Modular Appliances

[m741]

I've been thinking. There's a fair amount of machines that are driven by a rotating gear.
I've never seen this, but it seems like some subset of appliances would lend themselves to a modular function. Basically you'd have different power sources, some kind of plug-in way of adjusting gear ratio, and then the appliance.
It would work like this: suppose you had a blender, clothes dryer, washing machine, battery charger, breadmaker, etc. Each of these would have a socket where you insert a gear of some standard width and design. Then you'd have a way of adjusting the gear size, and then you'd plug-in a power source.
Here's the sell for average people: you buy one super-high quality motor, and you can use that in every device. Why make smoothies with a shitty motor when you can use the washing machine motor for smoothies, drying clothes, and other things? And, alternately, with the motor removed, high quality machines ought to be cheap.
But here's where it gets better. The power source could also be: wind power, treadmill, rowing machine, steam from a wood fire, arm-powered exercise bike, local river, horse, etc.
The limitations are: electronic controls would be pretty difficult, and the appliance would have to work at variable rotational velocities. For instance, a good motor would be a lot stronger than a gentle breeze.
The benefit would be ability to use dramatically different engines, simpler machines, more resilience, less energy loss than charging a battery, and direct observation of results of labor. Think about it like this: it's your upper-body workout day, and you want a smoothie, so you pick up your arm-cycling device, and then you plug in the blender; 5 minutes of exercise later, and your meal is ready. Or: you think it's going to be a stormy day, and you need your laundry done, so you grab the washing unit and plug it into the wind device. Or, you pick up 20 bags weighing 50 pounds each and toss them on a platform, and the clothes dryer gets up to speed and spins for 15 minutes.
This seems surprisingly plausible - am I missing something? Are all these sources of energy totally unsuitable for small appliances?

[Ego]

Your post brought pneumatics to mind. A small wind turbine, hand crank, treadmill or solar setup could run whatever devise fills the pressurized tank. Then all of your appliances run off of the stored compressed air.
Here is a patent for a pneumatic clothes washing machine.

http://www.patentauction.com/patent?nb=8048
I believe most of the energy consumption of a refrigerator comes from compressing the gases.
Pneumatic industrial blenders exist

http://www.nol-tec.com/pneumatic-blending.html
That said, I believe that storing energy as compressed air is not terribly efficient.

[George the original one]

Compressed air storage is just replacing the battery. Where m741 is headed is to replace the redundant motors.
Safety is the main concern with power transmission. Remember all the flying belts of a water-powered sawmill or loom? Many hands/arms were lost in that period. The further the motor is from the load, the more likely there will be physical accidents (vs electrocutions or steam burns or whatever happens when a compressed airline bursts...).
For an example of modular appliances for outdoors work, take a look at Stihl yard tools (http://www.stihlusa.com/products/multi-task-tools/) or BCS rototillers (http://www.earthtoolsbcs.com).

[George the original one]

Thinking about it for another minute, the practical method to safely provide power would involve bringing the motor to the appliance. Drawback is that only one appliance at a time would be powered and the time lost for making the connection.

[George the original one]

Also, every time a mechanical transmission goes through a gearing, you lose 5%-10% of the power.

[Seneca]

I have a Stihl KombiSystem. I had just bought a line trimmer (which was painful as I hate grass to begin with) and was really annoyed that I was going to have to buy other tools when I found out about it...sold the line trimmer and bought the Stihl and have added attachments as needed. I really like the tool, great concept and execution. I bought the biggest engine so it would run the cultivator and pole saw, and it does make for a killer line trimmer, better than the one I originally bought for sure. Stihl holds it's value too.
Dremel also uses a modular concept.
M741, I really like where you are going here. Hmmm.

[m741]

I'm approaching a mechanical problem from a computer science perspective. Basically there are two ways to be efficient. You can convert power to electricity as a standard, and then make everything electric. There, the interface is the actual electricity. The downside is that batteries lose power over time and I believe there's an efficiency loss. Plus, there's a dissociation between power and results. Rather than use power as an interchange, the thought is to use a standard physical interchange, which would allow reuse of high-quality components (the downside is, it doesn't interoperate well with the electrical grid).
The Stihl system is very close to what I was thinking of, but more conventional (and probably far easier to sell). I think you could put a similar system inside the home and do well selling it to people.
For my idea, the fitness adapter would be something like a rowing machine (Concept II). It's tough to get up to speed but once at speed the effort is reduced a bit.
Basically the power source, such as simulated oar handle, bike gear, or treadmill, would get a weighted wheel up to speed. The gears would engage in a single direction, allowing coasting to smooth speed differential if you pause for a second. Obviously the weighted wheel would slow down pretty quickly because of friction going to the appliance but it would be less jarring.
All this was brought to mind by watching some videos showing Victorian technology. I saw a horse powering a chaffing machine, some guys powering other farm equipment, and a woman putting clothes through a wringing machine (it looked like a pasta machine actually). All this stuff was transparently simple - you could see exactly how it worked in a few seconds. People had plenty of power although the machines were a bit slower than more conventional machines.
One more thing - I have a vitamix, and basically it feels like a lawnmower attached to a blender container. The motor is very powerful and I'd love to be able to use it for other things. I'm certain it could power a small washing machine, and probably also a vacuum, hair dryer, etc. Think about how powerful a vitamix motor attached to a hairdryer would be (heavy tho).
I think I might pursue something like this when I have some free time. Would be a good project to try to learn welding for.

