On this page you will find toubleshooting tips on: Coastal Planers, Newman Planers, Stetson Ross Planers Yates Planers, Woods Planers, Gilbert Planers and More

   Upgrades for : Stetson Ross - Newman - Coastal - Yates - Gilbert - USNR  
  • The Planer 
  • Hydrostatic Transmission Pump
  • Hyd - Pumps and Motors
  • Cylinders
  • Valves
  • Overheating
Troubleshooting

1. If clip or snipe appears on the front end of board
 
     1. Top head chipbreaker not holding stock down.
     2. Bottom head lower than platen after cut.
     3. Infeed rolls set low.
     4. Pressure bar too high of front end
     5. Platen before bottom head not level.
 
2. If clip or snipe appears on the rear end of board
     
     1. Pressure bar too high of front end
     2. Bottom head lower than platen after cut.
     3. Platen before bottom head not level
 
3. If clip or snipe appears on the left edge of board
     
     1. Board is not being held against guide.- Check bottom infeed  
        rolls for level.
     2. Not enough spring pressure on the left side head chipbreaker.
     3. Guide nose not in line with long guide, also not held rigid.
     4. Guide after sidehead is not in line.
 
4. If clip or snipe appears on the right hand edge of board
 
     1. Guide after cut is back of side head cut.
     2. Guide after cut not square with long guide.
     3. Board not traveling straight after cut, causing end to swing into 
         cutterhead
     4. Guide after side head not mounted securely.
 
5. If chip marks appear on the lumber
     
     1. Adjust scraper on out-feed roll.
     2. Shaving exhaust system not enough suction, due to leaks, not 
         correct size,  piping at to great an angel to main pipe.
     3. Too fast a speed
     4. Shaving hitting some obstruction and bouncing back at cutter
     5. Incorrect bevel on knife 
     6. Wire edge may have been left on knives when jointing
     7. Too light of a cut
     8. Moisture content too high
     9. Raised top out-feed roll
 
6. If lumber varies in thickness across board.
 
     1. Cylinder not level with platens
     2. Pressure bar not level with cylinder 
     3. Knives not being jointed straight, check jointer
     4. Platens may be worn
 
7. If poor or washboard finish or revolution marks
 
     1. Check knives to make sure all are cutting
     2. Knives unevenly jointed—joint may be too heavy on one or two 
         knives.
     3. Lumber not held firm—check chipbreaker and pressure bar
     4. Check cylinder and heads for unbalance- also knives should 
         be checked for balance
     5. Trouble could be caused by bad bearings
     6. A hard or soft knife
     7. Bed plate worn
 
8. If lines appear at right angles to knife marks, or finish is flaky
 
     1. Knives may be nicked or checkered by using to hard a jointer 
         stone
     2. By moving jointer stone too fast across knife
     3. Jointer slide loose on bar.
     4. Chips or slivers may have become wedged between roll and 
         table
     5. Pressure bar may be too tight
     6. Jointer slide loose on bar
 
9. If stock pulls away from guide
  
     1. Guide out of line
     2. Bottom rolls worn or low on guide side
     3. Pressure bar too tight on left hand side of board.
     4. Bottom head lower than platen after cut on the left side
     5. Ends of lumber out of square.
 
10. If stock twists in machine
 
     1. Pressure bar too tight on one side
     2. Top out-feed roll not parallel
     3. Top out-feed roll may have uneven spring tension
     4. Bottom feed rolls may not be parallel with bed plate
 
11. If stock hesitates or stops in machine
 
     1. Too much down pressure on chipbreaker
     2. Pressure bar too tight on stock can be due to knife wear
     3. Bottom rolls too low
     4. Guide after side heads too tight
     5. Side head hold-downs too tight
     6. Not enough down pressure on the hydraulic roll tension
     7. Bad hydraulic pump or motor in feed works—check pressure 
         on each pump system 
 
12. Knives raising the grain
 
    1. Excessive Feed roll pressure
    2. Heavy pressure bar force
    3. Knives may be too dull
    4. Moisture contact too high
    5. Cut is too heavy
    6. Feed may be too fast
    7. Cutting angle may be incorrect
    8. Joint may be too heavy or heel is too wide
 
13. Fuzzy Grain
  
     1. High moisture content
     2. Dull knifes
     3. Low feed speed
     4. Small depth of cut
     5. Incorrect cutting angles
 
