On Thursday, 30 November 2017 11:00:08 UTC, The Natural Philosopher wrote:
On 29/11/17 20:32, tabbypurr wrote:
On Wednesday, 29 November 2017 20:26:50 UTC, The Natural Philosopher wrote:
On 29/11/17 20:19, tabbypurr wrote:
On Wednesday, 29 November 2017 19:08:26 UTC, sm_jamieson wrote:

I have an aerolatte milk frother that is just about OK to make cappuccino style foam when the batteries are new. So having returned an espresso maker due to the feebleness of the steam outlet, I went back to the aerolatte frother, and tried it on 4.5v and 6v in place of the usual 3volts.
This improved it dramatically, but how do I know what is too much stress on the motor ?
I suppose it is related to how much the motor is slowed down in the milk, in which case what is the best way to measure the rotation speed ?
Simon.

If it's rated at eg 3v for 2 minutes, it'll run way less time before frying on 6v.



All depoends on the load. My model planes were running nominal 6v
brushed can motors on 11v+ lithiums, and provided I geared them down and
let them rev on lowish currents the limiting factor was the cheap and
nasty brushes..

I got about double the power and 50% more efficiency than people running
then 'on spec'

for a 3v motor try a single li-ion cell at 4.2v fully charged, 3.8v flat..

Are you suggesting that in a highly cost conscious consumer appliance the motor might be bigger than it needs to be when run on 3v? I would suggest that if anything it's smaller than it should be.

Yes, I am suggesting that.

These motors are churned out un vast numbers in far east factories by
the likes of mabuchi, sagami etc etc.

The voltage rating is practically irrelevanyt. In reality motors do not
have a voltage rating. They have a current rating, a maxium heat
dissipation, an RPM per volt rating, and an RPM limit, and a brush and
bearing wear limit.

Fan torque goes up rapidly as rpm increases. Current is proportional to torque. Thus by feeding the thing more volts he's also feeding it more amps. Thus it can run for less time. Typically handheld kitchen appliances already have short duty cycle ratings.


NT