is what keeps a Mereen-Johnson rip saw producing glue-joint quality cuts and meeting its full duty cycle year after year. Most cut quality problems and unexpected downtime trace back to the same handful of components — the feed chains and dip cams, the press roll and bed plate relationship, the arbor and bearings, the oil mist lubrication system, and the anti-kickback safety system. All of them respond to consistent, scheduled maintenance.

This general guide covers the maintenance program common to Mereen-Johnson rip saws across models, organized by service interval, plus the key procedures every maintenance team should understand. For model-specific schedules and full step-by-step procedures, see the model-specific maintenance guides linked throughout and the downloadable manual.

Safety first: Always disconnect the main power supply before servicing the machine. Clean anti-kickback fingers daily with air only — never oil them.

For the complete reference, view the full General Rip Saw Maintenance Guide PDF.

Daily Maintenance

Daily maintenance focuses on cleanliness, lubrication levels, and the anti-kickback safety system. These checks take 15–20 minutes and prevent the majority of wear and downtime issues.

  • Fill all oil cups with 10W non-detergent oil
  • Check anti-kickback fingers for wear, free-fall ability, and stuck or bent fingers
  • Walk around the machine to inspect for developing problems
  • Blow the machine down completely with compressed air
  • Clean the arbor shaft with solvent and apply a light film of 10W non-detergent oil
  • Check oil mist nozzles for proper aim and oil output
  • Check the dust extraction system is clear of sticks, slivers, and possible jams

Weekly Maintenance

  • Check arbor shaft run-out and bearing integrity
  • Check the overbeam relationship
  • Check arbor sleeves for damage and excessive wear
  • Clean and flat-file all aluminum spacers
  • Check the #3 rubber-covered press roll and rubber feed slat inserts for wear
  • Check the press roll to bed plate relationship
  • Check press roll pivot bushings for wear

Monthly Maintenance

  • Check and adjust all air pressures as needed
  • Check Bijur mist oil units oil output quantity
  • Check feed drive chain tension and sprocket condition

Quarterly Maintenance

Four times a year, perform these deeper inspections and adjustments:

  • Check dip cams, feed sprockets, feed chains, and chainway for wear
  • Check and adjust the press roll housing gib and the arbor motor gibs
  • Check lube level in the feed drive gear box
  • Check press roll housing adjust screws and brass nuts for wear
  • Check the arbor motor hoist for wear
  • Tighten all electrical connections and inspect all electrical components

Every 400 Hours

  • Grease the entire machine — do not over-grease the arbor bearings

Anti-Kickback Finger Maintenance

The anti-kickback fingers are the rip saw’s primary operator protection against material kickback, and they require specific daily attention:

  • Clean daily with air only — never oil the fingers (oil causes sawdust to accumulate, making the fingers less effective)
  • Replace any worn kickback fingers. Test for sharpness using the cardboard strip provided in the back of the manual
  • Confirm free movement — fingers should always swing freely and return to their original position
  • Dust collection: 680 CFM, 4″ water gauge, 5000 FPM minimum velocity

For complete operator safety procedures and kickback prevention, see our general saw safety guide.

Oil Mist Generator System

The oil mist generator provides essential lubrication to the bottom chain vees and chain pins. Without proper oil mist, the feed chains, extended pins, and cams will wear excessively.

Weekly Nozzle Verification Procedure

Check the position of the four spray nozzles weekly to confirm they’re spraying on the chain vees and pins. The feed chains must be running to check the nozzles — use extreme caution and have someone standing by the main power switch.

  1. With the feed chains running, hold a piece of white paper in front of each nozzle for 15 to 20 seconds
  2. After 20 seconds, there should be an oil spot the size of a quarter
  3. If there’s no stain, check the nozzles for obstructions — dust collects at the nozzle discharge fitting and should be removed during weekly cleaning

Oil Mist Maintenance

  • Check the oil level daily and refill the reservoir as required (fill to, but never above, the top of the Liquid Sight Gage)
  • Use only clean oil of the type and viscosity recommended by the machine manufacturer
  • Never remove the filler plug when the unit is in operation
  • Check filters periodically and clean or replace as necessary
  • Drain accumulated water and impurities from the air reservoir as needed
  • Replace the filter group once a year

For detailed lubricator service, see our Alemite lubricator service guide.

Press Roll and Bed Plate Relationship

The relationship between the press rolls and bed plate is factory-preset and critical to cut quality. On the standard 3″ air-loaded press roll system, with the relationship preset for 1/8″ smooth material:

  • The press rolls yield (raise) 3/16″
  • The bed plate yields (raise) 1/16″

Press roll height adjustment: Use the press roll height adjustment bolts to reset the rolls from 1/8″ yield (smooth material) to 1/4″ yield (rough material).

Pressure adjustment:

  • Roll pressure: turn the air regulator up — 40–45 PSI is normal, with a maximum of 60 PSI. When resetting rolls from 1/8″ to 1/4″ for rough material, do not increase the pressure
  • Bed plate pressure: turn the tension nut counterclockwise. Check four times a year to maintain .080″–.100″ clearance between the spring coils
  • Set spring tension to .060″–.080″ between coils

Important: Never attempt to achieve more holddown pressure by lowering the press roll assembly. Doing so damages the press roll to bed plate relationship.

