Recent content by George1

One of my students tried to check that a few years ago with Valkyries. He found that the outer wing bent downward and made the disc understable before there was any significant wear on the bottom rim. The dome also dropped, but, oddly enough, it also dropped on the control disc which wasn't...

I've made a simple web page on disc physics, including an introductory article on disc physics, a couple of projects done by my students, and a list of links to disc physics related sites. I hope to add more later. Please feel free to give me suggestions, corrections, etc. The URL is...

The Viper indeed deserves its own thread. I like the sharper-nosed DX Vipers (V mold, not VX). I carry two, one newish and one broken in. DX Vipers make great overstable discs for those of us who throw under 350 feet.

Oversimplified explanation: There are two kinds of drag, pressure drag and skin-friction drag. The air resistance of blunt shapes, such as golf balls, is dominated by pressure drag. The dimples on a spinning golf ball reduce the pressure drag but actually increase the skin-friction drag. The...

Classic Rocs used to be more understable. In 2003 I placed an order with Platypus Discs and the owner nicely put a free 150-class DX Classic Roc in with my order with a note that it was the best all-around disc. I liked it so I bought a heavier one that I used for many years. It was very much...

My eight-year-old son has been using a 150g DX Classic Roc (one of the older, more XD-like ones--Innova "cleaned up" the mold and the newer ones are more overstable) and a 147g DX Stingray. He likes them both and they are easier for him to grip than many discs. They were a little heavy and...

I hadn't thought of the porous membrane. What type of material were you thinking of? I'm also wondering about just putting a rig in a river. (We've got one right in the middle of our campus.) Another possibility would be a boat rig similar to your car rig. The big advantage over the car rig...

I've been wondering about cheap wind tunnel possibilities and car rigs as well. The car rig with strain gauges or something similar might be the way to go. I don't have a sun roof :( and it's Wisconsin in November. Could some of these measurements be done in moving water at slower speeds...

Physics and disc golf together? Sounds like a joyous, rather than bitter, end. :D

JHern, I’ve finally had time to think about your last figure. Treating the problem in terms of energy instead of forces certainly clarifies some things. Since you posted to get some discussion going, here are a few questions: How does the potential energy fit in to your three different...

Those are wise definitions and, at least in terms of the physics, it is necessary to keep clear the distinction. Is there a need to define similar angles for the perpendicular axis? I'm guessing that hyzer angle would measured with respect to the ground. What would be the analogous angle...

Here are a few disc physics links I've found. --George Frisbee Flight Simulation and Throw Biomechanics (http://mae.engr.ucdavis.edu/~biosport/frisbee/frisbee.html) Contains Sarah Hummel’s Master’s Thesis at UC Davis and other disc related research. Discwing’s Research Page...

Thanks for creating this thread, JHern. Here's my reply copied over from the old thread. ------- JHern, Your figure is excellent, thanks for posting that! I would add to your explanation that the weight of the disc affects the disc flight in (at least) two different ways. One is the moment of...

JHern, Thanks for the post--I agree entirely. I have a physics student looking for a disc related project and was contemplating a simple simulation, but probably quite a bit simpler than what you're thinking of. I've seen the UC Davis work. I see your point about the lift force vanishing and...

JHern, Your figure is excellent, thanks for posting that! I would add to your explanation that the weight of the disc affects the disc flight in (at least) two different ways. One is the moment of inertia (which you explain)—a lighter disc of the same shape will have a smaller moment of...