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Jointer Blade Alignment Fixture - A Small Step

Posted: Thu Feb 07, 2013 7:26 pm
by bobgroh
After more years than I care to think about (about 5 or so), I finally used my rebuilt 4" Jointer the other day. The last remaining task I had to do was setting the height of the jointer knives and, following the excellent writeup given to me by Bill Mayo (which is close to that in SS's manual for the jointer), I succeeded adequately. Not great but ok.

Bill's adjustment process uses a straight edge balanced on the outfeed table. You adjust the knives until they just 'kiss' the straight edge. As he commented (and as I can attest) the hardest part of the job is keeping the straight edge balanced on it's edge during this process.

Well, I 'thunk' about this for awhile and came up with a simple little fixture to hold the straight edge up.
[ATTACH]20180[/ATTACH]

This is nothing more than a hunk of scrap oak - it is 6" long x 2" high x 1" thick. I cut it to size and then did two thru cuts 1-1/4" high for the straight edge. The spacing between the 2 slots (forget the other one - it was a goof on my part!) was 3-1/16 inch.
[ATTACH]20181[/ATTACH]

That spacing matches the spacing between the two adjustment screws on the jointer blade and the lock down screws.
[ATTACH]20179[/ATTACH]

I inserted a small magnet in the bottom to hold it down to the outfeed table. Works very well indeed. I have 'broken' the sharp edges, sanded it and am now in the process of giving it a quick couple coats of shellac.

Posted: Thu Feb 07, 2013 10:57 pm
by BuckeyeDennis
Brilliantly simple = simply brilliant! I had exactly the same problem, and thought that my straightedge was to blame. Next time, no problem. :)

Posted: Fri Feb 08, 2013 12:20 am
by JPG
I prefer a straight piece of wood. No worries about steel straight edge dulling the jointer blades.

Posted: Fri Feb 08, 2013 11:51 am
by bobgroh
Thank you both for the comments. John, I agree about your misgivings about using the steel ruler - I also have some qualms about that. I have some aluminum strip around and thought about trying that. But you really need to have a dead flat bar and I am just not sure that anything I can gin up (e.g. wood, aluminum, etc) is going to give you that. However that is easily checked by using the infeed or outfeed table and a strong light.

I have considered using a bit of cellophane tape to 'soften' the edge of the straight edge a bit. It will, of course, add a couple of thousands of an inch but I can balance that off with a bit of cellophane on the other end of the ruler.

I have one 'straight edge' (from a cheap combo square) which is, in fact, not very straight - being about 10 thousands or so off. When you are looking for a setting just one or two thousands - well, you really have to be careful.

Which, in a rather circular fashion, brings you around to the jig using a dial micrometer. Harbor Freight has a decent dial micrometer for $17 or so and I am going to pick one up for general alignment on the SS's and my other tools. Might get to work and build a jig using it.

But for now, my little block looks very cool (I put two coats of shellac on it and carefully sanded it so it feels very nice!) and will be a definite asset. Another instance of this all being a 'journey'!

Posted: Fri Feb 08, 2013 12:17 pm
by JPG
bobgroh wrote:Thank you both for the comments. John, I agree about your misgivings about using the steel ruler - I also have some qualms about that. I have some aluminum strip around and thought about trying that. But you really need to have a dead flat bar and I am just not sure that anything I can gin up (e.g. wood, aluminum, etc) is going to give you that. However that is easily checked by using the infeed or outfeed table and a strong light.

I have considered using a bit of cellophane tape to 'soften' the edge of the straight edge a bit. It will, of course, add a couple of thousands of an inch but I can balance that off with a bit of cellophane on the other end of the ruler.

I have one 'straight edge' (from a cheap combo square) which is, in fact, not very straight - being about 10 thousands or so off. When you are looking for a setting just one or two thousands - well, you really have to be careful.

Which, in a rather circular fashion, brings you around to the jig using a dial micrometer. Harbor Freight has a decent dial micrometer for $17 or so and I am going to pick one up for general alignment on the SS's and my other tools. Might get to work and build a jig using it.

But for now, my little block looks very cool (I put two coats of shellac on it and carefully sanded it so it feels very nice!) and will be a definite asset. Another instance of this all being a 'journey'!
Who's "John"?:confused::D

Posted: Fri Feb 08, 2013 1:43 pm
by bobgroh
JPG40504 wrote:Who's "John"?:confused::D
Old age is a bummer! 'John' is this case is you, JPG.

Posted: Fri Feb 08, 2013 2:43 pm
by JPG
bobgroh wrote:Old age is a bummer! 'John' is this case is you, JPG.
Just call me 'Red'.:)

Oh, and I am NOT a pix file either.:D

Posted: Fri Feb 08, 2013 2:54 pm
by joedw00
That is what I like KISS. :D :D :D Thanks

Posted: Tue Dec 17, 2013 3:22 pm
by JPG
Got looking at this thread after adding a link to it in another thread.

Re the tape to soften the blade against the ruler. A couple of thou would allow for some wear before needing to re adjust. It also might just compensate for wood compression.

I am sure 'opinions' will vary!:D


Bottom line is, is adjusting the blade height to 'absolutely' coincide with outfence top surface the objective.;)