Hiya Folks, Well I think I got it working. I adjusted the height of the outfeed table relative to the blades and was able to get it cutting without snipe and without creating that taper I was getting. Thanks much for the info. If nothing else, it was a colorful thread! What I learned: The jointer needs to be set up to within a gnat's ass in the way of tolerances. And, I need to buy a better blade. I too use the jointer to remove the blade marks. Cheers. cc
:> Not a great analogy (though I do agree with the general point that getting :> parallel edges on a jointer is a matter of some luck, and is beter left to :> other toold entirely). The jointer tables, in theory anyway, provide a :> reference for a straight edge. Riping on a TS without a fence doesn't give :> you anything comparable. :> :> -- Andy Barss
: A straight edge is not the same as a parallel edge.
Indeed it isn't.
All I was saying is that comparing (a) jointing an edge of a board with a jointer (against the reference bed of the jointer) isn't at all similar to freehand ripping on a tablesaw (i..e without the fence).
You can make a : straight edge quite easily with only a plane. You can even make a : straight edge on two opposite sides of the same board. But getting them : straight AND parallel is an altogether different proposition. Do the : geometry ... without referencing the opposite edge, how will you know if : the two edges are parallel?
: There IS a way ... but the jointer can't use it.
As I clearly stated in my original post, I agree that the jointer is not the proper tool to use to create parallel edges.
-- Andy Barss
Well, as close as possible, within wood tolerances. Though I'm still puzzled how you got the beginning of a board, as presented, narrower than the end which followed. That's characteristic of table droop, not high outfeed.
What's most interesting about this thread is the number of people who don't understand how a jointer works. Hopefully you're not one of them now, having learned that the jointer removes a measured amount of stock determined by the exposure of the knives from a board rested on the table for best average straightness. If you have parallel edges, they will remain parallel if you use your properly adjusted jointer to clip the edges. Andrew seems to have set up his own straw man, but he's right in saying that you don't _make_ stock parallel with a jointer normally. Takes scribing and working it as the big plane it is to do that.
But, if your tablesaw produces a parallel but slightly fuzzy edge because you've gone too long between sharpenings, or you're feeding too fast and it vibrates, or you tuck it a bit into the side as you transition to the push-stick, &cetera ... you can clean it up with a quick pass on the jointer prior to gluing. Some of us are so lazy in the other areas we allow for one pass in our original rip. Or three, with lower grade lumber where we might release tension and get a bow in the resulting piece. Thing is to be smart enough to sight it and repair it at the jointer. Betting ripping misfeeds and less-than-great lumber are the reasons for people's stance against jointers. Had they sighted after the rip, they might have other opinions.
You seem to have some misconceptions about its use/misuse yourself:
Unfortunately, that is very often not true, as these threads clearly point out.
The edges, or faces, of dimensioned stock are usually "parallel", but rarely perfectly flat. Despite well set up machines and practiced technique, run that stock over a jointer and the edges/faces are guaranteed to be no longer "parallel".
Again, a jointers intended use is not for "dimensioning" stock, but for preparing it to be dimensioned.
Use it any other way and the unwary should be prepared to be surprised with stock that is tapered to some extent.
And I think we all agree including Norm that he does not always do things correctly.
That is true and place your self in the group that has not been properly trained by a qualified instructor if you still believe that a taper will not result.
With each pass of the board across the jointer knives which are banging against the board that they are cutting, the reference,"you", cannot provide absolute resistance like a TS fence or thickness planer base. There is too much give in your hands and skin to insure a perfectly straight path across the knives. The path may seem smooth and controlled however the resulting taper is proof that some give in your hold is the culprit. The shallower the cut the longer it takes for the taper to "visually" appear.
I see you *finally* understand the reason for using a jointer on S4S lumber.
But, apparently, not the obvious, which is that a parallel edge produced by ripping against a _jointer-straightened_ edge, not the straw man, will remain parallel if a measured amount is removed along one edge by the jointer.
Sounds like an operator problem. If you hold to the properly set _limiting_ references, nothing bad will happen.
So just how does a plane work, Leon?
If you are asking about how a hand plate achieves parallel edges, the user makes multiple passes and not all in the same spot.
LOL! Quite different from your earlier, blanket statement, but close enough for some purposes ... just like the results often obtained from using a jointer for other than it's primary purpose.
:> Not a great analogy (though I do agree with the general point that getting :> parallel edges on a jointer is a matter of some luck, and is beter left to :> other toold entirely). The jointer tables, in theory anyway, provide a :> reference for a straight edge. Riping on a TS without a fence doesn't :> give :> you anything comparable. :>
:> -- Andy Bars
: With each pass of the board across the jointer knives which are banging : against the board that they are cutting, the reference,"you", cannot : provide absolute resistance like a TS fence or thickness planer base. There : is too much give in your hands and skin to insure a perfectly straight path : across the knives. The path may seem smooth and controlled however the : resulting taper is proof that some give in your hold is the culprit. The : shallower the cut the longer it takes for the taper to "visually" appear.
