Hi there, all,
I expect you had all thought this project had died! Well, it's moving slowly but it is moving.
I'm intending to visit a motor rewinding firm tomorrow, not about a rewind but in the hope that they can supply me with a resilient mounting kit for the motor that came with the mini-mill.
I dug the motor out of its temporary stowage ready to take with me tomorrow and noticed something on the rating plate that seems rather odd.
Most of the rating plate data is normal, 'type GP/1906, Volts 230/250, PH 1, c/s 50, HP 50W, A 1.1, BS 170 Cont. AOM, Class E'.
However, the entry for frequency states 'RPM 1275'. How's that for odd-ball?
For induction motors running on a 50 Hz supply, I'm used to about 2850 RPM for two-pole (usually woodworking machines), 1425 RPM for four-pole machines (like my ML7 lathe, and rarely about 950 RPM for six-pole machines.
Squinting through the ventilation slots of this motor, I can't see any signs of a centrifugal switch so I'm wondering if it's a shaded pole motor designed to operate with a larger then usual slip speed?
I do have a Smiths tacho so I'll have a go at measuring the off-load RPM, maybe whoever stamped the data on the rating plate made a mistake.
Having thought about it for a while, maybe 50 W is a bit low-powered even for a mill the size of the Flexispeed - I think I have a 1/4 HP motor somewhere.
I'm still intrigued by the 1275 RPM though!