Anybody have success with a "magnetic knife setting jig" for a jointer?

[Michael Yadfar]

I bought a used 6" Jet jointer some time ago, and it's the 40th anniversary addition, so it's was made sometime around the late 90s. The jointer is actually in like new shape, doesn't appear to have much use. Anyway, it came with a patented "Magnetic knife setting jig" for Jet 6" and 8" jointers. It's in my shop, but I pulled up a picture off the internet of what it looks like:
295077

On the box it says that this jig is accurate to .001". I never changed blades yet or even use the jointer, so I've never tried it. From some research, and from the Robert Vaughn (or whatever his name is) knife setting video, I heard these jigs don't work, because the blade rises when you tighten the screws. I question this though, because like I said, this is a Jet patented product (no longer produced) and claims to be accurate within .001". Anyone have experience with these?

[Jay Hart]

I use one. The blades do sometimes want to shift up. I use a feeler gauge between the outfeed table and the jig to spot this problem, then re-align the blade and carefully snug the screws again.

[Harold Burrell]

I have one like that and tried to use it on more than one occasion. Unfortunately, I had too much trouble with it, so I got one of these:
http://www.amazon.com/Oneway-2289-Multi-Gauge/dp/B0002SA98I

No comparison.

[HANK METZ]

"this is a Jet patented product (no longer produced) and claims to be accurate within .001"."

"No longer produced" is a user comment all by itself. :)

[Wade Lippman]

I never got good results with it. But to be perfectly honest, I never got good results with any method before getting segmented carbide knives.

[Michael Yadfar]

295094

This is is the specific jig

[Tom M King]

Just use a small, straight strip of hard wood. I use Boxwood, or Hard Maple about a quarter by three quarters. Put a knife in just tight enough with the end screws to hold it in place, but allow it to move with some pressure. Start with a knife just a little high, and push it down with the wooden strip. Swing the head back and forth until you can just barely feel the knife brushing the strip of wood over the end screws. Tighten and try with the feeler strip once you think it's right. Once the end screws are tightened, hit the middle screws. This goes really quickly once you get a feel for it.

A lot of instructions call for setting the blades a few thousandths high, so you get more wear between sharpenings. To me, that's what an adjustable outfeed table is for.

Once you do this a few times, it goes so quickly that it's no issue at all. I'll take the blades out, and either sharpen them, or swap them when starting on a new job.

I have one of those magnet things somewhere, but haven't used it since the first time some decades ago.

[Jim Andrew]

Powermatic used to sell a jig similar to the one Harold linked to. It did not have a dial indicator on it, just a lever with a small dial, but it sat on the outfeed table, and you just used an allen wrench to move the blade up or down, and tightened the set screws. Setting blades on the old Powermatic jointers with that gauge was a breeze.

[Tom M King]

I have that Powermatic dial indicator too. It taught me the trick to using a strip of wood. You still have to swing the head back and forth to find top dead center. It's faster to do it by feel only, than to use the dial, and the wood won't leave a dull spot on a blade. The strip of wood also is what you need to push the blade in, right there in place. I took the jack screws out of all my jointer heads. They were a good indicator if you put the same blade back in the same spot, but when changing to new blades, they were just an extra bother.

[Judson Green]

+1 to what Tom said.

I was using the strip off wood method, but thought I oughta go high-tech so did the dial thing - very frustrating - went back to the wood strip... Peach's n cake. And this was for a 16" jointer.

[Mel Fulks]

I've found the magnet jigs for planers and jointer work best if gibs and knives are both cleaned and then coated with oil.
Then I can adjust a gib bolt on each end to where knife will move but not have any rocking. I like to make a reusable jig
to freeze head at TDC. Piece of tape on magnet prevents any damage to knives. Leaving the knives a bit too high is often
reccommended but makes the jointer cut a convex rather than straight edge. Many of us pick and choose knife setting tips
until finding a combination we like. If the mfg of magnet jigs didn't overstate ease of use ...nobody would buy them.

[Michael Yadfar]

I guess the strip of wood eliminates the need for a dial indicator... If I really need one Ill buy it, but even the cheap ones aren't cheap. The "cheap imported" one that Robert Vaughn uses he said he got for $25, and I looked up that exact one and now it's around $100 with the base. I believe the video was made in 1984, so I guess that's inflation

[John Donhowe]

Wood Whisperer did a review of several knife setting jigs a while back. I've had good results with a dial indicator with a jig like this: http://www.woodmagazine.com/woodworking-plans/jointing-and-planing/jointer-knife-adjustment-jig/ BTW, I've found a great source for rare earth magnets are worn out Sonicare toothbrush heads.

