DIYbanter - Jointer update.. the saga continues

stryped wrote:
I started it up last night. The belt is a few sizes too big so I am
going to have to fix that. I was a little disappointed. I rand the edge
of a board through. The board was junping up and down while I was
holding it as it was hitting the blades. It put "ripples" in the bottom
of he board. Not sure exactly what this means. Maybe the blades need
sharpened? Maybe the cutterhead needs to turn faster? I took the blades
off this mornign and plan to have them sharpened somewhere. I plan to
adjust the tables and everything this weekend. I think the blades
should be adjusted so they are level with the rear table, right? The
old manual I have says the front table but that has got to be a
misprint. I have never heard that before. The manual also says
somethign about adjusting the front tbale but elsewhere it says there
is no adjustment.

If the belt were "a few sizes" too long, it would be unlikely to have
enough tension to turn the knives at all under load. A half-inch in
length in a belt can make all the difference in the world. First look
at the motor mounting and see what is there for tensioning and use
that. I think I recall you saying this was a homebrew stand--if so,
probably simple enough to make whatever modifications needed. If the
belt is indeed too large or small in cross section for the pulleys,
that is different and you should get one that does fit properly.

First, if as you indicate you could actually feel and/or see the board
"jumping", it's likely that one knife in particular is way out of
adjustment in height relative to the others--it's important all are
precisely the same height. Secondly, if the knives are dull they will
hammer rather than slice so that's also a problem. Thirdly, once I
even saw a case where the knives had been installed backwards on a
machine in an estate auction!

The "ripples" indicate several possibilities and are related to the
above plus some other things. Again, knives not on the same cutting
circle (height), dull knives make it hard to cut cleanly. If the
cutterhead is actually slipping, then speed of cut would be slow and
compared to the speed of passing the material over the cutterhead can
contribute. It is a 3450 rpm motor, isn't it? The pulleys should be
sized so the cutterhead turns in the general neighborhood of 5,000 rpm
or so.

Unless the knives are in really bad shape you should be able to hone
them yourself good enough to set up the machine. I grind knives on a
simple homemade jig and a white wheel. All you really need is a base
to hold the knife at the proper distance and angle and to be able to
run it in a straight line across the wheel. You just don't want to end
up w/ a non-straight edge.

Yes, the knives should be set to be right at or just a tiny amount
above the outfeed table. A recent thread suggested the magnet
trick--that or a dial indicator work well. There should be an indexing
hole in the end of the cutterhead at each knife location to allow you
to lock the head in place so each knife is, respectively, at TDC while
doing the adjustments. If you're lucky, this cutterhead will include
the height adjusting set screws which are so helpful in keeping the
knife from moving as you tighten the gib screws.

Depending on the model, the front table may or may not be "tunable".
The old Craftsman I had the rear table was mounted on three large bolts
and that allowed for front-rear and side-side compensation/alignment w/
the front table. Very time-consuming initially, but worked quite well
once done. I've forgotten the exact way the front table was mounted,
sorry.

HTH. While not the easiest things to set up, my experience w/ a very
old Craftsman was that once it was, it did quite nice work and was, in
my opinion, preferable overall to many of the newer, inexpensive ones
as it was heavier and more solid overall.