General FAQs
How do I find the number for the part I need?
Most Mereen-Johnson machines manufactured after 1990 feature part numbers marked on every part. If you can’t find this number, simply call our customer service department with the machine Model and Serial Number and our Customer Service Team will identify the part for you.

How do I identify my machine’s serial and model number?
For most machines, both model and serial number will be displayed on a placard located on the electrical cabinet. Most machines manufactured after 1960 will have a serial number starting with MJ followed by four digits.

Gang Rip Saw FAQs

Why has the quality of cut deteriorated?
Many factors can influence cut quality. The following is a list of things to check:

Tooling – Dull tooling will run hotter, draw more amperage and can result in poor cut quality
Saw Spacers – Nicks and dings in saw spacers can cause tooling to run untrue
Arbor – A bent arbor can cause irregular tooling rotation (standard tolerance .002”).
Outboard End Bearing (if equipped) – can influence the arbor and cause the saw sleeve to be out of tram in relationship to the feed bed.
Select Saw Hubs (if equipped) Tooling mounted improperly, hub bearings worn, nicks or burrs on hub.
Feed Slats and Inserts – bent feed slats or worn out inserts can cause boards to be passed through the saw arbor in an inconsistent manner.
Rubber Covered Press Rolls – worn press rolls can lose containment or allow board to move in the cut.
Bed Plate – Miss-adjusted or worn bed plates may not properly contain material in the cut. Also check bead plate pressure springs, sleeves and pressure head screws and bosses.
Arbor Bearings – excessively worn or faulty
Arbor Slide Gibs -  are worn or need to be tightened.

Why does my pressure head bounce when boards go through the machine?
Check vertical adjusting bosses and screws located on the top of the arbor support column for excess wear.

Why won’t my arbor start?
Machine does not have enough air pressure.
Arbor access door is not completely closed or faulty door safety switch.
Starter overload tripped.
Low mist oil level.

Why aren’t ripped boards straight?
Press rolls or bed plate not set properly.
Feed bed in poor condition.
Feed Sprockets, chain, sprocket hubs/keys worn.
Excessive stress in material or not properly kiln dried.

Dovetailer FAQs

Why won’t the sides clamp actuate when the part is dropped into the machine?

Make sure compressed air is connected and set properly. Check fiber optic alignment is set correctly and free from debris. Note: If the machine will cut front/back components then the machine programming can be eliminated as a potential cause. 

Why won’t the fronts/backs clamp actuate when the part is inserted into the machine?

Check positioning of the four photo eyes by placing a front/back into the machine and confirm the LED actuation lights on each of the photo eyes comes on.

Why are spindles running hot?

The operating/ ambient temperature must be below 110 degrees (F).
Make sure there are no obstructions and spindle carriage is free of debris.
Over-greasing will cause excess heat.

Why is there a burning smell / squealing sound coming from the machine?
Spindle drive belt tension is set incorrectly. Proper air pressure should be 35 PSI.

Check for dull tooling.

Why are we getting chip-out on both sides of our parts?
Chip breaker / Backer plates are worn and need to be re-set or replaced.
Dull or bent tooling.

Why are joints tight on one side but open on the other?
Make sure material is square.

Bit height set incorrectly.
Guide is not positioned properly or 90 degrees to the table.
Front/Back table top set incorrectly.

Why have all machine settings changed?
Home proximity switch is loose or has moved (original factory settings can be found on the placard inside the starter cabinet).
The guide is not positioned properly or 90 degrees to the table.