Jointer Knives - a most frustrating experience

[Larry Fox]

I recently bought a Jet 6" jointer to support a cabinet project I am going to do over the winter. Jointer is in great shape, the acquisition process went very well and I got tons of good general ww-ing tidbits from the seller but it needed to have the knives changed. To say that my experience with jointers is limited would be an understatement. This inexperience combined with various posts I have read about changing the knives led me to approach this task with some degree of trepidation. WOW - what a frustrating experience. I spent three hours in the shop last night hunched over it trying to get the knives alligned properly. I am using a dial-indicator with flat "foot" and magnetic base to set it. I eventually got it to the point where knives are within a deviation of .001 in height from each other and about the same across their width. However, this did not come without my uttering some words that I wouldn't want my wife or mom to hear. So, my questions are these;

1) Am I shooting for too much precision?
2) Do those magnetic jigs make it any easier?
3) Are there alternative, and less frustrating, ways to do it that someone can suggest?

Thanks for reading and sorry for the long post . . .

Larry

[Mark Singer]

The easy way is to just use a good steel straight edge or small level set on the outfeed table and slowly turn the shaft letting the knife just touch the straight edge. Tighten each side...if you have jack screws it is pretty easy. Once they are all set...run a board throgh if it snipes lower the table a little. The true test is the workpiece.

[Steven Wilson]

It sounds like you went about it the right way and you're not being too AR to get it with .001 (or 2 or 3). It is somewhat frustrating, it does take time, and you will become more proficient at it with time. I chose a Euro Combo Machine that has a quick change cutterhead (Tersa) so I don't have knife changing issues anymore ( a couple of minutes and its done)

[Gene Collison]

I use a Jointer Pal magnetic jig. Woodcraft sells them, Grizzly too and probably others. Easy, fast and accurate, greatly simplifies the somewhat tedious proceedure.

Gene

[Mac McAtee]

The first board you run through that jointer will knock .003 to .005 off the sharp cutting edge of your knives. Worrying about .001 is pointless.

[Dave Richards]

Sounds to me like you're doing alright. It is a slow process and most of us have been through the same thing.

My brother takes the knives out head and all and runs them over to a guy he knows who will sharpen and hone the knives in situ. That ensures they are all at the same height and the time spent getting the head out and back in doesn't seem to be anymore than setting the knives the way I do it.

I haven't tried that because I don't know anyone who will sharpen them like that and I don't want to wait to ship the head to the guy my brother deals with.

[Brian Hale]

I'm happy to get .002 - .003 when i set mine, any less and i'd have a bunch of other things in the shop to fix. :rolleyes: Listen to what Mac said. Run a couple boards through and recheck your measurements, you'll be surprised.

Save your money, the steel straight edge method works fine.

Brian :)

[Timo Christ]

The present issue of FWW has a jig pictured in the famed jointer review...
It is basically a board with three magnets glued to the edge, you put it on the outfeed table with one magnet hanging over the knife.
It sounds simple and workable.. The table would have to be lowered a bit after setting the knifes this way, i think, but otherwise the method seems fine. Anyone try?
Regards,
Timo

[Floyd Cantrell]

The 6 inch Jet Jointer has jack screws to set the knifes. If you don't touch the screws the knifes are generally set about right when you change the knifes. It also helps if you have a sliding base rather than a magnetic base. You want to find the top dead center on the rotation of the head. I used a surface gage and dial test indicator as pictured. You can do the same with solid block of wood with a dial indicator, lots of pictures on the web. See link for wooden indicator jointer fixture.

http://home.pacbell.net/jdismuk/jointerjig.html

[Bruce Page]

A universal surface gage and a test indicator are two of the handiest tools a woodworker (or machinist) can have for setting tools.

[Randy Denby]

I have looked far a wide for a dial indicator ,or tips ,with a flat foot . Only one I've seen is in Woodcraft, but you have to buy their metal jig for a total of $70. Anyone have a link or know where I can find these flat tips for an indicator? Thanks in advance

[Floyd Cantrell]

Randy

McMaster Carr has an assortment of flat tips for indicator, the one pictured they have from 1/4 to 1 inch, see page 2089 of link
http://www.mcmaster.com/


http://www.mcmaster.com/catalog/111/gfx/large/20625ap5l.gif (javascript:chgimg(30);)

[Dennis Peacock]

Gee whiz fellers.......

Why not just glue 3 rare earth magnets to the endge of a nice straight board and let the REM hold the know as close to dead even with the OFT as humanly possible. Then just tighten the jib screws. :D

*-------------------------*
|//////////////////////////////|
*-------------------------*
  M-----------M-----------M

M = where each magnet goes. The one on the far right end is the one that gets set over the knife. Make two of these about about $2 and use one for each end of the knife.

Saves me about 2 hours of knife changing on my 12"er. :D

There's an article in Wood or FWW that shows this.