INDUSTRIES

Planer Test #2
Head-to-Bed Parallelism and Knife Positioning

If the readings taken in Planer Test 1 are not identical, you might have a problem (or two) with your planer that can be causing the results you are getting:

1. One end of a bed roller could be high,and may be elevating the material off the planer bed.

2. One (or more) of the knives could have shifted.

3. The head of the machine may not be perfectly parallel to the bed of the machine.

4. You may have a combination of any of the above.Since it only takes a couple of minutes to check, the first thing that I recommend you do is to check the parallelism of the head and bed of the planer.
 

The following procedure will allow you to check the parallelism of the head and bed of the planer.

1. Disconnect electrical power to the machine.

2. Assemble the A-LINE-IT™ as shown in the photo above, and install the wide, flat tip into the indicator.

3. If the planer has adjustable bed rollers, lower them below the surface of the bed.

4. Adjust the planer to about a 5" thickness, and rotate the head of the planer so that none of the knives is near the bottom of rotation.

5. Place the A-LINE-IT™ inside the planer. The end of the long bar should go in first. The dial indicator should face you, with the tip facing upward toward the head. Try to keep the face of the indicator parallel to the head.

6. Slide the A-LINE-IT™ under the head of the planer. If the tip of the indicator does not make contact with the head of the planer, you should adjust the table height so the indicator moves as you slide the A-LINE-IT™ front-to-back under the head. If the top of the indicator spindle hits the planer bed, you must increase the distance between the head and bed of the planer.

7. While pressing downward (to keep the mounting bar against the bed of the planer), slide the A-LINE-IT™ slowly front to back near the left side of the head. The pointer on the dial indicator will go upward, and then start back down. The high point on the scale that the pointer showed was the closest point on the head to the bed of the planer. Note the reading, or zero the dial indicator at this point, whichever is easier. Recheck the reading a couple of time to be sure you are getting an accurate reading.

8. Move the A-LINE-IT™ to the right side of the head, and repeat the procedure.

What is the indicator telling you?

If the reading on the dial indicator on the second reading went positive when compared to the first reading, the head and bed on the second side are closer together than they are on the first side.

If the reading on the dial indicator on the second reading went negative when compared to the first reading, the head and bed on the second side are further apart than they are on the first side.

What should I do now?

That depends on how well you would like your planer to perform, and how intimidated you are about working on themachine. If I had a planer that was out of adjustment by .005" (five thousandths) or more, I’d probably grab the manual and my toolbox, and try to fix it. Here’s the approach that I would take:
I would rip a piece of hardwood 12" (or so) long to 4" - 5" wide, and then cut it in half lengthwise. Making sure the pieces were exactly the same width, one would be placed under each end of the head of the planer. I’d adjust the thickness control until the head barely made contact with one of the boards. At this point, I would determine (by lifting the boards) which side of the planer head was not making contact. I’d loosen the hardware that held that end of the head in position, and lower that end of the head until it made contact with the board. I would then retighten the head and double check with the A-LINE-IT™ to confirm the head didn’t shift when I tightened it.