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Basic wood working question http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=3836 |
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Author: | John Kinnaird [ Fri Nov 18, 2005 2:01 am ] |
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If I am jointing a top on a jointer and there is a gap in the center of the two halves,(the ends meeting of course) should I lower the outfeed table or raise the outfeed table. I am of the school of thought that there is no reason why a jointer should not cut a perfect joint if it is set up right and I THINK that the outfeed table should be raised but I would like some concensus here before I go outside in the cold shop. thanks John |
Author: | Dave Rector [ Fri Nov 18, 2005 2:15 am ] |
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My understanding (and the way I have mine setup) is that the outfeed table should be dead level with the top of your knives. If it is lowered even a little too much the wood will drop after it is passed over the blades, resulting in a non-straight edge. I bought one of the knife setting gauges at Woodcraft and just recently corrected mine. I'm getting much better joints now. |
Author: | crazymanmichael [ Fri Nov 18, 2005 2:18 am ] |
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your out feed table should be coplanar with the top of your cutters at the top of their rotation. use a good straight edge to check. unless you have removed the blades and replaced them, or dressed them in situ with one of the tools used for that purpose, the outfeed table does not normally require adjusting. when i did volunteer work at a va woodwork shop i removed the crank so that the clients could not tamper with it. the other thing you may want to check is whether the tables are parallel. crank your infeed table up level with the outfeed and use your straight edge again. if the tables are not parallel you can get the situation you describe. if they are not parallel you will have to adjust the gib screws and perhaps install shims. |
Author: | Bobc [ Fri Nov 18, 2005 2:43 am ] |
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John the only time you would adjust the infeed table is if you would want to increase or decrease the depth of cut. If the outfeed table is lower than the blades you will get snipe at the end of your cut because the wood will drop. If the outfeed table is higher than the blades you will hit it with the wood as soon as they pass over the blades. Was the wood low in the center when you started? |
Author: | Paul Schulte [ Fri Nov 18, 2005 3:02 am ] |
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I think Crazymanmichael hit it about the infeed and outfeed tables being parallel. If the outfeed is too high you would have gaps on the ends and the middle would be closed up, too low and you get snipe on the ends. My Jet 6" has gibs you adjust for this. |
Author: | Pwoolson [ Fri Nov 18, 2005 3:04 am ] |
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John, I had the same problem awhile ago. After lots of hair pulling, I came to the conclusion that the outfeed table was not parallel with the infeed table. It slanted downward toward the end. So the first part of the cut was perfect, then as I made the board rest on the outfeed table the cut got deeper and then shallowed a bit at the end of the cut when it was resting more on the blade side of the table. I think that if your entire outfeed table was too low you would just get snipe at the end rather than an inconsistant cut. |
Author: | Bobc [ Fri Nov 18, 2005 3:08 am ] |
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Paul if the outfeed table is too high it would be above the high point of the blades. You can't get on to the outfeed table without the leading edge of your wood hitting it. You could feel that and would have to force the wood to climb on onto the outfeed table. As far as the infeed and outfeed tables not being parallel that's a good possiblity. |
Author: | Don Williams [ Fri Nov 18, 2005 3:12 am ] |
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It is definitely a parallel issue. |
Author: | Paul Schulte [ Fri Nov 18, 2005 3:26 am ] |
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You are right Bob, I was assuming that the blades are level with the outfeed table. Jointers to me are very difficult to get set up well. When I set up my jointer I go in 2 steps, first is table parallelism, then outfeed table to cutter height and it is always a time consuming effort. Adjusting those knives is a serious pain. |
Author: | John Kinnaird [ Fri Nov 18, 2005 3:47 am ] |
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I think at this point I am compensating for blade wear. I know that means that the blades need sharpening, but I what I need to know is the logic of the geometry. We are not talking about much movement here. I can lower the table till I get end snipe and there is a cup in the center of the joint. I have been raising the table in hopes of getting rid of the cup but have had little success so far. If I raise the table to the poin of having the wood hit the outfeed table and then lift the wood over that nick point, and passed the joint over the jointer, what would the majority of the joint look like? |
Author: | Bobc [ Fri Nov 18, 2005 3:55 am ] |
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John I know it's a pain in the rear end but your better off taking the time to get it right. That means checking to see that the tables are parallel, sharp blades set up properly so they are exactly even with the outfeed table. Once that is done it takes just a few seconds to get a perfect joint. I have spent the better part of a day getting this done but the end results are worth it. |
Author: | John Kinnaird [ Fri Nov 18, 2005 3:58 am ] |
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You are probably right Bob. Sigh. |
Author: | Pwoolson [ Fri Nov 18, 2005 4:02 am ] |
