Jointer Producing Uneven Surface

5416 Views 28 Replies 10 Participants Last post by Gaia, Feb 22, 2019

Gaia

Discussion Starter · Feb 19, 2019

4

I've spent many, hair pulling hours, setting up and adjusting my jointer.
Aligning infeed, outfeed, precision straightedge, setting outfeed in line with knives in cutter block etc,etc. I've used the special knife setting jig supplied by the machines manufacturer to set the knives correctly in the cutterhead.

I jointed some Ash today I marked the face with pencil lines to see what was coming off. I did about 5 passes at 1/32 to try to get one face flat, ready for the planer. I then got a wedge that I got rid of in the planer.

So something still isn't correct, in the Ash photos you can see the pencil lines to the left which haven't all been removed, perhaps I missed something setting up?

Is really frustrating I have spent a lot of time adjusting the machine and am still not getting satisfactory results.
Attached photo of Ash and also of the jointer which shows the position of the fence that I used for jointing the Ash today. The Ash board edge where has not removed, the edge of this face was down on the table opposite the fence.
I don't think my feeding technique is at fault.
Thanks.

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MikeMa

· #2 · Feb 19, 2019

Two thoughts...
1) The two tables aren't quite co-planer. I suspect your infeed table maybe out of square in relation to the fence.
2) The board itself may be warped, and will take multiple passes to get that face flat. If the board was already wedge shape, the jointer can potentially make that more pronounced. Remember the job of the jointer is to make a face flat, not necessarily to keep two faces parallel. Make sure you are not putting too much downward pressure on the board when passing through the jointer. There should be just enough pressure to push the board through the knives.

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woodknots

· #3 · Feb 19, 2019

Peter - first thing I'd do is to recheck the knives and reset them - could be that one of them is skewed.
I'd have to disagree with Mike's statement above regarding the fence - if your infeed/outfeed tables are co-planar, the fence should have no effect on flattening a face. The fence WILL determine if one edge is 90 deg. to the face

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difalkner

· #4 · Feb 19, 2019

Vince is correct. You don't even need a fence if you're cleaning up one face. Jointing an edge is a different story, though. Gotta' have a fence and it has to be 90° to the knives and bed(s).

David

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ger21

· #5 · Feb 19, 2019

Could be any of the following:

Knives at an angle.

Infeed table not coplanar to the outfeed table.

Board that is far from flat.

Poor technique.

I'd look at the knives first, then the tables.

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kp91

· #6 · Feb 19, 2019

3

My easy knife setting jig cost almost nothing, and makes it really easy to set the joiner knives perfect to the outfeed table. It also works surprisingly well at checking the alignment with the infeed table.

the jig is self explanatory, two boards with magnets on them, one for each end of the knife. You put the side with the 2 magnets far from the knife, and you put the side with the single magnet half on the table, half over the knife. This holds the knife in position, and parallel to the outfeed.

You can flip the jig around, and this gives you a check to see the alignment of the infeed table near the knife, and verify your cut depth. I use a 4 foot level to check if the infeed is coplanar to the outfeed.

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Cherryville Chuck

· #7 · Feb 20, 2019 (Edited)

All the setting gauge does is set the height of the knives relative to the cutter head. If trhe head is not quite level with the tables then you'll get the results shown. You could check that without knives in the head by cranking the outfeed table down until level with head and checking with a straightedge. The knife gauge will give you the approximate correct amount of blade height relative to the cutter but when I set my knives I lay a flat piece of hardwood on the out feed and bottom the knives against it. If they are spring loaded this is pretty easy to do. You may need to adjust the outfeed slightly then. When you rotate the cutter by hand you should just feel the cutter rub the bottom of the board. You should be able to find pictures on the web of how to adjust the outfeed to give perfect results. As long as the tables and head are all coplanar then it's the outfeed setting that controls whether you are getting good results.

Just remembered that the first jointer I bought, a Delta cheapo, had curved slots in the cutter head. How they managed to machine curves in the head I'll never figure out. Sight down your knives once they are tightened down and make sure they are straight just in case it's happened twice. The curved knife will give similar results. When I checked it more carefully I found the center of the knives lower than the outer edges.

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Gaia

Discussion Starter · #8 · Feb 20, 2019

MikeMa said:
Two thoughts...
1) The two tables aren't quite co-planer. I suspect your infeed table maybe out of square in relation to the fence.
2) The board itself may be warped, and will take multiple passes to get that face flat. If the board was already wedge shape, the jointer can potentially make that more pronounced. Remember the job of the jointer is to make a face flat, not necessarily to keep two faces parallel. Make sure you are not putting too much downward pressure on the board when passing through the jointer. There should be just enough pressure to push the board through the knives.

