# Physics Suggestions - Over my user level

1. Aug 24, 2010

### JeremyJohnson

Hi Everyone,

Ok, I have been trying to find a solution to a design that I am working on. There is a practical application in physics but I need to solve this piece before moving forward.

This is a hobby project and the know-how to do this is above my user level.

Here is what I am trying to do:

1. I have a model frame outline of a 6 sided cube.
2. The axis base will be one of the corners.
3. I want a method (possibly gear based) at the axis base that rotates causing each section of the cube frame to rotate independently.

Here are my questions:

How do I connect this together ?
How do I get a gear system in place that can rotate from one point causing all other sections of the frame to rotate?

This design has not given me much peace since I envisioned it.

Any help would be greatly appreciated.

Thanks

Jeremy

2. Aug 24, 2010

### Staff: Mentor

Welcome to the PF.

It's kind of hard to visualize what you are describing. Any chance you could post a sketch?

Can you just use 6 motors to rotate the 6 faces (or whatever)? Does it all have to be via mechanical linkages, or would separate motors do the trick?

3. Aug 24, 2010

### JeremyJohnson

Ok, here is a picture of what I am trying to solve as a basis for the rest of the project.

The frame is 10 inch long metal dowels.

There needs to be a base that this frame connects to (not necessarily the same size as the other frame sections as there will be another shape inside.)

I have no idea how to keep the frame portions connected and rotate independently.

Sorry for the poor image as it was done quickly in powerpoint just to give you a visual.

Thanks,

Jeremy

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4. Aug 24, 2010

### Staff: Mentor

Do you mean you want each of the 6 dowels to be able to rotate independently (not each face of the cube)? You can make them hollow, and have them over a non-moving 6-sided frame. Then rotate each of the 6 outer dowels using 6 separate electric motors (which you can hide inside the frame pieces).

5. Aug 24, 2010

### JeremyJohnson

Thanks for the suggestion. However, getting the metal dowels to be hollow would present another issue altogether. I cannot visualize the motor placement that you suggest. I really do not have a preference as to how this should work. Each segment of frame should rotate (spin) and the entire piece should rotate on the base.

6. Aug 24, 2010

### schip666!

If it is indeed the dowel/edges that you want rotating along their long axis you pretty much have no choice but to make them tubes and run a supporting axle structure inside them. I did a similar thing with a simple triangle: http://www.etantdonnes.com/KINETIC/fear_head.jpg although you may not be able to tell much about the mechanism from the photo... (There's a short movie linked off of http://www.etantdonnes.com/kin_summer07.html that might, or not, help).

Coming up with a driving mechanism that works from a single motor might be over your pay grade as well. I can imagine, but not entirely picture, bevel gears on the ends of each dowel that connect to others' ends to translate motion. Some edges would have to spin in opposing directions, which may not be an issue for you. Otherwise use six small motors mounted in the corners somehow. For my piece the axles are also hollow tubes and I ran the wiring through them.

Good luck Mr Phelps.

Last edited by a moderator: Apr 25, 2017
7. Aug 24, 2010

### JeremyJohnson

Thanks for the great insight.

This is the easy one. You should see the plans I have drawn up for a laser microsonic projectile.

Getting dowels to spin and hold that shape is hard now. The rest of that design & components as well as this next project will keep me busy for a bit.

Although, my interest in these things did not occur until late in life and within the last few years.

Jeremy