mechanical devices

[The Pressman]

Is there a way that you could enchant something (a fan, for example) to spin forever, using permanency or somesuch? Assume it is fixed to an axle.

[Escheton]

yes, though it would not actually be mechanical(obviously) and the effect would be suppressed by a dispell magic and such.

3rd lvl spell, cl 7 to make I'm thinking

[jseah]

Not sure if he's asking about homebrew.

It depends on how much physics you're willing to face. Do you want:

Simple? Reverse Gravity needs a custom item, but a wheel half in and half out will spin forever.
Clever? Wall of Fire makes a boiler that doesn't need fuel.
Complex? Ring Gates violate conservation of momentum and energy. To mimic Dr Rocktopus... Implementation left to student.

XD

PS: although I am more than willing to explain Ring Gates again. Just ask.

[Escheton]

what I meant was basicly that prestidigitation moves stuff, mage hand does it better but it would take the power of a 3rd lvl spell to really get a decent ceilingfan out of permency or crafting wondrous items.

[nedz]

You just need a giant hamster wheel inhabited by some creature which can keep going forever. A giant zombie hamster perhaps
There: I've just invented the Necromantic Industrial Revolution.

[DonEsteban]

The first things that come into my mind:

Craft Wondrous Item + Mage Hand or
CWI + Telekinesis or
Animate Object + Permanency (though Gust of Wind + Permancency would actually be cheaper)

I'd prefer the zombie hamster, however.

[The Pressman]

All it really needs to be able to do is spin continuously to stir a liquid. <think stirplate>
It would have to be available to a level 2 group, if possible.

[Ravens_cry]

You have something as 'simple' as a waterwheel powered by a Decanter of Endless Water, though I doubt that would be available to a second level group.
An item of continues mage hand mage handing a rope conencted to a set of pulleys so that 15 feet of five pounds force equals 75 pounds of force over 1 foot. Connect that up and down motion to a crankshaft and you have circular motion, for 1000 gp. Not very powerful though.
A item of unseen servant would be much better, as it can move much farther then 15 away from you and can lift 20 pounds. Same set of pulleys with the rope moving the same distance means 300 pounds of force over 1 foot.
It will cost you 2000 gold.