Trapped in jointer knife hell...

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Forum topic by Don Stephenson posted 03-24-2017 05:06 AM 1003 views 1 time favorited 11 replies Add to Favorites Watch
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Don Stephenson

37 posts in 630 days

03-24-2017 05:06 AM

Topic tags/keywords: jointer knives


So I recently purchased a new Shop Fox W1741W 8” jointer. I’ve spent the past week getting it put together, cleaning all that damn goop off it, getting the beds coplaner, and (attempting) to get the knives set. 2 nights in a row, I’ve been laboring over these stupid knives, and no matter what I do, I can’t get them set right! I make teeny-tiny adjustments to the set screws and when I tighten the knife down, it goes WAY out from where I had set it.

I literally want to set the stupid thing on fire.

So what do ya’ll think? Could it be faulty knives? Do I have to buy a Jointer Pal? Is this common with Shop Fox jointers? Any help would be GREATLY appreciated…

-- Don Stephenson, Ohio,

11 replies so far

View MrUnix's profile


6921 posts in 2341 days

#1 posted 03-24-2017 05:23 AM

Not sure I understand where you are having problems… according to the manual, that machine shipped with a knife setting jig:

And has jack screws to adjust the height, so they can’t drop any further than those. There may be some minimal movement when tightening the lock screws, but that can usually be compensated for pretty easily.


-- Brad in FL - In Dog I trust... everything else is questionable

View Holbs's profile


1958 posts in 2171 days

#2 posted 03-24-2017 05:29 AM

I have been getting pretty good at setting jointer knives. I have learned, any jig “roughly” sets the knives but once you start to tighten, things move. You have to learn how much a knife moves and make adjustments to expect the movement when it comes to final tightening. And, which gib/jack screws to work upon. I can do it in 2 hours with no jig where as the first time it took all day. I start 0.0030-0.0050 too high and tighten gib/jack screws enough to gently whack above each gib/jack screw then measure. You’ll find the pattern that works for your knives of which gib/jack screws to knock down

-- The Carpenter Bee is derived from the Ancient Greek word wood-cutter

View Don Stephenson's profile

Don Stephenson

37 posts in 630 days

#3 posted 03-24-2017 05:30 AM

It does come with that jig (not magnetic). The problem is with the jack screws…one tiny bit of a turn and the knife goes way up (or down), and the opposing side goes in the opposite direction. And when I think I’ve got it, I tighten down the lock nuts and it goes way off again…

-- Don Stephenson, Ohio,

View JBrow's profile


1366 posts in 1062 days

#4 posted 03-24-2017 02:23 PM

Don Stephenson,

I doubt you have a flawed cutter head. It is just the nature of the design. Because of the difficulty you describe I tended to run jointer and planer knives beyond dull. I finally upgraded to the helical cutter head on both the jointer and planer. But before doing so I had success with the “slow as she goes” method…

Once the knife is positioned where you want it, the gib bolts are tightened ever-so-slightly in the sequence prescribed in the manual. Ever-so-slightly means that you could go through 20 rounds of tightening before the knife is secured in place. Tightening very slightly would be turning the wrench by no more than 5 – 10 degrees at a time. During the first few rounds of tightening, there is a good chance that the knife, covered with a rag and while wearing a glove, can be held down tight on the jack screws. At some point there will be enough tension on the three gib bolts that as the fourth bolt is slightly tightened, the remaining three gib bolts will hold the knife in position during tightening. But since I can never tell when this occurs, continuing the “slow as she goes” method to the very end is probably best.

Before beginning to tighten the gib bolts, setting the gib bolts as tight as possible while still being able to adjust the knife up and down can make the slight-tightening method go a little better since the gib bolts will all require about the same number of turns to lock the knife in place.

I assume that any cutting and protective oil that may have coated the cutter head, the gib, and the knives has been cleaned away. I personally like to wipe away whatever oil I can with a clean rag and then wipe the part with acetone until no more dirt and oil is removed.

