Galaxy Z Fold 3: What happens when we draw 16,000 circles on it with an S Pen?

When new flagship phones come out, CNET doesn’t shy away from testing the durability claims made by manufacturers. We’ve done drop tests. We’ve done water tests. When the new foldable phones started coming on the market from Motorola and Samsung, we even did folding tests.

Even before the latest Samsung foldables were announced, I’d been trying to figure out a new kind of experiment to gauge the resilience of these phones. Could we test the strength of the hinges with weights? Maybe use it as a shovel at the beach to see if any sand got inside?

With the introduction of the Galaxy Z Fold 3 and its accompanying S Pen Fold Edition, I decided we should look at the durability of the screen itself. I was curious to find out how much one could draw on the screen with the S Pen before any ill effects could be noticed.

I knew randomly drawing on the screen for an extended period of time was no way to conduct the experiment, so I turned to my 3D printer, which I knew was capable of generating consistent repetitive motions. I modified my Creality Ender 3 V2 printer to make it a plotter instead and printed out a holder to make it work with the S Pen.

Then, with a little help from the internet, I had to teach myself how to program a little bit of gcode so I could make the plotter do what I needed it to. The key ended up being this little string right here: G2 F5277 I50 J0. With some trial and error, I figured out this bit of code would draw a circle with a radius of 50mm 1,000 times in one hour. Copy and paste 1,000 times in Notepad and voila!

Finally, once I got the Z Fold 3 in hand, I had to find a good drawing program that would be interesting to watch for 16 hours. I landed on Infinite Painter because of its clean interface and huge supply of interesting brushes.

So, now the time has come for me to see what happens when I put all these pieces together and run my experiment. You’ll note that I keep calling it an experiment, and not a test, because there’s nothing really scientific about what I’m doing. Samsung hasn’t made any claims about how much you can draw on the screen of the Z Fold 3 with the S Pen, so I’m not really testing anything. I’m just presenting a demonstration of what might happen if someone, for some reason, chose to draw circles on the Fold 3 for the equivalent of a 5K race.

Hopefully, it will also provide some zen to your day, having this experiment just running along in the background.

So tune in on Wednesday at 1 p.m. PT to see me kick things off and keep coming back until the wee hours of Thursday morning as I approach my goal of 16,000 circles, or just over 5,000 meters of drawing.

And if you’re curious, here’s some of the math behind my madness:

Radius of circle being drawn: 50 mm

Circumference of circle: 314.16 mm

The machine draws 1000 circles in 1 hour

1000 circles x 314.16 mm = 314160 mm/hr = 314.16 meters per hour

5 km would take 15.9 or basically 16 Hours

314.16 meters per hour = 1030.7 feet per hour

1 mile = 5.12 hours

3 miles would take 15.36 hours

5 km = 3.1 miles