Jim Eisenstein
01-19-2023, 12:09 AM
I've been using a Grizzly G0856 8" jointer with a helical head for
a while now. Basically, the machine works well, although I've had some
difficulty setting the outfeed table height as accurately as I'd like. In short,
if the outfeed table is at the correct height relative to the cutters at the near
edge of the table, it will be about 0.005" too low at the back edge 8" inches
away. This is not a big problem when face jointing wide stock, but it can
lead to snipe at the tail end of narrow boards being edge jointed for a glue-up.
The usual first suggestion is to check to make sure the infeed and outfeed tables
are perfectly parallel and apply shims to the ways on the outfeed side if they
are not. I've very carefully checked this on my machine and find the tables are
parallel to better than 0.002" across their entire width.
Another possibility is that the rotation axis of the cutter head is not parallel
to the tables. I've never seen this discussed, no doubt because it is easily fixed
on a cutterhead with straight knives. When the knives are adjusted to be parallel to
the outfeed table it doesn't matter if the rotation axis is slightly off.
With a segmented cutterhead like mine, this fix is not available; each
carbide insert is attached to the cutterhead in a fixed position, there is no wiggle
room.
I've solved this problem on my machine by inserting 0.005" brass shims under
one of the two cutterhead bearing blocks (the near side, in my case). This removed
the misalignment of the rotation axis relative to the tables and allows me to
set the outfeed table height correctly across its entire width.
Hopefully this will be useful to others owning jointers with segmented heads.
a while now. Basically, the machine works well, although I've had some
difficulty setting the outfeed table height as accurately as I'd like. In short,
if the outfeed table is at the correct height relative to the cutters at the near
edge of the table, it will be about 0.005" too low at the back edge 8" inches
away. This is not a big problem when face jointing wide stock, but it can
lead to snipe at the tail end of narrow boards being edge jointed for a glue-up.
The usual first suggestion is to check to make sure the infeed and outfeed tables
are perfectly parallel and apply shims to the ways on the outfeed side if they
are not. I've very carefully checked this on my machine and find the tables are
parallel to better than 0.002" across their entire width.
Another possibility is that the rotation axis of the cutter head is not parallel
to the tables. I've never seen this discussed, no doubt because it is easily fixed
on a cutterhead with straight knives. When the knives are adjusted to be parallel to
the outfeed table it doesn't matter if the rotation axis is slightly off.
With a segmented cutterhead like mine, this fix is not available; each
carbide insert is attached to the cutterhead in a fixed position, there is no wiggle
room.
I've solved this problem on my machine by inserting 0.005" brass shims under
one of the two cutterhead bearing blocks (the near side, in my case). This removed
the misalignment of the rotation axis relative to the tables and allows me to
set the outfeed table height correctly across its entire width.
Hopefully this will be useful to others owning jointers with segmented heads.