" I suspect your infeed table maybe out of square in relation to the fence." I checked infeed is square to fence. " The board itself may be warped," no it wasn't. "

Gaia

Discussion Starter · #9 · Feb 20, 2019

OK thanks Doug.

Gaia

Discussion Starter · #10 · Feb 20, 2019

Cherryville Chuck said:
All the setting gauge does is set the height of the knives relative to the cutter head. If trhe head is not quite level with the tables then you'll get the results shown. You could check that without knives in the head by cranking the outfeed table down until level with head and checking with a straightedge. The knife gauge will give you the approximate correct amount of blade height relative to the cutter but when I set my knives I lay a flat piece of hardwood on the out feed and bottom the knives against it. If they are spring loaded this is pretty easy to do. You may need to adjust the outfeed slightly then. When you rotate the cutter by hand you should just feel the cutter rub the bottom of the board. You should be able to find pictures on the web of how to adjust the outfeed to give perfect results. As long as the tables and head are all coplanar then it's the outfeed setting that controls whether you are getting good results.

Just remembered that the first jointer I bought, a Delta cheapo, had curved slots in the cutter head. How they managed to machine curves in the head I'll never figure out. Sight down your knives once they are tightened down and make sure they are straight just in case it's happened twice. The curved knife will give similar results. When I checked it more carefully I found the center of the knives lower than the outer edges.

Hi Charles,
Thanks for the positive suggestions. I'll check out the things you mention I hope later today and will get back to the forum to tell how things worked out

Peter.

smitty10101

· #11 · Feb 20, 2019

Peter when checking your profile I see that you have 2 handheld portable planers but I can't seem to find the stationary one.
you might want to let us know of the make & model of the stationary one ---just in case it might introduce some idiosyncracies of the machine into your dilemma. from the pics it looks like the blade guard doesn't pivot out of the way as you pass the board over the knives forcing you to reposition your hands.

IF it's a dual purpose machine ( planer/jointer) does it function correctly as a planer (parallel faces?).

just trying to think out of the box.

smitty

harrysin

· #12 · Feb 20, 2019

"All the setting gauge does is set the height of the knives relative to the cutter head"

Are you sure about this Charles?

Cherryville Chuck

· #13 · Feb 20, 2019

harrysin said:
"All the setting gauge does is set the height of the knives relative to the cutter head"

Are you sure about this Charles?

Absolutely certain Harry. Think about how it functions. The gauge has 4 legs that allow it to straddle the knife opening. It sits entirely on the cutter head with no reference to the beds. It is necessary to some extend as it controls how much knife sticks past the clamping bars. Too much exposure puts too much leverage on the knives which could cause them to move. But it does nothing to ensure that the knives are level to the outfeed bed which is the important one. If the cutter head were not level to the outfeed bed then one side could be a few thousandths different than the other edge which is exactly what Peter's photo shows.

Use the gauge to set the knife exposure and then adjust the outfeed bed until the knives will just tick against a hardwood board held down on it and the reset the knives level to the board. If that works then the permanent fix is to shim the cutter head level to the outfeed bed.

sreilly

· #14 · Feb 20, 2019

From my frustrating experience with my own 8" Powermatic I bought used from a "craftsman" who had been using it extensively, I found I was very proficient in making wedges. It was then that I bought my first two straight edges. My problem was all Gerry mentioned. I checked the bearings and they were fine but the blades were way off, chipped, and in need of replacing. I bought a magnetic jig to hold the new set of blades and set them properly. Then double checked that the tables were coplanar and had to make a few adjustments. That's the hardest part in my case. Every adjustment no matter how minor requires rechecking in all directions as it will likely change the opposing angle. I think it took the better part of an afternoon and a few migraine pills. But the results were fantastic and the effort leaves you feeling drained and yet very proud of yourself knowing what you did was no small feat, at least not for me. A good straight edge is essential for making the adjustments and it doesn't hurt having some scrap to test with along the way.

Now if there's an easy way to do this I never read about it so if someone knows this would be a great place to post those instructions in a clear concise step by step (illustrated if possible-I like pictures) procedure. I know those bearings will need replacing some day......

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Gaia

Discussion Starter · #15 · Feb 20, 2019

smitty10101 said:
Peter when checking your profile I see that you have 2 handheld portable planers but I can't seem to find the stationary one.
you might want to let us know of the make & model of the stationary one ---just in case it might introduce some idiosyncracies of the machine into your dilemma. from the pics it looks like the blade guard doesn't pivot out of the way as you pass the board over the knives forcing you to reposition your hands.

