Okay, can't sleep tonight so I thought I'd come back and read the
messages here :-).

I couldn't resist the 2.5 hp motor I mentioned last week. It took a bit
of thinking and several hours work to get it out of the factory, but I
got there in the end. Today I was excited to discover that this motor
was one of the very first steel framed motors, built in 1931, so it's an
interesting historical item too. I might build a phase convertor with
it, or alternatively save it for driving a machine, but so far I haven't
decided.


Looks like a very interesting motor! It is hostorical...

I am confused. The data plate says that it is a 400V motor. Are you
intending to run it off 220V?

Notice the data plate also says "Connection: Star/Delta". Most three
phase motors are wired in the star configuration for 400 V operation in
the UK, so I assume that the 400 V on the data plate simply refers to
the factory default configuration. There are six terminals under the
cover so it can be rewired in the delta configuration for 230 V.

I am not convinced that you need to bother. You are going to have an
idler, there is not going to be any tension or force momentum, other
than instantaneous spinning up of the motor.

You can set it on a wooden platform (maybe on wheels, make a cradle of
sorts (like a rectangular berm) with 2x4s, and maybe put little
diagonals above mounts to make REALLY sure that the motor does not
jump out one day.

My idler stands like this, and does not jump out of anything. It is on
a small steel tray though, but the tray is simply held by a few junk
wood pieces screwed to the platform neat the sides. The converter
shakes mildly when starting up.

I was thinking of repairing the motor mount for two reasons. Firstly I
was considering building the kind of convertor where a single phase
motor drives the three phase motor permanently, like Dan Caster was
talking about. Secondly I thought I might use this motor for something
else, in which case the mount would probably be handy. But you're quite
right; for the simplest convertor I wouldn't need it.

See

http://igor.chudov.com/projects/Phase-Converter/

http://igor.chudov.com/projects/Phas...e/dscf0011.jpg

the forces involved are very mild.

Your motor is even heavier and spins even slower.

I love seeing pictures, it is like watching a movie.

I love pictures too. Glad you enjoyed them. I'll post more as the
project progresses, though I probably won't begin immediately as I'm
currently working on a farm engine restoration. Might post some pictures
of that soon though...

Best wishes,

Chris