This Robot Drives on Wobbly Wheels (but HOW?)

i am fascinated by unusual objects and mechanisms objects that roll reciprocate wobble and wander in 2018 i shared some of my favorites in a video that went on to be one of my most popular on the channel ever so popular in fact that people began to rip it off and use my wobblers and oloids for their own clout chasing tisk tisk indeed but despite this blatant thievery it does bring me joy seeing so many people leave their thoughts in the comments and these comments lead to ideas imagine if cars were built with nightshade wheels wobbly wheels hmm imagine indeed could wobbly wheels actually be better than boring old regular wheels to find out i built this a remote control platform with wobbly wheels and i put it through the gauntlet to find out which wheel is best let's get started first we need the platform and i designed this up using fusion 360. the gear motors are cheap surplus units i found on ebay and i'm particularly chuffed with just how well the motor mounts snap into place and they're easily replaceable if i want to make any changes the body houses the control circuitry which is a pair of bot bits 30 amp brushed esc's and the radio controller receiver it's worth noting that the internal space looked huge during the cad stage but i know all too well that when you start adding plugs and wires dang doesn't get messy quickly in fact it barely fits now but good thing this color fits neatly over the top and hides my shame by the way if you're interested this is basically how you build combat robots they are remote controlled platforms and everything i use to make this can be replicated just with a slightly stronger chassis so if you do think this is interesting i highly recommend giving combat robotics a go it's a really rewarding hobby now for the fun part the wheels the comments on reddit about nightshade we're referencing this a fun toy known as a wobbler it looks trippy as it rolls because it seems unbalanced but in fact still travels along a circular path and has this uneerie levelness to it as it rolls and it rolls very well you create the shape by extruding a cylinder of desired final wheel size then you cut into it with a profile and as long as the profile is balanced on each side it will roll smoothly and here they are printed yet again in that gorgeous poly alchemy elixir nightshade purple pla what else would i use at this point to attach the wheels to gear motors i used some basic hex hub i bought locally from core electronics and they simply secure into place using an additional hub detail i modeled in so does this thing actually work oh yes yes it does [Music] [Music] there is no denying it this thing looks amazing as it dries around on its flappy little wobbly wheels while the chassis itself stays perfectly steady and is surprisingly controllable with the skid steering design that is each side can is controlled independently like a tank so it can turn on a dime flapping those little wobbly wheels in the process but here's the question could these wheels be better than wheels like this i really want to find out but i did have to keep the playing field fair these are hard plastic wheels so there won't really be any traction to talk about but what i did is measured the surface area to be around 2500 millimeters squared so it makes sense to me that any competing wheels should have roughly the same surface area and here's what i came up with first things first a basic disc what blows my mind is the fact it has the same surface area as the wobbly wheel despite having a shorter edge length geometry be weird sometimes next is the slotted design with each arm having a small contact area which adds up to that 2 500 millimeter squared last but not least i designed these curvy boys as a kind of in-between wheel instead of a slanted profile like the wobbler wheels they have this c-shape which made them a huge pain to 3d print requiring tons of support material but still they look pretty neat almost like a certain brand of chip let's call them prongle wheels now on to the challenges i find to test these wheels in two ways one is a simple pulling contest on the carpet to see which wheel design can pull the most weight and finally we'll be embarking on a sand dune hill climb challenge to measure pulling force i stole this digital scale from the kitchen and inverted the load cell with a chain attached i hope no one notices it's missing because i really did destroy it it's not the most elegant setup but i figure by grabbing an average measurement we should be able to get a pretty good idea of which wheels have better traction on carpet to attach the chain to the platform and design this little tow bar attachment and i went a little bit industrial designer on it but i reckon it looks pretty slick first up the disc wheels these are eight millimeters thick and just straight smooth plastic and are actually quite controllable in general but as you might expect have almost no pulling power whatsoever they just sit and do burnouts all day the force was quite uniform however and measured out at about 405 grams next up the wobbler wheels i'm really excited to see if these have more traction due to their shape even though they have the same surface area contacting the ground in practice however they seem to wander quite a bit when pulling they're not really that controllable and it was always to the right i even tried inverting the platform and got the same result despite this it is clear to see that they do pull quite a bit more than the straight up circles even though the number jumped around quite a lot i called these at about 530 grams the prongle wheels track a similar wavy path but are symmetrical so let's see if they differ well initially they were all over the shop and really hard to control but they did settle in some really stable pools much more so than the wobbler wheels and they look capable of about 550 grams of pull force consistently i found these bits of plastic on the carpet after testing which explains the initial controllability issues i think that they're acting like burs on the carpet and randomly biting in that little hooks because of just the way they're 3d printed but that gives me a bit of an idea maybe a velcro wheel could be a really interesting future test for some sort of platform that needs