Jointer knives - jack screws or springs?

[Doug Donnell]

I just completed setting up my GO586. Nice machine for the money, other than some frustrations with set up the experience has been positive. I got some great advice in the Workshops forum on wiring my 240v circuit, thanks again. I may do a mini review of the experience, but enough folks have reviewed their 586 that another would probably be redundant, and my experience with the machine type is limited.

This is my first jointer, so I have a question for the experienced among you. This model cutter head has the 4 knife set up, with the option of using either jack screws for height setting, or springs.

Is there any broad agreement on which is to be preferred, for a newbie and then later for a user with more experience. If there is I want to short cut right to it.

Of course this could fall into the same category as "taste great/less filling," "Ginger or Mary Ann," "9mm or 45," you get the idea! So your opinions will be appreciated.

Thanks!

Doug

[Dave Gaul]

I will define "experienced" as anyone who has set joiner knives with springs!!!

Jack screws all the way IMHO!!!

After setting my joiner which has springs, and somehow loosing one of the springs, it became very obvious to me that jack screws would have made this process much simpler!!

[Rod Sheridan]

In order of desirability;

1) Tersa or similar quick set knives (no adjustment required, one minute per knife)

2) Jack screws

3) Springs

Regards, Rod.

[Frank Drew]

My 12" Northfield jointer had neither springs nor jackscrews, and setting knives was a total PITA, with lots of time-consuming adjustments and re-adjustments.

In my very first woodworking job, at an architectural millwork shop, our planer cutterhead had springs under the knives and setting new knives, with the accessory jig holding the knives at the right height against the tension of the springs, was easy peasy and repeatably accurate. What's not to like?

I've also used cutterheads with jackscrews and liked that method fine, too.

[Steve Bigelow]

Definitely jack screws all the way! I also use a cheap dial indicator from Harbor Freight ($10 on sale), rigged up on a solid, "flat" chunk of hardwood.

The Wood Whisperer just had a good video on this. See
http://www.youtube.com/watch?v=gO746cuRqV4


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[Walter Plummer]

In the shops where I have worked almost all have been springs. Using the supplied jig or even a piece of acrylic you can get an acceptable and painless knife change. A head with jackscrews can be finicky also. You will get comfortable with either and hopefully wont have to change knives much, but I like the springs.

[george wilson]

If you will invest in Dispoz-A- Blade,which Grizzly also sells,you will have 15 minute knife changes. The cost per edge of the double edged knives that come with it is less than sending them out for sharpening. Plus,after some sharpenings,regular style knives get too narrow,and have to be replaced. Plus,there are some BAD sharpening services out there to take off WAY too much metal per sharpening,or not get them sharp enough.

So,give a good thought to biting the bullet and getting the first set of blade holders and blades. You just set the blades flat into the bottoms of your blade grooves,and tighten the gibs. Even thickness planers become very easy,taking about 15 minutes also.

The system is German made,and the knives are VERY sharp. You can get HSS or cobalt,which costs more ,but lasts longer.

[Myk Rian]

Since the question was about springs, or jack screws, and not what knives to buy, I'll say it depends on what method you use to adjust them.

If you use a glass plate with magnets, springs.
If you use a jig, indicator, etc., jack screws.
I've had both types, and prefer a ruler with either one.

[tyler mckenzie]

my poitras 12" jointer uses jack screws, changing knifes without them would be a pita.

[george wilson]

I used an old Delta at work till 2009,when I bought a new Grizzly,because of wear on the Delta's table. The old Delta had nothing at all,no springs,no jack screws. It was a lot of trouble setting knives.

One day I noticed that there were 2 holes drilled in each knife slot.One at each end. I drilled them larger,and found some springs smaller than ballpoint pen springs to put into the holes,to hold the blades up. Then,I THINK,I found that there was about a 1/4" hole drilled in the side of the cutterhead behind the knife slots. They must have been to index the cutterhead during manufacture. I drilled a 1/4" hole in the cast iron body of the jointer. The holes between the head and the body were only about 2" apart. Then,I made a big "staple" to insert in turn in each hole behind the knife grooves,which held each blade at just about top dead center. I made a fork of hardwood to bear down on each knife as the gib screws were carefully tightened. This made each knife come out at the same height.

It made blade changing much easier. After a time,I bought the Dispoz-A-Blade knives for both jointer and planer,and all was VERY easy from then on.

It was so easy that when we were running 700 bd.ft. of yellow pine shelving,we just changed the blades whenever scratches began to appear. The shelving was so smooth that no sanding was needed. It wasn't to be highly varnished anyway.

