Harry Bloomfield wrote:
Phil L wrote on 17/12/2008 :
connect live to
neutral and netral to live, it spins in the opposite direction,
although I've not tried it.

Doing that will make nil difference to the direction. Only swapping
one of either the field coils or brush connections will change the
motors direction.

Even if you get the motor spinning backwards, many of the designs seem
to be a semi centrifugal design compressor, so it will probably not
make much difference to the air flow direction.

My idea is to make a minature blowing machine of some kind, for
various jobs and just for ****ing about with, so if I reverse the
connections around in the motor, will it do as I want and start
blowing or will it just blow up? -

They do already blow, at the opposite end to the end they suck. Could
you perhaps modify the output end to accept a pipe?

Dry vac motors are cooled by the inward air blowing over the motor &
exhausting around the periphery of the motor. They do 'blow' but through a
series of small peripheral vents, so its difficult to channel the airflow -
and if its restricted too much it can cause overheat.

Wet/dry vacs discharge air around the periphery or via a tangential tube,
depending on the turbine. Tangential discharge motors are usually only
found on carpet cleaning machines, but they make excellent blowers.

The top picture here http://www.ametekfsm.com/ is a tangential discharge
motor, the second one down is a peripheral discharge.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk