The satandard unit is only 80W (not sure whether that is input or output, but probably input). It is not actually referred to as a motor in engineering speak. It is a 'geared unit' ie a motor and gearbox designed together as a single entity.
The reduction gears or whatever (often a large and smaller gear (expensive and larger), or crownwheel and screw ('worm drive') need to be matched for speed and torque. The torque increases as the output speed decreases for any given input speed), so JC is very correct in what he says about safety.
The normal electric motor runs at circa 1400 rpm and the speedier ones 2800, so a reduction of 10:1 is required for the normal drum extractor (280 rpm) as size is an important issue in this application.
Now, I cast around for a motor/gear for mine and picked up a whole extractor for thirty quid. The extractor was rubbish and the drive only a single direction. It was a Th*rne unit from earlier days.
That is the way I would recommend if you have time on your side.
The manual drive could be exchanged to the other extractor to recoup costs (fleabay?)
If going the 'make it', I might suggest a suitable windscreen wiper motor as a starting point? They are cheap and used to be very robust (not so much these days!) or the motor from a larger sewing machine (already has the contoller!)
Speed control for a DC motor could be a simple field current rheostat, for A/C a thyristor control (armature), or frequency changer if an induction type (squirrrel cage), motor.
I simply went the wait-and-watch route because it was simple and easy to make the change, and does not look too Heath Robinson. Even drive couplings can be a minefield these days.
Regards, RAB
