Please help! I’m getting tapered cuts on new jointer.
I (finally) bought an 8” “General International” jointer but I’ve been having problems with my cuts; the work piece gets progressively narrower or thinner – I’ve been getting 1/32” – 3/64” per 7’. After most of a weekend working on this I am baffled. I understand that an outfeed table set too high can cause this. So I tried setting it at several levels, including one so low to the knives that it sniped at the end of the piece and still got a taper. I also tried to finesse it by bearing down harder at the start of the cut, then backing off on the pressure towards the end. This knocked off about 1/64” but still resulted in a taper. I’ve worked with a few industrial strength jointers in a wood class and in a mill but never seemed to have this kind of problem. Then again, I never measured the result quite so closely.
Could I have done something wrong with the set-up? Is there some kind of flaw with the jointer? Or is 1/32” – 3/64” within normal tolerances?
I’d appreciate any comments and suggestions.
Replies
Check to see if the two tables (infeed / outfeed ) are parrellel to each other.
Philip
Well, it IS parallel as far as a 24" straight edge can indicate. Do you think a straight edge as long as both beds could reveal something that the 24" fails to show?
I assume you're talking about the face of the piece rather than the edge. If you are, I've had the same problem, and I haven't figured out how to fix it yet. But I know it's my technique and/or a misaligned table. I'd think it's most likely the outfeed table, 'though you'veworked on that.
My understanding about the correct places to bear weight are on the leading edge of the piece until it clears the cutterhead, and then on the closer part of the outfeed table as you pushe the rest of the piece through. I'll be real interested to hear what the experts have to say.
Good luck,
Mitch
"I'm always humbled by how much I DON'T know..."
I had the same problem. To fix it I hade to get a 6' straight edge and I found that the infeed and the out feed tables were out of parallel by 10 1000ths of an inch(check with feeler guage set). After the adjustment all is well and has remained this way for almost 2 years now.
Good luck it takes alot of adjustment to get it within 3 to 4 1000ths but results are great.
Thanks jrag, as well as all you others who've to respond. Based on all that you've said, I'll either get hold of a longer straight edge or make a 3-screw poorman's straight edge described in a past Fine Woodworking issue. From what I understand from you all is that a difference in parallel between the far ends of both tables can make a significant difference.
Spalted,
Two things are important:
1.) Machine set up as mentioned in the other posts, out feed table has to be 0.000" same height exactly as top dead center of your knives. Once set, you normally don't touch this again. Tables must be aligned properly.
2.) Technique is just as important, I never had a problem, until one day I had this special board, with which I took special precaution to remove as little wood as I can to be straight. My "special precaution" changed the way I normally joint and I got exactly the same problem as you. I had to stand back and carefully analyse what I was doing wrong.
It's difficult to describe in words, but you must keep the area of the jointer tables where you apply pressure consistent and in the same place. Within about twelve inches or so before the cutter head and in contact with the outfeed table ONLY a few inches after the cutter head. Imagine you are trying to face joint a badly convexed board. You want to try and get the center of the convex area in touch with the knives first, to try and remove as little material as possible. This means the end of the board will not touch the outfeed table on the first few cuts. If you push this end against the outfeed table at some point, you will continue to plane a convex shape.
If a board is almost straight, generally keep it in touch along the whole infeed table and only move your grip to the outfeed table once you have no more room.
"If a board is almost straight, generally keep it in touch along the whole infeed table and only move your grip to the outfeed table once you have no more room." This advice contradicts everything I've ever read about jointer technique, Jelly. The outfeed table is the reference for the cut and the sources I used while learning (Rick Peters Jointers & Planers, and Gary Rogowski, FWW #124) instructed that once the leading end of the stock has cleared the cutterhead, the main "holding" pressure is on the outfeed side, just past the cutterhead (down, and toward the fence). The trailing hand provides feeding force.
