Gerry, I have a couple of different slotters in my shop that I've used over the years and a Bridgeport brand was another that I had but was happy when it went away... I retro'd a K&T attachment to my #2 cincinatti and it works about as well a good Pratt and Whitney. A couple of things, is your Bridgeport a variable or a J-head? The variable you have to put it in back gear, run it all the way down before you shut it off and a tool will still turn on you - some. A j-head, leave it in high gear and throw your side lever forward and it will lock the spindle. I use either a 3/8" or 1/2" piece of cold rolled round, and silver solder a 1/4 or 5/16" HSS tool bit to the round and grind it to my desired shape, generally about a 60° or more included point and use that for cutting my mortice. Be careful not to get things too hot. Recently, switched from using HSS tool bits to using Tantung as it is a little more durable but it's more work and sometimes hard too find, even on eBay. I use my BP spindle for squaring almost all my castings, but when its an action from a piece of stock, the slotters are a better choice. As far as a clapper box or some such animal, I don't worry about it. Run a neutral or negative rake on the face of the tool, plan on roughing things out and I've taken as much as .025" in that pass, but follow with a re-sharpened tool and scratching with a .005 or less finish pass. The '74 Sharps is about the longest mortice to cut, plus the dual extractor cuts and I've had them turn out straight and square. There's a photo of a tool using tantung and one of several Hepburns I did. The tool shank diameter is dictated by what size mortice you're working on. The hepburn doesn't give you a lot of room to manuever in. Here's a most recent project, squaring the mortice on a Zettler, there's three of them now with this part done... A little patience and finesse, which you have, they'll turn out fine. Greg
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