[Dave Cav]

In order of desirability;

1) Tersa or similar quick set knives (no adjustment required, one minute per knife)

2) Jack screws

3) Springs

Regards, Rod.

I would put as #1 Helical Head......
(but that's a whole 'nother thread.)

FWIW, my planer and jointer at home are helical. The PM jointer at school is jackscrew; the Delta planer is springs. They both have their plusses and minuses.

[Tony Strupulis]

1. Mary Ann.
2. Jack screws. If you are lowering the jack screw/knife, be sure to push the knife down with a block of wood before you take a measurement.

[Chip Lindley]

+1 on Mary Ann over Ginger any day!

Having used two older Delta/Milwaukee/Rockwell 6" jointers for far too many years without any kind of adjustment, springs would be a big advantage. But, springs are *iffy* in knife-setting and not dead accurate, unless one is really lucky on a good day, and can hold their mouth just right while tightening the jib bolts.

Moving up to a Delta DJ20 8" jointer and ShopFox 20" planer with jackscrews made life wonderful! Amen to jackscrews! A cheap dial indicator held in a magnetic fixture will make short order of replacing a set of dull knives. Also, nicked knives are very easily shifted. Everything stays in register.

Tersa or Dispoz-a-blades are great for time-conscious shops where down time costs money! But, you pay for that time saving. I prefer to sharpen my own knives and have a fresh set ready to insert when needed. It doesn't happen that often in a home shop, except after a big job, or after some mishap.

[Chris Parks]

I can only comment on my jointer, it has springs that load the blade against a jig that sets the blade at the same height across the drum. The springs are fairly strong and the blade does not move at all and the whole thing takes about two minutes flat to replace the blades. I cannot imagine anything being simpler but I can imagine why blades move when the gib bolts are tightened. Pull them out and machine the end of them perfectly flat and it should not happen as the bolt cannot then try and rotate the blade, the end surface won't allow this to happen any longer.

[Paul Ryan]

I own a jet jointer that uses jack screws. And a powermatic planer that uses springs. Now I am not comparing apples to apples, but pretty close. It really depends what is easier. If you are sliding knives to compensate for a nick, then jack screws are easier. But if you are replacing sharpened knives and have the jig supplied for setting knives then springs are better. If you dont have the jig don't mess with the springs. I can set the knives on my planer in about 5 minutes with the jig supplied. My jointer with a straight edge or dial indicator it takes a little longer with either about 7-10 minutes. Since the planer knives are longer 15" that is significant time savings compared to 6" jointer knives. But apparently the guy I bought the planer from must of had a hell of a time using the jig or setting the knives. He sold the planer so cheap because he couldn't get it to plane decent. I got it home turned out he had the knives adjusted above the infeed and outfeed rollers. Took me a few minutes to learn how to use the jig and set the knives. I love that machine.

[Jim Becker]

I'm very much with Rod on this....Tersa/other quick change, jack screws, springs in that order.

[Chris Parks]

Very interesting, I wonder if all those who replied bar one or two have actually used both methods, I can't see how that would be possible. My observation is that jack screws create all sorts of problems and numerous attempts and jigs to make the use of them easier. In this thread we have advice which seems contrary to that, strange to say the least. I am confused now along with the OP I would guess. I have used screws in a thicknesser and they are a pain unless the ends are machined, I have a spring set up in my jointer and the factory jig it came with and it could not be easier so that is my experience. As I said I am totally confused myself now as to what is the best method and why due to what seems to be contrary advice.

[Paul Ryan]

I have a spring set up in my jointer and the factory jig it came with and it could not be easier so that is my experience.

Chris,


I completly agree with you. As a rookie setting with jack screws can be frustrating to say the least. On a jointer I think they would be a lot more user friendly compared to a planer. The reson being you dont have to work inside the unit above the bed below the head. But on a jointer that isn't the case. It has taken me about 1/2 dozen times to get a good method down setting mine on the jointer with a straight edge. That is my prefered method. But I agree I think the spring setting with a factory jig is very simple. If you dont have the jig it would be difficult though. I suspect many that commented on the springs being difficult did not have the factory jig available.

[Curt Harms]

parallel to the cutterhead, but for benchtop planers, I had good luck with planer pals. (http://www.amazon.com/Woodstock-W1226-Mini-Planer-Pal-Pair/dp/B0000DD1VL)

[Frank Drew]

I have no idea what everyone's experience has been, but, yeah, if you haven't used the different systems, or if you don't have the knife-setting jig (or if you've lost one of the springs, as one poster indicated), that's really not a very fair test of springs vs. jackscrews.