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Simple, easy to make, and fun, this model engine is made from cheap easy-to-find materials. It runs on compressed air supplied by your lungs as you blow the piston down and then suck it back up! It demonstrates principles of motion and engine operation, and allows students to learn the main parts of any engine: Crankcase, Crankshaft, Connecting Rod, Piston, Cylinder, and Flywheels.
I can't take credit for "inventing" this cool project but I've adapted this to make it a lot easier to build, and it can be done very quickly. This is an activity I do with my 7th and 8th grade students in a Small Engines Repair class, but it could be used for many other activities like drafting, measuring, studying the laws of motion, or even a history project, as it closely remembers an old hit and miss engine.
Content Learning Objective:
By building a Toilet Paper Engine, students will understand the basic principles of operation in an Internal Combustion Engine.
Language Learning Objective:
By building a Toilet Paper Engine, students will identify engine parts using their correct names; i.e.- a ping pong ball is not a ping pong ball, it is a Piston.
Please find included below an Instructions Booklet .pdf, a Template .pdf, and a Measurements Worksheet .pdf. Also included is a Google Sketchup model of the completed engine
Other Resources:
I have had a few people ask about other resources relating to engines that could be used when teaching, so here are a few!
http://www.animatedengines.com/ Excellent website that shows cutaway animations of just about every type of engine you could imagine!
http://en.wikipedia.org/wiki/Four-stroke_engine Wikipedia's take- a couple of great animations, TONS of information, and lots of other links to more websites.
http://www.animatedpiston.com/Home.htm A couple of animations of different motorcycle engines- neat because you can hide different parts of the engine while the animation is running.
I can't take credit for "inventing" this cool project but I've adapted this to make it a lot easier to build, and it can be done very quickly. This is an activity I do with my 7th and 8th grade students in a Small Engines Repair class, but it could be used for many other activities like drafting, measuring, studying the laws of motion, or even a history project, as it closely remembers an old hit and miss engine.
Content Learning Objective:
By building a Toilet Paper Engine, students will understand the basic principles of operation in an Internal Combustion Engine.
Language Learning Objective:
By building a Toilet Paper Engine, students will identify engine parts using their correct names; i.e.- a ping pong ball is not a ping pong ball, it is a Piston.
Please find included below an Instructions Booklet .pdf, a Template .pdf, and a Measurements Worksheet .pdf. Also included is a Google Sketchup model of the completed engine
Other Resources:
I have had a few people ask about other resources relating to engines that could be used when teaching, so here are a few!
http://www.animatedengines.com/ Excellent website that shows cutaway animations of just about every type of engine you could imagine!
http://en.wikipedia.org/wiki/Four-stroke_engine Wikipedia's take- a couple of great animations, TONS of information, and lots of other links to more websites.
http://www.animatedpiston.com/Home.htm A couple of animations of different motorcycle engines- neat because you can hide different parts of the engine while the animation is running.
Templates.pdf808 KB
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Signing UpStep 1Gather Materials and Tools
Lets start by getting everything we need together.
Tools Needed:
Hot Glue Gun
Scissors
Wire Cutters
Pliers
Ruler
Pencil
Drill or Drill press and Drill bit
Supplies:
Approx. 2 sq feet of cardboard
Toilet paper roll or paper towel roll cut in half
8" of wire (a wire hanger would be perfect)
Piece of wood dowel ( just over 4" long and about 3/8" dia)
Ping Pong Ball
2 used or worthless cd's
Duct tape (you never know, right?)
Glue sticks for the hot glue gun
Small piece of sandpaper or file
Additional items that come in handy (especially if building with large groups):
Trace-able templates for the cardboard parts made in step 2.
Several crankshaft bending templates
Instructions book
Pre-cut and drilled dowels for the connecting rods.
COST: I estimate each engine has roughly $1.00 worth of materials. The only things I had to buy was the Ping Pong ball (40 cents), the dowel ($1.00 was enough to make at least 6), and the wire (large role cost me $4.00). I had sandpaper, tape, hot glue sticks, and everything else laying around.