14. Noisy Machine -- Vibration and Pounding
 
     1. Knives may be too dull.
     2. Feed belt may be jumping on pulley
     3. Variable feed belt jumping
     4. Pressure bar set below cutting circle
     5. Machine may not be on solid Foundation
     6. Machine may not be level
 
15. Throwing Knives Out of Heads
 
     1. Gibb screws tightening out of sequence
     2. Not tight enough
     3. Screws are dirty
     4. Screws are mushroomed
 
16. Motor kick-out
 
     1. Knives may be dull and overloading motors
     2. Pressure bar may be set too low, putting drag on motors
     3. Motor may be drawing high current because other machinery in   
         use in the plant has pulled down voltage - check line voltages
     4. Machine may be out of adjustment
     5. Lower rolls may be set too low
     6. Joint may be too heavy
     7. Feed speed too low or high


1. If the bed roll pressure is set to high you might see incorrect planer feeding, excessive roll ganging, wood won’t go through planer easy, raising of the grain, and extreme shock to the planer
  
2. If  bed rolls are set to high you might see lumber sticking, board hesitating and snip on the in-feed end of the boards. The end results, breakups, down time and degrading of lumber.
 
3. If bed rolls are set to low you might see extreme shock to the top roll, sniping on the out-feed end of the board and wear and tear on the bearings, rolls, shafts,  resulting in less than optimum performance and loss of  tolerances needed to achieve maximum production

4. Indicators that bottom roll or rolls are not set at the right height, Set Square, or level lumber sticking or hesitating in machine, motor kick-out, stock twists in machine, a snip on in-feed of board, snip on out-feed of board, lumber not uniform, boards pull away from guide.

5. Indicators the pressure plate is not set correctly Lumber Sticking or hesitating in the machine, motor kick-out, stock twists in machine, washboard or wavy appearance, snipe appearing at in-feed end of the boards, snipe on the out-feed end, raising of the grain, lumber on uniform, material pulls away from guide and line appears at the right angles to the knife marks.

6. Indicators that the chipbreaker is not set correctly Lumber sticking or hesitating in the machine, product has a washboard or wavy appearance, and a snip appearing at in-feed end of board,

Lumber Planer Troubleshooting
Pump or Motor Problems?
Valve Testing
Cylinder Okay?
   Upgrades for : Stetson Ross - Newman - Coastal - Yates - Gilbert - USNR  
Troubleshooting Hydraulics
Hydrostatic Transmission Circuit and Pumps
Most planer hydraulic drives are hydrostatic transmission systems. A hydrostatic transmission consists of a variable-displacement pump and a fixed or variable displacement motor, operating together in a closed circuit. Fluid from the motor outlet flows directly to the pump inlet, without returning to the tank.   A hydrostatic closed loop pump is not only variable but can be reversed. From within the pump both the direction and speed of motor rotation are controlled. This eliminates the need for directional and flow control valves. 

