Replies

1. 
   hackmeister | Dec 16, 2013 11:25pm | #1

   .007 where?

   Where is the .007?  Is that a dip in the bed or are the tables out of parallel, and if so, is the .007 over the length of the bed or over a foot?  A .007 dip in the bed actually isn't too bad, and likely would not have much effect on the practical usefulness of the machine.  (On a side note, what kind of straight edge are you using?   Maybe that is some off the .007 variance.) I think my Unisaw has a good 1/32 dip in the top between the miterslots and more over the overall table, but I would be quite vain to blame the saw when my joinery is off --that is almost 100% operator error.

   If you were to have it fixed, have a machine shop grind it on a surface grinder or blanchard grindinder.  Thing is though, it may not come out much flatter than it is.  In my days as a machinist, i worked on plenty of metal machines that were out of flat more than .007; depending on what you are doing, that kind of slop may not matter.

   Don't jump on it on concrete, if you are worried about being accurate to the thousandth.  Might as well beat on it with a 2x4 or hit it with at belt sander then.

   If it were me, I would exhaust all other possibilites for sub par performance, before dealing with .007" of sag, I would be surprised i that had much effect if any on the overall resutls.

1. 
   tenderfootbob | Dec 17, 2013 02:26pm | #2

   JOINTER TABLE "DIP"

   The outfeed table measures 22-7/16" long and 6-3/4" wide. The "dip" occurs along the the entire length reaching .007" right in the middle of the table. It is uniform across its width.

   I have a 42" stainless steel straight edge with no indication of the manufacturer. The front and rear of the outfeed table are parallel with the infeed table. The infeed measures flat.

   My SawStop cabinet table saw rips a straighter edge then my jointer!

   Thanks for all your input,

   Tenderfoot Bob

2. 
   hackmeister | Dec 18, 2013 08:41pm | #3

   How much effect does the .007 have?

   Is the .007 sag causing any acutal problems jointing?  I can't think of any normal woodworking that requires that level of accuracy, except maybe some musicical instrument applications (harpsichords, organs, pianos).  

   Most of my metal machining back in the day was done to +/- .005, unless the specific application warrented greater accuracy (going from +/- .005 to +/- .002 doubled the amount of time requied --machining by eye vs by instrument, so I made the grad students and engineers justify the extra accuracy.  I worked in an underfunded University research lab on old WW2 era equipment). 

   Remember, a 12 inch wide regular hardwood board is going to change widths between 1/16" and 3/8" depending where you live due to just seasonal moisture changes.

   p.s. I would be estatic to inherit a X5 jointer, sag or no sag.  It beats the pants of my Jet 6". 

3. 
   oldwindowguy | Jan 01, 2014 04:12pm | #4

   I'll avoid the fascinating topic of measuring flatness.  I had a similar problem with the fence of a Northfield 12" jointer, a casting about 52" long and 7" wide.  I ended up at a machine shop that reconditioned diesel engines.  They had a grinder for flattening warped engine heads that worked wonders on it.  Yes, I was surprised it could handle a casting that long.  Automotive shops are more common than precision machine shops if you live in a smaller town and more reasonably priced in my experience.