Replacing jointer knives

[mindpilot]

I plan to make the jig, guage, whatever we want to call it out of a fairly thick piece of plexiglass--like the piece you can buy to make your own router table. (I have "issues" with glass in my shop)

I can recess the magnets just like the wooden jig. I also thought of recessing the magnets from the top side. That would eliminate the possiblity of a burr or anything else that might ruin the accuracy of the working surface. Another set of magnets on the other end will secure the tool to the outfeed table.

On the issue of level with the outfeed table or slightly above, it seems to me that the blade should be aligned with the top of the table, otherwise there is no true point of zero reference. Has anyone experimented with both ways?

If it does work better with the blade sitting slighly proud of the table, then that could be set accurately by making a very slight saw kerf across the front of the gauge.

Frankly, I'm a little suprised that SS doesn't sell a whole kit of set-up gauges and jigs.

[Bruce]

If it does work better with the blade sitting slighly proud of the table, then that could be set accurately by making a very slight saw kerf across the front of the gauge.

As said before, if you need the knives to be "proud" a bit, shim the gauge with paper. Why introduce inaccuracy by trying to trim your gauge with a saw.

[Spike13]

Spike (one of our three traveling academy instructors) has a cool jig, and I know he lurks around this forum. Maybe we can beg him to join in. Come on, Spike. I'll send you a case of your favorite motor oil.

With all good wishes,

Hey Nick,
I will get the correct angles for the jointer knife set-up board with the (3) earth magnets. I have been getting a lot of inquiries during my academies at what the distances, length of board and the hole angles for getting to gib and tightening screws. I need to send a copy to the "Boss"!

You owe me a case...

[Spike13]

I plan to make the jig, guage, whatever we want to call it out of a fairly thick piece of plexiglass--like the piece you can buy to make your own router table. (I have "issues" with glass in my shop)

I can recess the magnets just like the wooden jig. I also thought of recessing the magnets from the top side. That would eliminate the possiblity of a burr or anything else that might ruin the accuracy of the working surface. Another set of magnets on the other end will secure the tool to the outfeed table.

On the issue of level with the outfeed table or slightly above, it seems to me that the blade should be aligned with the top of the table, otherwise there is no true point of zero reference. Has anyone experimented with both ways?

If it does work better with the blade sitting slighly proud of the table, then that could be set accurately by making a very slight saw kerf across the front of the gauge.

Frankly, I'm a little suprised that SS doesn't sell a whole kit of set-up gauges and jigs.

Mindpilot,
I have designed an alignment fixture that I will put up some measurements on the forum in the next day (per Nick's request). Blade set-up: The blade should be even with the outfeed table. Remeber, pressure is applied at the outfeed table, NOT the infeed table when jointing.

Also, 3/4" diameter earth magnets are mounted from the bottom, 1/32-1/16" counter-bored below the surface. (3) magnets are required to hold it down on the table securely when adjustments are made. I will put some numbers on up on the forum over the next 2 days for others to view/enjoy/critique. It works well as I use it on my jointer that I use for the traveling academy on the road and my personal one back at the "studio". It's better than the $70 parallel bar/block set-up that you see in catalogs.

Special CAUTION NOTE! If you have a pacemaker, NOT a wise idea to use the earth magnets!!!

[dusty]

This seems like it should be a very simple task. Anyone with just a few mechanical skills and some coordination should complete it in less than an hour.

Well, yesterday I decided that I was going to do just that. I started at about 10:00 am; that way I'll be done before lunch and then I can spend the afternoon cleaning the shop and getting ready for the next woodworking task, a shoe rack just inside the entry way. My wife makes me take off my shoes when I come in from the yard or shop. Something about tracking "it" in on the carpets.

At 4:00 pm I decided to quit and take it up in the morning. One must pay attention to detail when doing this job. The knives can go in backward, the wedges can too, and the knives must be aligned not just up and down but also from side to side. I know. I experienced it all yesterday.

Incidently, if you adjust the knives so that they "take no cut" that is so that they are exactly at the same level as the out feed table the wood tends to hang on the infeed edge of the outfeed table.

So, with a piece of plexiglass cut just a bit narrower than the table top (access to the depth adjusting screws), rare earth magnets attached to the glass, wax paper for clearance spacing and allen wrench in hand I started over.

Being real careful so as to NOT repeat any of yesterdays mistakes, I got all done in about 50 minutes. Looks good, feels good, works good. I'd be proud to let any one of you see the final results.

That is until the very end when I learned another lesson in shop equipment maintenance. Rare earth magnets and jointer bands are not mutually compatible. While cleaning up and putting things away, one of the magnets became unattached from my piece of glass and relocated itself. You guessed it, to a cutter blade.

Maybe tomorrow will be better.

[ericolson]

I haven't checked this thread in a while, so I'm playing a little bit of catch-up. It sounds like the knife setting jig you're describing works on the same principle as the Jointer Pal or similar jigs. I prefer to set my knives co-planer with the outfeed table and top-dead-center (TDC) on the cutter head. I have never had a snipe issue doing this. With my one knife at TDC, I then use a Stanley Odd Job #1 (similar to a combination square) to check my depth of cut on the infeed table. My preference is no more than a 32nd of an inch depth of cut. Once set, I lock my infeed table in place, adjust the depth of cut scale, and I'm all set.

