Instructables

Gas powered pencil sharpener- for students that spend the entire class sharpening a pencil.

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Every now and then, a student will spend a big chunk of class making sure his/her pencil is SHARP.  For some reason, after a particularly long day, I was vegging at my desk staring blank-eyed at my pencil sharpener.  It was one of those *LIGHT-BULB!!!!* moments.

You, too, can have a gas powered pencil sharpener.  All you need is a weedeater, a pencil sharpener, and a few scraps of wood and metal.

This weedeater was left in pieces after one of my students decided they didn't want to fix it.  I managed to mix and match enough parts to get it running and piece this together.

Still isn't running quite right yet because the carburetor isn't correct, but it runs enough to sharpen a pencil and get real hot!





 
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Step 1: Gather Materials

Supplies:

A running weedeater.  If you can find one that has a clutch, it would work MUCH better than the one I used!
A useable pencil sharpener
Scrap of wood to mount to
Scraps of metal for motor mounts
Screws
Misc. nuts and bolts
Duct tape.  VERY important...

Tools:

Screwdrivers for screws
Saw for wood
Metal cutting tools- snips, shears, saw, whatever
Metal punching tools- pin punch, turrent punch, knockout punch, whatever
Bolt cutters
Hacksaw
Welder
Tap and Die set
Dr.Bill1 year ago
Ah nice belt drive reduction would make things interesting.
zomfibame1 year ago
awesome sharpener. too funny.
ToolboxGuy2 years ago
Time for an upgrade - Teach your kids that PTO doesn't just mean Personal Time Off...
It mean Power Train Option!

Get them to come up with how to interconnect something else to a PTO engine.
Any plans for a diesel model for the hard core industrial pencil pushers?
Ha!
DoctorDv2 years ago
Are you allowed to use this in your classroom?
-Doctordv
dorkpunch (author)  DoctorDv2 years ago
Sure! I don't let my students use it... It's more of a demo just to show them whats possible. More of a make-sure-you-stand-well-back and have-your-safety-glasses-on type of thing. They always want to try it out, so every now and then we'll fire it up and chew a few pencils down to the eraser.

My "classroom" is fairly conducive to this sort of thing- several vent fans, a large roll-up door, and lots of space
lol
Ohhhhhh I was thinking that was unsafe, but now I understand. Thanks!
-Doctordv
car powered :)
nfalduto2 years ago
this is the best instructable of all time.
kenbob2 years ago
This is art. Love it.
lemonie2 years ago
Quality.
Do you have plans for collecting the pencil-waste, or is this finished?

L
dorkpunch (author)  lemonie2 years ago
This is more of a pencil disposal tool... I tend to pick up all of the pencils left on the floor in my room. I've got quite a stack of pencils. As far as collecting it goes, anyone know any good uses for pencil dust? Fire starter, packaging material, or?!
I carry a pencil and a small, hand sharpener in my emergency kit when I go camping. It's both something you can write with and, as long as you use a real wood pencil and not one of the recycled pulp and glue ones, it works quite well for tinder.
Taimur lperkins2 years ago
@lperkins: seriously u have a pencil sharpener in your emergency kit?!

when I was a kid I used to sharpen the pencils with a knife x)
actually sometimes I still do it!!

@dorkpunch: about the dust of sharpening the pencil (if it is really dust if you let them airborne in a small space you could provide a explosive situation just like happens in cereal silos) if you have splinters of wood you could pile them soap them in flammable liquid and aggregate with glue or resin to produce fire-starters.

Again with the dust it is explosive.. but! there is still use for the dust as a filler with wood glue to repair some holes or you could use it dry to heat up a biomass boiler (the coal power-plants use dust of mineral coal) with that principle you can produce heat in a boiler with the dust. If you want a way to do so just ask.
lperkins Taimur2 years ago
For sharpening pencils for use I often use a knife as it's faster than rooting around for a sharpener. The sharpener in the kit is one of the ones which has a container to catch the shavings. Stick the pencil in, turn five or six times, presto, instant tinder that's not scattered all over the place. It lights and burns rather nicely.
If it is not V-8 powered then it is not a pencil sharpener. On the other hand, it is handy to have one in your emergency pack so you can ride it home if it gets too unpleasant for camping.
You might try putting the shavings around your Blueberry.
Especially if their made of Pine.
Sorry, was supposed to say "Blueberry Plants"
so, pencil graphite might not be as good lubricant as pure graphite (pencil has clay mixed in), but i imagine it still might be offering some decent lubrication throughout the sharpener.

That said, when very fine, it is also going to be somewhat explosive :p [like basically anything else flammable when it gets small and has a high enough surface area it can flash fire], i hope it never gets too bad. Maybe you should add a shrapnel shield around the whole device?
Build a removable-hopper perhaps? (swarf needs to be collected.)

