I have been in a few- started some-finished some;) . I have a few SS miter bars for my 500. I have drilled and tapped for some jigs that I made. But, I have found that even the SS made bars are not a precise fit in the slot. Incra bars have a patented eccentric disc adjustment that helps fit up on everyones miter slots. The industry standard is 3/4" wide. This does not involve the tab runners that make a "T" slot a "T".
Saw blade location is only a hassle on a few items. I think one of the reasons SS hooked up a Miter Express is the "Fit cut" that is part of the installation. I am extremely pleased with the Express on my Shopsmith Mk. V.
I am just not in tune with a company that believes it must resist integration of standards to financially succeed. If the Shopsmith were not amazing on almost all other counts, I would not be here. I actually enjoy making some tools and jigs- but I would rather be making the end product. When I have a real goal in sight, then I do not want to have to jury rig something that should fit across the board. If all of the power tool makers out there were making miter slots sized on their whim, I would not criticize SS- but the fact is that there is an industry standard- SS is the outsider. It is as though SS has chosen to impose a frustration surcharge for having the other benefits of a fine tool- maybe if you were left handed you would recognize the irritation. If you are lefty- use that perspective.( An aside- I find it funny that whomever invented the traditional bait casting reel must have been raised with formal table manners-cast with the right, switch hands- those people have been making lefthanded reels since then. What is sad is that there are lefties who actually buy "left -handed" baitcasting reels so that they can swap back.)
My work here is now done. Thank you for your kind attention. Mike T.

----Edit- I thought of a good point- I accept the lousy dust collection on an SS because the design won't allow for it and where they could offer better efficiency, they have done so.
1983 Mark V- beltsander, jigsaw, Stripsander,jointer, bandsaw-double carriage and tables with molders and drums, Over Arm Pin Routers(Freestanding x 2)Second Mark V.
