In this video I take on building theĀ
world's largest rideable hexapod, Megahex.Ā A passion project of mine that has takenĀ upĀ
the past year and a half of my life. What started out as a simple three-month build
turned into a year and a half of failures, breakdowns,Ā and rewrites. So close. And I think we have to cutĀ
our losses with this project. We evenĀ made three entirely differentĀ
videos before scrapping them in favour of this video thatĀ
you are watching right now. Do I ever have a story for you. It all started when I came across aĀ
video of a Princess Auto excavator which was capable of orientingĀ
itself by using the bucket to stand up and maneuver. So what stops more legs liftingĀ
more bodies, as one giant unit? As I was working on Power Loader andĀ
other hydraulic projects I was like this is doable like we could do this. All right guys, the plan is simple. Weld together six excavators, wire allĀ
the engines and then program the legs. I think we can do it in three months. The first month went great. We partnered with Princess Auto for this project. They provided us with six excavatorsĀ
and an in-store spending budget. Without them this project wouldn't be possible. When I first envisioned this thingĀ
it was just gonna be a rectangle. Like the plan was literally cut theĀ
frames, shove some box tube through it, throw a few welds on it. Each leg could just do the exact same motion, the only difference is whatĀ
time that motion happens at. But then the frame was way too largeĀ
it wouldn't fit through the door, the legs were way too close to each other whichĀ
made the frame even bigger and even less stable so we were like okay we haveĀ
to make this a hexagonal frame. And that just brought so many extra complexities. The joints and all the anglesĀ
had to be super precise, the motion of the legs was no longer goingĀ
to be the same between every single leg. Every leg had to have a specific motion profile and that just instantly it was likeĀ
okay we're in way over our heads. In SolidWorks everything lines up perfectly. You get to the real world and honestlyĀ
I should have expected this... Started chopping these frames apart we shoved inĀ
the box tube and then we started laying it out and we're like what is going on? Like one side is longer thanĀ
the other and we're like none of these legs are whereĀ
they're supposed to be. Obviously, they're mass manufactured. So like we should have known this. If the frame is going to be that far out thenĀ Ā like the motion of each leg isĀ
gonna be completely different and our stress analysis that we did inĀ
SolidWorks just not going to match up. Like something is going to break. That required us to start chopping theĀ Ā frames apart that we're you knowĀ
supposed to be used for alignment we're now being completely cut off and re-welded and we basically had toĀ
tolerance the frames ourselves. We had to make jigs we had to make like bracketsĀ
and it went from like a two-day welding job to over a week of just like trying toĀ
get this thing perfectly squared up. Once we were ready to start attaching the legsĀ
I was kind of feeling defeated at that point I was like if I've had this many problemsĀ
already this thing is going to be a nightmare. We started attaching the legs andĀ
things were actually going pretty well. Each leg was attaching properly,Ā
the spacing was all correct everything was moving smoothly. It was looking epic and I was startingĀ
to see what this thing could become. I knew this thing was going to be large butĀ
actually seeing it in person this thing is huge! Like this is going reallyĀ
well, we're making progress, we're gonna get to the test relatively soon. A lot of anticipation. A lot of like please work please workĀ
like there's so much riding on this. I had you know a lot of doubts IĀ
was like what if the welds crack? You know, what if the frame is slightlyĀ
twisted or we have a hose pop off and this whole thing justĀ
comes crashing to the ground. Honestly I told everyone this and I was surprisedĀ Ā that anyone even volunteeredĀ
to step foot onto this thing. Holy crap! All this work is finally paying off. So we need some computerized controlĀ
to be able to make this thing stable because right now it's a little hardĀ
to drive with four individual pilots. Well we know the system can lift its weight. Let's take a minute to talk about hexapod feet. As you can tell I've replaced the bucket on thisĀ
leg with a brand new design of a hexapod foot. The buckets, well they're great for digging but unfortunately they don'tĀ
have great surface contact. With a new design we have lots of ground contact have more motion with thisĀ
cylinder, and it looks way cooler. Ideally we'd like to be able to driveĀ
the entire thing with just one pilot. To do this we need a computerized control system. The whole control system startsĀ
right here at the Linux computer. It's responsible for calculating how to moveĀ
each individual leg based on the user's input. That data is then sent overĀ
to our Kunbus Revolution Pi. It's responsible for taking data in and figuringĀ
out how to move the legs to the right position. It does this by first calculating the position ofĀ Ā each individual joint basedĀ
on the row potentiometer. It then compares that valueĀ
