Make A Rotational Casting Machine For Under $150

Picture of Make A Rotational Casting Machine  For Under $150
In this Instructable I will be showing you how to make a rotational casting machine using ordinary items. What you decide to do with the machine after you are done is completely up to you. I will not be held responsible for any inadvertent pregnancies, rodent infestations, snow storms, or sightings of James Dean.

I can tell you that my plan is to use the machine to create hollow casts using urethane molds.

I tried to make the directions as obvious as possible, but clearly my day job is not as an assembly instruction director, so please email me ( if you have any questions that arise during this Instructable. I heavily stress relying on the schematic as your guide.

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Step 1: The Supplies & Schematic

Picture of The Supplies & Schematic
The totally cost of supplies will be $150 give or take. The most expensive parts are the chain rings ($20 a piece) and the gear chain (about $20).

The schematic I created for the roto cast shows you where things are going to go, but doesn't get into the details. Most importantly, it shows you where the secure and loose joints are going to be.

Here is what you will need.

Strong power drill
Full set of high quality drill bits
Pliers or Leatherman
Glue gun (w/glue)
Metal/Plastic epoxy (2,500 pounds per square inch strength)
Staple gun
Bicycle gear cutter tool
Hack Saw
Wood Saw

2x 20 inch 2x4
1x 25 inch - 2x4
4x 5 inch - 2x4
2x 18 inch - 1x1
2x 16 inch - 1x1
2x 14 inch- 1x1
2x 12 inch- 1x1

Threaded Rod:
2x 4.0 inch - 5/16 inch rod
1x 4.5 inch - 5/16 inch rod
1x 8.5 inch - 5/16 inch rod
1x 3.5 inch - 5/16 inch rod
3x 4.0 inch - 3/8 inch rod
1x 6.0 inch- 3/8 inch rod
1x 12 inch - 3/8 inch rod
1x 3.0 inch - 3/8 inch rod

10x 5/16 inch stop nut
13x 5/16 inch nut
5x 3/8 inch stop nut
5x 3/8 inch nut
Box of 4 inch wood screws
8x 3/8 inch washers (probably will have extra)
8x 5/16 inch washers (probably will have extra)
4x 3.5 inch 22 teeth bicycle chain rings with 4 pre-existing mounting holes, NOT 5
2x 1/8 inch t pipe connector - to support the rotation axle
2x 1/8 inch elbow pipe connectors - to use for the crank
12x L flat brackets used to strengthen joints for frames
3x 3.0 inch flat metal plate with 4 holes in it - this comes in packages of 4, and would normally be used to secure to pieces of wood together. These plates should be able to bolt into the chain ring holes. You will have to drill a whole in the center of the plate though, as there is no existing one there.
14x14 inch piece of mesh

jexter11 months ago

Nicely done!

ultraphil1 year ago

Check out this professional version that has motor

Woot woot! I am now in awe of you!!!! Looking at $$$$ machines, now I am going to follow your foot steps. Thinking metal instead of wood, though. Keep rockin' it DIY style homie!
heathbar643 years ago
This is my first introduction to rotocasting. Can you tell us more about the process? It looks like you are just turning the mold over and over so the casting material just coats the inside. Is there more to it that that?
ZBM heathbar642 years ago
And that just kind nailed the whole point of rotocasting. In that it is used to make hollow positive of the mold......
Vyger3 years ago
It sounds like you were chewing on your vodka infused bacon while you shot the video.
Pseudoreid (author) 4 years ago
I"ll be updating this Instructable, as I got a lot of good feedback from Maker Faire...stay tuned
waiting.... patiently... for the updates :)
Hey I was just wondering what are the sizes and weights of the molds you have put on the machine? I work with life sized heads a lot, and would like to start using some materials that require a rotational machine. Any information you could give would be a great help. Thanks. M
mfowkes5 years ago
i found that when i made one of these that i needed one of the sprockets to have more teeth, giving the central frame more varied rotations and giving a better, more uniformally hollow cast overall. would you in retrospect make any alterations to your design?
soundmotor6 years ago
The cast rhino head looks great, proof your instructable works! How about another on mixing & coloring resin before the pour?
Chaz-imus6 years ago
Was that some Crystal Castles playing in the background the song is Crimewave im a huge fan of them
Holy Crap, its the Reider in the hizzouse!
Geordiepom6 years ago
Interesting idea having one sprocket directly driving another. How are these components wearing?
Pseudoreid (author)  Geordiepom6 years ago
@Geordiepom Sprockets are wearing well so far. The only addition that I might make is a counterweight, as when the mechanism is turned, it has a tendency to speed up during certain parts of the revolution due to the imbalance.
Pseudoreid (author) 6 years ago
@spike shadows Thanks for the concern. If you go to step 7, you can watch a video where I actually have a mold mounted in the machine. Basically, I duct taped it to the mesh on the small frame. You could strap it in using some other method, but duct tape is quick and easy.
can you show where to mount the molds? I can't really see it anywhere in here