Hi Everybody,
I was glad to read Mr. Rogowski’s blurb on how frustrating his jointer started out, at least I’m in good company. Here’s my issue… I bought a Grizzley 8″ jointer a couple of years ago, the G0500 that FWW rated as Best Overall. It was a big machine for me, I don’t do anything I’d need that much machine for, but the thought was that I could grow into it. And I am, slowly (read, 3 kids asking to pitch baseballs). I have read and understand the jointer to be a simple machine in theory, and I understand the front to back taper that can be placed on a board when jointing an edge and how to get rid of snipe at the front or back when face jointing. BUT, I’ve come to notice a perceptible side to side taper on my work-pieces lately. I’ve been working on some 20″ long boards about 4″ wide and there is more wood removed from one side than the other. This is kind of an early post to get some initial opinions, I haven’t measured how much one side is off yet. But, I have checked the knives and on one of the three knives one side of the knife is set just a hair lower (as determined by allowing the knife to drag a straight-edge resting on the out-feed table about 1/16″ on all the other knives but not the fence-side edge of that particular knife, there’s no drag there). If only one knife is not set to full height would that cause the side to side taper? I’m going to get them resharpened soon anyway, so I’ll reset them, but…? Also, I read at Val Rose’s Woodwork’s site that too much pressure on the outfeed side could cause side to side taper, I can’t rationalize that as it is the only reference side of the machine when face jointing. Any initial thoughts? Thanks everyone!
Erich
Replies
Have you looked at the fence?
Erich,
I know of only 2 things that can cause this. (Must be a lot more I don't know)
1) the knives are not even with the table.
2) the fence isn't square to the table. Just because the gauge on the fence says 90 degrees
doesn't mean your square to the table. Have you checked it with a quality square?
Which edge of the board does the taper show up - the fence edge, or the middle of the blades? Since the portion of the blades near the fence usually gets more wear, that section might be cutting less agressively than the center area of the blades?
Misalignment is a more likely cause, however.
All the blades need to be aligned with the outfeed table. Even one blade will cause a problem--both a tendancy to taper and a rougher cut.
Jointers can fairly easily taper a board--where the initial warping is may determine the nature of the cut. If the grain will let you you can reverse the board to balance a little taper. Yhat said, Jointers aren't designed to make boards of even thickness, just to get one side flat and one edge straight and square to the one flat side. To get boards of even thickness, you need the complemetary tool, the thickness planer. It's an essential pairing.
Also you mention thinking there might be a problem with too much pressure on the outfeed table. As much of the downward pressure on the wood as feasible should be over the outfeed table. The force applied on the infeed table should be, beyond the first few inches of cut, be directed only toward guiding the wood horizontally across the cutting blades, while the downforce is kept on the outfeed table which provides the reference for being flat.
You might have started life on those blades with the entire tip edges level with the outfeed table but... that doesn't mean they are at this point. I see many not move the fence when edge jointing off of one spot which is usually totally forward so the majority of the cutter-head is not exposed during the cut. Not saying this pin-points the case here but.. if you do that and not equally use each section of the blade tips you will wear down the tips on the side favored. So.. if you do use the blade equally dis-regard and look elsewhere.
Good luck...
how tapered?
If you mean that one end of the board is more narrow than the other after jointing that could be a matter or technique. It is important to keep even downward pressure on the board (infeed table) as you start it into the blades and then shift this pressure equally to a downward pressure on the outfeed table. If you taper is one of the sides of the board not coming out as 90 degrees then make the checks mentioned above. Technique is the root cause of many jointer issues. It takes practice (on scrap stock) to develop your technique. Experiment.
Mention of "pressure" is
Mention of "pressure" is interesting - I was taught to allow gravity to apply the pressure to minimize the chance of copying a curl (? - ends on the tables, middle bowed up off the table)) in a flexible board. It certainly has produced good results for me.
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