setting jointer knives

[Gary Kittleson]

Hello,

I finally HAVE to put in new blades on my 6" General jointer. This will be the first time I've ever done it, and I've been putting it off out of fear...

I'd like to hear any tips you may have, including suggestions of knife holders (ie: magnetic) for making the job simpler...anything I can do to make this better...

I have a dial indicator, with a pointed tip. Other than that, just the basic tools.

Thanks,

Gary

[Kevin Post]

Welcome to the Creek, Gary!

The General jointer, I believe, has jack screws in the head that will permit you to raise and lower the knives before securing them in place. I have a 6" jointer from Jet that works like this.

I don't have a knife-setting jig. I do recall seeing one in one of the WW magazines this month (I can't remember which one) that you can make with a block of wood and some magnets. However, I don't think you need it.

I simply use a straight-edge to set each knife flush with the outfeed table. It's a finnicky process but not terribly complicated. A little patience goes a long way.

[Andrew Ault]

I use a dial indicator with a magnetic base to set the height of my jointer knives. I zero out the indicator referencing one of the old knives before removing it and then use this reference to set the height of all of the knives being installed. On my jointer, there are jack screws that I use to adjust the height of the knife before tightening it.

Another way is to use a jig with magnets to hold the knives at the right height as you tighten them. Per Swensen showed how he made his own jig in this post:

http://www.sawmillcreek.org/showthread.php?t=20579&highlight=swenson+magnets

- Andy

[Jon Farley]

I'm with Kevin. The straightedge/outfeed table method is the simplest, yet still very accurate method. Another bit of advice - wear gloves. DAMHIKT:eek: !

[William Parks]

So what does one do when the knives are adjusted as low as they can go and still are a hair above the outfeed table? I replaced the blades in my old (early 1960's vintage) Powermatic 8" jointer. Do I grind a hair off of the backside of the knives or do replace the 3/4" knives with 1/2" knives and hope I can raise them up high enough?

[Andrew Ault]

William,

Is the outfeed table not adjustable on your jointer?

-Andy

[Kevin Post]

So what does one do when the knives are adjusted as low as they can go and still are a hair above the outfeed table?

Two options... raise the outfeed table or, as you mentioned, grind a bit off the back side of the knives.

[Kevin Post]

This isn't part of this topic but... Does anyone here actually have experience sharpening the knives on their jointer using an oil stone while the jointer is running?

The Powermatic and Jet manuals detail this method of sharpening the knives with removing them from the machine. It involves adjusting the infeed and outfeed tables to the same height and flush with the knives so that the knives just barely contact a straightedge. You mount a stop-block on the infeed table to keep the stone from flying away. With the jointer running, you then move the stone across the knives, giving them a new edge.

I want someone to tell me it's ok to do this before I attempt it... :D

-Kevin

[Geoff Harris]

Hi Gary,

I also have a 6" General Jointer. I have not yet needed to replace the knives so I haven't tried this yet.

The jointer came with a knife setting jig (two Y shaped pieces of metal joined by a bar). To use it you lower the tables to expose the cutter head, place the jig on the head and raise the blades up till they touch at each end. Once all three blades have been adjusted then the tables are reset.

I understand this method only works if the cutter head is parallel to the outfeed table, mine is, but you probably want to check.

Geoff

[William Parks]

[QUOTE=Andrew Ault]William,

Is the outfeed table not adjustable on your jointer?

Andrew,

This qualifies as a duh on my part. Of course it does, and did, and now the outfeed is just above the apex of the cutting head. God I hate getting older!

Thanks,

William

[Andrew Ault]

William,

I hear ya' brother!

- Andy

[Gary Kittleson]

Ok,

So, I'm committed now.:( I removed one of the blades, so there is no putting off anymore. The General does, in fact, have the jack screws, enabling the leveling of the blade before tightening. The pain of it is the two springs, which are trying to push the blade out.

I am not sure why they are there. Should the blade not be bottomed out onto the screws? If it can be, then what is the purpose of the spring? Currently, I have the blade pushed down onto the setting screws, which are adjusted to the height I am desiring. But, the springs are puzzling me.

Any real knowledge out there, as opposed to my "figuring it out as I go"?


Gary

[Rick Schubert]

Gary, you're just about to the fun part where you have the blade adjusted with the setting screws just where you want it. (Can't help you with the springs-my Yorkie doesn't have them.)

Next step is to tighten the bolts that hold the blade in place. As you tighten them they force your blade to rise ever so slightly, pushing it out of alignment! Then you start over leaving the blade a little lower than correct alignment to allow for the rise and this time the blade doesn't rise as much leaving it out of alignment again!!

I'm new at this too, but that is what happened to me over and over. I assume it is what everyone refers to about PATIENCE being the critical element. It took me many times resetting each blade, followed by cursing as I tightened the bolts forcing the mis-alignment, followed by more cursing as I undid the bolts to start over and reminding myself to be patient.

It took many trial and errors and a number of hours before I finally got the three blades "close enough". (See quote below) :-)

I sure hope someone jumps in and tells us a better way to do it. Good luck and remember: PATIENCE

Rick

[Mike Zozakiewicz]

I have and old Craftsman 6" jointer that I am setting up for the first time. When I went to set the height on the first knife I was so careful, to then find it was too high after tightening the screws, and then when I reloosend the screws and went back to check the height and it was perfect!?! It actually took me two attempts to figure out what was going on (must be old age). I finally got it after about 1.5 hours. I think I will build the glass and rare earth magnet jig for the next time, it might help to hold the blades in place while tightening.

Good luck,

Mike

[John Gregory]

[quote=Andrew Ault]William,

Is the outfeed table not adjustable on your jointer?

Andrew,

This qualifies as a duh on my part. Of course it does, and did, and now the outfeed is just above the apex of the cutting head. God I hate getting older!

Thanks,

William

I share your pain about aging and memory. I am not sure if it is a memory problem or a "disk full" error