In theory that would be a tru test if you started with a perfectly
flat board. But if not, then it means nothing. Also, technique can
have a big effect on jointers also.

The key factors a

1. The infeed and outfeed tables should be totally parallel in both
directions (side to side and end to end). This is easiest to check
when infeed table is raised to be equal height to outfeed but should
remain true after infeed is lowered for usage(harder to check). So any
adjustments to make tables parallel are first step.

2. Raise cutters so they are equal to outfeed table height. There are
little frames with magnet that help set this up. You loosen the
blades, run the head to center the cutter at highest point and lock
down each blade. Use can use a straight edge if you don't have magnet
gizmo.

3. Side fence should lock in at 90 degrees exact to table.

Not much else to do.

On Apr 1, 3:19*pm, The Wolf wrote:
Someone showed me a way to check the jointer. Joint the first 12" of a
board, pull it back scribble pencil marks on it. Turn it around and run it
through the other way. It should remove the pencil marks on the second pass.

At any rate I am working on a jointer manufactured in 1944. It takes 2-3
passes to remove the pencil marks.

Can anyone help me with troubleshooting?