Spinning Tops: They Never Get Old!
3 flavors: aluminum, brass, and copper
Goal: create the ultimate spinning top -- one that gets at least 10 minutes on a good spin and that requires no tools to start.
Materials:
Processes:
Materials:
- Brass rod
- Carbide ball bearing (more on that later)
Processes:
- Lathe work (turning)
Another shot. On a hard surface, these tops will spin for 12+ minutes! The hard bearing ball on the bottom is key to that success -- with the hardest materials possible you get closest to true "point contact," which means less friction as the top spins and hence less energy loss and longer spin times.
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Top Wars: I think this game could catch on among kids and adults alike!
the process
My simple aluminum top after machining
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I was satisfied with the shape of this part (done free-hand), so I copied it into CAD and used it as the basis of my other models
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Post-turning of brass top
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Yummy finish
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Still learning how to use this mini-lathe knurling tool, but was satisfied with the results this time!
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Now for Sale!
I ended up making a huge batch of anodized aluminum spinning tops (pictured below) that we've been giving to friends, playing with ourselves, and donating to charities. We're also offering a few for sale via local shops -- please check Pennyweight in St. Helena if you're nearby, or contact me directly if you are interested in carrying this product in your store!
Aluminum spinning tops for sale!
How Big of a Spinning Top Can We Make?
My mom loves spinning tops -- this whole endeavor was inspired by her! For her latest birthday, then, there was no doubt in my mind that a huge spinning top would become her favorite gift. I just had to figure out how big I could make one.
I found a piece of aluminum (shipped via freight of course) that was about 15" diameter and 2 feet long. It weighed a few hundred pounds. My friend Alex owns a local machine shop, and I quickly realized that he was my only hope of getting the top done well and on time -- I've never turned anything like that before! The project came out beautifully, especially after some light bead blasting and clear anodizing. I also had a special base made for the top, with a divot in the center to keep the top spinning on the platform instead of wandering off and destroying our entire home.
Lastly, I 3D printed a custom bit (complete with a rubber o-ring for traction) to spin the top up via power drill. Check out the pictures and videos below!
I found a piece of aluminum (shipped via freight of course) that was about 15" diameter and 2 feet long. It weighed a few hundred pounds. My friend Alex owns a local machine shop, and I quickly realized that he was my only hope of getting the top done well and on time -- I've never turned anything like that before! The project came out beautifully, especially after some light bead blasting and clear anodizing. I also had a special base made for the top, with a divot in the center to keep the top spinning on the platform instead of wandering off and destroying our entire home.
Lastly, I 3D printed a custom bit (complete with a rubber o-ring for traction) to spin the top up via power drill. Check out the pictures and videos below!
WD-40 bottle for scale
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The custom drill tip that enables us to spin the top up to 3,500+ RPM
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The tip fits into the center drilled hole on top of the spinning top. That hole serves a double purpose, as it was used during manufacture and also during spinning
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A good spin can last for 35+ minutes with this top. Below you can see a couple of videos: first at startup (spinning fast), and then the final minute of spinning as the top holds on to the little bit of energy it has left.
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Bejeweled Tops
As discussed earlier, my mom loves tops! As her birthday comes around each year, I try to think of ways to up the ante -- it's a fun exercise! This year, with the help of some "scrap" jewelry that I was allowed to recycle, I had about 1.5 ounces of 18kt gold that I could use to make something really special.
I found a model of an air-powered top online, and modified it for the purpose: a top stem that fits a straw, scaling the rest of the model appropriately, and adding provisions for a ball bearing spinning surface. I printed the master with our wax printer at POP (a ProJet 3600W) and got to work with the investment process: spruing, investing, burnout, casting, and finishing. This time, because I was using a "synthetic" (lab made, real chemistry) ruby for the bearing, I could cast it in place (sapphires are able to handle very high temperatures without breaking down).
To my utter amazement, this casting was nearly flawless on the first try. I think that a lot of that was pure beginner's luck... and maybe some extra good luck since it was a gift for my mom! We can get spins of 5+ minutes with a straw and human air. Due to the impeller design of this top, it pushes a lot of air around and slows down quicker than you'd anticipate as a result. By spinning it up with a straw and then placing it in a vacuum environment, we were able to increase the spin time to over 13 minutes!
I found a model of an air-powered top online, and modified it for the purpose: a top stem that fits a straw, scaling the rest of the model appropriately, and adding provisions for a ball bearing spinning surface. I printed the master with our wax printer at POP (a ProJet 3600W) and got to work with the investment process: spruing, investing, burnout, casting, and finishing. This time, because I was using a "synthetic" (lab made, real chemistry) ruby for the bearing, I could cast it in place (sapphires are able to handle very high temperatures without breaking down).
To my utter amazement, this casting was nearly flawless on the first try. I think that a lot of that was pure beginner's luck... and maybe some extra good luck since it was a gift for my mom! We can get spins of 5+ minutes with a straw and human air. Due to the impeller design of this top, it pushes a lot of air around and slows down quicker than you'd anticipate as a result. By spinning it up with a straw and then placing it in a vacuum environment, we were able to increase the spin time to over 13 minutes!
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