Replies

1. 
   BruceS | Mar 23, 2006 01:24am | #1

   Sounds like your in-feed and out-feed tables are not parallel to each other.  Find a very long straight edge (36" or better)  Raise the infeed table till it's flush with the out-feed table and then give the whole bed a check with the straight edge.  Willing to bet the right side of in-feed table is high, or the left side of the out-feed is low.

   You'll get it,

   Bruce

2. 
   RickL | Mar 23, 2006 01:47am | #2

   Seeing as it didn't do that before the typical reason is your outfeed table is a few thousandths higher than your cutting circle. Drop the outfeed table down until you have snipe and slowly raise it up until the snipe disappears. This was correct the problem. When was the last time you changed the knives. As they dull this can cause a similar situation. If your outfeed table was excessively high the board would stop dead at the edge of the outfeed table. Being a few thousandths higher will allow the board to ride up over the table and cause the cut to taper in the way you describe.

1. 
   chiyonofuji | Apr 11, 2006 07:53pm | #15

   Success at last. With much fiddling about it now works fine. Shimmed here, shimmed there, shimmed everywhere. In the end took shims away and adjusted height of outfeed table for the final time before retiring machine to the scrapheap! It worked fine. Blades are a bit dull and do require sharpening. Thanks for your help. Will remember this for next time.

3. 
   hammer1 | Mar 23, 2006 02:02am | #3

   There's a chance that the outfeed table, height adjustment, wheel got turned. Just take a straight board and cut into it a few inches. Stop the jointer, pull back the guard and check to see if the cut lands perfectly on the outfeed table. This will tell you more than any gauges, books or what have you. Cut in several more inches. If the cut either rises off the table at the far end or at the cutter, you have a table misalignment problem.

   Beat it to fit / Paint it to match

   
1. 
   joepez | Mar 26, 2006 04:20am | #8

   I too just replaced my knives and got the same results, a wedge,  tail end being thicker. Never had that problem before. So I should lower my outfeed table to be level with the top of the cutters?

   sorry for being redundent..

   joe p

    

4. 
   JohnWW | Mar 23, 2006 03:04pm | #4

   Hi, I'm the John White who wrote the article you are refering to.

   Your first problem is that you are using veneered MDF on the jointer, it ruins blades instantly, the glues are way harder than steel.  If you must cut man made materials on a jointer you need to install carbide knives. 

   To get your machine set up correctly I'd suggest putting in a new set of blades and then testing with real wood to get the final alignment.

   John White, Shop Manager, Fine Woodworking Magazine

1. 
   sansmnd | Mar 25, 2006 11:53am | #5

   I realize this may be a bit off topic but I couldn't find one that directly applies to my question.  Where can I find information on how to adjust the knives on a Delta 6" jointer?  Thanks for indulging me.

1. 
   PeteBradley | Mar 25, 2006 04:25pm | #6

   There are lots of favorite methods floating around FWW.  Search the archives and you'll find everything from dead simple to all the whistles and bells you could ever want.  This article:

   http://www.owwm.com/FAQ/JointerTune.asp

   contains the method I use.

   Pete

1. 
   PeteBradley | Mar 25, 2006 10:14pm | #7

   Another article:http://www.owwm.com/files/PDF/FAQ/JointerKnives.pdfThis article reminded me that when you tighten the bars, the knife may rise up a bit. To keep this from happening, I push down on the knife with a piece of hardwood while tightening.Pete

2. 
   sansmnd | Mar 26, 2006 01:55pm | #9

   Thanks for the links, Pete.  Now, if I can just decipher the jargon and find the adjustment points on my Delta, I'll be an expert.  :)

1. 
   PeteBradley | Mar 26, 2006 05:27pm | #10

   I recommend the "just ticks a straightedge" method then. It's as simple as it gets. I did some calculations a while ago and verified that it's easily accurate to .002 with a good straightedge. You'll likely get recommendations about dial indicators, glass plates, and the like, and I'm sure the work fine, but simple and accurate works for me.Pete

