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How close to coplanar is good enough?

7107 Views 18 Replies 9 Participants Last post by  pintodeluxe
I recently bought and set up a new Powermatic 6" jointer. I attempted to set the jointer up following the instructions on wood whisperer (using a 50" straightedge and feeler gauges to check for coplanarity) and I found that the infeed table is about .010" lower at the cutter head than it is at the back of the machine. I checked this by referencing the straightedge against the outfeed table, and discovering that I could slip a .014 feeler gauge between the straightedge and the front of the infeed table and only a .004 gauge at the far end of the infeed table.

I believe the 8" Powermatic jointer, which was set up on the wood whisperer has 4 cams you can use to adjust the four corners of the infeed table. The 6" model, however, does not have these cams.

My question: is a .010 variance acceptable and is there anything I can do to get rid of this variance? I am not making super high end furniture in my shop, but I would like my jointer set up as best as is practically possible.

Thank you,

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i WILL CONTACT MY CONTACT AT WALTER MEYER AND WILL FIND OUT HOW TO ADJUST THE TABLE. oops sorry i am on the laptop and its hard to see the caps lock is on. Any way IMHO it should be dead flat Is this the 54a or 54h model I own that model but my table was dead flat and i check it every month and it has never been off it will be good to know how to adjust it though. Ill get back to you when they call me back but let me know first if this is the model we are talking about
Should be fine, and here is why: When the outfeed edge is aligned to the blade, the outfeed table will control the quality of your results. The infeed table needs to provide a close to uniform entrance to that blade. As long as the infeed table is sloping down to the blade, instead of climbing up to it, then anything you joint will be fine.

Keep in mind the first cut is on a bumping surface, the infeed table can be bumpy or the wood can, it won't matter. On the next passes, with an infeed table sloping into the blade, the first bit of the cut will produce a slight taper, because the wood is angled down into the blade, but that will be minor because the far end is supported higher .010" higher, and once the wood is supported over the outfeed table it won't matter. Your thicknesser will clean it up. And we are only talking about 1/100th over how many feet?

Its fine. You should be able to make it perfect, but I can't see how it would make a large difference (maybe your thicknesser would save an 1/8th on the longer boards.
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.010 is fine if you want all your lumber to be tapered. It needs to be dead flat and coplanar with the cutter head.
Rectangle Parallel Slope Font Logo

Yeah it will be tapered, but it will be very slight. Or get it square. If the infeed table was higher near the blade then on the far end, it sloped up to the cutter, then it would be a bigger problem (you would carve a bow in the front half, or quarter, of the boards).


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I remember reading from some manufacturer, of which I can't remember and can't seem to find at the moment, that 0.005" is acceptable and anything more should be addressed.. I tend to get as close to 0.000" as possible with 0.002" being about as much as I will accept. Bottom line is run some wood through it and see if the results are acceptable for you.. I've known people who had way out of whack tables and still got good enough results as far as they were concerned.

Thank you for the replies so far.

So far I've gathered that:

The degree of slope is probably on the edge of acceptability, though my actual results will depend heavily on my jointing techniques.
The .010" slope is over 1/2 the total length of the table, which is 60"/2 - 30".

I am going to call powermatic today to see if they have any recommendations on how to shim the infeed table. Does anyone have any links to resources on how to do that?

On another note, I also discovered that my fence is not perfectly straight. I was able to insert a .006" feeler gauge between the fence and my straightedge in the center of the fence. When I hold my straightedge up to the fence, it is clear that there is light shining through between the fence and the edge. To me, this seems like a more serious issue than the infeed table. Any thoughts? Should I return the fence to powermatic, or is this type of variance par for the course for that company?

