by the kilo

3D Printer Fun

It took about 90 min of assembly, downloading the app, getting the Bambu A1 mini 3D printer online, and loading the filament — but I did nothing — the 11 and 9 year olds managed it all on their own. That alone, made me a fan of this printer (ty Dave Nadig for the rec!).

They got the printer set up by Wednesday.

By Thursday, Zak sold his classmate this fish for $1:

next to a Milano cookie for scale

By Thursday night he rolled his eyes at me for inserting arithmetic into everything. By now he doesn’t complain, he just works it out to shut me up.

Me: How much material does it take to make a fish?

Kid: 10 grams

Me: The filament cost about $20, how much filament do we have?

Kid: 1 kilo

Me: So how much does it cost to make the fish?

Kid: $.20…I make 80 cents.

Me: What about the electricity?

Kid: Oh come on dad, I’m not paying for electricity.

Me: Ok fine, but you need to know the cost at least. [Quick Google search on how many watts the Bambu mini takes.]

It takes about 60. That means it uses 60 watts per hour.

Kid: How much does electricity cost?

Me: Here it costs about $.40 per kilowatt/hr. This is much higher than most places by the way. It’s more like $.11 where [uncle] lives. How long does it take to print the fish?

Kid: Half an hour.

Me: So what’s the electricity bill for the fish?

Kid: $2.40

Me: Bruh

Kid: [Laughs] Uhh, 2.4 cents

Me: Bruh, half an hour

Kid: [Laughs] 1.2 cents

Me: Cool. I cover the electricity, you use the profits to buy filament.

[We had 2 tangent discussions. He brought up the idea of higher-margin items. He has a friend selling a 30-gram fidget for $3 and he noted that it was the “same profit per gram”.

The other discussion was about heat and watts. We talked about one of the best YouTube videos we ever watched together about the discovery of the blue led. We learned that most of the energy, about 85%, in an incandescent bulb is turned to heat. Very inefficient. While LEDs, light-emitting-diodes, are way more efficient but also that they are an astounding and relatively recent innovation because it took so long to crack the mystery of the blue led. You’ll remember from the 80s that we had red and green LEDs in all kinds of electronics but we didn’t get white LED light bulbs until about 30 years ago. We needed blue. The blue led saga deserves a movie.]

Anyway, I’m sharing this because parents always tell me they like this stuff. I apologize to your kids in advance:

🚸Games and Word Problems For Kids

[Someone I’m close with who escaped the world of drug-dealing joked that my kid selling stuff in school (he’s not supposed to do that) is a gateway. That we bought filament by the kilo and Zak sold the fish an implied price of 5 kilos is a bit too on the nose.]

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