Pleae reread what I said, and/or the followup I posted. I am *agreeing with you* that a jointer isn't able to give parallel edges.
But you were comparing (a) trying to get a parallel edge on a board using a jointer to (b) trying to do the same thing on a TS without a fence.
As I said, it's not a very good analogy.
-- Andy Barss
What is it about a jointer that would cause it to produce a piece that is NOT tapered?
Well, that depends on what you are starting with. If the board already has straight and parallel faces, then a "properly set up" jointer in the hands of a good operator probably won't add a taper, if you're just making a single shallow pass. That is what people that "rip to width, clean up on jointer" rely on.
When you're starting with a cupped/twisted/bowed board and want to flatten both sides, the chances that the two flattened faces will end up parallel is pretty remote. That's why people flatten one side on the jointer, then dimension the lumber on a planer.
...but I'm sure you agree, and the current argument is about the "rip to width, clean up on jointer" process. (Some of the context has been lost by editing.) So why bring in the flattening process? Because I'm sure you'll also agree that the process of flattening will have rather different results depending on how the operator applies pressure, particularly in the transfer of weight from the infeed side to the outfeed side. Especially in the beginning stages when there is still lots of curve in the board - if you push one way to start cleaning up one part of the board, you'll get a different result from what you'd get if you started with pressure on a different point. That's where skill comes in.
...so I would argue (perhaps not strongly) that even when edge jointing the saw-cut face, an operator that doesn't shift and balance pressure between the infeed and outfeed sides runs the possibility of not making an even cut, because there is nothing intrinsic in the design of the jointer to prevent such uneven cutting.
...but I'd agree that this effect would be very small on a single, shallow pass. And I think you'd probably agree that an unskilled operator that takes several passes to both smooth the saw cut and reduce the board width runs a risk of accumulating single unnoticable tapers into a multi-pass noticable taper, because the jointer isn't going to do anything to prevent it.
No, just disagreeing on what to have for a snack.
I can think of two possibilities:
1) the board is bowed (not straight, end-to-end), and he's holding the board with the ends up and the middle down (as opposed to ends down and middle up), and he's starting the cutting with pressure on the front of the board, so the front edge is cut in the first pass. The tail of the board is then well above the knifes when it gets there, on the first pass. Subsequent passes keep cutting at the front, and eventually cut at the back as the surface flattens, but the end result is a flat face with a thin edge at the front (cut on every pass) and a thick one at the back (only cut on last pass). Put pressure on the back first, and the opposite occurs. You need to start with pressure in the middle, not the ends - or even better, turn the board over so it sits on the two ends and they get knocked off together. This is "technique". The less flat the board, the more important that the technique be good. 2) something is a bit loose in the jointer tables. With no pressure on them, everything seems to line up just fine - it is "properly set up". As soon as pressure is placed on the infeed or outfeed table, however, it droops. Thus, the droop or misalignment is there when cutting, but not apparent when measured during setup.
Cubby ... find a machinist who is willing to show you how. The whole thing takes just moments. The indicator is used for a single series of measurements with the understanding that you will need to do the same 3 second setup each time you start over.
I could show you how in 5 minutes and show you WAAAY mor than you will ever need to know in 30. But I doubt if I can write anything up here that will make much sense.
Understand that 1) the indicator must be firmly attached to a stable base. 2) this stable base is resting on / sliding over the reference plane (ie; on a jointer, one of the tables) 3) the surface being adjusted will end up parallel to that plane. 4) the adjustements to be made will consist of something called 'successive approximation' ... even if you make the measurements under laboratory conditions, there will always be measureable error left. If you can no longer measure the error, great. But a better test instrument could. 5) the smallest level of error you can reliably count on is 1/2 of 1 division on the dial. That is, a dial indictaor marked in .001" increments can be relied on to within .0005" +- .00025" To put this in perspective: at .003" you cannot see wich of two blocks is the larger. Below .001" it is highly unlikely that you can feel the difference between them.
All of which is to say ... don't waste time trying for more accuracy and precision than you need. If you can reliably make cuts to within 1/64" of where you intended them, you are a better man than I am and far better than many who nonetheless do outstanding work.
An indicator is an excellent way to set a blade. Mark my words. But it is not the only way to skin that particular cat.
Bill
What woud be a better analogy?
I'm not Leon but am an experienced plane user. It works much the same way as a jointer and it, like the jointer will not in any way ensure that the planed side is parallel to the other side.
Ok. So what is your point?
I think it is either that: A) I am a shitty craftsman B) I have higher standards for glue-ups.
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