Thanks again!
My Jet was once about .010 out, and I could not get a true piece of lumber out of it. Have to be true flat. Like the .005 number is about as far out as you want.
If the fence is not flat, that won't affect the surface you are jointing. Coplanarity of the tables is the most important. The fence should be 90° to the table; flatness of the fence; less important. has some great info on jointer set up to include shimming. Many of the methods are a bit crude, but I've never been steered wrong. Some of those guys have managed to restore some pretty sad machines back to brand new. Getting your machine into spec should be easy.
I was able to insert a .006" feeler gauge between the fence and my straightedge in the center of the fence. When I hold my straightedge up to the fence, it is clear that there is light shining through between the fence and the edge.

We should have asked first, how straight is your straight edge? measurements are only as good as the tools we use to measure.

Otherwise, what Tedstor said. If the fence is at 90° to the table it will do its job. A .006" low part in the center won't matter, especially if it does not extend that far. The wood will ride over the gap if it maintains support against the rest of the fence.
Richarrd I have a contact there and already said I would help so I need to know what model of jointer you have I asked this on the first reply to your post.
The model is a 54A, 6" jointer, purchased from Amazon. I wonder if I got one of a batch that wasn't quite write. I called Powermatic yesterday, was on hold for about 10 minutes and then left a voicemail. The saga continues…
Thanks Richard I have to go have another MRI in the morning but I should be done early enough to get ahold of Gail I will have an answer for you as quick as I can these guys are great to me and I know I love my 54 a and once you have it dialed in it will stay dialed in Cheers
Richard I found this in the manual i think you can find it on page 24 this is how to adjust the gibs it is pretty easy to do and should solve your problem. I will verify this with Gail tomorrow But I am sure this is the right information. Also make sure your using a good straight edge to set this up it must be a good one never drooped and it should weigh a ton.

Table Gib Adjustment
The infeed and outfeed table gibs on your machine
are factory adjusted and initially should not require
readjustment. After a period of use, the gibs may
become loose, introducing play and causing the
tables to sag. This requires adjustment.
To adjust (refer to Figure 18):
1. With a 10mm wrench, loosen the jam nuts that
secure the gib set screws.
2. Have another person support the end of the
table, slightly raising it while you make
3. With a 3mm hex wrench, tighten each
setscrew 1/4 turn starting with the lower one,
then the upper one. If a 1/4 turn does not
remove the table play, take another 1/4 turn.
Repeat a 1/4 turn at a time for both set screws
until play is removed.
Note: If the gibs are too tight the adjustment
handles© will be difficult to turn.
4. When adjustment is complete, hold the set
screws in position with the 3mm hex wrench to
maintain the setting while tightening the jam
nuts with the 10mm wrench.
Figure 18
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Thanks for pointing that out about the gib. Honestly, I didn't know what a gib was, until just now. I was expecting to see "cams" per the wood whisperer video, but I suppose cams only come on the larger powermatic models.

Regarding gibs, the manual seems to say they are for getting rid of any play in the tables or sag after extended use. Can they also be used to raise or lower either end of the table? I noticed the edge of the infeed table closest to the cutter head is lower by a uniform amount, meaning there is no "twist" in the table. I also noticed there are only two gib screws per table, and they are both on the back of the machine. Does this mean that adjusting the gib screws will allow me to raise or lower one end of the table without causing it to twist? If so, I may be able to achieve coplaner-ness by adjusting the gibs. Does this sound reasonable?
There is some confusion regarding what the things are called! Gibb screws are typically what holds the table securely to the base.. tighten them too much and the table won't move. Too loose and the ends of the table will 'sag'. The adjusting screws, or cams as they are sometimes called, are used to adjust the table level (to make it co-planer). I have not had the chance to play with a PM54, but it won't hurt to try adjusting those and see if it helps. If not, then you will probably have to resort to using shims like most other jointers without the table adjustment gibbs/screws/cams/thingies.. :)

Richard what are you using for a straight edge because I am worried that your straight edge may not be accurate. I wish you were close I have a marvelous 79 inch straight edge and I know its dead straight .I also think there are 4 gib screws. I will check on my next trip to the shop that said if your edge is straight and the table was not milled flat Powermatic will replace it with out complaint they are a great company and they want you happy.
I shoot for within .002 inch.
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