Replies

1. 
   finebuilder | Apr 10, 2002 03:21pm | #1

   I'll give it a shot.  The most obvious thing that comes to mind is that one or both pieces have a crown in them. The second possibility that comes to mind is that the jointer plate on the Left ( as you face it ) is not even in its plane. Raise the left side ( the only one that should more ) up about a 1/4" and place a level across it. Now measure down from the level on both the left and right side of the right table.  Same?  If not, the left table isn't coming up evenly. The last possibility that comes to mind is user error. ;)  sometimes ( though It never happened to me...hrumph!) the pressure applied varies as you're  changing positions w/ your hands ( usually at about the half way mark).  Don't know if I'm even in the ballpark.  Hope something is in the right direction. One question occures to me...What does the gap look like; very gradual tappering to both sides, or short and sudden and more pronounced to one side or the other? Let me know when you figure it out.We can all benefit from the lesson!

                                                       Miami   

1. 
   ed767 | Apr 10, 2002 03:27pm | #2

   Thanks, Miami.

   The gap is a very gradual one. The jointer cuts as soon as the forward end of the board hits the knives. Then it gradually fades until the back end of the board is untouched. It's like a very long French curve. I've tried hard to keep pressure the same. I've tested the table for level. Nothing seems to remedy the situation.

   Ed

1. 
   Rob_Weiner | Apr 10, 2002 04:20pm | #3

   Three suggestions:

   1)  Your jointer beds must be coplanar, meaning, if you had a perfect straightedge 6' long and you raise the infeed table to the height of your outfeed table, then the straightedge should touch both tables continuously from end to end, and the blade should just barely touch the straightedge at its highest point.  From the sounds of your problem, perhaps the two tables slope down on the middle.

   2)  As is suggesting in #1, your cutting blade should just barely touch a straightedge held on the outfeed table.  Your outfeed table may be a little high.

   3)  After about a foot of board has passed over the blade, you should be applying pressure on the OUTFEED side of the table.  (that is the part of the board that has been straightened, so you want to keep in flat on the bed).

   We all have have spent time turning nearly straight boards into bananas.  You will get the hang of it.  Keep with it.

   Peace.

   -Rob

1. 
   ed767 | Apr 11, 2002 03:08am | #5

   Thanks, Rob. I had incorrectly heard that I should keep pressure on the infeed table during the entire process. That one thing might do the trick. Also didn't know about height of the cutting heads in relation to the table. I know the table is level, so maybe that is the reason, too. I appreciate your time. Ed

2. 
   Danford_C_ | Apr 10, 2002 04:47pm | #4

   Ed,

   How did you check for "level".  The symptoms you describe indicate to me that the infeed and/or outfeed has a slight downward cant and/or the knives are too low.  The two opererative words for tuning the jointer are "coplanar" and "parallel".

   After unplugging the machine, rotate the cutter head so that none of the knives are exposed, raise the infeed to "0" then take your straight edge (preferably a machinists 48" straight edge) or test bar (one can easily be made from MDF and 3 screws) and check that the tables are coplanar.  You check parallelism with the straight edge or test bar with a feeler gauge by lowering the infeed table.

   Assuming that there is no sag, find the TDC of the cutter head by using a 3 or 4 inch long piece of wood that is flat and straight on one edge place it on the out feed table against the fence to where a knife just "grabs" it, scribe a line at it's end on the fence using a pencil, then rotate the cutter head, where the wood stops, scribe another line; TDC is the midpoint between these two lines.  The piece of wood should not move more than 1/8" if the knives are set correctly, I use a Magna Set to set them with and adjust the outfeed so there is about a 16th of total movement for the piece of wood.

   On a new machine it is doubtful that there would be a sag, this is usually the result of wear on the dove tail ways.  Sag can be eliminated by using machinist's brass shims.  If it is a new machine and there is sag, I would recommend notifying the manufacturer.  FWIW.

   Dano

   "Form and Function are One" - Frank L. Wright

   Edited 4/10/2002 9:52:06 AM ET by Danford C. Jennings

   Edited 4/10/2002 9:53:34 AM ET by Danford C. Jennings