Mounted on the rear of the main pump is a small fixed-displacement pump called a charge pump. This is used to ensure that the main loop between the pump and the motor remains full of fluid during normal operation. It pressurizes the "low pressure" side of the loop to between 110 and 360 PSI, depending on the transmission manufacturer. A simple charge pressure circuit comprises the charge pump, a relief valve and two check valves, through which the charge pump can replenish the transmission loop. Once the loop is charged to the pressure setting of the relief valve, the flow from the charge pump passes over the relief valve, through the case of the pump or motor or both, and back to tank providing flushing/cooling.  
When a pump or motor is worn or damaged, internal leakage increases and therefore the flow available to do useful work decreases. The condition of a pump or motor can be determined by measuring the flow from its case drain line.  The pump manufacturer will specify "normal" ranges of "friendly leakage".   Besides measuring the flow of the case drain you can feel the line with your hand and other lines similar to it function to see if it seems hotter.  This also hold true for motors.  Excessive heat generally means a problem is brewing with the pump or motor.  One sure sign you might have a problem with a hydrostatic transmission pump is loss of charge pump pressure. This would generally be caused by high pressure leakage that exceeds the charge pump flow capacity.  This should be the first thing to check on. If you don’t know what it should be, check the schematic if you have one, or look up the manufacturer's information online or email us.
For testing a 4- way valve, it is necessary to obtain access to the tank return ports so that the amount of leakage can be observed. To make the test, disconnect both cylinder lines and plug these ports on the valve. Start up the system and shift the valve to one working position. Any flow out the tank port line while the valve is under pressure is the amount of leakage.
Run the piston to one end of its stroke and leave it stalled in the position under pressure. Crack the fitting on the same end of the cylinder to check for fluid leakage. After checking, tighten the fitting and run the piston to the opposite end of the barrel and repeat the test. Occasionally a cylinder will leak at one point in its stroke due to a scratch or dent in the barrel. Check suspected position and run the piston rod against it for testing. Once in a great while a piston seal may leak intermittently. This is usually caused by soft packing or O-ring moving slightly or rolling into different positions on the piston, and is more likely to happen on cylinders of large bore. When making a test on a hydraulic cylinder the line should be completely removed from the cylinder port during the test, and open line from the valve should be plugged or capped since a slight back pressure in the tank return line would spill oil from the line it not plugged. Pistons with metal rings, and seals can be expected to have a small amount of leakage across the rings and even those ”leak tight” soft seals may have a small bypass during break-in of new seals or after the seals are worn in.
Why do Hydraulic Systems Overheat?
Heating of hydraulic fluid in operation is caused by inefficiencies. Inefficiencies result in losses of input power, which are converted to heat. An example would be high pressure leakage across a valve.  A hydraulic system's heat load is equal to the total power lost (PL) through inefficiencies and can be expressed as: PL(Horsepower) = psi x gpm leakage/1714.  
Hydraulic fluid temperature - how hot is 'too hot'? 
Hydraulic fluid temperatures above 180°F (82°C) damages most seal compounds and accelerate degradation of the oil. While the operation of any hydraulic system at temperatures above 180°F should be avoided, fluid temperature is too high when viscosity falls below the optimum value for the hydraulic system's components. This can occur well below 180°F, depending on the fluid's viscosity grade.  Your oil supplier can provide you with this information. 

Newman, Coastal, Stetson Ross, Woods, and more
New Planer Rolls
Improve the preformane of your planer
Cobra Technical Services
     Cobra Technical Services are specialists in high speed  planers and feed tables including: Newman, Stetson Ross, Coastal, Yates, Gilbert and Woods.  We have an extensive experience with improving the performance in planer tensioning and positioning, automatic tensioning positioning systems, planer hydraulic or electric drives, Top head side head servo positioning systems, feed table hydraulic or electric drives, and feed table tensioning systems . If  you are interested in improving the performance of your equipment give us a call! We hope you find this website information valuable, and we ask for your suggestions to help make this site even more valuable.

     Cobra Technical Services are specialists in high speed  planers and feed tables including: Newman, Stetson Ross, Coastal, Yates, Gilbert and Woods.  We have extensive experience with improving the performance in planer tensioning and positioning, automatic tensioning positioning systems, planer hydraulic or electric drives, Top head side head servo positioning systems, feed table hydraulic or electric drives, and feed table tensioning systems . If  you are interested in improving the performance of your equipment give us a call! We hope you find this website information valuable, and we ask for your suggestions to help make this site even more valuable.

Cobra Technical Services LLC 
435 HAZEL COURT, EUGENE, OR  97401
(541) 915-8323(541) 915-8323(541) 915-8323(541) 915-8323   FAX (541) 484-7507    
E-mail bjenson@cobratechservices.com

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Overhead Tensioning
&
Positioning Kits

Newman,Coastal,Stetson Ross,Woods, and more
Improve the performance of your planer
New Planer Kits

 Did You Know?
.05 of a second hesitation at a feed table with speeds of 2000ft/min = 12,852bdft/hrLoss in 
Production
Making older feed table
run like new
Specialists in planing mill performance Improvement
It only takes one to see a difference!
Specialists in planing mill performance Improvements
It only takes one to see a difference!
Cobra Technical Services
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Newman, Coastal, Stetson Ross, Woods, and more
Cobra Technical Services
Over 40 years 
experience with

Hydraulic Drive 
Systems
Cobra Technical Services
Specialists in planing mill performance Improvemens