to where each leg needs to be. It then sends signals to our servos toĀ
move the valves to their desired positions. Unfortunately the Kunbus system does notĀ
really speak the same language as the servos. It outputs 24 volt signals andĀ
the servos require 5 volt inputs so we've created a PCB using AltiumĀ
designer and got it manufactured by JLC PCB to act as a translator betweenĀ
the Kunbus system and our servos. By the way you can try Altium for free andĀ
get 25% off your purchase with my link below. Ben jumped into to this project and beganĀ
working on the control system and software. As you would imagine there's a lot of code. In order to test this without needing to useĀ
the actual Megahex, I'm using simulation. This simulation takes the CAD dataĀ
from SolidWorks and hexapod math combines it into one to give usĀ
an accurate visual of the Megahex. We were feeling confident,Ā
perhaps a little too confident, as we were about to enter integration hell. The design of this project is critical and justĀ
like our other projects, we use SolidWorks. SolidWorks is our favouriteĀ
sponsor because it is superĀ Ā powerful design software which empowers us to refine our ideas into manufacturableĀ
designs and build crazy things like Megahex. For the first time ever SolidWorksĀ
is available to you guys as the 3D Experience SolidWorks for Makers offer. This is actually a huge deal because SolidWorksĀ
is one of those industry-leading softwares that was normally only available to big companies. But with the Makers offer anyone can get access atĀ Ā a super affordable price of onlyĀ
$99 per year or $9.99 per month. Plus we have negotiated to get our viewersĀ
an extra 20% off if you use my link. This is like getting SolidWorks for 99% off! Which is unheard of in our industry. You can get the world's best design toolsĀ Ā and turn your ideas into reality orĀ
browse the gallery of online models. Join the global community of creative makers todayĀ
and use my link to get 20% off your subscription. Big thanks to SolidWorks for sponsoringĀ
this video, now let's get Megahex walking! After countless hours of troubleshootingĀ Ā we finally have all the hardwareĀ
and software integrated together for the first test of a Megahex leg. As you see behind me is theĀ
simulation of Megahex walking. The black leg is the real-timeĀ
position of this foot and theĀ Ā transparent legs are where Megahex wants to move. So if you can see me moving theseĀ
potentiometers, updates the real-time position. So theoretically once we get this engine startedĀ Ā up the Mega hex leg should move intoĀ
the same position as the simulation. And once we give it a command to walk hopefullyĀ
we'll have Megahex take its first steps. Starting up in three, two... Well it didn't explode and catchĀ
on fire so that's a good start. It looks like it was trying to move andĀ
that's what the simulation was telling us. I just don't think it was trying hard enough. We have a bit of tuning to do on the joints andĀ
we'll see if we can make it a little bit better. I think we need to slow down the simulation. So hopefully it has a better chance of keeping up. I'm trying to figure out what I actually needĀ
to do to slow it down the way we were thinking. Add another 50% to the PID values? Yeah. Still not responsive enough. Not on the tibia tarsus or femur.. Turn them up? I think the femur is whatĀ
we need more of right now. I trippled the leg liftĀ
height..that's a lot better, yep. Okay double the femur? Heck just go like three times more. That's walking! So what we're doing is we're turning upĀ
all the gains so it's gonna try about twice as hard as it didĀ
last time to try to keep up. The concern with this is if we go too highĀ
the leg will basically rip itself apart because they'll start oscillating. As it sees an error it'll try toĀ
overcompensate for it and basically overshoot and that gets worse and worse and worse. Up until the leg is basically goingĀ
full speed forward, full speed back,Ā Ā full speed forward, full speed back and doing nothing of whatĀ
we're trying to get it to do. Hey Bogdan I think I see an issue over here. So the reason we have all of theseĀ
plots and simulations everything set up is so we can diagnose weird issues like this. We tried looking through the code trying to figureĀ Ā out like what do we change you know weĀ
revert back to the old code we run it still having the same issueĀ
we're like what is going on? Like why is this one joint just not moving at all? So all three of these joints seem to beĀ
tracking fairly well except for the femur,Ā Ā I think there might be an issue with the servo. Oh the freaking servo. Oh yeah these are toasty. That one on the bottom especially.Ā
You have the thermal gun? In the middle, oh yeah that thingĀ
is over 100 degrees Celsius. See the other ones comparatively areĀ
like 60 which is still not great. These windings are supposed toĀ
be this bright orange colour, that black coil states that this motor is toast. Replacing a single servoĀ
would take like three hours, like oh great another servoĀ
failed...well there goes another week. We obviously know we have to replace all theĀ