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[QUOTE=Bobc] Paul if the outfeed table is too high it would be above the high point of the blades. You can't get on to the outfeed table without the leading edge of your wood hitting it. You could feel that and would have to force the wood to climb on onto the outfeed table. As far as the infeed and outfeed tables not being parallel that's a good possiblity.[/QUOTE] I was unclear. The blade end of the outfeed table is where it should be (the same height as the blades) but then falls away making the far end of the outfeed table lower. Sorry, Bob, thought you were talking to me. |
Author: | Mario [ Fri Nov 18, 2005 4:02 am ] |
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Everyone wrestles with jointers; you are not alone. All good help, so far. Next for you is to diagnose the problem, then we can offer corrective steps. On that note, I'm struggling with my 6" Delta, too. I've always been able to just tweak this and shim that, and get it nailed, but it's been progressively getting crazier and crazier. About every second month, I need a full day to just work on it, and these past few haven't seen me getting it spot-on anymore. Arghhhhh! Is there a website with a step-by-step, turn this screw to aleviate this and that, some place? Or a book? There are countless bandsaw and table saw setup books, but I've not seen one for jointers. |
Author: | Brad Goodman [ Fri Nov 18, 2005 5:08 am ] |
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Mario, Yes there is a place!! The best articles I have found are in Fine Woodworking magazines and books by Taunton press. The book I have is called Workshop Machines which is a compilation of articles from the magazines. The section on jointers is great-"jointer savy" and "jointer set-up".Great stuff! Every time I have to set up my jointer or planer I consult this book. |
Author: | Bobc [ Fri Nov 18, 2005 6:00 am ] |
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Well one thing I did to make things a bit easier was I bought one of those Magna-Set tools. They hold the blade flush to the outfeed table while you make your fine adjustments to get the blades flush. This step used to be a hit and miss pain. Much easier now. Getting the two tables parallel shouldn't have to be done very often. I actually havn't had to change mine in 25 years. One more thing I do is put a small micro bevel on the blades. They stay sharp much longer as there is a bit more meat behind the edge. |
Author: | crazymanmichael [ Fri Nov 18, 2005 7:24 am ] |
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another brian burns fan!!! |
Author: | paul harrell [ Fri Nov 18, 2005 9:12 am ] |
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Hate to be aa luddite, but a sharp hand plane and a shoodting board is just as fast and produces a much better gluing surface. Paul Harrerll |
Author: | paul harrell [ Fri Nov 18, 2005 9:18 am ] |
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After looking at my last post, I see that using a hand plane is so easy, you can do it even if you can't type. Paul Harrell |
Author: | rlabbe [ Fri Nov 18, 2005 9:32 am ] |
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Paul, I'll race you. We each get 1 dozen rough neck blanks, with the job of surfacing and squaring them up. You get a well adjusted plane, I get a well adjusted jointer, and we both get a table saw. Who do you think wins? |
Author: | Mattia Valente [ Fri Nov 18, 2005 10:15 am ] |
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We were talking tops, though, not necks. Each tool has its place, blah blah blah. |
Author: | RussellR [ Fri Nov 18, 2005 10:47 am ] |
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I use a hand plane cause I don't have a jointer, but if I had a jointer I'd use it. |
Author: | Mario [ Fri Nov 18, 2005 11:53 am ] |
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This week, I had 30 mandolin backs to joint. That 60, one(plus) inch thick, by 16-20 inch long, flamed maple boards that need to be perfectly jointed. I'd still be at it if I were trying to use a hand plane. As it is, I have two to go! And all this only took maybe 15 minutes of each day. But the dang jointer is out of whack again; I had to carefully set it all up before starting(new knives), and now it's cupping the cuts a little. I've gradually moved the fence back, using up all the knive's surface. But something in the tables has moved; always does.... I need to make up a jig(have it pictured in my mind...) using guitar tuners to bring some strings tight to use as straight edges. I have a feeling one or both tables is doing a slight twist. Any other ideas on how to check these? I have a machinist's straight edge that has been checked and is dead-on, but it is only 24" long... |
Author: | John Kinnaird [ Fri Nov 18, 2005 12:30 pm ] |
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Where can you get a jointer that does not need this kind of pampering? I want something that NEVER needs to have the bed realigned. I would prefer never to have to sharpen the blades either but realize the hoplessness of that. The jointer I have now is a delta 6 inch jointer. I moved up from an old Sears jointer which was a nightmare. But this Delta is letting me down too. John |
Author: | Mario [ Fri Nov 18, 2005 1:45 pm ] |
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Well, we could keep our eyes peeled for old ones, where the cast iron has done all its settling-in, and can be trued once and for all. The older, heavier machines were more stable, but I believe the new Deltas can be fine ocne set up. Mine was spot on, dead perfect for 4-5 years, then started moving. I'd just like to know what brought-on the movement, and how best to correct it. This machine was so sweet for so long.... As for knives, we're screwed. We need a soft enough knife to take a keen edge because of the softwoods we joint, yet we kill it by running the ultra hard, abrasive woods through it, also. We need one machine with carbide knives for backs, sides, fretboards, and another for tops. Hmmm, isn't this where the hand plane comes back in? Hmmmm! |
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