- Once the thing is on, I'm treating it like a bomb,
because that's the easiest way to like-
- And therefore, if you lose a couple guys to a bomb,
it's fine.
(people laughing) I don't want everybody.
- I don't wanna lose the hopeful tune.
(dramatic clunk)
- I'm here in Dallas at the REV Robotics warehouse
to build a BattleBot.
Switchback was accepted to compete in "BattleBots"
at the end of August in Las Vegas.
And we only have about six weeks to go from a CAD drawing
to a fully functional 250-pound combat robot.
And right now, we only have a pile of parts.
- All right, so, we got our parts from Sancuts,
and we got aluminum parts the other day.
So, that'll be good for wheels and molding.
This should be the frame parts.
(box clicking)
- They were all laser cut.
They're all based on a flat pattern
that just gets cut out in a profile out of a big sheet.
A lot of them have notches and tabs
that all interlock with each other.
And once we tab them all together, we weld them up,
and everything is just a really good fit
right out of the packaging.
- See that? - This is the base,
this is the bottom.
These are the wheel wells,
this is essentially just an access area.
These are the actual bulkheads.
(chill guitar music)
- Hey, yeah. - Pretty good.
- So, the plan is to take this together,
tack weld it all together, check, validate measurements,
put it in the preheat oven,
bring the metal up to temperature,
and then we'll go through and do the completion while it's.
- Here we go.
- Let's do it.
(warm electronic music) (welding torch sparking)
We use aluminum because it's great and easy to machine,
and it's really lightweight for its size
for things like motor mounts, and gearbox plates,
and things that don't take big hits.
When aluminum get, takes a big hit,
it does absorb a really decent amount of energy,
but it tends to chunk apart,
and it makes repairability a lot harder.
So, for the frame and the armor of Switchback,
we use AR500 steel, which has abrasion resistance,
and really strong.
And when this gets hit, it tends,
energy will glance off of it,
or if it does absorb the impact, it'll either dent or bend,
which is much easier to repair in the pits.
But in order to get a good weld,
we have to preheat it to 200 degrees.
(oven humming)
It's important to design your robot
for the oven that you have.
(warm chill music)
(welding torch sparking)
- I've been told that maybe
I can get to do some welding today.
(welding torch sparking) (chill electronic music)
- So, we decided that we wanted to do custom wheels
for Switchback, so that we have the ability
to try different durometers, 'cause we're not sure
what the arena floor is gonna be like.
We laser cut all these little parts
with little interlocks, and then made custom molds.
(drill hums)
So, the main thing I will say is that
when you spray the mold release,
anything it touches will not mold onto it.
- Dude, I know.
- Shake well before using.
No, I'm not doing this for camera.
(people laughing)
- [Cameraman] Never seen someone shake a can so high.
- I'm like, I don't wanna go down to the table,
because like. (people laughing)
Like, I do this and it's bad,
and I do this and it's bad.
And like, I'm trying to like, stay in this, like,
like,
you know that it's like.
(people laughing)
- [Speaker] That looks really bad.
- [Speaker] I'm over here.
- [Cameraman] That video is like
the best thing that you've shot.
I mean, I think that just means that
we gotta get better video than that.
(people laughing)
'Cause otherwise, that's what I'm going with.
(can hissing) (warm synth music)
- Brush.
(can hissing)
(parts clinking)
It's good.
Stop.
That is very orange.
- Real quick, before you keep watching, I need to tell you,
I had to remove a ton of interesting parts
of this video for it to work with the YouTube algorithm.
And I have to do it pretty much every time,
and it drives me nuts.
If you'd like to see the extended version of this video
that includes everything that I think is interesting,
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Nebula is a streaming platform
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Clicking that link really helps my channel
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Thank you.
- So, when Ryan and I designed the worm gear box,
and it's something we've never done before.
We didn't have to design the actual gears,
but the center to center distance,
like where the gears meet, and how they interact
is something we've never really worked with before.
So, one of the big things we're trying
to get done this weekend is testing that assembly.
(chill electronic music)
(equipment whirring)
(drill humming)
- So, why are we machining things
that were already cut with the laser?
Well, the laser can only cut essentially in two dimensions.