servos and we have to figure out a solution which ended up being changing different springs. When the bigger spring was installed everyĀ Ā time the servo moves it has toĀ
work on compressing the spring. With the smaller spring the servoĀ
is not going to be working nearlyĀ Ā as hard therefore generating less heat. The second thing I did was I addedĀ
this computer fan to keep some freshĀ Ā air moving across the servos to keepĀ
them all just a little bit cooler. And with different springs allĀ
of the tuning we've done thatĀ Ā week was just out the door. Completely useless. And that was just like a huge hit to our progress. With testing this whole thing I was starting upĀ
that engine stopping at every like 10 minutes. So we're like right we need new engines that haveĀ Ā a remote start but also wereĀ
a little bit more powerful which meant we can use bigger pumps and get a lotĀ Ā more flow hopefully increasing ourĀ
speed and power on all the joints. So we spent like two weeks just like pulling allĀ Ā the old engines off pulling all the oldĀ
pumps off undoing all of our hydraulics. Luckily mostly everything was you know drop-inĀ
replacements but it was still a lot of work to rewire all the engine starters together. We wire all the stops together, we hadĀ
to add that to our emergency stop system so it would actually shut all theĀ
engines off and that was a lot of work. The exhaust, honestly we could haveĀ
probably gotten away without it but even just having one engine running and tryingĀ Ā to like get a vent over topĀ
of it while we were testing was just really annoying. And I was like there's six of theseĀ
things not only is it gonna be crazyĀ Ā loud like right around me butĀ
also it just smelled terrible and I was really worried about my health orĀ
anyone else who was gonna be near this thing. I got Mike to actually takeĀ
some time and plumb in someĀ Ā proper exhausts as well as some properĀ
baffles, quiet the whole thing down. And you know exhausted out the backĀ
so it's not blowing into my face. This point was like five months, in likeĀ
two months over the estimated timeline we still have not seen aĀ
single proper stand-up test. With all the new engines and the theĀ
new pumps that we had to get and theĀ Ā replacement servos that you know didn't burn out the new springs, the budget.. We spent the entire sponsorship budgetĀ
in the first like three months and nowĀ Ā we're just like this is coming out of our pockets. This was the day.. actually not the first day. We tried it the first day and thenĀ
some of our engines weren't firing up. We tried the second day we'reĀ
getting hydraulic leaks. Try the third day some of ourĀ
senses were misreading values. So we're gonna fire up all six enginesĀ
and see if the platform rises to the air. This is without people on it,Ā
fully computerized controlled. so we should be able to just hit aĀ
single button and the whole thingĀ Ā should rise more or less evenly off the ground. Safely right? As long as there'sĀ
no one near it should be OK. Firing up! I'm trying to stand this whole thingĀ
up and at first it's like going well and this whole thing like five feet in theĀ
air starts curling up like a dying spider. Me and Ben are just like looking at eachĀ
other being like are you doing this? I don't have the controller I'm not doing this. And so like I slam on theĀ
e-stop and we're both likeĀ Ā confused as hell we're like how do we fix that? It could have been any number of things. It could have been hydraulic issues,Ā Ā it could have been software issues,Ā
it could have been electrical issues it could have just been you know mechanicalĀ
issues with the valve getting stuck or something. Luckily we look over all the data and itĀ
turned out just to be a simple code change. Our leg was actually trying to go past its limit. Two lines of code, uploadĀ
it again, ran the system. Restarting. And this thing just perfectly rises into the air. All the legs on the ground. It was a sight to behold. Now the legs lifted up and moved around soĀ
we're like okay we're on the right track, we need to figure out howĀ
to get this thing outsideĀ Ā because there was no room in the shop to test it. We spent the last eight monthsĀ
or something working on this and now we're just draggingĀ
it out of the concrete. We were obviously optimistic becauseĀ
the simulations were working. Starting robots. And like this thing just likeĀ
barely lifted its foot up just like drags it across the ground and just like slowly stumbles over just like dropping theĀ
weight onto every single leg. Once there's a lot of load onĀ
them they're not really moving. It brings the leg over butĀ
it doesn't actually have thatĀ Ā much force to actually push its own body forward but overall it's not on fire and weĀ
didn't break anything I don't think so, good first test. And we're looking at this data we're looking at this thing walk. We changed a lot of tuning values, weĀ
changed the way it's going to try to walk. And every test following thatĀ
we'd spend a day dragging thisĀ Ā thing out it would like stand up take two steps, one leg would fumble, the position would be off,Ā
the whole thing was just tip damage something. It was just so frustrating.. It was really upsetting just to see thisĀ
