Cheshirechappie":3nxmbmea said:
To avoid dubbing the ends of a board, apply pressure to the toe and heel of the plane appropriately. At the start of the cut, place the plane with its toe on the board, and use full weight on the toe to press the plane down - apply NO downward pressure with the heel hand, just forward push. As the stroke reaches the middle of the board, about even downward pressure should be applied by both toe and heel hands, and as the cut exits the far end, NO downward pressure at the toe, and full downward pressure at the heel end to keep the plane sole parallel with the board.
That's not an easy thing to do at first, but concentrate on it, and it quite quickly becomes second nature. You do it without thinking about it.
It has nothing whatever to do with cap-iron settings.
Edit to add;
Actually, that's only half the story. The FIRST thing to do on planing a face or an edge is to identify and plane off any high spots. If a board has a crown in the middle, plane that off first to get the board pretty well flat, or even very slightly hollow. THEN use the method above; if you try to do so with the crown still there, you'll never get rid of it.
Planing the high spots off is first in any planing regimen - which doesn't involve long through strokes. It involves finding the high spots and then removing them before moving to the next. If the high spots aren't easily identified by eye, run a long plane over a board, find them, and decide whether or not the plane in your hand can remove them quickly enough. If you couldn't see them, and you have a try plane in your hand, it probably does. If you can see them and they are significant, you probably shouldn't have a try plane in your hand in the first place. Once they're removed, what's left should be planed by through strokes. No straight edges or squares to do any of this, just eye and feel - and no straight edge or square until you're just about complete with the fine part of the work.
As to whether or not the cap iron has anything to do with actually executing this, it most certainly does, at least if you want it to be efficient. It makes sure that every shaving is consistent thickness from start to finish, even in grain with runout or where it's completely reversing. The efficiency of actually getting a constant thickness cut from end to end regardless of the wood cannot be understated. It also tells you when you've gone far enough in that the entire shaving has no breaks in it (which you'll still have after jack work unless you're only planing downgrain, but even the jack ridges will cause a shaving to be broken). There's no reason to move on until the shaving is continuous and unbroken or at least unbroken to a point that two passes with a smoother will finish off the job.
These are the kinds of things that apprentices probably knew 200 years ago just from sensibility (and human nature laziness to get a job done without wasting effort). Even if you can't see high spots in a board, you can feel them when they're only a few hundredths. But you can't feel them the first time you plane - it takes a bit of practice. You also might be in the crowd of folks who doesn't believe the cap iron makes a difference in any of this, but history would suggest otherwise given that it eliminated single iron planes and lightened the wallet by more at the same time (if it was pointless, nobody would've bought it when money counted like it did 200 years ago).
The mechanical principle of this is the same regardless of the plane (where the pressure is at each end of the cut), but the execution of it relies on a cap iron or a high pitch. If you decide to use high pitch instead of a cap iron, and you're still at the "high spots" part of the work, you're torturing yourself. If you use high pitch only for the fine work on an edge, no problem. if you then turn and use it on the face of the board, you're again, torturing yourself. All of this ties together, but until you intentionally get good and efficient at rough work (which is derided by most of the gurus now, as well as forum trolls), it's not going to be well understood.