[hfmann]

Dusty and all,

I too started making the alignment jig. I've gottten side tracked on some other non wood working projects, but wanted to post a picture my almost final design (several mistakes along the way I will post later).

3" wide double strength glass, 2 - 3/4" rare earth magnets hot glued at end of the glass. I now realize I should use magnets to also hold the glass plate in place rather than the wood block and clamp in the picture. It's important to put the alignment magnets at the very end of the glass so you can get your allen wrench into the screws.

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Once I got the system worked out, it sure made short work of getting the knives aligned.

Hal

[dusty]

Hal

You've taken exactly the same approach as I did except that you used glass.

I like your final solution better than mine because you can see the entire cutter head, the wedge locks and all five of the screw heads (per cutter head) that must be adjusted.

Earlier this week, I did this procedure but was not completely satisfied with the results so I decided to do it again.

This time, I used a piece of clear plexiglass (rather than glass), a pair of rare earth magnets (as you did) and a heavy magnet that I had in the shop to hold the plexiglass on the out feed table. I thought this worked well because I could move the whole setup around if I wanted.

I am still left with some questions regarding my procedures. I started by very carefully adjusting the outfeed table to the same height as the infeed table. I then began installing the blades and wedge locks. I expected the magnets to pull the blades up against the underside of the glass but they did not do so until I began adjusting them upward with the leveling screws. When that happened, I was then uncertain whether or not the leveling screws were high enough and I found out that they were not when I tightened the three wedge lock screws. The blade moved. I could see the gap below the plexiglass.

During the repeat procedure, after the cutter blades were against the glass, I carefully adjusted the leveling screws until they felt firm. Then I carefully snugged the wedge lock screws (center one first, then the outsides) then I went back and tested the leveling screws. No adjustment required. I then firmly secured the wedge lock screws and proceded.

The other blades were installed using the modified procedure. All went well.

If you don't knick your cutter blades during this procedure, the whole thing can be done in 30-45 minutes.

All of this having been done as described, I tested the cutter blades with a piece of wood as described in another part of this thread. Much to my surprise, the block moved about a 1/16". Same results for all three blades. Obviously, the blades were just a bit above the surface level of the outfeed table. No wax paper required.

This may have just been luck but it may also have been the result of the way I snugged the leveling screws up against the bottom of the blades (very carefully and very slowly).

If these blades last as long as the set they are replacing, we'll never know. I'll leave instructions for my grandson to post the results when he does this.

I was about to purchase a dial gauge, for this and table saw adjustments, but now I am not certain I can justify that.

Feedback Please.
___________________
Making Sawdust Safely

[hfmann]

Hey Dusty,

My first attempt at creating this device was rather frustrating. The second one worked ok, but the next version will have some refinements.

I found that the magnets just wouldn't adjust the knives once the wedge screws had been slightly tightened. I'd try letting the magnets place the knives and then I'd raise the leveling screws to just touch the bottom of the knife. Invariably I'd get the leveling screw too high and couldn't tell it from the position of the glass. By that time the wedge had sufficently locked the knive in place and I'd have to start over again. So after a dozen ineffective tries at this I rethought the process.

So I'm sure this is heresy but here's what I did.

1) Forget about the leveling screws until the end.
2) Let the magnets raise the knives level with the outfeed table.
3) Gently screw down the wedge screws.
4) Then tighten the wedge screws. This should lock the blade in place.
5) NOW raise the leveling screws to the bottom of the knives. This keeps the blades from getting pushed down from the cutting action.

When I glued down the magnets the first time, I didn't have them at the end of the glass. Consequently I couldn't get the allen wrench in place to tighten the screws. My second version has the magnets butted up to the very end, but my next version will have them haning over it a little.

I used hot glue for the magnets and let it set up about 10 minutes. Seems to work fine. I was able to recover the magnets from my first version by heating up the glue with a hair dryer.

In designing this, I wanted to make sure I placed the jig in the exact same place every time. I first visually determined where "top dead center" was on a knife.

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Then I placed the end of the glass where the magnets would be over this tdc point. Then using a square I drew a magic marker line on the glass right over the end of the outfeed table. That now becomes the line I use for placing the jig.

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Once I got this jig configurtion and technique down, it took about 15 minutes to align all the knives. Pretty darn fast.

And today, I've got the heat cranked up in garage, and I'm doing some woodworking. My first attempt at making a small box. For my chisels. And then another one to hold this jig.

Take care,
Hal

[dusty]

Hal seems to have this procedure well refined. I have followed his lead as detailed in this thread and it has been with a fair amount of success. I am very satisfied with the current status of my jointer. Thanks Hal and others who have contributed, I appreciate the feedback and the photos have helped immensely.

Once I develop some patience for this sort of work I know I will become better at doing it. It sure has been a blessing for me during this recovery time. I'm about ready (physically and mentally) to take on something bigger.

Hey - Nick, Spike were're waiting from that input.