high traction on carpet finally the eight spoke design these jumped all over the shop during the test so the data is pretty chaotic the numbers are comfortably within the 600 gram range making them the highest traction out of the lot it's important to note as well this platform has no traction control or torque vectoring or anything like that at all there's no feedback on which wheels may be spinning faster due to lower traction than the others it's just a basic brush speed controller maybe future versions will incorporate smarter control electronics and feedback but it's a bit beyond my skill set at this time but i just have to know what if we throw convention out the window and try all of them at once this looks so incredibly stupid i have no idea how it's going to work i have no idea how that worked as well as it did but having a different wheel on each motor yielded a quite stable 540 grams of pulling force it's sorcery i tell you time for the hill climb and this mini sand dune presents a whole new set of challenges we filmed after a night of rain so the top surface of the sand is harder than usual but it's at a challenging slant nonetheless once we get past the first and second flag the robot must climb up quite a steep embankment before tracking across a narrow stretch of dry loose sand with lots of potholes before rounding past a steep mount of vegetation and back down a very steep slope to the finishing line each flag must be passed in the direction it faces and every flag after the start is worth one point for the maximum of six points for completion of the entire course so let's kick things off with the disc wheels to no one's surprise they bogged almost instantly and were barely able to get past the starting flag if the sands flat they can drive perfectly fine with very low traction but any hiccup and they'll bog and be stuck permanently no points next up the wobbler wheels let's go it's pretty easy to lose sight of scale but a single footprint in the sand here is enough to spell doom for such a small vehicle so i tried to keep the course as fair as possible between runs and smooth them out but it wasn't fully consistent and you can see the wheels carving the sand as they move forward in a really interesting way they just don't have the ability to throw the sand backwards enough to push the robot platform forwards and out of a bold situation instead it seems it prefers to just bury itself in sand like a crab and hide its shame i already wanted these wheels to do better but in the end they only just passed the first checkpoint so one point but what about the prongle wheels the pull test already proved that they're more controllable with a similar amount of traction at least on carpet so let's find out oh well it was a really strong start but just like the wobbler wheels it's all over once it gets bogged and the wheels just simply carve out a rut instead of pushing the robot forwards i gave every platform a few chances but it became very clear that these wheels are no match for that slope more promising than the wobbler wheels perhaps but again only one point we've done three wheels so far and only two have gotten past the first checkpoint so it isn't looking too good and it's all up to the spoked wheels on carpet these wheels bounced around quite a bit and weren't fully controllable but it's a whole other story on sand not only are they controllable but they're also fast so i have high hopes indeed let's find out oh maybe like the other wheels they really are digging into that soft dry sand but unlike the others they're starting to fling the sand backwards and it's actually working you can see this deep track it's making as it does so flinging small slithers of sand backwards as it slowly edges forwards and it did it up the embankment and now it's heading towards the next checkpoint so it is so close to the fourth checkpoint and although it doesn't look like it it's a very steep incline indeed to get past it despite navigating an incredibly uneven surface with footprints deep enough to easily highlight the platform it just couldn't get past this point no matter how many times we tried and eventually it too buried itself in sand to hide its shame three points i'm not going to lie i'm a bit disappointed that none of the wheel designs were able to fully complete the course but why did the spoked wheels work so much better than the others well if you look at real sand tires you'll see quite a lot of similarity instead of conventional tread they have these large distinct scoops around them designed to bite into large portions of sand at a time and propel the vehicle forwards they're also known as paddle tires for this reason and with this functionality in mind it means that the spoked wheels might actually be a bit unfair when compared to the rest as it's this additional front scoop area that was pushing the sand backwards and propelling the platform forwards so what do you think would this disqualify them or should there be a different limiting criteria to be used for future designs and with that i have another question do you reckon there is another wheel design out there that could perform even better than any of these when they're faced with the same restrictions if so you can find the hub template in the video description below i will print and test your designs in a future video both in terms of pulling ability and on the mini hill climb they don't even have to be concentric i mean the wobbler wheels aren't even dynamically balanced and they still worked better than i could have ever imagined so if you're interested you can find more information in the description below i'd love to see them and if you don't want to miss that maybe consider subscribing to maker's muse where it's my aim to empower your creativity through technology and finally if you'd like to print and assemble your very own wobbly wheel platform or you could use this for all manner of remote control projects or even autonomous you can find the files linked below and they're also available on my patreon anyway thanks for watching guys i look forward to seeing you again very shortly here on makers news bye

Channel: Maker's Muse

Views: 3,230,417

Rating: 4.8951473 out of 5

Keywords: 3d, printing

Id: r9ZTWQtzk2Y

Length: 14min 44sec (884 seconds)

Published: Sun Mar 14 2021