my oligopoly i miss understood the "3/8 /1/4" thing (im all metric here ).. so in short i could in theory us a lager G 3/8th centre inlet however i dont think i've seen a G3/8th bard for sale from the usual PC places not that i've looked for one?
currently and rather painfully my CAM software doesn't support slitting saws so I'd have to get something new OR write the code by hand ( which IS possible ) which is why id prefer not to
i would do both however it would seem there is little market for this kind of block. So it would be alot of time and money to not sell it .. ( LIKE this one )
What software are you using? I remember in mastercam you could pretty much create any geometry of tool you felt like. You should be able to just create a series of lines, one for each slit with the correct offset already applied and tell the cam software to just move in the y direction a little further each pass. Even writing up some G-code shouldn't be too hard, if you've got a g code viewing program (red/cam if your program won't do it). You could just get a chunk of delrin for the first run, that way you can't break tools. Just a thought. There isn't really anybody else making big TEC blocks, so you might be able to find yourself a niche.