Help! Problem with Face Jointing

[Robin Frierson]

Yes, I prefer the cutters to be about 3 thous above the outfeed. I use this method to set the outfeed.

"Tip: Some advanced woodworkers have found
that they can virtually eliminate snipe by setting
the outfeed table in the following manner:
Repeat Steps 1-4 using a freshly exposed
insert. Then lower the outfeed table slightly so
the insert lifts the straightedge off the table.
Place a ruler next to the straightedge and rotate
the cutterhead, watching how far the carbide
insert pulls the straightedge. Adjust the outfeed
table and recheck until the straightedge only
moves 5
⁄32"

[Alan Schwabacher]

The knives should be a little above the outfeed table, though how much depends on feed rate and knives. If you look carefully at a jointed board, you will see very subtle scallops where each knife has cut. As the board rides on your outfeed table on the points between scallops, the knives rise a little above to make the scallops.

Think of it this way. If the board were not moving, the cutters would make one cylindrical cut into it. As the board moves along, each cutter moves up into the board and then down out of it, one after another. The faster the board moves along, the bigger the difference in position of the cut from each knife, so the lower the point between a pair of curved cuts. The outfeed table height should be set so as to support these points to allow the board to move past in a straight line. Consequently, the outfeed table should be set just a little below the top of the knives, but how much below depends on knives, cutterhead speed, and feed rate. A height that allows a knife to move a straightedge a small amount (5/32" suggested above) is a good amount.

Use your jointer more before making changes to settings. It may be set just fine. If it does turn out that your observed curve is due to knives being too high (and it may not be the case) a faster feed rate could take care of the problem.

[Joe Adams]

I used a Starrett dial indicator and determined that the knives are at most 0.004 above the outfeed table. These are individual carbide cutters on a helical head and there is some variance. I don't think the individual cutters can be adjusted.

[John Lankers]

It probably just boils down to technique. As far as planing a board to thickness a flat jointed face provides a flat reference for the planer... banana in banana out.

[Andrew Hughes]

Joe I would like to suggest my method of setting up a jointer after changing knives.It should work the same on your Bryd head.
Take two pieces of hard maple that are thick and tall enough so that when you handle them on the machine you cannot change their shape with pressure.Face joint them then pass the edges separately across the head.
When they are held together with your hands they should look like one board.
Since they are white you should be able to see any snipe or gaps in the middle or ends.
A darker wood will hide a gap.
A good length would be about 3 ft +

Aj

[larry senen]

I used a Starrett dial indicator and determined that the knives are at most 0.004 above the outfeed table. These are individual carbide cutters on a helical head and there is some variance. I don't think the individual cutters can be adjusted.

Shouldn't be any variances. Remove the inserts, clean the head below them and use an inch torque wrench to set them all the same.

[Andrew Hughes]

Yes there should be a variance the inserts have a slight radius edge.

Aj

[glenn bradley]

Your material is longer than your infeed table. Since we joint concave side down (when present) it is possible that with the board in the starting positions, the end of the board is hanging lower than the eight of the infeed table. The table is true, your material is not. This means that during material feed, the portion of the material that is not supported will try to follow the irresistible plane of the table once encountered. In the case of a concave board the arch will climb the leading edge of the infeed. This usually results in thinner ends but, the point is that a fouled feed path on a jointer can provide sub-optimal results.

[Joe Adams]

The height adjustment correction seems to have done the trick. I used the Starrett dial indicator to adjust the outfeed table to top dead center of the carbide cutters.

Afterwards, I face jointed the same two boards that were giving me problems along with a half dozen others with no issue. All dead flat. I also edge jointed them without issue.

Then on to the planer for thicknessing and the table saw to rip parallel edges. Lots of sawdust went into the dust collector today.

Once again, I really appreciate everyone's help!

Joe

[Danny Hamsley]

Joe,

Look forward to seeing you and Erich again. Since you were here last, I added a 12" jointer to the planer room, and I absolutely love that thing.