 Did You Know?
.05 of a second hesitation at a feed table with speeds of 2000ft/min = 12,852bdft/hrLoss in 
Production
New Stetson Ross
Feed Table Stands
.
Tensioning 
&
 Positioning Kits
Improve the performance of your planer
New Planer Kits
Planer Feed Roll
for 
Newman, Coastal,
Yates, Stetson Ross, Gilbert,Woods
New Planer Rolls
Stetson Ross Planers
Bringing a New Dimension of Performance to Planer Mills
Coastal Planers
Gilbert Planers
Yates Planers
Woods Planers
Newman Planers 
Feed Rolls for Coastal Planers
Upgrade your used
Coastal Planer
&
Coastal / USNR Feedtable 
Pineapples for Coastal Feed-Tables
Used Coastal Planers
feedtables and Parts
Feed Table Bed Rolls for Coastal Planers
Troubleshooting the Coastal Planer
Drives for Coastal Planers 
Feed Rolls for Woods Planers
Upgrade your used
Woods Planer
&
Woods
 Feedtable 
Pineapples for Woods Feed-Tables
Used Woods Planers
feedtables and Parts
Feed Table Bed Rolls for Woods Planers
Troubleshooting the Woods Planer
Drives for Woods Planers 
Feed Rolls for Stetson Ross Planers
Upgrade your used
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&
Steson Ross Feedtable 
Pineapples for Stetson Feed-Tables
Used Stetson Planers
feedtables and Parts
Feed Table Bed Rolls for Stetson Planers
Troubleshooting the Stetson Planer
Drives for Stetson Ross Planers 
Feed Rolls for Newman Planers
Upgrade your used
Newman Planer
&
Newman Feedtable 
Pineapples for Newman Feed-Tables
Used  Newman 
Planers & Parts
Feed Table Bed Rolls for Newman Planers
Troubleshooting the Newman Planer
Drives for Newman Planers 
A pineapple  designed to Perform ! 
Specialists in planing mill performance Improvements
Cobra Technical Services
Over 40 years 
experience with

Hydraulic Planer Drive 
Systems
Cobra Technical Services
Specialists in planing mill performance Improvements.
Cobra Technical Services
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Newman, Coastal, Stetson Ross, Woods, and more
Planer Feed Roll
for 
Newman, Coastal,
Yates, Stetson Ross, Gilbert,Woods
New Planer Rolls
Cobra Technical Services
Did You Know?
The Difference between 75% uptime and 95% uptime
with 10ft boards at
2000ft/min is over 164,563 bdft
loss in
production a day
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Overhead Tensioning
&
Positioning Kits

Newman,Coastal,Stetson Ross,Woods, and more
Improve the performance of your planer
(541) 915-8323
New Planer Kits
A pineapple  designed to Perform ! 
The Cobra Pineapple
Specialists in planing mill performance Improvement
It's about Efficiency!
Cobra Technical Services
Did You Know?
The Difference between 75% uptime and 95% uptime
with 10ft boards at
2000ft/min is over 164,563 bdft
loss in
production a day
A pineapple  designed to Perform ! 
The Cobra Pineapple
Specialists in planing mill performance Improvement
It's about Efficiency!
Cobra Technical Services
Stetson  Feedtables
Feed-Table Upgrades
for used planer  equipment with the Newest Technology
Coastal Feedtables
Gilbert Feedtables
Yates Feedtables
Woods Feedtables
Newman Feedtables
Feed Rolls for Newman Planers
Upgrade your used
Newman Planer
&
Newman Feedtable 
Pineapples for Newman Feed-Tables
Used  Newman 
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Feed Table Bed Rolls for Newman Planers
Troubleshooting the Newman Planer
Drives for Newman Planers 
Feed Rolls for Yates Planers
Upgrade your used
Yates Planer
&
Yates 
 Feedtable 
Pineapples for Yates Feed-Tables
Used Yates Planers
feedtables and Parts
Feed Table Bed Rolls for Yates Planers
Troubleshooting the  Yates Planer
Drives for Yates Planers 
Feed Rolls for Coastal Planers
Upgrade your used
Coastal Planer
&
Coastal / USNR Feedtable 
Pineapples for Coastal Feed-Tables
Used Coastal Planers
feedtables and Parts
Feed Table Bed Rolls for Coastal Planers
Troubleshooting the Coastal Planer
Drives for Coastal Planers 
Feed Rolls for Yates Planers
Upgrade your used
Yates Planer
&
Yates 
 Feedtable 
Pineapples for Yates Feed-Tables
Used Yates Planers
feedtables and Parts
Feed Table Bed Rolls for Yates Planers
Troubleshooting the  Yates Planer
Drives for Yates Planers