Small Stirling engine drives 20" box fan blade - 630 rpm!

[watzupdawg]

600rpm and 95dB.

[approtechie]

@watzupdawg I accidentally had my mic boost turned on. It's actually quieter. My new one is a lot quieter.

[BobGardnerInOrl]

3 candles is 3 BTUs. 3412 BTUs is a KW, so looks like the fan is running on about a watt.

[nata911]

love that crankshaft lol

[safdarblog]

very good effort

[Rupertbilpus]

You could in theory put a generator where the fan wheel is and create enough current to separate the water into hydrogen to produce the flame and power it indefinitely. You'll still have to use an out side flame

At first but once the hydrogen is being produced it should run it's self. Any thoughts?

[approtechie]

@Rupertbilpus If it were that simple I believe it would have been done long ago. The laws of thermodynamics always seem to get in the way of these sort of processes.

[Wyomingfarmer]

@approtechie yes and power loss by friction!

[PhyUL09]

@approtechie So right... non-statistical thermodynamics are a mess of partial derivatives that you shake around hopelessly until you come up with the right Maxwell relation :p  wikipedia. org/wiki/Maxwell_relations

[stupidgenius107]

@Rupertbilpus The problem you often run into with that sort of thing is that the energy required to make hydrogen puts a load on the generator which creates too much resistance for the stirling to run. The sad truth is that energy cannot be created, only transferred, and lots of energy is lost from the open flame. However, I suppose the seemingly impossible has been accomplished before, and we're certainly not going to discover perpetual motion by shooting down ideas in youtube comments.

[gnucklehead]

@Rupertbilpus In practice, Hydrogen from water: it takes more energy to separate it than you can get out of it. Nonetheless, this is a nice motor.. Should try to run a mechanical water pump from the shaft power.

[5610winston]

@Rupertbilpus As in perpetual motion? I'm sure it's been tried, but like all such apparati, it would always need an outside energy source.

[PhyUL09]

@Rupertbilpus It's because the entropy at the end of the cycle is higher than at the beginning... in other words the input energy is lost with dissipative phenomenon like friction, light, sound...

[spandaucrabbies]

any chance of a tutorial vid/ pics/ schematics? looking to build one of those things for a laugh/ bragging rights

[approtechie]

@spandaucrabbies Hope to have some plans in the works soon.

[16strings]

Very well done! That is a great speed for a small engine with a load of that size.

[16strings]

Very well done! That is a great speed for a load of that size on a small motor. The old Stirling engine fans used the wick and burner from a kerosine lantern for heat. I think that might work for you too.

[approtechie]

@16strings I tried running it on the waste heat from a kerosene lamp and it worked well. I could probably remove the globe and get the flame closer to the head and it would run even better.

[acerkiwi]

Great job. how is the piston sealed are u using a diaphram? wats it made of?

[approtechie]

@acerkiwi The piston is a diaphragm made of inner-tube-like rubber and sealed by squashing it between the two wood pieces with six screws.

[ashuntu2010]

Great Job!!!!!!!!1 Cheers



[ASSEMblerEX]

How long would the entire candle last?

[approtechie]

@ASSEMblerEX I've not tried it yet but maybe 12-15 hours. I've noticed some of them burn faster than others depending on the scent, no idea why. I'll try the experiment one of these days and time it.

[specallez]

What is your method of attaching the cooling tube to the side of the tuna can ? I've tried RTV and epoxy, but both leak after a while. Thanks,

[approtechie]

@specallez I glue 1/4" grommets in the holes, insert short brass tubes into the ends of the plastic tubes to make them a tad larger and stiffer, then insert them into the grommets. The fit is tight and I've not had leaking issues that way. I think the plastic tubes soften with heat and distort, but the brass tubes help them keep their shape.

[varmintslayer311]

Outstanding indeed! :-D

[TheGrayman1234]

Outstanding

[tracycolorado]

impressive