Jointer Table Tolerences

[Michael Gabbay]

I'm having some jointer issues with my 6" Bridgewood... :confused:

I was milling some poplar earlier this week. A couple of 6' boards were bowed along the length. My normal technique is to place the concave side down so the the high points are at the ends. I made a few light passes (1/32) until the whole board was being cut. So, I thought the board was flat. After checking for flatness against a straight edge (ripped 3/4 birch ply on edge), the piece was still bowed.

My next step was to check the tables. The outfeed table was checked for coplaner with a 24" LV steel straight edge. It was basically dead on. Then I check for any sagging on the outfeed side. Using the infeed table as my reference point, I placed a few inches of the straight edge on the infeed side and pressed down to check the outfeed side. The outfeed was off by .004. I also reset the outfeed height and reran the board. It still has a bow. :mad:

So, could the .004 sag in the outfeed be causing it? Is it the nature of poplar being springy? I try to run my boards with just enough pressure on the outfeed side to pull the board across and take very light cuts.

Thanks, Mike

[pat warner]

Jointers are strange animals. Lots of skill? Then, often, an operator can joint perfectly even if the machine is "out". SOme tips at the FAQ no.12 (http://www.patwarner.com/faq.html) link.

Notwithstanding, I'm thinkin' your pressing the bow out, only to have it bounce back after a pass.

What to do? Just pull the ends, one at a time, across the blades until they're even with the center (Bow down). Once the ends quit cutting, take one light pass from end to end.

[Michael Gabbay]

Pat - Thanks, I'll give it a try. I think poplar is too soft to get good results on the longer boards.

Mike

[Mark Singer]

Michael,
i think Pat is correct...it may be technique. The pressure starts down on the in feed table.....and once there is a good length on the out feed table apply the pressure there...