Tools Needed:
Hot Glue Gun
Scissors
Wire Cutters
Pliers
Ruler
Pencil
Drill or Drill press and Drill bit
Supplies:
Approx. 2 sq feet of cardboard
Toilet paper roll or paper towel roll cut in half
8" of wire (a wire hanger would be perfect)
Piece of wood dowel ( just over 4" long and about 3/8" dia)
Ping Pong Ball
2 used or worthless cd's
Duct tape (you never know, right?)
Glue sticks for the hot glue gun
Small piece of sandpaper or file
Additional items that come in handy (especially if building with large groups):
Trace-able templates for the cardboard parts made in step 2.
Several crankshaft bending templates
Instructions book
Pre-cut and drilled dowels for the connecting rods.
COST: I estimate each engine has roughly $1.00 worth of materials. The only things I had to buy was the Ping Pong ball (40 cents), the dowel ($1.00 was enough to make at least 6), and the wire (large role cost me $4.00). I had sandpaper, tape, hot glue sticks, and everything else laying around.
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I built a V4 model, and it works! There is a new step at the end called Variations 2 with more information on the V4.
I also added a picture there of all three engines together AND a picture of the 20 or so engines my class just finished building.
Teaser pics for ya'll.
I sometimes do holiday projects with my 6-year old and a few of her friends. This may well be featuring!
You could make valves using more toilet roll tubes and ping-pong balls.
This time, you would attach a ball to the shaft, so it spun with the engine inside a toilet roll. It would want an "inlet" hole in the front (away from the engine) and an outlet hole (well, groove) in the side that matched a hole in the side of the tube. Then, as the engine turns, the valve opens on the power stroke (outlet hole lines up with groove in ball) but then once the ball turns so the groove is past the hole, the hole is blocked and no more air blows in. A tube would take air to the calendar head and another valve on the other end of the shaft would have the opposite timing as an outlet.
Two cylinders could run off one pair of valves by having their inlet holes on opposite sides of the tube.
Not sure if that makes any sense but it works in my head!
where does the air you blow in escape from and how does the piston come back ?
The air that was blown in is sucked back out when you inhale. If the engine is built well, you can just time your breaths out- but you have to take your mouth of the engine a little to let the air inside come back out.
If you make an air out let on both the cylinders and then blow air into it
you wont have to coordinate the breathing hopefully.
The placement is very important.
I am not sure if it will work or not.
What do you think ? + I really liked the work you have done
thank you
A ball shaped piston gets around complex linkages at that end, and it's all nice and easy to get parts. One thing that I DO wonder about is the possibility of an "exhaust valve". Obviously lung pressure takes care of inlet valve and ignition timing, but the only engine that has a "suck" on the exhaust stroke is a Newcommen Steam engine where the stem is condensed in the cylinder.
I'm wondering if a "Pallet Valve" might be possible with a trip on the flywheel or something?
I was thinking of having a flapper valve or reed valve that could be tripped open by having an extra bend on the crankshaft that hits a pushrod - sort of an over head valve 2 stroke. Hard to explain, guess I need to build a model and see how it works!
I think in a pinch you could live with out the ball piston- pretty sure if you cut a disk the right size out and glued that to the dowel, it would still work. Theres a LOT of room for error on this engine...
Valve Wise, that's more or less what I was thinking. I suggested a trip on the fly wheel to get around having to bend the crank shaft in more devious convolutions, and I'm not sure it'd run on compressed air without an INLET valve too. If you have an exhaust valve it'd certainly be POSSIBLE to add an inlet valve, and I imagine it would run adequately fron the air in a baloon if you did, but I like the way that the user has to TIME their breath to get the thing to move correctly. Makes it a more interactive demonstration...
Or put both valves in and make them MANUALLY operated...
A bazillion imaginary internet PBL points. Love the language acquisition objective, too.