IF it's a dual purpose machine ( planer/jointer) does it function correctly as a planer (parallel faces?).

just trying to think out of the box.

smitty

Hi,
I havn't updated my tools listing for a long time. Quite a few of the tools listed I no longer have, been replaced with upgraded items. The Jointer/planer, here is called planer/thicknesser. The machine is an Axminster AT107PT.
" IF it's a dual purpose machine ( planer/jointer) does it function correctly as a planer (parallel faces?)." To use the thicknesser part of the machine I have to remove the fence completely and hang it on brackets on the side of machine. The fence is quite heavy and is cumbersome to remove. I could see it getting dropped onto the concrete floor and getting dented out of shape and being unusable. Axminster don't carry spares for such large parts of their machines. They would have to order a replacement. This would meaning waiting for 3 months for the next lot of shipping containers to come over from China.

kp91

· #16 · Feb 20, 2019

Cherryville Chuck said:
Absolutely certain Harry. Think about how it functions. The gauge has 4 legs that allow it to straddle the knife opening. It sits entirely on the cutter head with no reference to the beds. It is necessary to some extend as it controls how much knife sticks past the clamping bars. Too much exposure puts too much leverage on the knives which could cause them to move. But it does nothing to ensure that the knives are level to the outfeed bed which is the important one. If the cutter head were not level to the outfeed bed then one side could be a few thousandths different than the other edge which is exactly what Peter's photo shows.

Use the gauge to set the knife exposure and then adjust the outfeed bed until the knives will just tick against a hardwood board held down on it and the reset the knives level to the board. If that works then the permanent fix is to shim the cutter head level to the outfeed bed.

The jig I posted references the outfeed table independent of the cutter head.

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Gaia

Discussion Starter · #17 · Feb 20, 2019

5

"All the setting gauge does is set the height of the knives relative to the cutter head. If trhe head is not quite level with the tables then you'll get the results shown."

There is a gap of 1.2mm between the outfeed table as is and the barrel of the cutter head.

The knives have small springs under them. When using the supplied knife setting jig I took great care to set the height of the knives in the cutter block, repeating the process several times, just to be sure.
The knife setting jig is quite substantial isn't a cheapy bit of pressed aluminium.

Using the moving ruler forward method.
The flat batten positioned on outfeed table next to fence crossing over cutter head to infeed table.
Knife 1 moves batten forward onto infeed table by 2mm.
Knife 2 by 5.5mm.
Knife 3 by 4mm.

Batten positioned opposite side of tables.
Knives 1,2 and 3 don't move at all.

Part of past communication with Axminster engineer on advice on adjusting the machine.

Tolerances.
When the wood moves forward 5mm, this means the blade at it's highest point stands roughly 0.10mm proud of the surface of the outfeed table.
If you end up with the wood moving 4mm on one side and 6mm on the other, it's unlikely you will notice this when operating the machine.
As long as the blade is slightly higher than the outfeed table, the machine will work. If it is too high the material will be cut but won't be perfectly flat.

One thing I've been aware of but I didn't think was crucial, was the infeed table is very slightly askew in relation to the cutter head.

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Gaia

Discussion Starter · #18 · Feb 20, 2019

The machine is an Axminster AT107PT planer thicknesser with a 3 knife cutter block. Attached is a pdf from an Axminster service engineer showing quite detailed advice on how to adjust, set the machine up to get the desired results I have gone through all the procedure..... took me several days!!! I also have email content about adjusting too. Which I will locate, as may shed more light on the problem

Gaia

Discussion Starter · #19 · Feb 20, 2019

Gaia said:
Hi,
I havn't updated my tools listing for a long time. Quite a few of the tools listed I no longer have, been replaced with upgraded items. The Jointer/planer, here is called planer/thicknesser. The machine is an Axminster AT107PT.
" IF it's a dual purpose machine ( planer/jointer) does it function correctly as a planer (parallel faces?)." To use the thicknesser part of the machine I have to remove the fence completely and hang it on brackets on the side of machine. The fence is quite heavy and is cumbersome to remove. I could see it getting dropped onto the concrete floor and getting dented out of shape and being unusable. Axminster don't carry spares for such large parts of their machines. They would have to order a replacement. This would meaning waiting for 3 months for the next lot of shipping containers to come over from China. I have a Dewalt 733 planer/thicknesser, which does an excellant job.

Cherryville Chuck

· #20 · Feb 21, 2019

This article about setting a jointer up seems pretty decent: https://www.woodmagazine.com/tuning-up-your-jointer
As stated at the very end of the article, the outfeed table needs to be set dead level with the tops of the knives. This is why setting the knives using the outfeed table is the best method of doing that. When you lay a board on the outfeed and turn the cutter head you should hear and feel the knives tick the bottom but the cutter shouldn't roll the board ahead.

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