thing slowly damage itself more and more. Yeah Bogdan we left some paint behind. Wore it all the way. We just lost our alternator. Do we have enough fluid in the reservoir? Why are we having issues all of a sudden? Should I just bump the startingĀ
threshold up a little bit? The issue of it dropping as it'sĀ
taking steps has gotten a lot worse. That sensor is gone. Yeah, I don't think it's going. I haven't changed anything. One more try? Why are the servos...theirĀ
legs aren't moving up now. We've killed the starter on this motor right here. It's out of regular interval. Oh yeah we [ __ ] that wheel off. Break them in half a second we're so [Ā __Ā ] close. Everything is set up right now to work and now with the engines are being problematic. It's ready. It's good to go. We've got everything.. it's tuned. Six legs that were working. The efficiency of the testing it's not like oh make a simple code change run it againĀ
make a simple code change run it again. No like if something goes wrong if one sensorĀ
fails, spend a week fixing it drag it back out. Right now our femur which is our mainĀ
lifting cylinder doesn't have enough power when we're lifting three legs at a time. So what's happening is when we're givingĀ
flow to other cylinders it's slowly dropping so after two or three steps the actual frame whichĀ Ā was four or five feet above the groundĀ
is now basically touching the ground. So we want to make sure that when it'sĀ
taking steps it's got enough pressure and it's got enough flow to sustain that height. Daryl take a look at this data. All right all right um if you want to zoom in or whatever take a look. Okay based off of that right there.. yeahĀ
um.. just gonna need a little bit more work. Right there.. yeah awesome. I think I think I know exactly what he means.. Should be done in a couple days. Maybe the femur needs more work.. that'sĀ
it, needs more displacement over time. That's what I was going to say.. Femur..100% oh we just need to double ..Double it. So whatever the screw is set to andĀ
the pressure thing just double it. It's called the pressure relief. If we just turn it a little bitĀ
should make Megahex walk better. Still not perfect but itĀ
is definitely a lot better. When we were seeing it walk backwards the bodyĀ
was not dropping nearly as much as it used to and we didn't blow off any hydraulicĀ
lines which is really good too. So..I kind of want to ride it. I don't think this thing will kill me. Worst case scenario just mild injuries. That first rise up off the ground,Ā Ā like when you're all the way upĀ
high it feels really satisfying. when it starts dropping off itĀ Ā it really loses a lot but honestlyĀ
the ride is smoother than I expected. We need to max out all theĀ
motions I think we need toĀ Ā increase that step over distance definitely yep. Because when it's loaded it's not movingĀ
very much and it's slipping a lot. If we can get the legs off the groundĀ
for sure it'll walk so much better. So let's bring it back inside for now. Lucky for us Princess Auto soldĀ
other sizes of hydraulic cylindersĀ Ā which were almost perfect drop in replacements. We decided to try smaller cylinders on theĀ
tibia and larger cylinders on the femur. We made the cylinder bigger because this joint wasĀ
lifting a majority of the weight of the Megahex and it wasn't quite standing upĀ
with a slightly smaller cylinder. My grandfather. Six months ago. I'm not kidding. Hey Daryl, you know how many days IĀ
wanted to punch you in the face XD. Cool..we sprung a leak. We killed the cylinder. Well that answered that question very quickly. Covered the whole thing inĀ
hydraulic fluid..oh my laptop. After a spectacular cylinder explosion onĀ
the tibia we had to change those ones back,Ā Ā but the femur cylinders.. they worked! Get back out there the next day try it out again. Every test that we ran it wasĀ
walking just a little bit betterĀ Ā just a little bit better just a little bit better and like the only thing that kept us going wasĀ
that we were seeing consistent improvements. We could see we're like oh maybe ifĀ
we just change this one more thing like next test is gonna work, next testĀ
is gonna work, next test is gonna work. And we're like months into testing makingĀ Ā marginal improvements but it wasĀ
it was almost there almost there. We've upgraded our feed lines fromĀ
the pumps to make sure we can get the full flow that the pumps canĀ
provide without a loss in pressure. We changed over the step overĀ
distance so how far it's moving. We changed how fast it's moving. There's a lot of changes so we'reĀ
expecting this not to work but itĀ Ā kind of give us a better idea ofĀ
what changes have what effect. Finally we get this thing powered up at this point we have like no hope. We're like all right one moreĀ
test let's just go for it. And it took one step. And it took the next step. And it took the next step. Three steps in a row like this is aĀ
good start like keep going keep going.. and it just kept going and going. The platform was staying above the ground. Nothing was failing like all theĀ
sensors were reading properly and just like one step afterĀ
the next and there was thereĀ Ā was mud all over the ground and itĀ
was just like splashing in the mud. Like, yes! Like this thing just walked across theĀ
