setting jointer knives

[welldigger]

I'm getting ready to do the dreaded knife changing on my jointer. I have read that the knives need to be the same height as the outfeed table and I have also read that they need to be lower than the outfeed table. Which is best? Also do both ends of the knives need to be exactly the same distance from the outffed table, or is a thou or so difference acceptable? Thanks in advance for your help.

Welldigger

 

[walnutjerry]

I'm getting ready to do the dreaded knife changing on my jointer. I have read that the knives need to be the same height as the outfeed table and I have also read that they need to be lower than the outfeed table. Which is best? Also do both ends of the knives need to be exactly the same distance from the outffed table, or is a thou or so difference acceptable? Thanks in advance for your help.

Welldigger

The jointer knives should be on the same plane as the outfeed table at both ends of the blade. The outfeed table must be parallel to the infeed table. If they are lower the stock will hit the edge of the outfeed as you try to pass over it. If you lift the stock up to ride the outfeed you will not get a straight edge ----------defeating the purpose of a jointer.

Jerry

 

[jmauldin]

Yes, the top dead center of the knives must be level with the outfeed table. Also, both ends of the blades must be the same, else you will joint a bevel. I just finished changing the blades on my jointer. Really wanted to replace the cutter head with the spiral cutter head, but couldn't justify (or afford) the price. It took about an hour to change all three blades.
Jim in Mayberry

 

[cpowell]

Don't sweat it too much. It's not as hard as it sounds.

I tried a few different techniques and have settled on a technique using a dimensioned stick of wood to align. I type too slowly to provide the details but the technique is described in detail on woodnet.net. Here's a link http://www.forums.woodnet.net/ubbth...mber=3235708&page=&view=&sb=5&o=&fpart=1&vc=1 jgrout describes the technique. I promise it works and is easy.

Using the "stick" alignment technique will guarantee the blades will be parallel with the top and the SAME height above the top. However, all blades will be too high. Simply move the outfeed table upward once you're done leveling.

Edge joint a board and check the jointed edge against a flat surface (like the outfeed table). Make very small adjustments in outfeed table height until the jointed surface is perfect. My experience has shown the blades need to be +/- a sheet of paper higher than the outfeed table surface. I have adjusted the blades perfectly even with the top and it just doesn't work for me.

BTW the first time I did this I started with the outfeed table at the top of its adjustment range. When I'd gotten the blades set I needed to move the table up slightly...and couldn't. :BangHead: I make sure to give myself a little adjustment room now.


Chuck

 

[DavidF]

I also aim to set the knives a hair higher than the outfeed - 1 to 2 thou

 

[woodArtz]

I used the little magnetic knife setter do-hickey to set mine recently. It sets the knives about where David indicated, a tad higher than the outfeed. I wondered if that was ok.

 

[walnutjerry]

I used the little magnetic knife setter do-hickey to set mine recently. It sets the knives about where David indicated, a tad higher than the outfeed. I wondered if that was ok.

It has been my experience to get a snipe at the end of the cut if the blades are higher than the outfeed table. Am I reading that you guys setting the knives high leave them that way? Or do you adjust the outfeed to match?:eusa_thin:eusa_doh::-?

Jerry

 

[tom hintz]

I've tried all sorts of methods for setting Jointer knives and finally got a MultiGauge (Oneway) and could set them dead flush with the outfeed table in minutes. I sometimes set the knives for fun, or just to check. See the link below for a story on the process and other things about the jointer.

http://www.newwoodworker.com/basic/usejntr.html

 

[DavidF]

It has been my experience to get a snipe at the end of the cut if the blades are higher than the outfeed table. Am I reading that you guys setting the knives high leave them that way? Or do you adjust the outfeed to match?:eusa_thin:eusa_doh::-?

Jerry

My experience has been that if the blades are a thou too low then the wood being jointed will hit the outfeed and that's a show stopper. A thou too high makes no discernable difference to the snipe and prevents the board hitting. If you are getting noticeable snipe then the blades are usually in the 5 -10 thou region above the outfeed.

 

[Bas]

I sometimes set the knives for fun

Are you out of your !@!@#!@ mind? :slap:. I'd rather clean glue clamps all day. We're talking baked on gorilla glue here! I don't care what kind of gauge you have, some things are just not meant to be classified as fun :eyeslam:

[banana]BWAHAWAAAGGH[/banana]

-) sorry, I spent several hours last weekend and it's still not properly aligned....)

 

[walnutjerry]

My experience has been that if the blades are a thou too low then the wood being jointed will hit the outfeed and that's a show stopper. A thou too high makes no discernable difference to the snipe and prevents the board hitting. If you are getting noticeable snipe then the blades are usually in the 5 -10 thou region above the outfeed.

OK----------I understand what you are saying now. I have a habit of expecting perfection in set ups, don't always get that but strive for it. I am in agreement it is better to have knives a thou high than low----my preference is to have them dead on the same plane though.

Different strokes for different folks!!:rolf:

Jerry

 

[Bernhard]

I also aim to set the knives a hair higher than the outfeed - 1 to 2 thou

Amen! I set mine the same way: 1/1000 to 2/1000 higher than the outfeed table. I use a Oneway block with a dial indicator to set the knives. It is tedious, but not too bad.

Good luck!
Bernhard