Christmas has come and gone, and no doubt garbage cans are filling with toys that got but a single use before giving up the ghost. If you scrounge around, you might get lucky and score a busted RC car so you can be like [Mike] and build a completely unnecessary nitro-powered pencil sharpener.
This is one from the [Tim The Tool Man Taylor] “more power” files. To be fair, [Mike] acknowledges as much right up front, and as a learning tool for these super-powerful internal combustion engines, we think it’s a pretty cool project. After dealing with a seized cylinder on what looks to be a VX .18 engine rated at about 1.1 horsepower, [Mike] learns the basics of starting and controlling the engine. Once coupled to a pencil sharpener that clearly isn’t engineered to work at a bazillion RPM and jury-rigging a damper for the clutch, [Mike] fires up the engine and races through a pack of 10 pencils in record time.
As silly as this hack seems, it could come in handy if you decide to go into the colored pencil jewelry market at production levels.
There was at one point, a company offering a series of hand power tools that had these sorts of engines as prime movers. This was of course before Li battery technology made cordless power practical for this class of tool. These gas fueled units were never that popular, but they did have some adherents among the off-the-grid crowd, as they reportedly could be run on home-made fuels.
Yes, the US Army had several gasoline powered hand tools when I was a member. A drill, a grinder…
Hot items for theft.
I want one!
I would love to give this to my 17 year old son he loves using pencils and has a shitty sharpener…
And I know it would drive my wife insane………..
Great job.
Just bought that sharpener!…good to know if it crank it at 20k rpm it will likely seize.
awesome job
kind of reminds me of the gas powered blender available from Can tire
http://i.imgur.com/v4jgj.png
ROFL there is really such a thing!
http://blog.jcarter.ca/?p=327
Wow, that’s a tiny horse.
Wait till you see a brushless DC motor =D
I still have my old Castle Mamba Max setup, 3s lipo (11.1v), 100amps continuous, 1.1kW of bad arse!
I put it in a cheapish 1/10th scale LRP Truggy a while back, the poor plastic spur gear lasted about 2 minutes before it completely stripped. It was fast as all hell for 2 minutes though!
Has anyone ever built an RC has engine generator? One horse power is about 700 watts or so. That’s a LOT of power in a small package. I could see a sound dampening enclosure around it with a decent muffler. Would really be nice to have something like that in an emergency that doesn’t weight hundreds of pounds or sound like a lawnmower running nonstop.
gotta gear it waaaaay down or get a really good power controller to deal with rather high frequency AC. Close to a kilohertz output from a handheld package..
Or have the engine spin a DC generator and go with an inverter design instead, like the Honda Eu series backup generators. You’d still have to gear it down, but it looks like the engine [Mike] used already had a gearbox.
A kilohertiz is practically DC, superfast rectifiers don’t cost significantly more than 1N400s (and on a good day they are cheaper)
It also drinks gas like crazy…
Yeah, 2 stroke fuel efficiency is measured in gallons per mile.
i built one. tiny nitro engine, low kv/rpm motor, 3 phase rectifier. charges a small lead acid battery. haven’t worked on it lately, was trying to convert it to spark ignition but got frustrated and put it to the side.
These little 2 stroke motors make allot of power but not much torque, they need to rev super hard to make that power, they won’t last long being run at WOT for extended periods of time, the life span of these motors is not significant enough to be anything but a fun project. They also need to be thermally managed, fuel mixture/load has the biggest effect on temperature, too lean and too much load will cause the engine to run too hot and end up destroying itself. Too cool or rich and it won’t make decent power, 1.1HP ratings are at the optimal temperature at a specific RPM with a specific nitro/meth mixture (typically 10-20% for hobby use, 30-40 for race), if like the article says it’s a VX .18cc engine it delivers peak power at 32,000 RPM.
There’s many different sizes of engines for different classes of vehicles, the “big block” .46cc+ motors in large monster truck style cars make 5HP and above!
Tim Allen’s “Home Improvement” show had a cordless screwdriver with a 2 stroke motor with a belt to the bit shaft. Interestingly enough, the prop had the throttle attached to the rocker that ran the original battery drill. so when he presses it the engine winds up and you can see the increased exhaust smoke. Sure it had no torque but for a throwaway gag it was well done.
More power!
Well any pencil sharpener that makes it’s creator laugh maniacally is a good pencil sharpener.