"I would like to know if someone in the group can make me a 12x1 mm female to 14x1 mm male converter with emco unimat threads, thank you"
This is awkward to do because the difference between the major diameter of the M12 thread and the minor diameter of the M14 thread is only about 0.5 mm. An adaptor that moves the chuck out about 10 mm would be possible but would have to be made carefully to ensure that the 12.00 mm diameter register is concentric with the 14.00 mm one. I would do this on my old SL if I still had it, although it really needs a good strong steel which would not be easy to machine on a little Unimat. I'd like to start with a bit of EN24T bar (817M40/1.6582/34CrNiMo6) as it is tough but machinable.
I did a chuck conversion some years ago for someone in the Shetlands who wanted to convert a four jaw independent chuck from M14 to M12. He posted it to me and I put it up on my brother's large lathe. I bored out the back and tapped it M18 × 1 and glued in a? mild steel plug with epoxy resin. I only used M18 × 1 as I had a bit of bar with that thread on it and a tap for the same thread. I then bored it out for M12 × 1 and tapped it, and reamed out the 12.00 mm diameter recess. I then put it on my SL and checked concentricity - it was better than 0.001" runout on the diameter, and similar on the back face. There was no noticeable vibration at maximum speed, with the U90 motor. Good enough for a four jaw chuck, and much better than one which doesn't fit.
My SL is now in Australia, but I have plans to machine up some Morse taper arbors to fit the bigger lathe, one with the 12 mm DB/SL spindle nose on it, and another with the 14 mm U3/Basic/PC nose. I was also considering making one with an 8° taper so it could be used to true up bad ER collet holders - I have a few.
Tamra
Carl