L
Willy Wonka claimed that's what breakfast cereals were made from. You could use the shavings to add additional interesting layers to your homemade Micarta:
sdobbie2 years ago
Now, if it were hydrogen gas you were using to power the engine, I would be interested.
Wouldn't work if it's a two cycle.
Sure it would. Substitute a gas mixer for the carburettor, put a flame arrestor on the exhaust port, and make sure it doesn't get hot enough to auto-combust the hydrogen. Overheating would probably be your major concern since most small engine designs use fuel vaporisation to soak up a lot of heat.
Where does engine oil go?

Now if it a four cycle it wouldn't be a problem. I've converted several mowers over to propane.

Anything than runs at a specific RPM for it's job is simple.
It depends on the design. Some two cycle engines do have separate oil systems. Otherwise you have a few options depending on how heavy-duty the engine is and its internal geometry. You can inject oil with the fuel as usual, you can find a spot to add oil ports, or, since a gaseous fuel doesn't wash the oil off of the cylinder walls like gasoline will, you can replace the oil with a high temperature, high pressure grease. There are pros and cons to each approach.
Many, more sophisticated two strokes don't use premix, but regular gasoline with a separate oil injection system. Shouldn't be too hard to come up with something that's "good enough" for this application.
not true it takes some modification
How would you get the oil into the combustion chamber to lubricate the internal workings? I'm confused. Explain please. I have several two cycles I'd like to convert to propane.
I am working on a new dezine but so doing a dripe sistume
carusoml2 years ago
If you really wanted a "V-8" powered version, there is a company that machines miniature versions for RC Cars. Crafting a coupler for the transmission output shaft wouldn't be hard at all. And for the truly insane, there is even a supercharged version.

http://www.conleyprecision.com/609.htm
This would be great for my son. He has a battery opperated pencil sharpener and he has more fun sharpening the pencil then he does writing with it.
This is for the person who has everything. So cool.
You just gave me an idea. A gas powered razor.
be careful don't shave your head off but have fun
awalls2 years ago
Alot better then The version we did at school, We made a video on youtube(On the youtube channel NickLTR) and we couldn't find one picture or topic related to a weedeater powered pencil sharpener. I would of loved to have atleast had something to go off of. I am going to say your idea is better then what ours was.
annarosesc2 years ago
You could have have it automatic , where it takes the pencil, sharpens it for .2 seconds then ejects it. You could sharpen 1000 pencils at once.
You made the Instructables newsletter which is how I saw this.
This is worthy of a Tim the toolman award for sure

I can turn letters into words, http://wordunscrambler.com , but you are the real deal. But please don't try to upgrade to a jet engine powered pencil sharpener.

Anna
mkeith542 years ago
Nice 'Ible.

Have you considered using a vacuum food saver machine to make a cheap vacuum press to clamp the parts together without the need for clamps. The machines can be bought cheaply from goodwill and second hand shops. The bags are available from wally world and the box stores.
bLiTzJoN2 years ago
Guys on Top Gear would approve as well:
I do as well... Or we could make a V8 pencil sharpener... :D
yoyology2 years ago
I would think that a human-powered one would be more likely to discourage the sharpener-addicted student. Got any old bikes? :-)
i thought the whole freakin point was to be gas powered!?!?!? haha :)
motorbike.
Sure. That was the point of THIS instructable. The next one...
dorkpunch (author)  yoyology2 years ago
lots and lots... Hmmm.....
I'm PS118.
The only way this could be better was if it had a blender attachment, so when not sharpening pencils, you could make 'ritas with it.
5 stars all the way!
Actually saw on in the pits at a race track. The guy called it "The Daiquiri Wacker". Needless to say he was very popular.
nurdee12 years ago
Awesome. I gave you 5 stars. I always like things that swat flies with hydrogen bombs.
Manny B2 years ago
Hey, how about a gas powered eraser? I need something that's faster than all the mistakes I make!
cardesnr992 years ago
You've inspired me!

Watch for my 2-stroke 50cc pepper mill, soon!
PS1182 years ago
This is among the most dangerous and pointless things I've seen in my life!

I gave it 5 stars. ;)
. . . not exactly pointless . . . many points . . .
dorkpunch (author)  PS1182 years ago
I do believe that is one of the highest compliments I have ever received!
anode5052 years ago
SO over the top! LOVE it!
jolshefsky2 years ago
Dangerous and absurd. Excellent job! I laughed when I saw the title and initial image.
ventifact2 years ago
Cutting butter with a chainsaw.
dreamberry2 years ago
This could only be more ridiculous if it had wheels and you could take it for a spin down the hall while sharpening your pencil. I love it! Now you need to make a matching pencil duller, in case someone over sharpens their pencil.
Make it solar powered and you can have sharp pencils AND save the planet. Probably i little more quiet too...
blkhawk2 years ago
Tim the Tool Man would have been very proud of you!