So, this is an example of a part straight off the laser.
And sometimes we need things that are much more complex.
This has had clearance milled out here.
It's had holes drilled from the side that were tapped,
and then this bearing was pressed in.
And this is all to make assemblies like this.
This is the gear box to raise and lower the arm.
- It's been 16 hours.
We're now taking these apart to check
on the first batch of wheels.
(parts squeak and click)
(people laughing) - Ooh.
- [Worker] Ooh.
- [Bearded Worker] Man, that actually worked way better-
- [Worker] We got a better free print.
- That worked way better than I thought it was.
That is a solid wheel right there.
- We've decided to use brushless motors in Switchback.
They're way more efficient for the given weight
as opposed to the older school brushed motors,
but they're way more complicated to control.
In a brushed motor, you pretty much just give it power,
and it spins.
You control the amount of current,
and that controls the speed, and the strength of the motor.
However, for brushless motors,
this controller has to alternately energize
different coils of wire every revolution of the motor.
So, it has to be really tightly coupled
with the position and speed of the motor.
And if you screw that up, all hell can break loose.
Every bit of weight we save on the motors
we can put towards armor and weapons,
but there's a lot of opportunity for things to go wrong,
and leave us completely dead in the water.
- So, this is the first time we're gonna try,
and spin up one of our drive motors.
I got some green lights on the screen, that's a good sign.
Now we're gonna do the flux linkages.
No spin.
- What's concerning me is we're not hearing any squeal on.
- Yeah.
- Even.
- So, this is the inside of the motor controller,
and we opened it up, after the, a loud pop.
The gate driver has a crater in it,
and then underneath this thermal pad,
which is now nice and charred,
these are the H bridges.
Basically, some copper vaporized,
they started desoldering themselves, it's dead dead.
Make sure our connectors are good.
- Oh.
- They came from the factory with tinned wires.
We cut off the tinned wires to put on our own connectors.
These are the winding wires, which have an epoxy coating.
- Oh, you need the solder pot.
Yeah, that's what they do at the factory.
So, the winding wires, when they wind the motors, right?
They are coated wires, right?
Because they, so they can't touch each other, right?
In little individual wraps.
So, when you put a connector on the end,
you have to burn or heat off the actual coating.
- [Worker] How does this thing-
- To make a connection, otherwise you're like,
your wires are not connected.
So, they cut those off to put crimps on them.
The crimp was going to the outside of the winding wire.
And so, then it was like making connection
with like almost nothing.
So, your resistance went to like infinite,
and it was essentially a dead short.
- Oh, right. - Until they bumped up
the current, and then they fried the chip.
- Okay, so, after we fixed the motor wire problem
by tinning the wires, we're hoping
that this makes a better connection.
And so, we have the sensor cable, motor wires.
Going to run the test.
(motor whirs)
(bell rings)
Sweet.
Let's just go straight to controlling it with a radio.
(motor humming)
Here we go.
- I've heard we're just about ready
to put the robot together for the first time.
(parts clinking) (upbeat electronic music)
- Yeah. - This is definitely applying.
- Yeah.
(parts clicking)
- We're ready to start working on chains.
- Ready to get greasy.
- Extremely dirty.
(soldering iron whirring)
Ooh, look at that thing.
(parts clicking)
(drill hums)
- That's getting a little heavy
(parts clicking)
- Like- - Hands off, everybody.
Full speed 100.
- Yeah, just do it.
- [Worker] Go for it.
(motor whirring)
- That actually sounds really good.
- Yeah, okay, let's put the belly cam back on.
(parts whirring and zipping)
(Switchback clicks)
(upbeat rock music) (motor whirring)
Width turns are gonna be so easy.
(Switchback rattling)
- [Worker] That is cool.
It is so fast!
(Switchback rattling)
- Was that a hundred percent?
- That was a hundred.
- [Worker] Wheels look okay.
- Yeah, we should pass this around a little bit
out here before we destroy it.
(Switchback rattles) See what we're doing.
This motor.
(Switchback rattles)
Yeah, something was up with that side.
- So, we've lost drive on one half of the robot, one side,
and don't really know why right now.
- It drove for like, yeah, drove well.
- Without a guess. - Yeah.
