Learning to read a board for imperfections will save hours in adjusting a planer to operate properly. Following are some problems that may arise and their probable solutions:
FEED RESTRICTION:
This is caused either by the table rolls being set too low for roughing operations or from a low pressure bar. About 90 percent of the time, the pressure bar is too low. As the sharp edge of the planer knives wear, you must compensate for this wear by raising the pressure bar an equal amount on each side. Your first indication of knife wear is hesitation in feed of the material through the machine after it leaves the corrugated infeed roller on its way out of the machine. Turn machine off and adjust the pressure bar acordingly. The material will free up and feed through smoothly.
CAUTION: Never attempt pressure bar adjustment while the machine is running.
Feed restriction can also occur due to pitch buildup on the table. Be sure the table surface is clean. Dusting the surface with talc occasionally will aid in smoother feeding and help prevent pitch buildup.
WASHBOARD FINISH:
A very pronounced washboard finish down the full length of the board results from one knife being too high and forced to do all the cutting. See Figure 18. Reset the high knife accordingly.
CLIP MARKS:
If "clip" marks occur 6" (152 mm) in from each end of the board, the pressure bar is too high. See Figure 19. Turn both right and left hand adjusting screws the same amount, 1/4" turn clockwise or less, and take another 1/16" (1.58 mm) deep cut.
Continue the
SNIPES:
If snipes appear on each end of the material, as shown in Figure 20, a table roll is too high causing a slight lift of the material as it passes through the machine. Normally these snipes are more noticeable on the trailing end of the board than on the lead end, and most often occur during planing of rough lumber. Table rolls must be elevated for running rough or resaw lumber through the machine. When material is turned over to surface the other side, and you neglect to lower the table rolls for a finished cut, then definite snipes will appear on the ends of the material.
15