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Iituem
2010-12-24, 02:11 PM
Nothing major, saving up some druid-based feats for the next real post. This concept occurred to me, though, and I wanted to see how broken this really is;

Perpetually Turning Gear

This small bronze gear, no more than an inch in diameter, perpetually turns with a force of 5lbs. It can be attached to other devices to power them (such as millstones) but if the total power requirement is more than 5lbs the gear will not be able to move the machinery and simply stop. Multiple perpetual gears can be hooked up together to provide additional power with a DC 10 Craft (Machinery) check.

Any device that would be able to resist torque of 5lbs (such as an iron vice) will stop the gear as well.

Faint Transmutation; CL 1st, Craft Wondrous Item, mage hand; Price 1000gp. Cost to construct; 500gp + 40xp.


Bear in mind that this will turn forever, thoroughly violating the laws of physics.

Halna LeGavilk
2010-12-24, 02:16 PM
I don't think it's that broken. At least, not more broken then other applications of magic are.

Debihuman
2010-12-24, 02:17 PM
How many of them can you hook together?

Debby

Iituem
2010-12-24, 02:42 PM
As many as you can lay your hands on. You could stick a thousand of these together and create a machine that can regularly use five thousand pounds of force.

Of course, for a million gold you could probably do quite a bit more than just 5k of force, so on balance it's less broken than you might think.

I was looking for a cheap way to create a perpetually powered fan for the mining industry in an adventure module (to explain why there's enough fresh air in the deeper levels), but 1k per fan just isn't viable. For 1,000 gold you can build a small waterwheel for centralised power and try and connect everything with wires and gears.

So fortunately, this does not violate Tayler's Donkey Law and invalidate mundane industry for accomplishing the same thing.

The Mentalist
2010-12-24, 02:46 PM
Less broken that has a permanent unseen servant turning it's crank. I'd use it.

I'd personally do it as an item that for 1000gp turns with a Str 10-18 (what is the strength score of a mule? Yeah, whatever that is.) Call it X's Mule Engine

Iituem
2010-12-24, 02:52 PM
I suppose a more pertinent question isn't about power generation but power transfer. Say you're building said mine and you don't want the cables or axles transferring the power to be cut (sabotage, rampaging beasts etc). What about gears that could simply transfer power from one source to another (they turn in tandem) without intervening material? Could the same item be reworked into one, two or a set of gears that all turn in tandem, up to say a mile from each other?

Iituem
2010-12-24, 02:57 PM
Less broken that has a permanent unseen servant turning it's crank. I'd use it.

I'd personally do it as an item that for 1000gp turns with a Str 10-18 (what is the strength score of a mule? Yeah, whatever that is.) Call it X's Mule Engine

And yet running a mule for its lifetime would still be cheaper. Even if it costs as much as 10gp a month to feed, house and care for a mule (it really shouldn't, given mules cost 8gp each) you could still run it a good 8 years before it became less profitable. In this case the problem becomes available capital - noble houses might have a Mule Engine, and governments might employ them for public transport or war, but most people are still going to be using mules.

That said, the very existence of a mule engine would be subject to the Donkey Law and change the game world much as the steam engine did (albeit a steam engine with 1 horsepower). That said, a 10 str subject can pull something like 400lbs (x4 for a quadruped), and a level 1 spell (unseen servant) could only manage 20lbs. So probably not balanced for a cantrip level item.




If your magic can accomplish the task for less or more easily than the donkey can (in this case, the task of pulling a cart), your world has just been broken. You need to ask yourself why everyone isn't using magic to pull their carts. If mages can create a cheap, easily available light source, congratulations - you've just put all the candlemakers in your world out of business.

The Mentalist
2010-12-24, 02:58 PM
That would be cool. I don't know what level spell effect that would be but I'd price it around 1000 for a small gear, 5000 for a medium gear, and 10000 for a large gear.

The Mentalist
2010-12-24, 03:01 PM
And yet running a mule for its lifetime would still be cheaper. Even if it costs as much as 10gp a month to feed, house and care for a mule (it really shouldn't, given mules cost 8gp each) you could still run it a good 8 years before it became less profitable. In this case the problem becomes available capital - noble houses might have a Mule Engine, and governments might employ them for public transport or war, but most people are still going to be using mules.

That said, the very existence of a mule engine would be subject to the Donkey Law and change the game world much as the steam engine did (albeit a steam engine with 1 horsepower). That said, a 10 str subject can pull something like 400lbs (x4 for a quadruped), and a level 1 spell (unseen servant) could only manage 20lbs. So probably not balanced for a cantrip level item.

I wasn't thinking of it as a cantrip level item. I think that 1000gp for a 10str force is quite reasonable. Particularly if you make it large (like 100kilos) and then maybe a version thats 3-4k for a pocket sized one.

Iituem
2010-12-24, 03:06 PM
1000gp for a 10 Str item is reasonable - it just violates spell effect rules. A continuous item along these lines will cost 2000gp x spell level x caster level, so a cantrip did cost 1kgp.

