Making wedges on the jointer

Owad · Post by **Owad** » Sat Oct 25, 2014 12:45 pm

I set up and ran my Shopsmith jointer for the first time today. This is also the first time I’ve used any jointer. After a couple of passes, my boards are significantly narrower on the end that goes through the jointer first. I’ve noticed that if I stop the board half way over the jointer, I can rock it slightly. I presume that shouldn’t be possible, and that this means my outfeed table is lower than my blade? When I check it with a straight edge, they seem level, but it seems to me they can’t be. I have a jig similar to this one for setting the blade parallel to the outfeed table. Is that a practical approach for the shopsmith jointer?

On a tangent: There’s a label on the jointer saying not to joint or plane more than 1/8” per pass, but the jointer can be adjusted to 3/8”. What is the function of this extra depth?

algale · Post by **algale** » Sat Oct 25, 2014 1:15 pm

When jointing it is absolutely normal for the thickness of the jointed board to be tapered. http://www.newwoodworker.com/jntrtaprs.html
If you take deep passes and/or run the same end through first every pass it will be even more pronounced.
The jointer makes one faces flat; you can then make one edge square and flat to that jointed face. To get the other face parallel to the jointed face, you need a planer. To get the other edge parallel the jointed edge, try the table saw.

I have no idea why the scale let's you adjust for such a heavy cut. Just don't do it or you will have a projectile.

As for the rocking, there will be rocking between the outfeed and infeed table. To check if the blades are too high, take a steel straight edge (the blade of a combination square works well) and put it on its edge resting on the outfeed table and hang it over the blades. Spin the hub by hand. The blades should just kiss the bottom of the straight edge.

STB · Post by **STB** » Sat Oct 25, 2014 2:18 pm

Owad wrote:On a tangent: There’s a label on the jointer saying not to joint or plane more than 1/8” per pass, but the jointer can be adjusted to 3/8”. What is the function of this extra depth?

The Jointer can be set up to cut rabbits with the maximum depth of the rabbit determined by the depth adjustment .

Note: The beads were cut with a moulder attachment.

[ATTACH]26650[/ATTACH]

[ATTACH]26651[/ATTACH]

dusty · Post by **dusty** » Sat Oct 25, 2014 4:29 pm

Far be it for me to take exception with a published wood worker but I do believe you can cut straight edges on the jointer.

The infeed table and the outfeed table must be exactly co-planar and the cutter head must be at the same elevation as the out feed table. After getting the setup perfect, it all becomes a matter of technique.

As you pass the work piece across the cutter head, the outfeed end of the work piece must remain in contact with the outfeed table at all times. If the infeed end of the work piece is allowed to drop down onto the infeed table - a taper is born. It begins looking more like a snipe but quickly grows into a full blown taper.

Once the taper is established it is very hard to get rid of except by ripping the board again.

The best way to learn how to avoid cutting tapers on the jointer is to learn how to deliberately cut tapers on the jointer. Just keep downward pressure on the infeed end of the work piece.

I would attach photos but I don't have any.

dusty · Post by **dusty** » Sat Oct 25, 2014 4:33 pm

algale wrote:When jointing it is absolutely normal for the thickness of the jointed board to be tapered. http://www.newwoodworker.com/jntrtaprs.html
If you take deep passes and/or run the same end through first every pass it will be even more pronounced.
The jointer makes one faces flat]there will be rocking between the outfeed and infeed table.[/B] To check if the blades are too high, take a steel straight edge (the blade of a combination square works well) and put it on its edge resting on the outfeed table and hang it over the blades. Spin the hub by hand. The blades should just kiss the bottom of the straight edge.

I respectfully disagree.

Not if they are perfectly co-planar and the cutter head does not rise above the plane of the tables.

dusty · Post by **dusty** » Sun Oct 26, 2014 5:52 pm

I may have to eat those words. I may not be getting as perfect a cut as I thought.

I need to do some more jointing to be sure. I appear to be getting wedge cuts of about .003". This is someything that I would never notice if I wasn't checking specifically for that.

Results will follow but not immediately. This "care giver routine" is demanding of my time.

algale · Post by **algale** » Sun Oct 26, 2014 6:20 pm

I will agree with Dusty to the following extent: If you start with a board with a perfectly flat face or edge and run that dead flat face/edge over a well tuned jointer with perfect technique, it is possible not to cut a taper. About the only times I can think one runs a dead flat edge or face across a jointer is to cut a rabbet or to remove very minor mill marks. I seldom use a jointer this way.

I use my jointer to flatten boards that aren't already flat. Usually the board started life with a consistent thickness but has acquired some degree of cup, bow or twist (and if I bought it at the Big Orange Box Store, usually all three defects

).

A board with these defects is going to be tapered by the time the defects are removed. Why? Because you get different amounts of wood removed at different places rather than an even slice removed everywhere. Usually you get close to a full depth cut along some part of that first couple of inches. As that developing flat area on the leading edge is held against the outfeed table, you get less wood removed in the middle and end of the board.

If the jointer could flatten defective faces and edges without cutting tapers, we wouldn't need to run the board through a planer to get the opposite face flat and parallel to the jointed face and we wouldn't need to guide the jointed edge along a rip fence to get the second edge straight and parallel.

If you try to use the jointer to accomplish this (parallel faces and parallel edges), your board will end up looking like an M.C. Escher drawing.

wodnek · Post by **wodnek** » Sun Oct 26, 2014 7:11 pm

Correct me if I am wrong, but can you make one side straight with a jointer, then use a tablesaw with the rip fence to cut the other side parallel?

dusty · Post by **dusty** » Sun Oct 26, 2014 7:17 pm

wodnek wrote:Correct me if I am wrong, but can you make one side straight with a jointer, then use a tablesaw with the rip fence to cut the other side parallel?

Absolutely. In fact, I consider that a standard procedure when working with rough cut lumber.

dusty · Post by **dusty** » Mon Oct 27, 2014 1:17 pm

This is a thread from some time back that discusses this topic.

Within that thread there is a video that shows how I check to verify that I have the cutter head just slightly above the outfeed table height. In the video, the infeed and outfeed tables were set to be co-planar (basically a 0 depth of cut).

PS (Oct 31): What you see in this video is meaningless unless the infeed and outfeed tables are perfectly co-planar when the infeed table is set for 0.0 depth of cut. What is seen in the video can be accomplished even though the tables are not co-planar; however, this does not mean that the jointer is properly tuned. "Properly tuned" means that the tables are co-planar along with the blades being properly adjusted.

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