- That's almost a whole BattleBots, man.
All right, let's call it a day.
(cart rattling) (warm synth music)
- The first step, I think,
will just be to get this running again.
Okay, it's doing the pulsing it was doing out there.
(motor whirring)
Yeah, that doesn't sound good.
I'm going to swap, I'm just gonna move the connections over
from the good motor, the good side, to the bad side's.
So, now it's not running at all.
Looks like we burned an ESC.
- These are about a hundred bucks each.
It feel like it's gonna be an expensive problem to fix.
Trash.
We'll replace it and move on again.
- Now we're gonna focus on putting the arm together.
Let's explain this.
- So, this is the gear box- - This is kind of a critical.
- For the arm.
It uses a worm gear in order to turn this chain
mechanism into these compliant couplers that-
- All right, and so, this then fits in here.
- [Goggles Worker] Yep.
- [Segment Host Worker] Like that.
- [Goggles Worker] And there's another shaft
that gets attached to that.
- [Segment Host Worker] Yep.
- That shaft passes through this hole right here
to another chain., and then that's what we're using to move-
- Articulate the arm up and down.
- The whole arm, yeah.
This is the one where like, we have the most nerves
about working, right?
Like, spinning a blade really fast,
that's not that complicated.
The drive train's not that complicated.
With this, moving the arm that's fully loaded-
- That be true.
- The dynamics, that's where all the complication is.
And that's also what I like.
All the doubters are saying, what are you guys doing?
(segment host worker laughing)
So, we're gonna learn really quickly
if they're right or we're right.
(parts clicking)
(engine humming)
- I am doing just kind of a dry fit
of all the weapon components. (chill electronic music)
And so, I'm putting all the plates together,
and I'm gonna put some screws in the top,
and try to lock the whole assembly down.
- [Cameraman] How much does this thing weigh?
- It's 80 pounds.
And that spinning at 10,000 RPM.
That's gonna be crazy.
- Holy moley.
(group laughing)
Little bit more than you're used to lifting.
- Ugh!
- You don't wanna get hit by that.
- Oh.
(group laughing)
That's heavy.
Oh yeah.
That's gonna do some damage.
(drill whirring)
(hammer thumping)
- Oh, no, that's probably good enough.
- Okay. - Yeah.
- [Ponytail Worker] Done.
(drill whirring)
(engine humming)
- So, the real question is, is that like,
so Switchback, it's kind of like its family name.
- Yeah, it's a very weird thing that I think like
people don't understand is that
we're not building a single robot,
we're building two or three robots that all look the same.
- Correct.
Every one of the rows "BattleBots"
is has multiple robots in their pits.
So, when you see it in the box,
you don't actually know which one it is.
- Right.
(engine whirring)
(group laughing)
- I got slimed.
(parts clicking)
- All of a sudden, it looks like Switchback.
- Oh, at least. - Yeah!
Looks like a robot, Lance.
- Oh, and it can spin now.
- Yay! (laughing)
A little- - Holy.
(group laughing)
- Never mind, too much.
We need to now make it a point that like,
nobody's moving this by themselves anymore, right?
It is far too heavy, sharp, and dangerous, like-
Do we wanna like back up, and just like,
make it rotate slow?
Just to like, make sure that stuff actually spins.
Everybody who doesn't need to be anywhere close,
we are going to back way up from this.
We will control it over radio, but I wanna limit it
to like, literally like one percent.
- Right.
- We are about to test the weapon,
so we are all ducking behind this polycarbonate barrier.
- So, I'm gonna turn on the arm.
(Switchback whirring)
- [Dark Beard Worker] That's good, right there,
right there, right there. - Yeah, that's perfect.
- Weapon on.
- All right, Frank, Frank.
- [Work] Frank, come this way, right.
- Come this way, behind the.
(group laughing)
I want you to literally just,
just throttle up until it barely starts spinning.
- Yeah.
- And just leave the throttle right where it is.
- Yeah.
- And then just, and then we're gonna shut it down.
- [Robot Driver] That's one percent, two, three, 10,
11, 12.
(Switchback screeching)
13. - Nice, there it goes.
- Okay. - All right,
you can go a little bit higher than that.
