Jointer H E L P!!

Warren White

Member
Messages
51
Location
Livermore CA (SF Bay Area)
OK, I have done it again. I started to edge joint two boards, about 2 feet long and 6 inches wide, 1/2 inch thick.

Started with the outfeed table at an equal height as the knives (as determined by taking an 1/8 inch off a soft piece of redwood and raising the outfeed table to match). I believe my infeed and outfeed tables are coplanar (as measured with zero cut and using an expensive straightedge across both tables. Pressure on the infeed until there is sufficient wood on the outfeed and transfer the downward pressure to the outfeed.

I marked the length of the edge with chalk so I would know when the entire edge was jointed. It took many passes at 1/32 per pass.

OK, get ready to laugh.....

I now have a board that is 6 inches wide at one end and 4 1/2 inches wide at the other end!

What in heaven's name am I doing wrong?

Thanks! This just ain't right....

Warren
 
I'm not sure if I have an accurate picture of your setup, so let me tell you what I think you said.

You have your infeed and outfeed tables at the same height and your cutter running 1/32 above the height of both tables.

Am I close?

I'll wait here
 
Nope. It isn't surprising that I didn't make myself clear. The outfeed table is even with the knives at tdc. The infeed table is set for 1/32.

They are only equal when I ran the infeed table up to zero, rotated the knives out of the picture and measured the parallelism of the two tables in relationship to each other.

That better?
 
That better?

Well, yes and no. Your setup sounds fine - at least that that's the way I do it.

If you got a taper then the problem must be technique. It sounds as if you might have had a hollow (concavity) on the edge. (this would work better with diagrams) Depends on the length of the piece realitive to the jointer also.

I started to explain what might have happened, but I'll skip to the last scene. If there's a hollow, spot plane the two ends alternately until you get a continuous cut the length of the board. If there's a belly (convexity) spot plane the middle only (or wherever the belly is) until you get a continuous cut the length of the board.

This requires you to hold the board more or less level as you remove either the ends or the middle, as needed. Many folks are more comfortable making a board jig for the tablesaw and putting the straight edge on that way.

I don't know if this helps, or if it's even comprehensible, but it's the best I can come up with.

Lemme know, but I'm hitting the sack soon, so it'll have to wait til tomorrow. Maybe some else will chime in before then.
 
Thanks, Ian. That does make sense. I thought that my boards were fairly straight and parallel, but they are redwood that I had resawn and perhaps there was stress internal to the wood that revealed itself as a bow, either concave or convex after the resaw.

I should have taken more time to study the wood before I started whacking away at it. Patience isn't my strong suit I guess. I just want to start the milling process.

I am just making a new bird feeder. You would think that it wouldn't be rocket science....

Thanks again. Have a good night.

Warren
 
I am just making a new bird feeder. You would think that it wouldn't be rocket science.... You'd be surprised how complex the simplest project REALLY is ....
:doh:
I've made some doosies over the last few years !!

Maybe you're putting uneven pressure on the board as you push it through. ie: pushing down too hard at either the front or rear of the board and not enough at the opposite end ? Smooth even pressure allowing the tool to do the work.Just a thought.
Elliott
 
Last edited:
Warren...one other point to be sure on. You set the tables parallel, with the knives out of the picture...that's fine. But...after lowering the infeed table... was it still parallel with the outfeed one? It's not guaranteed, to stay parallel, when moved.
 
That is of course a possibility that I hadn't thought of. It should be relatively easy to check however.

So I did....

It looks like the end of the outfeed table is about .060 low. It appears you were right on. Now, I will have to re-read the manual (I have a Jet 4" Jointer) and see how that gets fixed.

Thanks Jim (and all who helped)

Warren
 
Any chance you are only applying pressure to the tail end of the board through the entire pass over the jointer?

You should be moving your hands to the outfeed side and pressing down and 'pulling' the board through for at least the second half of the pass. Pressing down and guiding from the infeed side only might cause the board to lift off the outfeed table and take a heavier bite on the second half of the pass.

Sorry if that is not really clear.....it's real early here!
 
Ok, it wasn't quite that much! :dunno: I exaggerated for effect, but it was smaller on one end than the other. Given enough time and enough passes, it would have been just that.

I think it boils down to technique, plus having the tables coplanar. I think they were when I began the project, but in an effort to blame something other than my technique, I loosened up the gib screws on the outfeed end and it dropped as mentioned. Once I tightened them back up again, they were just fine.

I really appreciate all of the help. I did this very same thing once before, but I thought I was over it.

Thanks again to all!
Warren
 
The outfeed should be about the thickness of a Cigarette paper less than the height of the blade. Depending on the sharpness of the blade there will be a compression of the cells that will show up as the wood piece passes over the cutterhead. Does I make myself clear here? Probably Knot, but there is a compression of the fibers as the wood is fed across the cutter head. The outfeed table must reflect that compression and be set that thickness lower so the resulting cut will be true and w/o snipe, or taper.
 
I always set my PM 54A's out feed table as exactly TDC of the knives as I could. Everything always came out just fine as long as I considered the desired outcome. That is, slight bow as mentioned can be exaggerated at the end of the board after multiple passes.

Personally I would have used a hand plane on a 2' length--one possibly two passes--and then straigtline ripped the second edge on a TS [if I still had one available else now I would on the BS] and took a single swipe with the handplane. Whole thing is as fast as firing up the jointer [which is why I sold the 54A].

Take care, Mike
 
Hi Warren;
It sounds as though you've worked out the problem. I have learned a couple things with my floor 6" jointer in a mobile base. After rolling it around, into working position, I must recheck both tables and the level of the whole unit.

A couple big items with me are: Don't joint edges the night before and try to glue up the next day. DAMHIKT :eek: The edges probably will not be as perfect as when they came off the jointer. After checking with a straight edge, I had to run a pass or two, then glue up right after.

Second, if I'm having trouble with a board or edge, after checking the alignment of the jointer, it's probably my technique. I must rethink where I'm exerting pressure as I move the piece over the blades from one table to the other. Again - DAMHIKT :wave:
Good Luck, Mike
 
Top