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Author Topic: DIY Metal Beigoma Casting  (Read 81 times)


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DIY Metal Beigoma Casting
« on: November 21, 2020, 06:35:43 PM »

Hello Everyone!
It's been a while since I've posted. I've been busy learning how to make molds for casting Cerrotru allow, a non-toxic mix of tin and bismuth. Why learn this? With the rarity of beigoma tops in the states I wanted a way to take my 3D printed beigoma and cast them in metal. To make a beigoma good in the arena you need to heavily modify them. Since, I am quite new to modding beigoma I didn't want to alter my antique one and make a mistake....nor did I want to wait close to a month for new ones to be delivered. So I decided to make my own...again...!
IMG_20201117_000125975 by Joah Tang, on Flickr

The first step I took to making my own metal beigoma was to redesign my original 3D printed ones.
beigomamasters by Joah Tang, on Flickr

I did this in Tinkercad, a free 3D design software. I printed them out and gave the tops a test spin. I did my best to sand and balance them before moving on to making a mold. I used PETG for the print and sanded it smooth with 400 grit sandpaper. I found a good tutorial on Crafsman YouTube channel for making low temp metal molds with EasyMold silicone putty. I followed these two videos:


Side note the CrafsMan is one of the best maker channels on YouTube in my opinion steady craftin!!!!

...anyways back to the tops...
Once the supplies arrived I took some sulfur free clay and Legos to make a two part mold.

IMG_20201114_192731255_HDR by Joah Tang, on Flickr

I was able to make two molds from 1Id of EasyMold. My third mold was made from 100% silicone and cornstarch. For a more in depth tutorial check out this tutorial on mold making from the amazing CrafsMan:

After the molds had cured I took some Cerrotru alloy and melted it down in my HotPot2, basically a hand held foundry.  The nice thing about this alloy is it melts around 281ยบ F and it contains no led! The alloy is made in PA and can be found here:

IMG_20201114_204351210 by Joah Tang, on Flickr

Here's a quick video of my dragon beigoma being casted.

After lots of sanding I spun them and quickly realized yoyo string was not going to work so I made my own by doubling the string wraps in this yoyo string tutorial:

I found 12 - 14 wraps work best. Also winding the string on the tight side helps too.

IMG_20201121_164411323 by Joah Tang, on Flickr

To sand the beigoma down I used a wood file and 100 - 800 grit sand paper.

IMG_20201114_215733634 by Joah Tang, on Flickr

IMG_20201117_000125975(1) by Joah Tang, on Flickr

IMG_20201121_135943525 by Joah Tang, on Flickr

Here is a compilation video of the beigomas battling:

In the future I hope to improve my design to spin longer in canvas arenas. Right now the Cerrotru beigomas will spin for 30 seconds in a canvas arena but will come close to 2 minutes on a plastic surface! It may just be my arena that is effecting the spin will be upgraded in the future too. You can find the STL files here:

My next iteration will look something like this.
newbeigoma2 by Joah Tang, on Flickr

newbeigoma1 by Joah Tang, on Flickr

If anyone has any ideas, tips, or questions let me know I would love to discuss them!


« Last Edit: November 21, 2020, 06:43:15 PM by Joah »


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Re: DIY Metal Beigoma Casting
« Reply #1 on: November 21, 2020, 07:16:16 PM »

Amazing! Never have I seen anyone do that sort of thing here. For your string I would suggest using chalk/mason line, although I can't quite remember what number works for beigomas; I know it's thicker than no. 21 cord.
You could make some decent money from making those!  8) 8) 8)
« Last Edit: November 22, 2020, 04:29:56 PM by Texture »

Jeremy McCreary

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Re: DIY Metal Beigoma Casting
« Reply #2 on: November 21, 2020, 09:42:50 PM »

Brilliant! Every part of it.

Of course, using LEGO to frame the mold was especially brilliant.
Playing with the physical world through LEGO

the Earl of Whirl

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Re: DIY Metal Beigoma Casting
« Reply #3 on: November 21, 2020, 11:06:23 PM »

Wow!!  Very impressive.
Happiness runs in a circular motion!!!


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Re: DIY Metal Beigoma Casting
« Reply #4 on: November 22, 2020, 11:06:10 AM »

Joah: 'Side note the CrafsMan is one of the best maker channels on YouTube in my opinion steady craftin!!!!'

Even though I'm not a caster/maker, I found the CrafsMan channel a while ago and really enjoy his creations. Great video production and style. A unique character to be sure. Keep on steady craftin!