Tires on the ground ...

<b>[Mark Vitrone] " ... the thing could probably be made half out of plastic, ... "</b>

I'm hopeing for 90% or better.

<b>[Mark Vitrone] " ... lets send the plans to radio shack and see what the toy makers can construct. These folks have more experience at this than NASA and JPL put together."</b>

I'm not sure if you are right about the relative experience levels (how many toys are designed to operate in a vacuum at continuous sub-zero temperatures?), but I like the way you think. We should absolutely look to the toy world for ideas, construction materials and techniques, etc. And perhaps ultimately for manufacturing.

There is also a very active and very creative hobby-robotics industry out there. Check out the Web, and the magazine racks at the larger book stores. Go to a hobby store that has a big radio-controlled vehicle inventory. They usually have monitors around the store showing a 4WD truck doing all sorts of jumps and sliding turns and other high speed maneuvers. We don't need the speed, <u>but the ruggedness of these toys is impressive</u>.

LB

<b>[Mark Vitrone] " .. what types of martian conditions environments are there on earth for testing the rovers?</b>

Seems like I remember seeing a History Channel show last year about the rovers, or prehaps about planetary exploration in general. They mentioned a place used by JPL for rover testing. A high plateau in the mountains of Argentina or Chile, I believe.

But it seems to me that any high (at a minimum, above the timberline) plateau that is arid and cold would fit the bill.

A little less realistic, but easier to get to, would be a "lifeless" portion of just about any desert during the winter.

===

At this time we are a long way from needing something like this. But one of these days ...

For the vacuum balloon I get a maximum thickness of the wall of 26 cm. The ball would float but we have to take into account its momentum through the air of lower pressure. So, I think the 5 cm mark is about what it would have to be.

On the testing areas. We have to allow that there's nowhere on Earth that matches. One problem is low temperatue boiling off of lubricants. Another is the temperature changes from day to night. Another is that surfaces become super clean and can weld.

(edited) On the bucky ball design, if we make it so that the "tail rod" is rigid one way but can wrap up the other way, then if the ball runs away down a slope, the rod can wrap itself up and avoid too much damage. It might also help to have it have a little bit of sideways bending. That way when the two motors go at different speeds, the pole bends to help the steering.

I've added little tubes to the node points, these would hold springs to pull the strings and make it rigid. The model looks good but it's hard work finding out what the length of the chords are.

I think if we called this thing a scrambler ball, we'd have a perfectly good radio controlled toy, best not to see radio shack about it, as they could very well say they have a patent on it, even if they haven't[] Not that I'm cynical of course[8D]

<b>[Stoat] " ... we'd have a perfectly good radio controlled toy, ... "</b>

Hmmm.

<b>[Stoat] " ... best not to see radio shack about it, as they could very well say they have a patent on it, even if they haven't Not that I'm cynical of course"</b>

Yet another reason to discuss any business related issues in the member's forum. It is less visible to casually prying eyes.

Here's the treaded rover with the body fitted to fill the track gaps. Obviously this one can carry a lot of experiments.

I wonder if it would be possible to make a toroidal wing mongolfier balloon? I'm thinking of two clock springs, left and right spirals, that expand on release inside of a plastic toroid. They create a wing shape by having strings tied to them and the balloon skin. The springs would serve a second purpose in storing heat during the day (maybe a use for a filament with a near vacuum core) I'm just trying to play around with the idea of a ballon with a bit extra lift. making one should be easy, the hard bit would be packing it for travel.

Stoat, if you have time could you remove the central filler and return to the disk shaped center, then fill in between the driving wheels. I am concerned about ground clearance. Thanks, Mark