2. 
   hdgis1 | Mar 26, 2006 06:08pm | #11

   Not all that experienced with jointer tune up yet but is it true that on jointers that use reference pins to ensure proper installation of knives, that if you tune up at any other point than when the knives are first installed, the next time you install new knives you will end up with knives higher than the table? (by more than .001")

3. 
   PeteBradley | Mar 26, 2006 06:13pm | #12

   I don't have any hands-on familiarity with machines with special knives, but I would expect the straightedge method to work with any machine that has a normal raise/lower mechanism for the knives such as jackscrews. I know the Delta JT160 (new 6" benchtop) manual recommends this method.I think your question refers to what happens if you make adjustments for wear or sharpening, then later replace knives. At that point, you just adjust the new knives down.Pete

   Edited 3/26/2006 11:28 am ET by PeteBradley

4. 
   sansmnd | Mar 28, 2006 01:59pm | #14

   Success!  With the suggestions here and reference to the links provided, I managed to remove, clean and reinstall the knives on my Delta 37-280 jointer.  I'm beginning to learn that model is not the latest and greatest but it's mine.  lol  I am late in coming to woodworking and need all the help I can find, especially in becoming familiar with power tool maintenance and tune-up.  This and the other forums on this site are great!  Thanks to all.

    

   Jim

2. 
   chiyonofuji | Apr 11, 2006 08:25pm | #16

   Hi John, all OK now. Take your point about the MDF but only used it to test where the knives were cutting, as I knew it to be flat.
   So my knives may need a little sharpening now! In your article you recommend removing and replacing only one knife at a time. Only problem is that I don't have a spare set and not likely to with these exorbitant UK prices. Apart from finding some metal the same size as the knives would you recommend, as a last resort, making some blanks out of hardwood , such as Maple or Oak, as a replacement to avoid distorting the cutterhead whilst the knives are being sharpened? Obviously there would be too much give in a softwood.

1. 
   JohnWW | Apr 14, 2006 06:05pm | #17

   Chiyonofuji,Not all manufacturers warn that you shouldn't take out all of the knives at once. To be honest, I've never seen a jointer with a distorted head and I'm sure that some of the machines I've worked on must have had all of their knives removed more than once. My suspicion is that this may have applied to one type of machine once and it has been repeated mindlessly ever since in literature that is rarely updated by anyone with real technical knowledge.I presume that the risk of distortion would be caused by the pressure of one knife still being very tight while all of the other slots are empty. In this case perhaps the filled slot would be wedged open and the other slots would narrow. Of course if you follow the wisdom of changing only one knife at a time you would have to wonder why the pressure of several tight knives wouldn't distort the single empty slot. So I'm skeptical about this advice myself, but I include it in blade changing instructions because it would seem to do no harm and I didn't want to wreck someone's machine if it did in fact have a head that could be damaged by not following the "one blade at a time" procedure.If you want to remove all of the knives at once for sharpening, I'm 99% sure you could do so without damage to your machine. If you want to reduce the risk, I would loosen all of the gib screws a little bit at a time going around the head a few times until the knives were loose. When the knives are reinstalled reverse the procedure: set each knife for the proper height but don't fully tighten the screws until all the blades are installed, then work your way around the head again, in two or three steps, gradually tightening the screws.You might try to do an Ebay search for a second set of knives, they can often be bought new in an auction for less money than buying them from the manufacturer. Knife sizes are pretty much universal and standardized, if the knife is the correct length, width, and height it should fit your machine no matter who manufactured it.Hope this helps,

   John White, Fine Woodworking Magazine

5. 
   highfigh | Mar 26, 2006 06:24pm | #13

   MDF is a really bad thing to run through a jointer or planer. True, it's a lot like paper in the way it went together, but it's really abrasive. Bad for knives.

   "I cut this piece four times and it's still too short."