If you only think of wheels as round, you’re limiting yourself from experiencing the true wider world of whacky designs. [wadevag] has been experimenting with some such concepts, and has had success building an amphibious robot platform using star-shaped wheels built out of pool noodles.
The concept is similar to that of whegs. A portmanteau of wheel-legs, they’re in effect a form of leg that moves with a rotating motion. Essentially, the points of the stars on the wheels act like legs, pushing the robot along one by one, rather than having continuous contact with the ground as in a typical round wheel.
The flotation provided by the foam allows the robot to easily sit on top of the water’s surface, and the star shape allows them to act as viable paddles too. This is perhaps their primary advantage. A round wheel would not provide anywhere near as much forward propulsion.
[wadevag] shows off the concept’s abilities on water, concrete, and snow, and it handles them all ably. Impressively, it can both enter and exit the water under its own power. While it’s probably not a viable solution for a very heavy robot, for a lightweight design, it could work wonders. It’s not the first time we’ve seen some oddball wheel designs, either. Video after the break.
there was a toy i had when i was a kid with wheels like thatlittle 4wd and they were sponge, amphibious. horrible thing that couldnt keep water out of the battery commpartment
First thing I thought of also. Stompers https://g.co/kgs/H9Lbz5
That’s using your noodle! I’ll let myself out.
Those toys from the 80s with the 4WD, foam wheels, and sometimes amphibious design were Stompers ( https://en.wikipedia.org/wiki/Stompers_(toy) )
Needs a few more wheels…
https://en.wikipedia.org/wiki/Amphicat
6 wheels makes everything more interesting. All the coolest, if not necessarily practical vehicles I can think of have at least 6 wheels, with a few honourable mentions in the lower wheeled categories!
That said using tank steering I’m not sure it would work on land with such wide wheels at all well if it had more of them – not that I have any idea how grippy pool noodles are, let alone cut into that paddle wheel style shape… Maybe it would be fine. Still giving it conventional steering – perhaps 4 wheel would act like an effective rudder too.
Still neat bit of fun, and its nice to see Lego in use here again, with how versatile and reusable it is it shocks me how little we see it in the hackaday feeds, even if its just the early prototype models or as a source of good gears – Sure 3d printing is great, CNC machines are cheap(ish) now, but nothing gives you a real feel for how well an idea really works than being able to tinker with variables the way Lego lets you (other construction toys that would do the job fine are also available), and Lego gears are a natural fit with 3d printed devices, but way smaller, smoother running and tougher than your 3d printed approach.
The thing with lego is that it is prohibitively expensive compared to other “hacker materials”.
Not really – yes its far from cheap, especially new, but to do that project with 3d printer would cost a fair bit in filament, time, lots of electric used too, been only single use and got a probably far worse result, at least the first 4 times you print, iterate design and print again, maybe after that you can really get a good enough result, about as good as you are going to within the limits of the 3d printer.
Not knocking 3d printers – they are great, but very wasteful for that sort of initial experimentation when something like Lego can be used easily (some things you just won’t want to try in Lego). As Lego (construction toys in general even) are so reconfigurable buying that heap of second hand for early prototypes, fixtureing (its ‘high’ precision stuff, so great shortcut), mold making etc… So Technic Lego for instance works out very cheap for that initial prototype phase, as its useful in a great many future projects as well as letting you easily gather data on which direction you wish to develop for your desired result. Also the only justifiable reason to pay the Al 20-20 type extrusion costs – its basically another construction toy, damn expensive but easy to reconfigure…
That 3d print (etc) everything approach might be cheaper for just one project, but who only ever does only one project!!! And even that is in doubt – you can get quite alot of cosmetically poor condition Lego very very cheap if you look for it, and when you are abusing it you don’t even need to care if the bits are broken..
I got a megalodon RC car for like $30. It is rad. It has big foam wheels, looks like a shark, and you can drive it straight into the pool. It’s fast and charges with USB. Saw commercial during Saturday morning cartoons and had to have one.
I’m currently considering building something similar but with 3d printed wheels (vase mode) filled with foam and coated in something “gummy” (don’t know what yet)