Jointer Question

[ssmith1627]

Looked through a bunch of my woodworking magazine but couldn't quite find the answer I wanted. I thought I had something that showed the results from improper jointer setup so you could diagnose the problem and correct it.

After edge jointing a board, if I sit it on the jointer table or against the jointer fence or table saw table, I have a high spot in the middle of the board. I can continue to joint it to take out the slight bow but it doesn't go away. It's not a lot but it's there. I need to edge glue some maple boards for the table to the dresser I'm working on so I want to get this worked out.

Does this imply the outfeed and/or infeed table is sagging a bit ? Would that account for the problem ?

Basically looking for a trouble shooting type of guide. Thanks guys.

Steve

[footprintsinconc]

steve,

i am not sure how you are orienting the piece on the jointer. i believe that you need to position the wood such that it "concave down" or makes a sad face. this way, you get rid of the the ends and sooner or later, you will have removed enough material from the ends and be level with the middle, thus giving you a level edge/face.

hopefully you are doing this already.

regards,

[mashtun]

Jointer Question

I saw a section in the manual for my Delta, that covered this, but I can't really remeber the specifics, but it sounds like it may be a blade height problem.

The blades need to be level with the outfeed table.

If the balde was too high or too low i caused what you are describing. I can't remember which it is offhand, but I will look it up tonight when I am home, and let you know.

John

[siliconbauhaus]

It sounds like your blades are high to me as well.

[gsmittle]

I saw a section in the manual for my Delta, that covered this, but I can't really remeber the specifics, but it sounds like it may be a blade height problem.

The blades need to be level with the outfeed table.

If the balde was too high or too low i caused what you are describing. I can't remember which it is offhand, but I will look it up tonight when I am home, and let you know.

John

I believe it means the outfeed table is too high. Too low would give you snipe on the end of the board.

g.

[ssmith1627]

Thanks guys. I'll play with the height of the outfeed table when I get home tonight. I'll try to make sure that's adjusted to the height of the blades.

And yes, making the passes with the concave side down -- as was said, frowny face. But it doesn't matter how many passes you make, you still have that slight bit of concavity. It's not going to let me glue up this top very well so I'd like to fix it.

I searched FineWoodworking and quite a few other sites. I really thought there was a trouble shooting guide somewhere but I have yet to find one.

Steve

[ssmith1627]

The below seems to answer it -- most likely the height of the outfeed table. I'll play with it some tonight.

Steve



http://www.taunton.com/finewoodworki....aspx?id=27719

Fine-Tuning a Jointer

Q: I recently changed the knives on my 6-in. jointer and set them level with the outfeed table. Now the jointer leaves boards slightly concave in the middle. Do I have to adjust the outfeed table again? -- Bill Smith , North Attleboro , Massachusetts


A:
Yes. No matter how carefully you install new knives, you can nearly always improve a jointer’s accuracy by fine-tuning the outfeed-table height after the knives are in place.

This fine-tuning is easiest if the outfeed table has a handwheel for height adjustments. It’s almost impossible if the table has a lever for height adjustments.

Begin with the outfeed table a bit low, and edge-joint two boards that are one-half to two-thirds the length of the jointer. You’ll almost surely see a gap when you put the jointed edges together. Raise the outfeed table in small increments and joint the boards after each adjustment. When the edges match perfectly, you’re done.

Photo: David Heim; Drawing: Kelly J. Dunton

[sweensdv]

More downward pressure should be placed on the outfeed side of the board than on the infeed side. If you're putting too much downward pressure on the infeed side it could slightly raise the board up resulting in high spots as you described.

[Lonnie in Orlando]

Steve -

Jointer misalignment diagrams ...
http://home.usmo.com/~rfwoodworking/jointer.html




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- Lonnie

[LCHIEN]

I agree with Lonnie and the other posters about the height.

If the tables are parallel (easy to check) and the blades are tuned up then tweaking the outfeed table height just a tiny bit w.r.t. the blades can make a concave or convex board or preferably in-between - perfectly straight.

[Slik Geek]

You didn't indicate the brand or model of jointer. I used to have cheapo Craftsman jointer that would never completely adjust properly, in spite of many hours of tuning. I gave up when I discovered that the direction of infeed table adjustment affected the parallelism of the infeed table.

The best I ever got it was a 0.003", but as soon as I adjusted the infeed table, that value degraded. Adjusting the infeed table in the "wrong" direction resulted in gaps of easily 0.015".

[ssmith1627]

Yeah, this is the lowest end jointer. Bought it on Craigslist for $125 with the mobile base and dust chute installed. It's the HF 6" jointer.

I played with it a good bit the past 2 days. I certainly found a way to make it WORSE. But I only got it working slightly better than what I had before.

I'll go back to work on it this weekend with a feeler gauge to see how close I can get it. I need to make sure the infeed and outfeed tables are parallel.

It's a good exercise. I need to learn all my machines and how they work so I can learn to better tune each one of them.

Steve

[Slik Geek]

I should clarify - my measurements on the cheapo jointer were on the resulting jointed boards. I don't recall the "sag" in the table, probably because the number varied so much depending upon how it was moved up or down.

[LCHIEN]

Yeah, this is the lowest end jointer. Bought it on Craigslist for $125 with the mobile base and dust chute installed. It's the HF 6" jointer.

I played with it a good bit the past 2 days. I certainly found a way to make it WORSE. But I only got it working slightly better than what I had before.

I'll go back to work on it this weekend with a feeler gauge to see how close I can get it. I need to make sure the infeed and outfeed tables are parallel.

It's a good exercise. I need to learn all my machines and how they work so I can learn to better tune each one of them.

Steve

Some good measuring tools help a lot.

I use this, it helps me check, as I move the beds, exactly how much, down to the .001", also good for setting the knives.

[eddy merckx]

this is the lowest end jointer. Bought it on Craigslist for $125 with the mobile base and dust chute installed. It's the HF 6" jointer.

I wouldn't worry about the quality of that jointer. A lot of people have them and are pretty happy with them. Here are two more things to throw out there:

1) Some of the more experienced guys try to get a little gap on purpose. The theory is that the ends of the glue-up are less likely to open if the middle is sprung shut. We're talking .002ish. It's not a bad thing at all.

2) Did you try shimming the dovetail ways on the outfeed table? That can correct tiny problems. It's really easy. Just cut some strips from a beer can and slip them between the table and the base. In your case, it would be at the far end of the outfeed table. All you have to do is to loosen the two adjustable screws at the back of the outfeed table to create enough slop to slip in the shims. Then re-tighten the screws and feed a couple of boards through to check the gap.

Eddy