Concave Jointer Cuts

[Jason Tuinstra]

Sometimes the wonderfully relaxing hobby of woodworking can drive me nuts!!! I'm sure I'm the only one though :D. For the life of me I couldn't figure out why I've been getting concave cuts on my jointer. I just came across this website and thought I'd pass it along for anyone else who could stand to tune up their jointers. It looks like my problem is going to be a simple one to fix. Shooooot! And I thought the fix was going to be a new DJ-20. :p


http://woodworking.homeip.net/wood/Tuning%20Tools/Jointers/Jointers.html

[Mark Singer]

Jason,
The beds are peaked! They need to be co planer...put a long straight edge across both infeed and outfeed.

[Dick Parr]

Jason,

I find if I am pushing down to hard with my right hand on the back end of the wood trying to feed the board into the blades, it will cause this problem. I have learned to put moderate pressure over the out feed (front of the board) and feed with my left hand and arm. This seems to eliminate the same problem I had making a table top.

Good luck

[Jim Stastny]

Jason,

Thanks, that's one of the BEST tutorials I've seen on tuning a jointer.

[Michael Ballent]

If the infeed and outfeed are co-planer, you need to make sure the knives are even with the outfeed. Here is what I do and it's pretty quick, it probably take you longer to read the posts than to do the following proceedure ;) :

1) get a piece of scrap about 3-4 inch in width and about 10-12" long
2) set the infeed to take about an 1/8" cut
3) lower the outfeed table 1/16-1/8"
4) edge joint the wood about 3-4 inches and stop the machine
5) unplug the machine :D
6) raise the outfeed table until it touches the wood you just cut.
7) for giggles you can move the fence just to make sure that the knives are level as well with feeler guages.

This has worked for me and others as well. :)

-Michael

[Joe Bourbois]

Shooooot! And I thought the fix was going to be a new DJ-20. :p

Don't forget there's more than one way to fix the problem!

[Jason Tuinstra]

Thanks everyone for the advice. I went home for lunch and tried messn' around with the jointer for a bit. It seems that most of the problems have been tweaked away with the gib screws. The problem is that with short pieces (12" or so long) the joint looks acceptable. With long pieces (36" or so long) there seems to be a convex now. I guess there's more tweaking in my future :mad:

Thanks again for all the help.