Cast Aluminium Gears
Intro: Cast Aluminium Gears
STEP 1: Watch the Video
I made a full tutorial on creating these gears. I recommend watching it, as it goes a little faster than reading this instructable, and goes into further detail.
STEP 2: Templates
STEP 3: Cutting Foam
STEP 4: Casting
Make sure while doing this, that you have all the necessary safety equipment at all times. This includes: face shield, fire proof gloves, long handled pliers/tongs and a fire extinguisher.
STEP 5: Filing/Finishing
After I pulled my gears out of the mold, they looked very rough and uneven. Since these gears aren't going to be held or touched very much, I won't need to polish them as much as my Aluminium Handled Knife, but I still want them to look better than coming straight out of the molds. I first clamped the gears in the vise and cut off the bit of aluminium that filled the chimney. For the first gear, I used a normal hacksaw, but it took a very long time so for the second round, I used a Sawzall with a metal cutting blade. Then I flipped the gears in the vise and used an angle grinder to grind the faces down to a more silvery finish. After that, I used a drill to cut out the holes that had been filled in the casting process. Finally, I used an assortment of metal files to fine tune the teeth and sprockets of the gear. In the end, I could have spent a lot more time on them but I didn't have a use for them, so for now, they will stay rough.
When I cast the gears, the larger one didn't fully take shape and ended up not having several teeth. To solve this problem, I used IFixit, a kind of putty-like epoxy, and sculpted the teeth by hand. It actually turned out very well and worked better than I had hoped.
13 Comments
laffinm 9 years ago
mkovtchega 9 years ago
I don't know pretty much anything about casting, but I want to try it. So I don't really understand how the molten aluminum takes the gears form?
gasperi 9 years ago
How many cans do you need to make something that size?
pfred2 9 years ago
I've cast cans into ingots and it takes quite a few cans. The main trouble with melting down cans is how thin they are. Being so thin they tend to oxidize more than they melt. Oxidized metal is not the nice shiny stuff that you're looking for. I find that submerging the cans to melt them helps out a lot, but that has its own hazards doing it too.
The other thing to note is that cans are pure aluminum. Pure aluminum is not the best casting alloy of aluminum, it isn't an alloy at all. You can alloy your pure aluminum with some zinc and have a better material.
jarikcbol 9 years ago
If you want to add zinc to your alloy, remember that pennies are made from zinc, with a copper coating, which can be removed any number of ways. And no, its not illegal to melt pennies down for the zinc, the law about messing with money is very specific, and indicates that defacing them to change their value is illegal (making a silver dollar out of a quarter) but turning them into something that is not money is perfectly fine.
pfred2 9 years ago
You would have to add quite a bit of zinc to reach the ratio that Zamak is. Diecast metal is mostly zinc. I think that would be more economical material to use than pennies.
Jobar007 9 years ago
This is exactly what I was going to post: cans are pretty cruddy to cast with. A better solution would be to go to craigslist and find an aluminum block lawnmower in the free section and haul it off. Yes, it does require a lot of work to disassemble and clean (clean material = less crap to skim), but it is a casting alloy and will be night and day in difference in your results.
laffinm 9 years ago
baecker03 9 years ago
laffinm 9 years ago
neo71665 9 years ago
babaguru 9 years ago
Tom Hargrave 9 years ago
My uncle used to cast replacement Studebaker parts like door handles from melted down pennies, but pennies were 100% copper back then. He used the lost wax process then would clean & polish them up and send them out to a plating company to have the parts nickel then chrome plated.