entire parking lot we were so excited. Turn this thing around bring it back around. And this thing starts turning around andĀ
we lose communication with the controller and the thing just like steps on our trailer. And we're like uhhh. I'm willing to bed that..we lostĀ
communications with the controller. One of our wires ended up coming unplugged butĀ
like we knew that like okay this thing is working. We had a couple of YouTuber friendsĀ
come over I think it was Jake Laser,Ā Ā Nigel from Nile Red, and Allen Pan I think. As long as we keep the fatalities toĀ
under three we're doing pretty good. Driving around the power loader having fun. I looked at Ben and I'm like do youĀ
want to drag this thing outside? And like get to show it off to them? Power this thing up and just just like theĀ
last test we just gave her the forward command. I think they were blown away. Dude!! Here we goooo! The following week later we just got to work andĀ
there was just fog across the entire facility. Dragged it all the way outĀ
to our field, super cool. Walked around the dirt you know threw up someĀ
of our lawn, the Power Loader in the corner. Stepped on the pumpkin, the fog in the background. And then I'm walking I'm turning I'm turning andĀ
then it's out of nowhere like the side dropped. What's going on? Get ready to hit the e-stop and look over and theĀ
leg is like completely not attached to Megahex. I could not believe my eyes. The thing is.. these excavators.. we wereĀ
pushing these things way past the limit. I'm surprised it didn't failĀ
earlier to be completely honest. But yeah the excavator frame justĀ
completely tore itself in half. This is why companies goĀ
bankrupt when they build mechs. I'd probably have a better return on investmentĀ
making a video where we dig a big hole, put a bunch of cash inside and light it on fire. Brought it back in the shop,Ā
got the whole thing welded. Next day we take it back outsideĀ
ready to do another test. And same leg, different spotĀ
crash into the ground again. I go over to look and the frameĀ
is just twisted and torn in half. This was a main part of the frame. This one's going to require choppingĀ
the frame again realigning everything new bushings, new body tubes, weldingĀ
all around, new gusset supports. This was probably another two weeks to fixĀ
and like I looked at this and I'm like.. All right well for better or forĀ
worse like we're done filming Megahex. Frame that the leg is connectedĀ
to it is now just ripped in half. If a single wire corroding a single connectionĀ
going bad could take days to diagnose. And I think we have to cut our losses withĀ
this project because at this point it'sĀ Ā it's doing us no returns. There is no way that we could keep just allocatingĀ
so much time and so much money to this project just to have it you know take fiveĀ
steps and another thing breaks. You know we got our goal, it was walking, that was our goal. We reached it andĀ
honestly it was time to call it a day. You know what without the support of youĀ
guys and making continuous videos thereĀ Ā was no way that this is going to be sustainable. Like this project was so much time, so muchĀ
effort, so many different learning opportunities. But really like completely honesty with you weĀ
really should not have green lit this project. This project should not have happened. It was way more complicated than we anticipated, we had way more issues than we thought. The the timing and the difficultyĀ
was just way underestimated andĀ Ā literally the only thing thatĀ
kept us going, was you guys. Every one of these failures was content. It was going to teach us something,Ā
it was going to teach you something. And we really hope thatĀ
that comes across on video. This project is the reason we haven't beenĀ
able to post as often as we normally would and to make sure we show this journey in theĀ Ā best way possible we initiallyĀ
edited a three-part video series but we felt like it didn't tell the whole story. We do think there's a lot of interesting detail inĀ Ā those videos and so we've made each ofĀ
those videos available to our members. I do not know if we're gonna ever be ableĀ
to do another project like this again. If you'd like to see us tryĀ
something like this again andĀ Ā hopefully do so without coming near bankruptcy, please please justĀ Ā subscribe like this video share it to anyoneĀ
else who you think would be interested and consider becoming a member. Because this was really expensiveĀ
not just in terms of parts costs,Ā Ā but the amount of labour that went into this, all the engineering time all the after work hours, we could not have done itĀ
without support of our members. So thank you so much for watching this video,Ā
thank you so much for your support and hopefully we'll see you guys back here with someĀ
other cool projects in the near future.
make you wonder how much money and resources San Magnolia put in to designing the Juggernauts...
Fellow Hacksmith Watchersšæ
Check mate Boston dynamics
When do we mount the 57mm gun?
Sweet Christ. So it begins. Iāll see you guys in the 86th Sector
So it begins
they have about 120 years to figure out the rest so we're making great progress.
"still just an aluminum coffin" - Shinei Nouzen
yes it is