Spring-Loaded Press Rolls (Older Machines)

Machines with the older spring-loaded press roll system follow the same yield specs (3/16″ press roll, 1/16″ bed plate for 1/8″ smooth material). On these models, check the spring pressure on the press rolls every 90 days — the gap between spring coils should maintain 1/8″ of clearance. Compression of the urethane grommets from normal wear will eventually require readjustment of the vertical height adjustment nuts.

Feed Chain and Dip Cam Maintenance

  • Dip cams are Quad Life. If worn on one side, switch the left-hand cam with the right-hand cam. If worn on both sides, remove the .018″ cam spacer from under the cams and repeat. Before starting, remove the outside tie bar, bed plates, and inside tie bar
  • Feed chains: Over time the chain pins wear on top. If the flat spot on the chain is 3/16″ or greater, replace or rebuild the feed chain (58 links)
  • Daily compressed-air cleaning dramatically reduces sawdust buildup that accelerates feed chain and dip cam wear

Contact Mereen-Johnson Customer Service to order new dip cams or feed chains.

Electronic Shear Pin (Current Sensor)

Mereen-Johnson uses a current sensor as an electronic shear pin — it monitors normal current draw on the feed motor, and if current climbs above the set level, it trips out and shuts off the feed drive to protect the machine.

  • Trip delay potentiometer should be set full counterclockwise for no delay
  • Adjust the trip point clockwise until the red LED light goes out. Turning this up too far can cause severe damage to the feed drive system
  • Automatic reset: If the sensor trips, it resets automatically. Before restarting, locate and correct the reason it tripped
  • VFD-equipped machines: The frequency controller has a built-in, factory-set current sensor

Caution: Disconnect all voltages before making connections to the current sensor.

Slip-Off Bearing Service

The slip-off bearing (outboard arbor bearing) is serviced by dropping the arbor lock into position, removing the clamp nut and lock nut, removing the clamp plates and arbor lock, removing the bearing cap, and pressing out the sleeve and bearing. On reassembly, wash all parts in solvent, purge old grease, lubricate and press in the new bearing, and confirm the sleeve assembly turns freely while the arbor lock is disengaged. Full step-by-step procedure with part references is in the downloadable manual.

Arbor Motor and Bearing Service

Arbor motor bearing replacement is a detailed procedure requiring a dead-blow hammer and careful bearing handling. Key points:

  • Hand-pack bearings 1/3 full with Molylube 126-EP grease or equivalent
  • Heat the front bearing inner race to approximately 120°F–140°F using a bearing core heater, oven, or light bulb to slide it onto the journal
  • Apply anti-seize compound to the arbor shaft before final assembly to ease future disassembly
  • If equipped with an arbor brake, remove the brake assembly before removing the arbor (mark air lines for reassembly)

The complete step-by-step disassembly and reassembly procedure (with numbered part references) is in the downloadable PDF. Given the precision required, arbor motor service is a good candidate for factory technician support.

Varimot Drive (Older Machines)

Machines built with a Varimot variable speed drive (rather than a VFD) consist of a motor with dovetail slide, drive disc, hollow shaft with friction ring, and torque compensator (lobe cams). Friction disc replacement, bearing regreasing (Shell Alvania for needle bearings; Lubriplate GR-132 for cam lobes), and driving cone removal are detailed in the downloadable manual. When regreasing, do not overfill the cavity — too much grease generates excessive heat.

Infeed and Outfeed Conveyor Setup

Proper conveyor integration directly affects cut quality.

Infeed conveyors should:

  • Run at the same speed as the rip saw feed bed (speed mismatches affect cut quality, jam the feed bed, double-feed, or kick boards to one side)
  • Be parallel with the direction of feed
  • Have at least the closest roller parallel to the saw arbor

Outfeed conveyors should:

  • Run no more than 10% faster than the saw’s feed bed
  • Accept material straight out of the saw
  • Be level with the saw’s outfeed

Infeed nip rolls should jump down as material passes under, raise off the material by the time the 2nd press roll touches it, run at the same speed as the feed bed, and be positioned parallel to the arbor and level with the infeed table.

Electrical Components

Electrical components should be replaced on an “as needed” basis. There are no electrical components that should be replaced on a scheduled maintenance basis — but all electrical connections should be tightened and components inspected during quarterly maintenance.

Model-Specific Maintenance Guides

This general guide covers maintenance common across Mereen-Johnson rip saws. For schedules and procedures specific to your machine, see the model-specific guides:

Related Troubleshooting and Reference Guides

Need Service or Replacement Parts?

Some maintenance — particularly arbor motor bearing replacement, slip-off bearing service, and Varimot drive work — benefits from factory expertise. If you’re planning a major service event, training your maintenance team, or need exact-fit replacement parts (dip cams, feed chains, bearings, anti-kickback fingers), our factory team can help. Mereen-Johnson maintains the original manufacturing records and parts inventory for every rip saw we’ve built — including legacy machines dating back to 1930.

Contact Mereen-Johnson service or call (612) 529-7791 to speak with a factory technician.