At only 4" wide the Shopsmith jointer is small by comparison to today's Chinese imports, but it just about lives full-time on my Mark V and for me is irreplaceable even though I now also own a large jointer too. The inventors of the Mark V were smart enough to know that the jointer would be needed while sawing, so while the upper spindle is spinning around 3500rpm the lower drive spindle that drives the jointer is spinning 1.6 times faster at 5600rpm.
As for its size, ask yourself how often you'll be jointing boards that are thicker than 4" and you'll see that 4" is wide enough for all but face-jointing. Just like the Shopsmith Bandsaw, the inventors of the SS jointer took a fresh look at the tool and came-up with some unique features that have proven the test of time. Some of these innovations are:
- One captured handle is used to loosen and tighten the fence tilt as well as for locking the fence in the proper place over the blade. Why move the fence? As you use a jointer the knives will begin to dull, so when you need to make a final pass on your stock you can move the fence to the sharpest point on the knives. In my case, I like to move the fence to the back of the jointer if I know the wood I'm jointing has the potential to nick the knives. For example, even though I do this rarely I do occasionally find the need to joint a piece of plywood. The glue line on the ply is murder on the knives, so for this, I'll slide the fence over to the far right and leave the left side pristine.
- Most jointers have an adjustable front and rear bed. You raise and lower the front bed to expose more or less of the blades to remove a set amount. I usually have mine set to remove 1/16". The rear bed on most jointers also moves up and down to allow you to line it up with the blades whenever you change them for a freshly sharpened set. The SS jointer doesn't need an adjustable rear bed because the inventors patented a unique cutter head that allows you to accurately position the knife's level with the fixed rear bed. You'll notice that several companies sell knife setting gauges because all jointers except the SS jointer have goofy knife holders which can cause the knives to shift left, right, up, or down when they are being tightened. Worse yet most jointer knives can come loose if they aren't properly tightened. The SS jointer knives are ground in a wedge shape, and they are locked in place with an opposing wedge. If the capscrews which hold the wedges in place are even lightly tightened, centrifugal force will cause the knives to hold tight against the locking wedges. I'm not explaining his well, but most importantly this design is just plain smart.
- Ever wonder if the piece you're thinking of jointing is long enough to safely joint? A little-known feature of the SS jointer fence is that it has two bumps cast into the top. If your board fits between the bumps it's too short to joint.
- The current SS jointer features an improved guard which is called a feather-guard. It combines a guard that can be set to limit how much of the cutter head can be exposed and a feather board that helps to keep the board held tightly against the fence. If your SS jointer has the older cast aluminum "pork chop" type guard it can be easily retrofitted with the new feather-guard by purchasing the feather guard retro kit from Shopsmith.
- One last recent improvement to the SS jointer sounds a little gross, but the motive is pure and the results were very effective. A few years ago SS increased the diameter of the cutter head and increased the size of the knife locking wedges in order to tighten-up the spaces that can cause injury if an operator happens to get their hand too close to the running cutter head. Again, this is available as a service part, but I'm not prepared to go to this extreme. My feather guard keeps me at a safe distance, and my fear of injury handles the rest.
Here's a neat tip on how to increase the bed length on your Shopsmith Jointer