"Almost straight" doesn't count, and if the pressure is on the infeed table, any aberration will affect the straightness of what comes off the outfeed table. If the pressure is on the outfeed side, that provides the straight reference as the board passes over the cutterhead. An exception would be a board in twist ("wind") where most of the downward pressure needs to be on the high points, diagonal to each other.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Forest,
I hear you clearly. So, I stand corrected, and admit I have never had the need to read a book about how to joint a board.
Thinking about it though, for a board which is shaped so that the leading edge is in contact with the knives and the outfeed table during the first pass, your literature holds true. For a board which is shaped so that the leading edge is not in contact with the knives immediately, during the first, or first few passes, your method will not work.
At the end of the day, common sense prevails.
If I had to write a book about this though, I would quote your first paragraph exactly, but with a few small changes...
"The trailing hand provides feeding force."
With only one hand providing the feeding force, being the trailing hand on the infeed table, it means stopping every so often, when you run out of stroke and have to re-position your hand. On a well tuned jointer you can get a "final" finish with the correct technique, but that means constant feed speed, nice and slow with no stopping.
Edited 5/25/2005 12:55 pm ET by Jellyrug
Edited 5/25/2005 3:12 pm ET by Jellyrug
JR, in my post above I was simply responding to the specific instruction you gave to "only move your grip to the outfeed table once you have no more room" when jointing a board that's "almost straight." Obviously, there are different tweaks to technique that need to be made according to the configuration of the board. Also, with said narrow focus, I didn't go into the whole hand-over-hand thing.
Although I did have to learn from a book (I always read first, power up 2nd, to avoid nasty accidents with a new tool -- don't have access to a shopmaster to provide instruction), my jointer technique seems to be serving me well. As long as I pay attention, the boards are coming off flat and true.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I agree with your first point, guess I have just never really paid attention.
My father taught me, many, many, moons ago and the only thing I remember clearly from his instruction, is that this is one of those DANGEROUS tools where you really have to pay attention to what you do with your hands, else a finger or two may disappear.
"...else a finger or two may disappear." No kidding! Any time I see that head spinning around it gives me goosebumps. One or two of our members have somewhat shortened fingers if I recall correctly. Glad you're working safely!
This week, I've had my two most successful efforts at salvaging wood that's in wind without shaving it to veneer. The jointer and I are now officially friends! forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Drywall T squares are fairly cheap and handy.
A few things that help:
1) Joint the "stable" side first. Usually, that is with the sap side down and the heartwood side up. The growth rings will make a "U" shape when looking at the board from the end. The board will look like an upside down "U" from the end.
2) If the board rocks on the table, put pressure on the same side (left or right) of the board every time.
3) Put pressure on the board on the outfeed side (after the first 12" or so of the cut).
4) The knives should be the same level as the outfeed table.
Good luck.
-Matt
If you go to the Delta website, and download one of their Jointer manuals they not only show how to adjust your jointer but also how to use it.
Rogera
Bingo!
People are trying to make setting up a jointer and using it effectively seem like Chinese arithmetic.
When I got my Delta 6" jointer it was the first time I'd ever laid hands on a jointer.
The manual and three hours of painstaking effort resulted in a well tuned machine that joints near perfectly.
That said, I'm not looking forward to changing out the knives some day. I keep them honed, in place, with a device I bought from Highland Hardware.
But when I do have to change the knives I'm confident the manual will walk me through the entire process again.
All,
Such angst over a thirty-steenth and a half over what was it, 7'? I call that a "sprung joint" and go on, likely it'll move more than that, (or straighten out) by tomorrow anyways.
Cheers,
Ray
Spalted, are you sure your knives are at top-dead-center when you're adjusting the outfeed table to be flush with them?
If you're interested in that Delta info, here's the link. Big download - 2.7MB. Didn't have quite as thorough instructions as I'd hoped though.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Forestgirl, I'll be recalibrating everything this weekend and see how it goes.
Thank you for your time and thanks to all in the Knots community for your help. You're all amazing!Spalted
I had the same problem until I got the top of the blades and the outfeed table at exactly the same height.
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