Now I might pay 10k for a gear that could transmit power across an unlimited distance in the same plane. There could be quite a number of uses for that, not least of which might be tying the master gear to some sort of immense source of power (an enormous waterfall or dam, perhaps) and then using it to route power across the world to the various cities of an empire. If sufficient technology does not exist to do this with electricity, it would beat the risks associated with running belts or axles.

NichG
2010-12-24, 03:35 PM
Only addendum I'd make would be to give it a fixed maximum rate of rotation just to avoid sillyness when its not under load (e.g. otherwise it'd spin up nearly forever in a decent vacuum, and would become a highly dangerous bomb after a few days).

I don't think the price really matters too much - its high enough that they're not going to be common except for large engineering projects within a kingdom where they really need it to be going all the time, or occasionally used for a rich noble's dumbwaiter or mage's lab. You could have an elevator for 100000gp, though you'd better only go up one person at a time.

I'd almost want to make them cheaper, perhaps 100gp, so that they don't become prime targets for theft. Otherwise there's no way you could use them in a mine or at some open site or they'd just vanish.

Tvtyrant
2010-12-24, 03:39 PM
I would use them primarily for dikes and other drainage purposes. A mule drowns underwater, a gear doesn't.

mootoall
2010-12-24, 03:39 PM
Frankly, I like this as a Tippyverse invention. Its cost is low enough that it's a useful utility thing, but high enough that it takes fart too much money to really break it.

Temotei
2010-12-24, 04:42 PM
1000gp for a 10 Str item is reasonable - it just violates spell effect rules.

I feel the need to point out that they're not rules, but guidelines. If it's reasonable, it should be made that way.

Iituem
2010-12-25, 07:04 AM
Alright. Artefact time. Let's see what we can put together from all that speculation.

The Mandala
This ancient bronze gear is covered in brightly coloured paint in a variety of patterns. It spins of its own volition at a very slow rate of 1 revolution per minute, but has immense torque. Slaved to machinery, it can generate roughly equivalent to 10,000,000 lbs of force at any one moment before grinding to a halt.

Major Artefact. CL 25th, Epic, epic telekinesis.


Brotherhood Gears
Each member of this set of 100 seemingly ordinary bronze gears is slaved to all the others such that if any one of them turns, the force is spread out amongst all the other gears. The gears will turn in tandem irrespective of the distance between them, provided all the gears are on the same plane of existence. Any gears taken to a separate plane will only function with gears of the same set on that plane. If a gear is not connected to anything else, it takes 1lb of force per round to turn - thus turning all 100 gears if they are unconnected to other machinery will take 100lbs of force.

The gears can be destroyed one at a time by the use of Mordenkainen's disjunction but there is an 80% chance of a gate appearing to a random plane when a gear appears. The gate will remain open for 2d10 rounds, during which free travel between the two planes may happen in either direction.

Minor Artefact; CL 25th, Epic, gate.



Chain the Mandala and the Brotherhood gears together and you can power a small empire.

Debihuman
2010-12-25, 10:34 AM
You could pay for 1000 Perpetually Turning Gears that work together only to have some idiot NPC come long with a 5 lb torque screwdriver and break it.


Debby

Keinnicht
2010-12-25, 01:02 PM
I don't think it's "broken" really, because it doesn't really address any issue that could be unbalanced. I'm sure some player somewhere is going to figure out some way for these to be the most lethal objects ever devised, but as it stands, they're mostly just flavor.

It doesn't really matter if it's mules or magic gears.

Havvy
2010-12-25, 04:07 PM
Or if they are decanters of endless water, which are also perpetual energy devices. Infinite energy is at the fingertips of DnD. You don't have to really worry about the laws of thermodynamics, unless your DM tells you otherwise.

ericgrau
2010-12-25, 09:12 PM
Ya perpetual stuff isn't a big deal in D&D. It becomes scary IRL when it offers limitless energy, but even then if you have to pay so much money for it then it's not all that special. Assuming it moves up to 15 feet a round, like mage hand, the work is force x displacement = 5 lb. x 15 ft./6s = 12.5 ft.-lb./s = 2.08 Watts. For 1/5th the cost of a house. Something tells me the world's energy problems are still unsolved.

Come to think of it you need to define the motion better as it's missing a speed. 15 ft. per round would match the spell well. If you want to define it by rotation then you need a torque and rotational speed instead. 5 lbs. at 1/2 inch radius equals 5x0.5/12 = 5/24 ft.-lbs. ~= 0.21 ft-lbs. of torque. 15 feet per round with a diameter of 1 x pi = 3.14 inches means it rotates 15' / (3.14 /12) = 57 revolutions per round = 570 rpm. If you want it to rotate slower or faster then multiply or divide the torque by the same amount. For example, if it's half as fast the torque should be twice as much, and vis versa.

enigmatime
2010-12-26, 09:24 PM
I will have you know that I will be using this. For more than just regular gears. *insane giggle* :smallbiggrin:

Honestly, I think it was balanced at the start. I'll tweak it to fit my realm, though. If I may suggest, the price should be slightly lower. Not to 100 gp. Say, 500?