When I was that age I cut toy helicopter rotor disks out of tin can
lids. The launcher was string wound around a modified nail. I had to
fly them outside after my parents noticed the circles they carved in
The plastic ones from the store didn't have enough inertia to keep
spinning as long as my steel ones, wouldn't glide sideways and bounce
off walls, and I could pull the string on mine harder to make them
spin faster. Never mind that the first few still had the sharp outer
edges left by the can opener. Even at that age I became concerned
about a free-flying spinning scalpel ricocheting around the room, and
learned how to file them smooth and marginally safer.
I was at harbor Freight, and it was cheaper than that. Sam's club
had a decent price on a case of cans, but I doubt it would take more
than half a can to make your point. ;-)
The reason I was looking is the A/C on my truck quit and needs
recharged. I have everything I need, BUT enough R134 so I was checking
the prices. :)
BTW, they used to make 'Rate of Rise' fire alarm that was freon
powered. An alarm guy I knew had a bunch of ones he's used for demos, so
I removed all the horns, and put one together with a handful of Tee
connectors. Someone was tampering with a desk in our office. Imagine
their surprise when they opened the drawer, and that contraption went
off? They were nearly deaf before the can was empty. ;-)
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
My shopping list is a pair of Grover Organtones, and a nice 1/3 or1/2
HP compressor - the Thomas TA-3101DC or TA-4101DC Something I can use
a rattle-gun with, short of putting the full on 13-HP 30-gallon in the
I have to crawl under the truck to see how much receiver I have room
for under the bed - I can probably get a 12-gallon under there.
R-134 is cheap enough that you should be able to buy a full bottle.
Shop by price - the only difference between the "Automotive" and
"Refrigeration" is the fitting on the bottle, and that might trip you
up if you didn't expect it.
"Automotive" tanks have the Acme buttress fitting, and "Refrigeration"
has the standard 1/4" Flare hose fitting. Adapters in both directions
are readily available for cheap.
Model cannon? I did one with a nephew. Didn't get as far as
trunnions and a carriage. He loved it.
Functional would be cool, but an invitation to mischief. I intend to
do a functional one for myself some day. Maybe model Napoleon.
If they are creative and like to draw you might set them up making
freehand versions of the old summer-camp ashtray project, with
aluminum flashing, a hammer and a bag of sand. They could make chest
armor for an action figure, for example.
Couple of months ago at a Maker Faire, I saw a quicky project to do
en masse that was building a metal tray with handle of the sort you find
in tool boxes. I think the design was whittled down to just cutting,
bending, and pop rivets, but it was a popular activity.
A full sized tool box with lid and tray would be a memorable project with
a useful result, even if it gets filled with toys and not tools.
Myself, I made an electric vehicle for my (then) 12-year old daughter.
I mashed up a free second-hand four-foot diameter "cupcake" tin with $50
as-is electric scooter (ended up only needing new charger and batteries).
The bulk of the project was making a chasis to attach the cupcake tin to
Electric or two-stroke engine go karts, and similar wheeled items, are a
lot of fun for that age range, and off-the-shelf devices can easily be
repurposed into more interesting creations. I've seen leaf blowers made
into small hovercraft and cordless electric drills used to power bikes.
What makes a good suggestion will vary a lot with what tools and skills
you and they have and what budget you have.
is a lot more comfortable with electric than gas engines
I made some scupltures from TIG filler rod, bolts and nuts, maybe mini
gears if you have them, using tig welding. They sell those to tourists
in Mexico and they are surprisingly easy to make and end up very cute
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