Spiral Drive

what if you had 4 independently rotating spirals as a drive train do you think that this would work?

Sounds like it would work but could u draw a quick sketch? not quite sure what you mean

Nobody’s tested it yet, that I know about.

One caveat, and this may be the deal breaker: If it damages the carpet extensively, or is made of metal, it will not pass inspection. (<R08> governs traction items.)

It may be possible, but you’d have to test it.

Like this? :slight_smile:

yes that is exactly what i meant, kind of like those machines that shape half pipes in snow

but would this work like a crab drive?

My guess is that snow is one of the very few surfaces that that type of drive can work on. And since we don’t see vehicles like that in common use on snow, it’s probably not a very good idea.

But it is interesting

It would work, but I would be concerned about the screws tearing up the carpet…

Probably. But you’re reinventing the mecanum wheel, to some extent.

Take a look at http://www.andymark.biz/mecanumwheels.html and see if those are pretty close to what you mean.

should’nt these screws be way less efficient than a wheel?

Didn’t say they wouldn’t be. A screw like that would be like locking all the rollers on a mecanum wheel. (And then reducing the friction on said mecanum wheel, hopefully.)

It seems like one of the key elements is that its digging into the snow, so I doubt it would be very FIRSTable.

That is so cool… Thanks for sharing it.
Looks like something out of a old old James Bond movie.
I guess track drives are more functional.

I have two of these at my house and have always wanted to make a larger one, but have never gotten around to it. Turning is not easy they have to tilt the screws and travel in an arc.

For 1929 that is insanely impressive. Neat idea, I’d love to see it working on someone’s robot within the coming weeks.

It might be allowed, but it’s hard to say. The rule about what you can have in contact with the field seems to make it unlikely.

<R08>  ROBOT wheels, tracks, and other parts intended to provide traction on the FIELD may be 
purchased or fabricated (“traction devices” include all parts of the ROBOT that are designed 
to transmit any propulsive and/or braking forces between the ROBOT and the FIELD). In no 
case will traction devices that damage the carpet or other playing surfaces be permitted. 
Traction devices shall not have surface features such as metal, sandpaper, hard plastic 
studs, cleats, or other attachments. Anchors (i.e. devices that are deployed/used to keep 
one’s ROBOT in one place and prevent if from being moved by another ROBOT) shall not 
use metal in contact with the carpet to “stay put.” Gaining traction by using adhesives or 
Velcro-like fastener material is not allowed. 

well i was thinking that you could get like 2" ABS or PVC and then wrap the treads from the Plaction wheels from andy mark in a spiral thus not violating any rule about damage to field or metal contact with the ground

also if you had 4 of them i think that then it would have the ability to turn like a tank and move horizontally like omni wheels

please correct me if im wrong

Correct on not violating a rule (unless unforeseen results happen).

Correct on turning like a tank.

However, moving sideways will be horribly inefficient, due to the amount of traction generated by the treads. You may even get enough to destroy the treads, or break them loose from their attachments. At that point, consider mecanum or omni wheels, as either will allow you to go sideways.

The problem with this idea is that the spiral works by having the ribs slide easily over the surface, and the conveyor belt treads like that do not slide on carpet at all. And the rules seem to prohibit any type of thing that would, as it would likely be considered to be a “cleat”.

I would envision this could be made legal using specific materials. The other factors I also considered is the space in which you have to work and the power of the motors available. 29 x 36 is a small footprint in which to add four of these devices. You also will not be able to climb very well without having the center line of the screw be fairly high. I am guessing with all the limitations, a screw could not be made to climb the bump due to the size and power needed.

I like this, simple to bulid
Team 1946