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Changing jointer blades

Some things, I'm either too dumb to understand.
Or too smart to need help. :eek: That's not likely.
When mine needed changing I (unplugged first) just took out old and put in new.
All is well. Wats the deal? Did I get lucky?
 
That is what I was thinking Frank. I know a lot of folks work on setting with dial indicators and such. That is why I was asking, if it was such a big deal to just swap the dang things out. I understand some folks are making aerospace parts with their woodworking tools.
 
Frank Fusco said:
Some things, I'm either too dumb to understand.
Or too smart to need help. :eek: That's not likely.
When mine needed changing I (unplugged first) just took out old and put in new.
All is well. Wats the deal? Did I get lucky?
Click to expand...

By most accounts you were very lucky or have indexed knives. After sharpening, knives can be different sized to a degree that disallows a good result when jointing. The Bob Vaughn video is great. Even if you don't use his method, he gives you a deep look into just why some folks may have one or another issue during the process. Like Don, I used a piece of glass with magnets on the surface opposite the knives. The magnets hold the knives up and the glass prevents them climbing any higher as the tightening is done. Eeezee-peezee.
 
The only place I use a dial indicator is setting up joiner and planer blades. Let's say you have a 3 blade head and it's an older one where you actually have to set the blade height. I assume some of the new ones have a way around this, mine don't. I just drop in the blades and tighten them up I have going to have mess. If you have a three blade head and you don't get them all the same height your going to have one blade doing all the work. It only has to be a couple of thousandths of inch higher than the others to be the only one cutting.

More likely they are going to be slightly crocked and the first one will cutting the left side of the board, the next is a little low and it's not doing anything, then the third one is just cutting on the right side of the board and you are not getting a flat board. All three blades are not doing the work so why have a 3 blade head??

Is a dial indicator the only way? Or course not, there are other methods that I am sure work close enough. This is the one place I prefer to know 100% where they are so I don't have to wonder if my problem is blades or something else. Once you get past the small learning curve it's pretty quick and painless.

And no, I do not line up my table saw with a dial indicator, I have never put in on the blade to check it's run out. I use a combination square to line up my fence to the bade. Then I look at the quality of the cut and if it OK then I run with it. Multi-bladed heads however need something with some accuracy to set then up right. You may get one like mine to work by eyeballing it, but you not going to get really good results like you should.
 
Steve,
If, by "hockey sticks" you mean that you're getting snipe on the ends, then your problem is misaligned tables, not the blades. It's usually caused by the outfeed table being too low.

If you do need blades, you might wanna check into the Esta Dispozablades. You put them into a holder, and just drop them into the head and tighten the gibs. Knife changes take less than ten minutes. Kinda pricey for for the initial setup, but after that the replacement blades (two sided) cost about the same as getting them sharpened. Right now, they have a 'special' going on thru the Wood Central forums. Mention Wood Central and you'll get an extra set of knives with your order. Overall, thet's the equivalent of four sharpenings.

BTW, I have the Estas in my jointer, and also in my 15" planer. Love 'em!
 
What is was doing was making a V shape, for lack of a better words. Almost dead center of the piece. A 48" piece would be around 1/4" high in the middle. When I looked at the blades the part I normally use, up by the fence was pretty rough. I moved the fence out and the problem went away. I can't really figure out what else it would be, as the thing never moves. I don't even adjust the cut depth.
 
I use a magnet setup too. Got a dial indicator left over from my previous life as a Tool & Die Maker, but don't use it much. You can wear yourself out getting too accurate. Sorta like using 15,000 grit abrasive for sharpening. Overkill.......that's a good description.
 
Here's my shop made knife setting apparatus. It's obvious that this is an extremely high tech device.:D I used some 1" mdf scrap, 4 rare earth mags, and two 3/8 12" pieces of aluminum rod. I have some other mags that weren't as strong as the rare earth's on the opposite side that was a failed attempt. I switched to the rare earths and it worked great.

jointer jig 024.jpg

The way it works is I found top dead center for the jointer knives and scratched a line that corresponds to that on the fence. It's hard to see in the picture but it's there.

jointer jig 025.jpg

I then drew a line that corresponds to the center of the magnets and I align it with the line on the fence. The mags in the first pic aren't the rare earth mags, they are from my first attempt. The second shows the rare earths.

jointer jig 026.jpgjointer jig 022.jpg

Here's how it works. I stick the jig on the outfeed side of the jointer and align the mark on the jig with the mark on the fence. The rods keep both of the mdf pieces aligned. I spread the jig apart so that I can have access to the jib screws. With the screws loose and the knives in place, I rotate the cutter head slowly. When the knives get close enough to the magnets they will pull them up to them. When this happens I know they are at top dead center. I then tighten the jib screws. My jointer is a three knife head and it takes about 10 min. to replace a three knives. Here's a profile shot of the jig.

jointer jig 023.jpg
 
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