- Okay. - It's so nice.
- [Robot Driver] 14.
15. - Oh,
that's already terrifying.
- This is 15%. - Yeah.
- And these motors are actually throttled at 50%
'cause they're the wrong KV.
Do we wanna go a little bit faster
in here while it's stationary,
or do we wanna just go immediately outside?
- No, I think we should go outside.
- Go out, let's go outside. - Let's break some-
(forklift beeping)
- I'll see y'all on the side. - Just stay.
- [Worker] Don't die and good luck.
- Wait a minute. - What?
- Why do they get to go up there,
and these two poor slackers have to stand down here?
- 'Cause these guys have to turn it on.
- So, how is it safer for them?
- Because until he turns on the radio over there,
it's dead, killed.
It won't move here.
- But it's unsafe for them but safe for these two guys.
- Yes.
- (laughs) Okay, okay, I'm just making sure I understand.
- I'm just trying to like, once the thing is on,
I'm treating it like a bomb,
because that's the easiest way to like-
- And therefore if you lose a couple guys to a bomb,
it's fine.
(group laughing) Just not everybody.
- I don't wanna lose the hopeful tune.
- Right, okay.
- Phil, ready?
Arm on!
Okay, then stop, stop!
Weapon on!
- Parker. - We are logging.
- All right, we're all.
- Enabled.
10.
(Switchback screeching)
20.
- Holy smokes.
- [Robot Driver] 90, 100.
- [Dark Bearded Worker} Yeah, what's the current
limit right now, 80?
- Yeah, maybe 80. - 80.
- [Dark Bearded Worker] So, that's not spinning very fast.
- [Worker] Honestly, that's way slower than I-
- Can I go configure that to be 80?
- Disabled. - Higher than 80?
- Go to 120. - Okay.
- We were only at 20 amp. - Aha.
- That explains so much.
(group laughing) (warm synth music)
- 30. - That's a.
- [Robot Driver] 40.
- Okay, now. - Oh, there we go.
There we go. - Okay, yeah.
- 50. - Yep,
no, that's scary.
- [Robot Driver] 60.
- [Worker] Yeah.
That's what we're talking about.
- [Robot Driver] 70.
- [Worker] Oh, that's terrifying.
- 80. - Oh!
(group laughing)
- [Robot Driver] 90.
100.
(group laughing)
- [Worker] That's sketchy.
- [Worker] Something is rattling out.
- Yeah, let's shut it down.
Let's go to 50%. - Okay.
- And then we can just move the arm,
just like within like a 10-degree span.
- [Robot Driver] Okay, arm down.
Arm up. - Okay.
- Okay, crank the speed up.
(Switchback rattling) Oh.
Something just happened.
- [Robot Driver] Yeah, what should I do?
- Just stop, kill it, let's make it safe.
Something's not right.
- This motor controller's a bit warm.
- Ooh.
- Yeah, it's hot. - Toasty.
- All right, well, that was sufficiently scary.
But that worked, we did it.
- We have successfully competed on "BattleBots."
- Congratulations, everyone.
(triumphant synth music)
- Now. - Hey!
- Hey, let's get it.
- Ready? - Let's round robin.
- [Group] Hey!
(group laughing)
- Wow.
(group laughing)
We got it spinning.
We have what, a month?
- What? - Just about a month.
- Just about a month to build two fully functional.
- Fix all the issues with this one,
finish the system integration,
and build two more from scratch.
- Good luck.
I'm headed back to New Mexico, so I'll see y'all in Vegas!
This video was shot last summer,
but only came out now because I had to recover
from my head injury first before I could edit it.
We competed with Switchback in Vegas last August,
and ended up going one and two.
You can watch those fights on Discovery+,
and there's a bonus fight that's available
that's free to watch on YouTube.
I'll put links to all of those down in the description.
Switchback also fought in "BattleBots: Champions,"
Our fight is airing this Thursday, August 25th on Discovery.
So, be sure not to miss that.
And if you'd like to follow the Switchback team,
you can find the team pages on Facebook and Instagram.
Links are, again, down in the description.
In the meantime, I'm putting the finishing touches
on my new shop here in Colorado,
and diving into some exciting new projects.
I'll see you again soon.