Stetson Ross

The toe of the pressure plate should be approximately 0.003 to 0.006 above the knife tips. The heel of the pressure plate should be approximately 0.003 to 0.006 above toe of pressure plate. Front to back and side to side should be within 0.001 to 0.002 in. To keep the boards down tight on the bed plat, keep pressure plate within 0.001 to 0.002 toward the cutter head

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.

The main bed plate should be set below the receiver plate equal to bottom cut required to eliminate skip. Using a 12-in.precision level measure the main bed plate side to side. You want it to be 0 – 0 but not more than +-0.002 in. Measure the main bed plate using the same level from front to back. Back of the bedplate needs to be approximately 0.008 in. /foot higher than the front end of the main bed plate. When making adjustment over the 0.008in, which is required sometimes when you get pitch build up on the main bed plate make sure never to exceed 0.012. Too much of an incline with the main bed plate can cause sniping bumping resulting in heat and lower quality product.

Lumber not uniform, washboard or wavy appearance, and lumber sticking or hesitating in machine.

Stetson Ross pressure plate should be approximately 0.003 to 0.006 above the knife tips. The heel of the pressure plate should be approximately 0.003 to 0.006 above toe of pressure plate. Front to back and side to side should be within 0.001 to 0.002 in. To keep the boards down tight on the bed plat, keep pressure plate within 0.001 to 0.002 toward the cutter head

The top head Stetson Ross chip breaker should always be set tight enough so it doesn’t hinder the feeding; generally lighter for softer woods and heavier for heavy woods. The toe of the chip breaker should be approximately 0.125 below planer cut line. The chip breaker heel of the shoe should be a little bit higher than the incoming lumber. When set correctly you should see a slight amount of movement. When you see a large amount of movement it generally means the chip breaker is running too tight. You might even see boards sticking in the machine. See your manufacture’s manual for recommended psi settings. In many cases this is around 10 to 15psi.

Lumber sticking or hesitating in the machine, product has a washboard or wavy appearance, and a snip appearing at in-feed end of board,

This needs to set for the narrowest board and should be parallel to the main guide

One way to set this is to…. jog a board into the machine, up to the side head and stop it. Bring down the shoe on top of the board so you have a shine. The next step would be to rise in small increment until the shine goes away.

First start by leveling the in-feed roll. Place a sterrit level which has a accuracy of 0.005 in. per foot on top of the first bottom in-feed roll fitting into the grove of the level. Make sure you are aware of the wear on the roll where the level is placed. Check side to side. It should be approximately 0.005 in, or one line high on the guide side. This measurement can be different depending on the brand of planer. There are a few planer manufactures that require no lead on this bed roll so check your manuals. The reason for this lead is to move the board into the guide. After making sure bottom in-feed roll is level, lower it and bring it back to cutting position. Finally check it once more to make sure it remained level or to desired degree of lead.

The bottom feed roll should also be square to the machine. Check this out by measuring to the side head rails or from the top head stand if possible. If roll is not square it could pull the board away from the guide

In this procedure you will be using the receiving plate to level. It’s best to lower the second bottom bed roll first so you have a clearance for the level and no interference. Take any slop out of the adjustment and screw by lowering the roll first, then raising it up. Lay the straight edge across the receiver plate and first bottom in-feed roll. You want the bottom in-feed roll to be level with the receiving plate.

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.

Place a sterrit level which has a accuracy of 0.005 in. per foot on top of the second bottom in-feed roll fitting into the grove of the level. Make sure you are aware of the ware on the roll were the level is placed. Check side to side it should be approximately 0.005 in or one line high on the guide side. This measurement can be different depending on the brand of planer. There are a few planer manufactures that require no lead on this bed roll so check you manuals. The reason for this lead is to move the board into the guide. After making sure bottom in-feed roll is level, lower it and bring it back to cutting position. Finally check it once more to make sure it remained level or to desired degree of lead.

The bottom feed roll should also be square to the machine. Check this out by measuring to the side head rails or from the top head stand if possible. If roll is not square it could pull the board away from the guide.

In this procedure you will be using the receiving plate to level, and the first in-feed bed roll .if not lowered already lower second bottom bed roll so you have the clearance for the level with no interference. Take any slop out of the adjustment and screw by lowering the roll first. Lay the straight edge across the receiving plate and first bed roll. Start raising the second bottom bed roll up to the straight edge until you have approximately 0.012 in. between the roll and the straight edge. Having this slight downhill motion takes pressure of the chip breaker shoes and applies a larger portion to the bed plate. Always check the manufacture manuals for their recommended settings

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.

Place a very accurate level on top of the last bottom out-feed roll fitting into the grove of the level. Make sure you are aware of the ware on the roll were the level is placed. Check side to side it should be level and not have a lead like the first two bottom in-feed rolls. (This measurement can be different depending on the brand of planer. So check you manuals) After making sure bottom in-feed roll is level, lower it and bring it back to desired position. Finally check it once more to make sure it remained level. The reason for not having a lead here is ,this roll needs to start preparing the boards for a controllable landing on the out feed belt.

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.

confirm bottom rolls are set correctly and haven’t moved due to ware and shock. Check for ware and clean out all compacted fibers imbedded into the knurls. Set the first top in-feed roll for the thinnest board and the second in-feed roll at ether the same as the first roll or a few thousand higher. The mid and out feed roll should be set low enough to just touch and pull the boards out of the planer, meaning within thousand of an inch of finished product. This setting might be different depending on what planer you have, check manual. Make sure there is almost no movement in this top bed roll at least 80 % less than the in-feed rolls. Check the top bed roll tension system that it is correctly adjusted for the product being ran. the hold down pressure needs to set as low as possible, at the same time keep all boards traveling smoothly without slipping or hesitating in the planer . 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. 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. 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

the ideal is a LOW BUT CONSTANT tension that keeps the boards traveling smoothly without slipping or hesitating. The tension on many planers causes the rolls to have varying tension based on the thickness of each piece of lumber. This works well when all the lumber is similar in thickness. In a normal run of lumber, however, thickness variation causes the rolls to “hammer themselves”, leading to a premature failure. The planer operator has to constantly try to balance the tension settings based on how the lumber is running, or continue running all lumber with the same settings. This creates wear and tear on the bearings, rolls, shafts, and results in less than optimum performance. When variations exceed 1/8 inch or more the lumber will at times hesitate in the planer and cause break ups requiring the planer operator to stop production. The Cobra system provides constant tension, even with high variations in lumber thickness, using specially designed cylinders, accumulators, and adjustable pressure controls. The Cobra tension system takes the harsh “banging” out of the operation and makes the whole system much smoother. The result, better production, fewer breakups in the planer and longer service life on the machine.

The positioning aspect of the planer feed roll system allows the setup man to individually position the top feed rolls based on thickness of lumber. We remount these cylinders to a position where the angle of the cylinders gives the planerman a better ability to fine tune these positions accurately, within a 1/8 of an inch. This system replaces the current electric motors and gear boxes along with many older hydraulic positioning components. If the rolls are not set correctly, it will be putting the planer through much abuse with enormous wear to sleeves, bearings, and shafts. This also results in a loss of the tolerances needed to achieve maximum production. Cobra’s automatic positioning system takes all this to another level.

AC or DC drives work great, and we do recommend these when appropriate, however they are not always affordable for the typical mill. Through the years Cobra Tech Inc. has successfully applied many high efficiency hydraulic motors on planers and feed tables. We are able to apply this knowledge and choose the motors that will work best on your specific planer drives. Unless your planer runs at speeds slower than 800 FPM, we generally recommend hydraulic drives.