It looks to me like you bought a nice very jointer with plenty of power and length and width capacity. Once you get it where it can cut some wood, I am sure you will really enjoy the machine. Congratulations!

View waho6o9's profile


8406 posts in 2719 days

#5 posted 03-24-2017 02:30 PM

View eflanders's profile


310 posts in 1992 days

#6 posted 03-24-2017 03:26 PM

Examine the heads of your gib screws. Sometimes the heads are more flat than slightly domed. When the head is flat, it tends to move the blade as you describe. Putting a very slight crown to the head of the gib screw should help that issue.

View Don Stephenson's profile

Don Stephenson

37 posts in 630 days

#7 posted 03-24-2017 03:42 PM

I just told my wife how much I appreciate all the advice I get from you all here on Lumberjocks. Helps to make up for the fact that I was never someone’s apprentice! Plus I never took woodshop in high school…if I had, I might’ve found myself with a very different career path. Rather than discovering my love for woodworking at age 45.

So thanks again. I’m going to take all of this knowledge and put it to use in my shop tonight. I’ll come back and comment to let you know how it went…

-- Don Stephenson, Ohio,

View Spitfire1's profile


57 posts in 880 days

#8 posted 09-02-2017 06:54 PM

I realize I am a bit late in my response.

I found that after setting the first knife it’s best to set the remaining knives slightly below the height of the first knife with the jack screws. Then as you tighten the gib screws the knives will inevitably raise up slightly. Once you have all the knives to the same height then you can set your outfeed table to the desired height and finally the indeed table.

View EricTwice's profile


237 posts in 675 days

#9 posted 09-02-2017 07:49 PM

setting joiner knives is a simple process
I use a straight board 2in. wide x 1/2 inch thick and 18-24 in long, wrench for gibs, adjustment screwdriver, a block of wood and a small hammer.

sorry, I don’t have pictures.

Put a mark on the outfeed table parallel to the cutter head about 3 inches back from it. (ref mark 1)
put 2 marks about 3/16-1/4 inch apart on the board (ref marks 2 and 3)

Place the blade in the head and tighten the gib screws finger tight. (you want to be able to move the knife, but it should not slide around easily)
stand 1/2 board on edge aligning the marks 1 and 2.
gently turn the cutter head until the edge of the blade engages the board. If it does not adjust blade up until it does.
adjust until the board will roll back and forth and the marks are aligned where the blade releases the board, forward and backward. If the blade pulls the board beyond the marks adjust it (the blade) down.

There should be enough tension on the blade, so when the blade is too high you will need to set the wooden block across it and tap it gently with the hammer.

You will do this at both sides of the cutter head. when the blade is right tighten the gibs and check again. If it has moved try again until you get it right. then go on the the next blade

this is the simplest way I know (movement of 1/4 inch is about .003 above the outfeed table. right where it feeds nicely, with no snipe)
Blades done this way are installed parallel to the outfeed table. if an alignment problem exists between the cutter head and the outfeed table. It will not be an issue.

I hope this helps

-- nice recovery, They should pay extra for that mistake, Eric E.

View Richard Lee's profile

Richard Lee

165 posts in 917 days

#10 posted 09-03-2017 01:21 AM

eflanders has the answer, check your bolts.
The bolt heads need to be slightly rounded.
When I do mine I use my Oneway Multiguage, and when I tighten the bolts it rarely moves.

View jonah's profile


1840 posts in 3440 days

#11 posted 09-03-2017 02:48 AM

I don’t know how anyone can ever get jointer knives set if they aren’t referencing off the outfeed table. It seems like it’d be pure luck to get things right if you move the outfeed table even a millimeter after setting the knives. Every time I’ve done it, I leave the outfeed table locked down, reference off it with a dial indicator and set the knives one to two thousandths above the outfeed table, then set the infeed table for a 1/32nd inch cut.

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