Best way to tighten jointer gib screws?

[Jim Kirkpatrick]

I always hate having to change out my jointer knives. I have a Grizzly 8" (G0586). Before that I had a 6" Delta. Problem is, after I have the blade all nice and aligned, no matter how careful I am when I retighten the gib srews the blade always raises up a few .00. It's easy to set up the knives with the outfeed table using an "a-line it" jig (http://www.in-lineindustries.com/a-line-it.html) and the jointer's jack screws.
Just wondering if there are any jointer gurus here that can enlighten me with their knowledge and techniques.

[Myk Rian]

You aren't alone. I just keep at it till I get them right. It can be a PITA at times.

[Peter Aeschliman]

With you too. I hate it, but it's the way it is unless you get a nicer machine with quick setting knives, or one with a spiral cutter head.

I typically go online and start looking at new jointers and planers with one of those features around the time I need a knife change. Then I look at the price tag and realize setting knives ain't so bad!

Kind of therapeutic, actually!!

[Eddie Darby]

Have a piece of wood with the end-grain exposed, like in a dowel, and a hammer to tap the blades down.
When you start to just tighten your gib screws a little, just set a dial gauge on the knives, and tap the knives until they back off the right amount. Then tighten a little more, and check your dial gauge readings again. Soon you will be snug and all will be aligned.
I have Jack Screws on mine, and spent a bit of time gettig them just right, and so tapping the knives down causes them to bottom out on top of the Jack screws, and it's a little easier this way.

[Jim Kirkpatrick]

That's a great tip Eddie, and it makes sense....thanks!

[Peter Aeschliman]

That is a good idea.

It must not cause any damage to your new knives, or I doubt you'd do it. But that would be my main concern.

I wonder if it would help to spray everything with some WD-40 before installation, so that when you tighten down the jib screws, the knives will stay put a little better... meaning that the surfaces being compressed together (the knives and the cutterhead components) will not stick to each other as much as you tighten down. That might also makethe dowel/tapping technique easier.

I might try that next time.

[Jason White]

Be sure to take the "slop" out of the jib screws right before setting your knives to TDC.

What I mean by that is... Once you have the new blades in, get the jib screws just barely finger tight (don't use a wrench). Then adjust the knives TDC to the outfeed table with the allen wrench and jack screws. Then do your final tightening of the gib screws.

In my experience -- with the slop in the jib screws gone before adjusting the knives, they're less likely to move on you when you tighten down the jib screws.

Hardly a perfect science and I'm no expert, but it seems to work for me.

Jason



I always hate having to change out my jointer knives. I have a Grizzly 8" (G0586). Before that I had a 6" Delta. Problem is, after I have the blade all nice and aligned, no matter how careful I am when I retighten the gib srews the blade always raises up a few .00. It's easy to set up the knives with the outfeed table using an "a-line it" jig (http://www.in-lineindustries.com/a-line-it.html) and the jointer's jack screws.
Just wondering if there are any jointer gurus here that can enlighten me with their knowledge and techniques.

[Joe Kieve]

Peter,
The block of end grain wood works great and will not harm jointer knives. Been doing it for years. As for coating everything with WD 40, I don't have a good reason for not doing that but I personally would not. Seems to me that you might get some slippage of the knives or gib screws. That's just my 2 cents.

joe

[Jim Kirkpatrick]

Tried Eddie's tip last night to no avail. While we're on the subject, what's an acceptable tolerance? .05?
I'm going to try Jason's tip tonite perhaps in conjunction with Eddie's. BTW, this jointer has 4 knives not 3. Sounded good when I bought it.

[Tom Esh]

Been there - yet another reason I changed out the head for a Shelix. However before that, I found that the bolt tightening sequence can make a big difference. Contrary to what the manual instructed I tightened the bolts that caused the most creep last. Still took some time to find the right sequence but I got there eventually.

[Eddie Darby]

Tried Eddie's tip last night to no avail. While we're on the subject, what's an acceptable tolerance? .05?
I'm going to try Jason's tip tonite perhaps in conjunction with Eddie's. BTW, this jointer has 4 knives not 3. Sounded good when I bought it.

This video might help. It sure helped me!

"Jointer Knife Setting with Bob Vaughan"

http://video.google.com/videoplay?docid=2983839096587014177#

Also it helps if your gibs have been lapped smooth, and blow out/clean the area to avoid small debris from making things difficult. It, debris, compresses and throws measuring out the window.
If you also measure while you are tightening, you can adjust the height by using extra pressure by varying the degree of tightness. As long as the screws are all holding.

I set my 3 knife head all to within 0.001" with a dial indicator and a holder that has a fine adjust.

[John Nesmith]

I have tried all sorts of methods, and am constantly frustrated. The last time I changed my knives, I used the approach shown in this video. For me, it was by far the easiest and quickest method, and the jigs are pretty inexpensive to make.

http://www.finewoodworking.com/ToolGuide/ToolGuideArticle.aspx?id=5294

[Pete Bradley]

+1 for holding them down with the end grain of a block of hardwood. It takes more than light pressure.

Pete

[Rick Lizek]

Have a piece of wood with the end-grain exposed, like in a dowel, and a hammer to tap the blades down.
When you start to just tighten your gib screws a little, just set a dial gauge on the knives, and tap the knives until they back off the right amount. Then tighten a little more, and check your dial gauge readings again. Soon you will be snug and all will be aligned.
I have Jack Screws on mine, and spent a bit of time gettig them just right, and so tapping the knives down causes them to bottom out on top of the Jack screws, and it's a little easier this way.

You've got the right idea. Slight tension on the first and last gib screw to keep the knife in place works well. When I tighten them down they stay in place. That's the key that so few folks know about.

I have been tuning and repairing machines for 25 years and change jointer knives 1 to 10 times a week. I always work the knives down with by tapping them down with a hardwood block. I stopped using jack screws years ago when I did my first Crescent jointer which had no jack screws. Do not use the magnet on a magnetic base. You need to be able to move the indicator around quickly. A block of hardwood is even better. My indicator tip is a 1/2" button type and with this method I can set a 4 knife 20" jointer head in a leisurely 20 minutes and get the knives within .0005" which is a bit more finicky than need be. Don't forget, in a few hours of use the knives get beat back a bit.

[Jim Kirkpatrick]

This video might help. It sure helped me!

"Jointer Knife Setting with Bob Vaughan"

http://video.google.com/videoplay?docid=2983839096587014177#

Also it helps if your gibs have been lapped smooth, and blow out/clean the area to avoid small debris from making things difficult. It, debris, compresses and throws measuring out the window.
If you also measure while you are tightening, you can adjust the height by using extra pressure by varying the degree of tightness. As long as the screws are all holding.

I set my 3 knife head all to within 0.001" with a dial indicator and a holder that has a fine adjust.

Thanks for posting that video link Eddie, this is the method I used. Using the jack screws, I set the knives 2-3 thousands below the outfeed table, tightened the gib screws a little, then tapped down with a hunk of wooden curtain rod. rechecking and tightening some more. Once I got the system down it took me almost 2 hours of very tedious work.
I got the knives +/- .01 and worked very smooth, giving the wood a burnished finish. But now, I must have nicked the blades right in the middle, there is a 5/8" ribbon of ugliness down the middle of each board. Argh! :mad::mad::eek:
I'm not going to do this again, going to research switching to a spiral head cutter if my wallet allows it.