The flat bar was as well as epoxy...best sort of taps are spiral flute taps...buy a load on ebay from China they're cheap as chips. Most taps are made for steel, even the cheap black spur ones they sell in pound shops. If you've a good printer, a decent centre punch and a hand drill you can make a decent gantry. Sure a mill helps but ultimately care and attention to details and hand tools are enough if that's all you've got and you want to make a CNC router ;)

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