Need help on jointer adjustment

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
I have a Powermatic PJ-882HH that I cannot seem to get adjusted correctly - What in the heck am I doing wrong?
The machine is taking a deeper cut at the leading end than on the trailing end - for a test I set the infeed table to take a slight cut and edge jointed an exactly 2" wide board that is 24" long. I run it thru three times always with the same end first.
At the leading edge the measurements were 2.00 - 1.960 - 1.920 - 1.870
The trailing edge measurements were 2.00 - 1.990 - 1.980 - 1.970
I have set the outfeed table to be even with the cutters, but that is somewhat hard with the carbide cutters - I think I have it right
I spent three hours adjusting the indeed table to be parallel with the outfeed table within .002
To measure the parallelism of the table I used a 50" long precision (so I am told) straight edge and feeler gauges and also a 78" Stabila level. Both methods showed the same.

What am I missing ?
 

chris_goris

Chris
Senior User
Im not sure I follow your logic here Phil, a jointer is designed to get a surface flat, not parallel with the opposite side, that is the planers job. Is the surface flat? . The depth difference you are measuring could be a function of the tables being out of parallel within .002" , although that number will vary depending on how far from the cutter centerline you measure it.
 

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
Chris, I am not attempting to create parallel edges I just want to keep two edges parallel. I like to rip boards .020 oversized and then take the last .020 off with the jointer which also cleans up the saw marks
The .002 was measured at 36” from the cutter
 

creasman

Jim
User
Phil, maybe the outfeed table is slightly below the cutters and this is causing the board to be ever so slightly tipped down as it moves through. I assume you have the helix head which would make this adjustment a bit harder to gauge. I have the three-blade head and use a magnetic gauge to set the knives even with the outfeed table.

You might get a more accurate test with a wider board, say 6". With 2" you're probably using push sticks or something similar to keep your hands away. Using a wider board would allow you to hold it with you hands and "feel" the board contacting the table as it slides through. Just a thought.
 

chris_goris

Chris
Senior User
Chris, I am not attempting to create parallel edges I just want to keep two edges parallel. I like to rip boards .020 oversized and then take the last .020 off with the jointer which also cleans up the saw marks
The .002 was measured at 36” from the cutter
Going back to the jointer after everything is parallel and square is like starting over again. unless the 2 tables are dead on parallel ( a near impossibility) the board is presented to the outfeed table at a different angle so it cannot be parallel to the opposite side any longer. I use a drum sander to accomplish what youre trying to do for this reason, gang them together on edge and run them through.
 

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
Jim. When I face joint a board I can hear and feel the cutters taking more off the lead edge and sometimes stop cutting before reaching the trailing end This would indicate bowed board but if I turn the board around it again cuts heavy on the lead and almost nothing on the trailing end
This afternoon I am going to attempt again. I will start again with the outfeed to cutter alignment which you are correct it is hard to see
 

pop-pop

Man with many vises
User
To get the outfeed table close, try dropping it a bit. This will produce a snipe as the board leaves the indeed table. Slowly raise and test until the snipe disappears and you’ll be close.
 

KenOfCary

Board of Directors, Secretary
Ken
Staff member
Corporate Member
I had this problem with my Grizzly Jointer when it first arrived. Tom Ferone had a jointer workshop (I think Mike attended) and I learned a lot there how to adjust it. The outfeed was out of adjustment. To adjust:

Set the infeed and outfeed to equal or the zero point of the infeed. Place a 3-4" piece of wood or something very flat like a ruler on end across the gap. Manually rotate the blade and adjust the blade up or down until it barely makes the straight edge move back and forth as you rotate the blade - note the word barely. Once you have the 3 things (infeed, outfeed, and blade) aligned then you can lower the infeed to the depth of cut you desire - I leave mine around 1/64 to 1/32 at the most.
 

Mike Davis

Mike
Corporate Member
I had this problem with my Grizzly Jointer when it first arrived. Tom Ferone had a jointer workshop (I think Mike attended) and I learned a lot there how to adjust it. The outfeed was out of adjustment. To adjust:

Set the infeed and outfeed to equal or the zero point of the infeed. Place a 3-4" piece of wood or something very flat like a ruler on end across the gap. Manually rotate the blade and adjust the blade up or down until it barely makes the straight edge move back and forth as you rotate the blade - note the word barely. Once you have the 3 things (infeed, outfeed, and blade) aligned then you can lower the infeed to the depth of cut you desire - I leave mine around 1/64 to 1/32 at the most.
I did not attend this workshop, but that is how I adjust jointers. If using carbide inserts then adjust the outfeed table by this same method. Raise or lower the outfeed table till the wood block or ruler just moves an 1/8 inch or so as you rotate the cutter head.
 

llucas

luke
Senior User
Phil
I know my comments will raise some eyebrows, but I had this exact problem a few months back on my G490x...and I did exactly what everbody knows is the right thing to do without fixing the problem
In adjusting the parallelism I eventually discovered that I could make the problem worse by taking the beds out of parallel and then I could sneak back up toward "perfect parallel" while taking sequential cuts. I found that I totally cured the problem before I got all the way back to parallel.
I do understand the need for parallel beds, but when they measured parallel, the were not, I guess.

In any case, what I wanted was a proper cut (not beds that measured parallel)...so I settled for that.
All my adjustments were made by raising/lowering the outer end of the infeed bed.
Good luck with a frustrating problem
 

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
FIXED. Charlie came over this afternoon and really helped me thru this.
First we verified that the tables were parallel within a few thousands - good enough, but still had a tapering issue
Next we checked the outfeed table which need to be even with the cutters. I had it just barely high - you could fell it slightly touch a piece of wood placed on the outfeed and extending over the cutter. Some of the cutters would would just kiss the wood while others would miss but not by a measurable amount.
We moved the table down slightly and then started to get snipe - then we moved it up to just eliminate the snipe
A test board or two then showed no tapering. I am still trying to figure out why a .002 change in table height creates a .040 taper along a 24" board. My jointer works much better now.
Thank you Charlie
 

Mike Davis

Mike
Corporate Member
Phil’s infeed table was slightly below the outfeed table.

On a jointer, if you intentionally want to create a taper on a workpiece, what do you do? Lower the infeed table a good bit and make repeated cuts.
But, not full length cuts. To make a taper I cut a couple inches, lift and pull back, cut 4 inches, lift and pull back, cut 6 inches, lift and pull back, when it is almost there I make a full length cut.
 

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