My Hamster Wheel...

[raj]

My hamster wheel will consists of two drumwheels, one large and one small, each with one side open, facing one another on separate axles.

Inner rim of large drum wheel serves as a rotating ramp.

Four bars with weights at each end of bars (in the form of barbells), slide to and fro/ up and down, through diametrically opposite openings on rim of smaller wheel( serving as hamster).

When smaller wheel rotates, the bars will slide through the openings on the rim and the weights will move nearer to the axle on the ascending side and further from the axle, on the descending side, in time to be lifted back at the six o'clock position, helped by the rotating ramp.

The weights will be hooked at the 6 o'clock position and get released at the 10 o'clock position.

As the weights touch the rotating ramp, they will provide torque to both small and large wheel, and will continue their move to the lowest point at the 6 o'clock position, while being gradually lifted up by the rotating ramp, to their reset position every 45 degrees turn of the small wheel, which is the driving wheel.

The small (driving) wheel is expected to be continuously unbalanced.

What do you make of this concept?

Raj

[path_finder]

Dear raj,
Very clever.
What is interesting in your concept, is the fact the whole mass (eight weights) of the small wheel is involved in the shift process.
This design merits a building for test.

[rlortie]

Raj,

Your concept shown above will not work! It has been tried not only by myself but by others.

The weights are pushed up at six but without a two way latching system there is nothing to retain them in this position.

Like any such ramp design, regardless if the ramp is stationary or rotating you are still ending up with a wheel within a wheel showing a prime example of the "width for height scenario.

Check my album and you will find pictures of a test device I made years ago that allowed for testing of all ramp variables. None worked.

Ralph

[raj]

Thank you very much Path_Finder.

Ralph,
A two way latching system to keep the weights in their positions from the 6 o'clock position to the 10 o'clock position, can be easily implemented.
There is no synchronising need for the latching.

The small inner (driving) wheel is in fact the inner RIM of a much larger wheel (can be larger than the ramp wheel).
I have not shown this in the drawing.

Raj

[raj]

A slight precision!

The larger wheel in the drawing above, acts more than a rotating ramp. It acts more like a conveyor belt.

Raj

[AB Hammer]

raj

What I have learned is that as soon as the arm touches out from the smaller wheel the center of gravity of the wheel changes and it tends to become more of a form of action stopper. My walker I built had a similar approach and it had great over balance but the change of center of gravity stopped it cold.

Good luck with your test.

Alan

[raj]

Here you are guys!

My humble attempt to my hamster wheel concept testing build.

Next weights and bars will be added.

Frankly, it is beyond expectation to see it turning...

Raj

[preoccupied]

I'm jealous raj. I can't seem to get a prototype going for any of my ideas but you have lots of material and buildings skills! Way to go, dude.

[raj]

Preoccupied, I always try to use cheap household items that are easily available, because I am never trying to build a runner, but only trying to test my proof of concepts.

I am on the look out for a concept that pass this initial test. The chances of this successful test remains only in my dream so far.

Raj

[raj]

The hamster wheel concept testing prototype is made of two old bicycle wheels, one large and one small children bike plastic wheel.

I have used thin cardboard sheet wound around large bicycle rim and a cut old plastic flower pot on the small plastic wheel rim.

I, only, had to buy the thin cardboard, for fifteen mauritian rupees (about thirty pence UK).

Raj

[raj]

Hi everybody!

The bars and the weights are in the wheel.

I am feeling a bit more hopeful now.

I have identified two handicaps that need to be rectified.

1. My prototype is too crudely built.
It DOES BADLY need precision build.

2. The weights are fixed to the bars. This increases friction on the rotating (ramp) large wheel.
The weights have to be fixed in such a way, so that they can ROLL on the rotating ramp.

Otherwise, I am giving a PASS mark of 50/100 for my hamster wheel concept testing.

NOW we wait for the next test. I am hopeful to get higher marks.

Raj

[path_finder]

Dear raj,
Don't use some weights sliding on one rod: the friction is important.
Instead use this mechanism, where the only friction is located on the axle pins.
The geometry must be respected, in accordance with the first drawing.
You have just to elongate the central bar on the both ends.
The first animation shows the motion of one single pair, the second one include four pairs.

[path_finder]

Dear raj,
If you want to delay the sliding action within 90 grades, I suggest to read this old topic (and the following) here: http://www.besslerwheel.com/forum/viewt ... 5508#65508, where the pair of weights are used for the actuation of an extra rod.
Sometime the old ideas can be useful.

[Tarsier79]

In addition to PFs observations:

The end of your arms need to be rollers/bearings. This eliminates the need for the outside wheel to rotate, as well as your previous friction issues. You can then reinforce your outside drum as you see fit.

The outside weights: for weight positioning OB (in any build), the weights do not matter if they are on the very outside of the bars, or located at the center, or anywhere inbetween. You are relying on the amount of shift the weight gets. So they can be located wherever suits your build most.

Best wishes.

K.

[raj]

Dear Path_Finder and Tarsier79,

Thank you both for your kind proposals.

Raj