Official Luthiers Forum!

I have a new Jet JJ-6CSDX which I have not turned on yet because it doesn't seem to be within tolerances. I have spoken to a Jet tech, but he is now gone until next year. I want some input as to what I should accept as reasonable before I talk to him agian.

I have made some adjustments suggested, but the machine has these residual discrepancies. With the front edge of the infeed and outfeed tables parallel and at the same elevation, the back edge of the outfeed table (along the fence) is 0.006" lower than the infeed table. With the fence square to the infeed table, the outfeed side of the fence has a 0.007" gap from square at the top edge. This is the opposite direction than would occur if it was from the twist in the outfeed table. This is actually the second fence, because the one that came with the machine had even more twist, and Jet sent me a new fence. Jet told me that there is no adjustment for the tables to compensate for twist relative to the infeed and outfeed tables, and implied that they would replace the machine if there is twist; however, we did not discuss how much tolerance is acceptable. Naturally, I would like no twist, but I am not sure if that is realistic. I am using accurate, machined straight edges and squares.

Any input would be appreciated; but, as the machine is new, I will not be improvising any adjustments or repairs that are not normal for new equipment.

Bill-
I checked a FWW article which reviewed 6" jointers- perhaps you've seen it? (If you need a copy, you can pm me with your email address and I can send it to you.)
Two pertinent things from that article- the Jet had .007 twist in the table, and the "acceptable" tolerance they quoted for all the machines was .006" gap along the length of the table, .003 across the width.
You should probably check the specs on your straightedge as well- the LeeValley aluminum straightedges are within .003 of straight, the steel ones within .001.

My 'jointer' (Inca) has such short tables that there's probably no point even checking it for the kind of tolerances you're interested in here. I generally have to use a hand plane to shoot the edges if I need a good joint.


Cheers
John

Bill,
I have a similar model Jet jointer that is several years old and and was purchased in good used condition. I have been less than thrilled with the alignment of the tables. I recently received a copy of the Fine Wood Working article that describes in detail how to adjust and shim the tables. I am going to try this to see if I can get it closer. I guess if I had it to do over I would have purchased a better quality machine (maybe an older Delta or Powermatic 8")

I will say that even if I get the jointer working better the quality of a good plane and shooting board is a really quick way to get get a perfect joint.

_________________
Brad
Avon, OH