Homebrew PCBs

On Thu, 22 Jul 2004 13:36:25 -0000, cruizzer77 <atlantis7@...> wrote:

> Yes that's it! The 3-hole version works basically. I actually did
> angle the holes a bit and at 7'000 rpm the water splashed out of the
> holes up to about 5 cm from the bottom. The drill I used to drive
> cannot spin faster, so it seems as if I needed a high speed motor.
> Once this is done I will probably also try a base plate with only
> one hole in the middle. Does someone have an idea from what kind
> of "everyday device" a motor with a speed range up to 10'000 to
> 12'000 rpm could be salvaged? I think not even a vacuum cleaner
> spins that fast, apart from the fact that those motors are
> considerably large. Another problem will be that my bearings in the
> condition being will not withstand those high rpms.
>
> Regards
> Martin
>

smaller DC motors (like for model building) are build to spin that fast. 
For higher
power look at grinders, angle grinders and straight grinders that is.
You have good chances a "universal motor" (the kind with carbon brushes) 
is that fast,
where a "squirrel cage" motor without brushes is surely not.
You can also buy a $10 "dremel clone" they have a 12k or so 100W motor on 
ball bearings,
basically nothing else.
Model building motors (which in fact are simply small industrial permanent 
dc motors
like Johnson and mabuchi makes) can obviously be bought in model building 
shops.
(look for "speed" 550 or 600). You can find a 550 or 600 in every battery 
handheld
vacuum cleaner.
I'm not sure about other universal motors like big vacuums, or power 
drills without
the gearing, but looking at a power drill output and contemplating
the gearing ratio it might well be enough on the motor.

ST