[wheatstate]

This is a neat idea.
Ego@ I agree that pneumatics are one good implementation of this concept. The compressed air is driving a gearbox, as opposed to an individual electric motor in the tool. Machine Shops use compressed air to drive a variety of tools; sanders, drills, drivers.... Money was put into the long-life compressor to take cost out of the individual tools. This saves cost and weight. I don't think that high energy efficiency has been a driving design factor of this system.
This would be great to see developed with any motor/power source.

[jacob]

This is already being worked on. See e.g.

http://opensourceecology.org/wiki/Power ... _Rationale

There are also people building stationary bikes to power things like blenders, drill presses, scroll saws, washing machines.
I'm interesting in working on something like this too.
I think the biggest problem is standardization. Also, "average people" were mentioned. Well, average people prefer idiot proof plug'n'play tools which means one enclosed no-service engine per tool. Companies prefer this too because it's more profitable. Hence, this remains DIY until resources become so expensive that it makes sense.
Also, people of average fabrication skill (like me) are not good enough to build these things on their own. Hence for now they remain the interest of those "who can" or those who have a lot of money to splurge.

[JasonR]

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[jacob]

@JasonR - Rather ... the problem is that if my washing machine breaks, my blender is broken too.
Conversely, if you have two engines, none of your umpteen appliances will ever be down due to engine failure.

[Seneca]

@wheatstate- Oh, there is a lot more energy that was put into mechanical efficiency of pneumatics than you might think. The compressor in an auto/machine shop is a lot different than the one you get at Home Depot for $200. Shops run them slower, they run multi-stage, some with intercooling etc etc. Higher end they start running screws instead of pistons.
@M471- Not sure if you know about tractors, but many, especially older ones, have a Power Take Off that was to do just what you are saying in the fields.
http://en.wikipedia.org/wiki/Power_take-off

[jacob]

It would be mind-blowing (mine anyways) if tractors didn't still have that. How else would you run a seeder or a rake? Lithium-Ion batteries?

[KevinW]

I like this idea as well. I agree with Jacob that it's worth looking at the appropriate technology and 3D printing communities since they're probably already on this.
There is a technical obstacle, that motor designs have a torque vs. speed tradeoff locked in. (I'm not a ME so those terms might not be 100% precise.) This is true of electric motors, internal combustion engines, and human motion. Household applications have a wide range of torque/speed requirements so you'll never pick one point on the spectrum that meets all needs.
This can be overcome through some kind of transmission, probably involving gears or belts. But as has been mentioned this incurs a penalty of inefficiency, bulkiness, and complexity.
Another working example of a PTO (power take off) is the KitchenAid stand mixer, which can power a variety of attachments:

http://www.kitchenaid.com/content.jsp?sectionId=844

[KevinW]

(deleted duplicate post)

[Seneca]

There are AC and DC motors. AC speeds are standard because single phase motors are harder to do speed control on.
Brushed DC motors have nice linear power curves, max torque at 1 RPM min torque at max RPM. They also are easier to speed control, you alter the voltage at its most simple, or you can do PWM which is superior but requires a more elaborate speed control. Brushless motors are a bit more complex in their controls. The price you pay is you have to have a rectifier circuit to get the DC if you use grid power.

[ICouldBeTheWalrus]

I think that this idea was much more common 75-100 years ago, when small motors were relatively expensive. Sizable industrial facilities had large numbers of machines driven by mechanical power distribution from a single large electric motor (which possibly was a drop-in replacement for some earlier mechanical power source like a steam engine.)
It seems that in modern times, 1/20th to 2 horsepower electric motors are so inexpensive (and fairly reliable and nearly maintenance-free in many cases) that it just isn't worth it. All that mechanical power distribution isn't cheap to make (with today's labor costs or materials costs.) Also, I suspect that a lot of the tendency toward motors-built-in-to-the-device is cemented in place by modern safety concerns/regulation -- it's a lot easier to make it safe against errant fingers or misuse.
On the other hand, when you get beyond the level of power (~2 HP) available in a typical plug-in appliance, it seems like there's still room for this idea. That Power Cube thing is pretty brilliant.