Cast a Metal Spinning Top That Spins for 7+ Minutes
Introduction: Cast a Metal Spinning Top That Spins for 7+ Minutes
I love spinning tops! When I need something to help me chill out and relax I grab a top and spin it. Over the past year, I have learned how to cast low temp alloy for the sole purpose of making my own tops. In this Instructable, I will show you how to cast your own metal top that has the possibility to spin for 7+ minutes. The performance and duration of your top will depend on how well it's cast and sanded.
Safety Advisory: Working with metal alloy is dangerous please wear proper safety equipment when casting and detailing: goggles, mask, boots, heat resistant gloves, apron, etc. Also, please use proper supervision when casting metal. If you choose to attempt this Instructable you are responsible for your own safety and materials.
Supplies
Materials
* Cerrotru Alloy
* Easy Mold
* Corn Starch
* Petroleum Jelly
* 3D Printed Top
* Sulfur Free Modeling Clay
* Wooden Skewer
* Super Glue
Tools
* Do-It Mold Hot Pot 2
* Heat Resistant Gloves and Apron
* 600 - 1500 Fine-Grit Sand Paper
* 60 Grit Sand Paper
* Metal File
* Pliers
* Laser Thermometer
* Clamp
* Rubberbands
* Hobby Knife
* Something To Stir the Metal ( I used a thick piece of steel wire)
* LEGOs
* Plastic Nippers
* Silicone Ice Cube Tray
Step 1: 3D Print Spinning Top Master
3D print the spinning top I designed in either PLA or ABS. This will act as our master for the mold-making process. I used an Ender 3 and PLA to print my top. Using 600 grit sandpaper sand down and rough spots on the top. You can find the top I designed here:
If you do not have a 3D printer check your local library, makerspace, or university. Many public libraries offer a 3D printing service. Where I live my public library offers a free 1 hour 3D printing service. The makerspace and university in my town offer a $5.00 per hour printing service. If you cannot find a place to print there are online services available. For example, Shapeways.
Step 2: Make a Mold Box
Using basic LEGO bricks and base create a structure around the top. Make sure there are at least 1 to 2 studs of extra space between the spinning top master and the walls. The structure should be at least twice as tall as the top. I made my box two bricks tall and ten studs wide. Once you are happy with the box remove the top and fill it with modeling clay 1 brick tall. Do your best to make the clay even and flat. Press the top with its tip facing up about halfway into the clay. Tip: Press the top slightly off-center to leave room for the funnel and exhaust holes. 646
Use a skewer stick to tightly pack the clay around the top. Use the 3D-printed stem of the top to make registry holes in the clay at each corner of the box. These will help align the two-part mold evenly when put together. Using plastic nippers cut two bits of the skewer to make an exhaust and funnel hole. Press half of the skewer bit for the funnel hole in the top center of the clay. Press half of the second skewer bit into the clay at an angle to the left of the funnel hole. See pictures for reference.
Step 3: Make the First Half of Mold
Take Part B, the purple putty, and fill half the mold box. Remove it from the mold box and roll it into a ball. Create a ball from part A that is the same size. For accuracy, you can use a kitchen scale to compare weights. Make sure everything is set in your mold box. Easy Mold sets really fast once you mix A and B together, you have about 2.5 minutes to work with it before it becomes hardened. Quickly mix A and B together until it's a consistent color. Roll the putty into a ball and press it into the mold. For the best result, when adding putty to the box start with pressing it onto the spinning top then spreading it to the rest of the box. Make sure the putty fills every corner of the box. Lightly massage the center and each corner of the mold until it begins to stiffen. Let the mold dry for 25 minutes.
Step 4: Make the Second Half of the Mold
Once the first half of the mold cures. Remove it from the LEGO box. Clean off the flashing with a hobby knife. If a piece falls out of the mold replace it back into its cavity. Remove the clay from the box and replace it with the mold. The master and the skewer bits should be facing you. 556