Emco Mentor Mill conversion

[Swarfing]

That DC motor is it a 90v or 180v by the way?

[Ross77]

just opened it up and the motor is 180v and 4800rpm so a little slower than I was hoping for. Driver board looks quite compact and control panel is fed from one muiti core wire so shouldn't be to difficult to hack the speed commands.

On the down side it is 10mm to big (diameter) to mount on the existing motor plate so to use that motor I will have to make a new mount and move the motor position over to clear the top of the quill. Looks like I'm going to have to have a go at rewiring the AC motor for 240v and fire up the vfd.

[Swarfing]

Go for it, at the end of the day your other options are to spend some money. If i does not work...then just spend some money :-)

[Ross77]

finally found time to rewire the motor and it was embarrassingly easy, don't know why I was so worried about doing it. Coils measured 50 ohms on their own so in delta config you basically have two coils in series which are also connected in parallel to the 3rd coil, so if I have it correct then that gives 100 ohm and 50 ohm in parallel which is 33.3 ohms. tested each pair of wires and always got 33.3 ohms so hopefully I have got it right.


Also worked out how to set up the vfd, connected a forward/reverse switch and a speed pot. tested it on a another motor and all works fine. so hope fully tomorrow I can rebuild the motor and see if it works.

[Swarfing]

Well done Ross

[Ross77]

ta, its good to get something done rather than just talking about it. onwards and up wards.........you never know I might have a working mill by the weekend.

[Ross77]

Problem 1 and 2 solved. Motor works fine on 240v with the vfd and got the gearbox fixed so all 4 speeds are working.

I wasnt going to bother fixing the gearbox as the vfd would have taken care of the speed control but unfortunately though the 1 speed that worked was the slowest (350rpm ish). The previous owner had some replacement gears made but they didn't quite match the gear profile so I had to file them down, not ideal but needs must and at least I can test the rest of the machine.

A BIG THANK YOU to all that have help sort his especially Geoffery, M-C and Swarfing, cheers guys I know most of the info is somewhere on the net but to have you point me in right direction is great.