[Myk Rian]

I've used those jigs, glass with magnets, dial indicator, but the only way I have success is with a ruler.
I adjust the knives to move the ruler 1/8", call it a day, and adjust the out-feed table up a tad.

[Tom M King]

With the strip of wood, as you swing the head back and forth, you can see where the TDC is as it lifts the strip off the outfeed table. Use the wood to push it down to level at TDC until a rock of the cutter head allows you to feel the knife brush the wood without lifting the strip, tighten the end screw it's over just enough to hold it in place, but still allow the other end to move as you did the first end. A lot of this is feel, but it comes very quickly. I keep the wrench in my right hand, which also moves the cutterhead. I'll bet money I can set a knife in 15 seconds without getting in a hurry.

[Mel Fulks]

Lot of times when changing knives in a commercial shop you see a knife that was lower than the others and still sharp.
If you understand when it is necessary to adjust out feed table and how to do it ,you can get good result even if all knives
were not installed exactly the same height. But we have also had a number of threads about table adjustment, and that is
harder to do on the newer "stick shift" machines than on the machines with adjustment wheels which can easily be calibrated to move the table up or down exactly a thousandth. I don't like the stick types which have stops to limit table
movement and are more finicky ;that's why on those I favor a method which stands a chance of simplifying or eliminating
table adjustment.

[Bob Vaughan]

The activity of setting jointer knives to a datum line is pretty much the same regardless of what device one uses to observe the results. A dial indicator will tell the observer where the knives are set in the most graphic manner available.. I used the stick method with my first jointer years back and was satisfied because I didn't know any better. Close was good enough to get the edge I wanted. When I first tried a dial indicator, I observed exactly how much variation there was in the position of the knives relative to the outfeed table.

Over the years, I've come to realize that its the hands that do the work, not the eyes. Practice with ANY method is the key. Doing jointer knives the first time is daunting on a much higher level than setting the blade on a hand plane, that's for sure, but the activity is just as necessary on one and it is on the other. Try. No matter how badly the knives get set, they are still likely to work.

A couple of weeks ago I swapped knives in four 6" jointers, one 8" jointer, two 18" planers, one 22" planer, and one 20" planer between the hours of 10:30AM to 4:30PM in three different schools. Practice and familiarity with your tools is the only way to achieve proficiency. We all started somewhere. The big point is to start. Don't let fear of failure keep you from that.

[Kent A Bathurst]

I have one like that and tried to use it on more than one occasion. Unfortunately, I had too much trouble with it, so I got one of these:
http://www.amazon.com/Oneway-2289-Multi-Gauge/dp/B0002SA98I

No comparison.

Dead-nuts. The mag jig is better than nothing, but not better than other options.

The Oneway is one of two "Most Valuable Tools That You Very Rarely Use" that I own.

The other is a Starrett 48" straight edge.

They nearly always come out of their shop-made cases as a set. Then disappear again for months.

[glenn bradley]

When I had knives I used a shop made version using glass and rare earth magnets; worked beautifully.

[Matt Day]

I picked up a Oneway multitool recently and it is sweet. Setting the fence at a 90 is a breeze with it, and I almost look forward to changing knives next time I need it!
Solid, heavy, accurately machined, cast iron.

[Chris Parks]

The blades won't move if the end of the screws that contact them are machined flat. If there is a high spot on the screw end it will contact the blade first and drag it when the screw is turned. If the screw end was machined slight concave it would most probably be even better.

[lowell holmes]

I have a magnetic jig. It was a total waste of money for me. I use the strip of wood on my 6" Jet .

[Matthew Hills]

Stick works great for my 6" jointer. (I also have a OneWay that I've used for checking evenness; but the stick method works just as well)

For planer blades, I pretty much follow Bob's methods with a small dial indicator and the homemade bases.

Matt

[Tony Leonard]

I've used that jig for many years. It works well for me. I use it to get the knives set consistently, then adjust the outfeed using the ruler (1/8 travel) technique. I also check my setting with a dial indicator. It isn't a trivial task. Takes a little technique and patience. My knives move all around when tightening, so I have to allow for that. I also learned to hold the jig down with a finger or two.

Tony