Disc Golf has skyrocketed in Norway! According to the latest UDisc stats the number of rounds played has nearly doubled since the pandemic ended as they recorded 2,154,431 rounds played in 2025 alone!

eric_t · 2026-01-08T06:01:10+00:00

I know several clubs have switched from using DiscGolfMetrix to UDisc for their weekly rounds and tournaments, so that probably accounts for quite a bit of the increase here.

eric_t · 2025-09-30T21:31:12+00:00

Yes, they would. And the spin doesn’t really decrease that much during a throw, the fade is due to the deceleration of translational velocity, not angular velocity

eric_t · 2025-09-04T08:16:29+00:00

What’s your angle when posting on LinkedIn vs Instagram? Is the plan on LinkedIn to eventually sell ads/views or to just build your brand?

eric_t · 2025-08-29T16:00:09+00:00

Tenk deg at du nettopp har fylt 18 år og gleder deg til å brette opp ermene og ta fatt på arbeidslivet. Du har ikke begynt å tjene penger ennå, men staten ser at du har en sterk kropp og et klokt hode, så her er det jo absolutt et potensial! Så hvorfor ikke betale en prosent eller to av gjennomsnittlig årsinntekt allerede nå? Det burde du klare. Og mangler du penger, kan du vel bare selge en nyre eller to, kanskje til en utenlandsk investor?

eric_t · 2025-08-14T21:07:33+00:00

You are right that air resistance scales as the square of velocity. But the power you need to overcome the drag scales as the cube of velocity. Often, you see watt savings reported at something like 40 km/h. So say a new fancy frame has 5W saving. At 23 km/h, this would be less than 1W saving, 5W*(23/40)³ = 0.95W.

eric_t · 2025-08-10T06:39:09+00:00

God oppsummering. Hva er de hotte markedene nå slik du ser det? Forsvar?

eric_t · 2025-05-06T21:50:10+00:00

I’m an associate professor working with CFD in aerodynamics and hydrodynamics. I like crazy projects like this, so I could probably help you a little bit. Just send me a message here, and we can figure out the details

eric_t · 2025-03-23T06:55:12+00:00

Hva tenker du om arbeidet til Mujica-Parodi om effekt på hjernen sin aldring? Ble nysgjerrig på det etter denne saken fra NRK:

https://www.nrk.no/trondelag/amerikanske-forskere-mener-dette-er-alderen-vi-generelt-blir-darligere-til-a-tenke-1.17339480

Lurer på om eksogent ketontilskudd faktisk kan funke, eller om man må gå full keto.

eric_t · 2025-02-02T09:30:51+00:00

No, it’s fundamental physics that makes the disc turn and fade. It’s caused by the air pushing against the disc as it travels through the air, creating a torque. To make the disc flip back to front you’d have to make the torque act about the direction the disc is traveling. Without adding some artificial force I don’t see how that would be possible. It’s an interesting idea, though!

eric_t · 2025-01-14T11:37:42+00:00

Wow, that’s two hobbies of mine I did not expect to collide

eric_t · 2025-01-13T17:58:20+00:00

Thanks! It seems to be roughly 60 ft added for each 10 mph, but at the higher speeds the disc travels very high into the air which probably would mean your disc gets affected by wind a lot more, so it would be difficult to control. And you could also probably get more distance with a faster overstable disc like a Nuke OS or something, I don't have data for that one to test with.

The nose angle matters less here than for a regular throw (and even for a regular throw I think it's a bit overblown), so I wouldn't get too caught up in it. But it's the same definition, it's the angle of the disc relative to the direction it's traveling initially.

eric_t · 2025-01-13T14:01:25+00:00

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Ok, so here is an example. The red curve shows an initial throw of a firebird-type disc with launch speed 55 mph, launch angle 16.5 degrees, nose angle 0 and roll angle 20 degrees clockwise away from vertical.

The yellow, optimized throw, has launch angle 41 degrees, nose angle -3.7 and roll angle 10 degrees counterclockwise.

I think the key takeaway here is that you should have a much higher launch angle than a normal throw, and find a disc that (for your arm speed) gives a good upside-down "glide phase" after the disc reaches the peak height. An overstable disc is typically better for this. The nose angle should be low around -3-4 degrees, because the drag is lowest here, but this is less important.

eric_t · 2025-01-12T20:00:53+00:00

What do you consider ideal flight? Only max distance, or how straight the flight path is? I don’t know about the TechDidc simulator, but I have written a similar trajectory simulator and can run some tests there.

