How to Almost Build an Engine With Only Parts From the Hardware Store [video]
howtolou.com
howtolou.com
While some people do make tiny internal combustion engines the work involved in incredible.
(http://www.youtube.com/watch?v=mLn7xG8vuPQ)
World's smallest V12 engine: (http://www.youtube.com/watch?v=m3KdpzL3Hkk)
Making model IC Engine valves: (http://www.youtube.com/watch?v=Nofj1CGSCM4)
But, being a boy, I wanted it to work better. So I replaced the battery with a lamp cord and plugged it in. It promptly burst into flames. Awesome!
But instead the car got REALLY, REALLY, REALLY fast, shoot out of the track and smashed into the wall.
Of course, I happily put a second car on it, and changed the track so that the car does not end smashed, and indeed, I could launch cars all over the place. Also as the car raced, sparks came out of the contacts with the track.
Now that I am older and know even more physics, I have no fucking idea on how I made a DC motor work only forward with a AC current.
The sparks would come from feeding way too much voltage in, enough to jump the gaps caused by momentary losses of contact between the track and a fast-moving car.
Another possibility is that the motors in the slot cars had electromagnets for the stationary field instead of permanent magnets. That's what an ordinary power drill, especially one without electronic speed control, has. Such a motor will run pretty much the same on AC or DC. When running on AC, the rotor and stator both change their magnetic fields in perfect sync so the net effect is substantially the same as running to same motor on DC.
Wikipedia has an article on "Brushed DC electric motor" with a section on "wound stator". It doesn't specifically mention running the motor on AC, but there's enough there to show you what's going on.
The combustion engine equivalent to the toy electric motor would be a simple stirling engine or even a Hero engine. These can be very easy to build.
http://www.customcdr.com/cgi-bin/ccp51/cp-app.cgi?usr=51H817...
(I've built both kit versions and "from scratch" motors built with parts ratted from cd rom drive motors with a few bucks worth of rare-earth magnets.)
Building your own controller for it is somewhat more challenging…
http://esden.net/2010/09/19/open-bldc-v0-3-hardware-based-cl...
Even in the late 70's the mechanical technician courses in the UK required you to be able to design an old school belt drive.
Compressed air is used because the powerhead is much smaller and lighter than an electric motor (at available voltages) of comparable power. This makes it suitable for handheld tools. Otherwise, compressed air represents a NET loss of energy, and would be avoided.
In any case, compressed air is directly analogous to electricity here. It's a way to transmit energy generated elsewhere.
Gasoline cars were popularized before electric power generation was widespread. It would be decades before the power grid could possibly have supported electric cars.
The Model-T started in 1908 (and there were of course cars before that), the War of the Currents was in the late 1880's. The Model-T represents cars becoming popular, but the War of the Currents was just the beginning of the electric grid.
The first Gasoline car was also around the 1880's (must have been an amazing time to be alive with all those inventions).
It was not until the late 1940's that electricity was widespread, i.e. rural areas which are of course important for long distance travel.
So the electric car would not have been practical until then, and by then of course gasoline was completely entrenched.
Electric cars were the 'good' cars, easier to run, not as dirty or hard to start, more luxurious. But they were an expensive luxury. The Model T was cheap, easy to fix, and adaptable to many other uses (like hooking a wheel to a belt and running a saw to cut wood.) The Model T was a classic disruptive invention: less good but much, much cheaper; it created an entirely new market of car buyers.
It may be that that electric is a better option now: oil is expensive and non-renewable, and burning fuel pollutes. But neither of these reasons were very compelling a century ago.
Look at the way he's dressed. (With no protection clothing or eyes or anything).
Look at how close he comes to the gasoline.
Look at how he's seated so he can't even get away quickly.
Look how there is no protective shield.
He doesn't even appear to have anyone else there in case of an emergency.
He has enough intelligence and curiosity to attempt this but not enough to protect himself. More or less what I would imagine from someone much younger, certainly not a grown man.
I'm sure he took the safety precautions he though were worth it. It might not be worthwhile for him to use an additional 20% of his time/money/whatever for the slightly reduced risk.
Though seriously, when was HN ever about health and safety?
The computer version of safety is called security. And HN cares a lot about computer security.
Yeah, I wouldn't deploy it on a public internet exposed network, or give it to someone else who wasn't aware of the implications or consequences of such an insecure machine – but in the privacy of my home network it's just fine.
I assume this guy is the same – he needs some increased safety if he wants to show this thing off in public, but in hs own shed he's got every right to accept risks for himself that are inappropriate for other people.
I've seen equally and much more "dangerous" projects at Burningman – hell, if he gets this running with any sort of reliability, attaching it to a bicycle and riding it around at Burningman would be a _fabulous_ idea!
My motorcycle motor produces a beautiful cloud of gasoline droplets standing maybe 4 or 5 inches tall above the carburetor throats when you crack the throttle open.
There's thousands of car/bike enthusiasts who see that in their garages every weekend. They're not dying in catastrophic accidents all the time.
Your concern for safety is rather laughable for the size of the engine he's doing this with. Ether if improperly stored is the most dangerous thing as a can of 50% either having crystallized is a good few grams of TNT equivalent, which would make it a small hand grenade. (however an aerosol can with peroxide inhibitors in is extremely low risk if its new)
Talk to anyone who has worked in a mechanics garage and this video is extremely weak tea. Try being near a V12 when you've just filled every spark plug with ether and you're spraying it into the air intake. Now that'll give you an uneasy feeling like you've just made a potential bomb, but the fact of the matter is that the failure points in engines are valves and gaskets long before any metal part fatigues and becomes dangerous.
His piston chamber appears to copper piping, which don't fragment they split, so there's really no risk there. Think bronze cannon over cast iron.
To be fair, it would take lucky (or unlucky, depending on how you look at it) ignition timings, since with that system they're all over the place.
He could have built an enclosure and put this on a table similar to what is used in lab experiments.
But please tell me what this has to do with whether I have personally tried to build, in particular, engines?
I think you'll find a vast number of "grown men" who'd recognise the risks you identify here, and say "Yeah, it's not as safe as sitting on the couch watching TV. Grab a beer and stand back in case this explodes…"
And while you might question their intelligence – they'll just as incorrectly question your manhood for doing so…
There's a lot of engineering in internal combustions engines and all that info is readily available. Things like compression ratios, spark timing, and fuel-air mixture ratios; all very important but it seems he didn't give any thought at all to this before jumping in.
A little thinking ahead of time could have saved him a lot of time and money I think.
I'd suggest the author spend a bit of time looking at the designs of the Wright Flyer engine and that in the original Model T and going from there. These two engines are of very simple design and worked reasonably well. And there's a ton of technical information out there on these, too.
Oh, and some fabrication skills with a lathe and mill could be handy, too. I'm always amazed at the length some folks will go to with building stuff from hardware store stock. A community college class in machining and a cheap lathe and mill opens up a whole new world for any maker.
I disagree, though, about needing to go crazy with the craftsmanship. I mean, if the purpose of this is to build something experimental, or something that could be used to illustrate to kids how an engine works, having it NOT be craftsman-like might help demystify the whole thing.
I really like that he has built it onto a piece of plywood. It reminds me of those old electronics builder kits you could buy at radioshack. Would you want to actually use one of those as a real radio? No. But building a simple radio that actually functions where you can see all the pieces really helps to make it real.
So, from an educational perspective, I think the simplicity of it is helpful.