Dynabee/powerball wrist exerciser terminology

  • Thread starter Thread starter Robin Hooper
  • Start date Start date
  • Tags Tags
    Terminology
AI Thread Summary
The discussion focuses on the terminology related to the mechanics of the Dynabee/powerball wrist exerciser, specifically how the rotor center pin rotates in opposite directions relative to its ends. The mechanism involves a single rotor pin spinning in a circular race, which prevents conflict in movement direction. The user, Robin Hooper, has explored patents and found terms like "induced perpendicular precession" and "Larmor precession" to describe this unique motion, although he acknowledges that these may not be perfect fits. He expresses a desire for simpler terminology to explain this principle effectively. Overall, the conversation highlights the complexity of the device's mechanics and the search for accurate descriptors.
Robin Hooper
Messages
9
Reaction score
0
Good day, and thanks for having me on you forum.

I’ve been searching the web for the terminology used to explain the principal involved that causes the Dynabee/powerball wrist exerciser, rotor center pin to rotate in an opposite direction, relative to each end of the center pin. I understand that a single rotor pin spins in an inner circular race or channel where by one end of the pin rides against the upper part of the guide and the other end spins against the lower part. This I understand eliminates conflict in the direction the pin moves in its channel guide. I find this a very interesting principal, unique to the wrist exerciser mechanism but I’m at a loss to explain it in simple terms.

Thank you
Robin Hooper.
 
Engineering news on Phys.org
Well this post has been up for a little while now and since then I've found several patents describing the Dynabee dynamics and nowhere is a simple term or terms that describes the principal involved. But in my search I did come across induced electron spin that resembles this what I'm looking for and its called "induced perpendicular precession". Since this type of movement needs to be induced by an outside source and it causes a spin along the primary axis as well as causing precession these terms may suite very well. Anyways that's what I'll call it until I'm corrected. What do you think?
 
Thanks to the many readers that have read my post. As I mentioned previous "untill I"m corrected". An even more accurate term is "Larmor precession". When an electron spin domain is induced/torqued by an electromagnetic field, it causes the domain to flip , if I understand this correctly, removing the EM field causes it to flop back. In the Dynabee application there is no EM field but this torque is replaced by the force form your hand.

Anyways, thanks again
 
Last edited:
How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...

Similar threads

Back
Top