Is There a Max Board Length for Jointer?

[-MIKE-]

Well, I'm diggin all this talk about table saws, now that I have a good one.

[Maxwell Lol]

Well, once they get to be a 1/4 mile long, it becomes problematic. Curvature of the earth can be a bitch.

[diggerop]

Best tool in the shed from my point of view. .... To Samuel Miller (1777, ) I dips me lid

diggerop

[Larry Jaques]

On Thu, 05 Nov 2009 15:27:59 -0600, the infamous -MIKE- scrawled the following:

Then the limit is human error coupled with lumber error. How big can you handle safely and precisely? A few interrupted passes can take down a bowed board, but you have to be able to manipulate it during those passes without error. Got twist, or both? Forget it.

-- "To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical." -- Thomas Jefferson

[Larry Jaques]

On Thu, 05 Nov 2009 15:40:06 -0600, the infamous -MIKE- scrawled the following:

Good.

One doesn't "joint half of a benchtop", suh.

Then you'd have to train your hands to feel precisely 90 degrees (though there are training wheels for that.) It's a skillset which can be learned, but it takes lots of practice for it to be maintained.

-- "To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical." -- Thomas Jefferson

[dpb]

...

There had better be no snipe on a jointer--if there is, the knives aren't set correctly wrt to the outfeed table or there is too much downforce on the workpiece directly over the cutterhead at the end of the pass.

Even w/ very long work that's up to the verge of what can physically deal with, one should be able to get a clean edge that will match edges over the entire length including the ends. (That's where the effect of long-term experience/familiarity/practice I mentioned previously really comes to the fore when pushing the limits, of course...)

Snipe should be a problem relegated only to planers...

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[-MIKE-]

My outfeed and infeed extension are 1500 meters, so I should be ok.

[-MIKE-]

It's not the same thing, but.... I have a electric hand-held planer and I'm better at using it *without* the little fence guide that came with it. It just seems to get in the way. I can feel and see the surface getting flat. I suppose one gets the same feeling, probably stronger, from hand planing.

[-MIKE-]

You're correct about that. Even the manual for this jointer refers to that in the section about setting the height of the blades. Since I'm used to running one edge through the jointer, then moving to the planer to get the other edge parallel, I still leave it longer than finished length.

[Chris Friesen]

Within reason. Due to the basic geometry of a jointer and the fact that wood compresses slightly, once you start getting significantly longer than the bed length the accuracy starts to drop.

As a thought experiment, imagine passing a 10' board over a jointer with a 10" bed length.

Chris

[charlie]

given high enough strength holddowns over the outfeed table, wouldn't it still work? the end of the board may sag, but the part of the board just past the cutters should still be on the table so the cut would be accurate. if the board is high enough, the tension in the board could even hold it straight without support.

[dpb]

-MIKE- wrote: ...

YIKES!!!! You're running stuff thru the planer _on_EDGE_!!??? Now that _IS_ scary.

That's what ripping's for on the TS. W/ a planer ripping blade and saw set up well, you should be able to glue directly from there. Or, at worst, a single skinch cut on the jointer.

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[dpb]

...

I'm "thoughting" skyhook... :)

[Chris Friesen]

Possibly...but who has powerful holddowns on their jointer? My hands are my holddowns, and given that they're also moving to push the stock through there's no way that I can be sufficiently accurate to give good results in really long stock.

Personally, I find it really easy to joint stock that is the length of the outfeed table. This ensures that a concave board can ride on the low points at all times. Once the stock gets longer than the outfeed table, then you need to care a bit more about technique but it still works. So far I haven't had to go much more than about 1.5x the length of the bed. I wouldn't want to go much more than 2x the length of the bed, and for something like that I'd probably knock off the high points with a handplane first anyways.

Chris

[-MIKE-]

Never had a problem, probably because I'm not running one at a time.

If I have five or six boards I want at the same exact width, I run them all through side by side. I'm not talking 8" wide, here. Generally 2" and under, like cabinet stock.

You know how they can look the same and measure the same, but when you set them together, and run your finger across, you can feel they aren't exact? That gets them exact for me.

Keep in mind, this is technique developed by someone who didn't have a good table saw.

[Larry Blanchard]

A rule I heard a long time ago was that the max length equaled the total length of the jointer. Another version was twice the length of the infeed table.

In any case, if the edge is warped very much, I make a few partial passes to bring it closer to flat before running a full length pass.

[Larry Jaques]

On Fri, 06 Nov 2009 12:52:33 -0600, the infamous dpb scrawled the following:

What a perfect time to buy a new tool! They'll also help you stack your lumber piles, move machine tools, etc.

"To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical." -- Thomas Jefferson