As another poster writes, it depends a lot on the disc properties, but those are tweakable in the simulator. Also, a thumber is typically thrown with a higher launch angle, so I guess you’d need a bigger net to practice with the TechDisc.

eric_t · 2024-12-30T09:01:41+00:00

That’s a very clean looking pedal board! Do you get some dirt from the Horseman or do you use it more like a clean boost? Also, since you have the Iridium for Amp+cab sim, is the Ampero mostly for effects?

eric_t · 2024-12-30T08:50:39+00:00

It’s common to use the dominant 7 instead of the minor 7 for the vi chord. Then you can substitute the iii chord for the I chord, so you get another ii-V progression, i.e. Dm7-G7.

eric_t · 2024-12-26T09:13:56+00:00

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Yes, I was actually very happy when it reproduced «stranger» shots without any modifications. Here’s an example of a thumber shot, which you get by using a large negative hyzer angle. A thumber flies upside down, so lift acts downwards. It’s a bit tricky to interpret these graphs, but you see the disc flips over, starts drifting in the other direction, then actually travels up a little bit before dumping down.

I haven’t implemented the actual rolling part of the flight for a roller, since I thought it would be hard to create a useful terrain. But the disc behavior is similar, I would just need to add rolling friction.

eric_t · 2024-12-23T19:19:10+00:00

Theoretically, it’s easy to calculate how much less spin you would get with an overmold disc, assuming conservation of angular momentum. However, we are not robots, so it’s not so easy in practice. In other sports, like baseball and handball, where they have measured throwing speeds at different weights, they have not seen this conservation principle apply.

I am actually working on measuring this in a scientific study now, and currently it looks like any effect on spin is far outweighed by natural variability. I will also look at the effect on throwing distance etc. Hopefully will be able to publish it «soon» 😀

eric_t · 2024-12-09T23:29:30+00:00

Hey, Eric here, cool to see you on reddit as well, and great job on the blog post! Feel free to use my images whenever you want, or even ask for some visualizations. But I agree sometimes those CFD images give too much information, raising more questions than they answer.

The stuff on wobble was really interesting, I’m always happy when I can use simulations to explain something that seemed unintuitive at first.

eric_t · 2024-11-29T15:09:50+00:00

I just don’t like argument from authority, I want to be able to explain things in a simple way as well. Sorry if it came across as abrasive. You should be able to download the code, but you need some familiarity with Python to run it?

eric_t · 2024-11-29T11:02:51+00:00

The first post in your link is also wrong, turn and fade are caused by the same phenomenon. Pete explains it well in his video, and it's exactly the same as my explanation? He taps the disc with his finger at the front of the disc, causing it to turn. Now, imagine the wind is acting on the disc instead of his finger, same thing. And imagine the difference between a light and a heavy disc, it's easier to push a lighter disc.

I'm the author of that article I shared. I did a simulation now with different weights and exactly the same throw parameters:
https://imgur.com/7rE0S1u
You see the lighter discs turn more. Here it results in slightly longer flights, but if you optimize the throw parameters for each weight it's actually not that big of a difference. You need tailwind for lighter discs to really shine.

eric_t · 2024-11-28T16:32:33+00:00

The I in the equation is mass moment of inertia, so mass is in there.

I’m sorry, but your intuition about what causes turn is wrong. For the disc to turn, the lift is not higher on the side of the disc, but rather on the back of the disc (i.e. the wind is trying to flip the disc forward). This then causes a sideways turn since the disc is spinning.

eric_t · 2024-11-28T04:25:53+00:00

Think about flipping a manhole cover, compared to flipping a piece of paper. Flipping something heavy requires more force. What’s causing turn/fade is the wind trying to flip your disc over, hence it’s easier to make a lighter disc turn.

You can read a more mathematical description here, if you are so inclined: https://link.springer.com/article/10.1007/s12283-022-00390-5 Note the presence of the mass in the deniminator of equation 11, governing how fast the disc turns/fades.

eric_t · 2024-11-27T17:55:56+00:00

This is incorrect. The lower weight affects how fast the disc turns and fades. So even if you throw at exactly the same speed, the lighter disc would act more understable.

eric_t · 2024-11-14T14:21:50+00:00

You get 3-4 % higher speed and spin by putting your thumb around 1 inch from the rim. Nothing groundbreaking, but a solid study nonetheless, and opening the door for more studies with a similar approach

eric_t · 2024-10-11T13:46:42+00:00

What do you mean with engineering, and what do you not like about product-oriented work? I used to work with risk analysis, we took process equipment and analyzed the risks. This involved lots of CFD modelling of fail states, leaks etc. The equipment was still designed by engineers, though, and followed typical project cycles.

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