On the scale of importance when driving a vehicle, steering is up there with some of
the most important. If you remember, we did have working power steering here on this electric
humvee, but it was super loud….or rather, more annoying than anything. It had a hydraulic
pump that was constantly running in the background, adding pressure to the power steering and
braking systems. We ended up getting rid of that for the braking for something far more
silent. And as well, for the power steering, we have a solution. The solution is this guy
- an electric power assist motor that attaches directly onto the steering wheel shaft that
goes down to the steering box. I’ll explain more in a minute. Let’s get started.
[Intro]
So how this electric motor assisted power steering works is that one end connects to
the steering wheel, and as the steering wheel turns it amplifies the force heading out to
the wheels, which are right here. With smaller vehicles like sports cars, you don’t really
need power steering. The car is light enough that you can do it with just your hands. But
when a vehicle weighs 5 or 6,000 pounds, or you’re towing a load behind the vehicle,
you really can’t do it with just brute force anymore. You need some help.
Taking a look at the geometry underneath the dash. Ignore the wiring and we’ll fix that
later. So we can see as I move the steering wheel, all of that linkage starts moving as
well, and the bottom of that shaft heading through the firewall comes out through this
side and into the steering gear down here. So we have to put this motor somewhere along
that shaft.
This guy right here is the steering column that goes from the steering wheel all the
way down to the steering gear. And technically without power steering we still would be able
to steer just not very well. And like turning the wheels while the vehicle is not moving
is near impossible. We have taken the power steering motor and am just kind of testing
it out really quick. We jerry-rigged it up to a battery just to make sure everything
was working. So have hooked a 45 pound weight up to this end of the power steering pump,
and by pump I just mean motor. And this is the side that’s going out to the tires where
the force is being amplified. This is the steering wheel side and right now if there’s
no power connected to it, I can spin this side it’s like a one to one. But there is
zero percent chance of me ever being able to lift up that weight. It’s barely moving,
but, like, the screwdriver will break before that weight moves. So now if we take this
wire, very carefully connect it to the 12 volt system. This is the signal wire which
basically tells the pump to turn on.
Now we should be able to take this steering wheel and incredibly easily start lifting
up this weight. I’m using my pinky to lift 45 pounds with the steering assist coming
off this motor. Now obviously, driving down the road or going up mountains is going to
be slightly different than just lifting a weight off the ground, but you get the point.
One little finger can now move a lot more weight. Now we just need to weld these adapters
onto our steering column.
[Motor sounds]
In order to put our steering assist motor into the steering column, we have to cut the
cone. We do want to keep the jointy bit though.
[Welding sounds]
I’ll punch out the center of the jointy bit and then comes the complicated part. Apparently
no one really makes bolt on parts for electric humvees. So we gotta make our own. The silver
couplings do fit the assist motor, but not our steering wheel shafts. So we chopped off
the bits that we don’t need from those silver couplings, and then I tried to bore out the
insides with my stand up drill press. That didn’t work out too well.
[Drill press sounds]
It’s twisted. Ugh. Luckily my buddy, Jacob, has access to a lathe and we were able to
drill out the inner diameter of the silver coupling to match the out diameter of the
steering shaft. That solves one side. The more exact we are now means the straighter
the shaft is going to be. If the shaft isn’t straight it puts stress in weird places as
it’s turning the tires. And we’re trying to avoid that. Since, if you remember, steering
is rather important. For the other side we cut a small adapter that fits between the
jointy bit and the silver coupling. That was the motor can sit right there next to the
jointy bit where the shaft used to be. It’ll all make sense in a second when you see it
put together. Jacob turned this piece of metal down on a lathe and it’s going to sit inside
of this hole. We’ll have to press it into place and then this coupling gets pressed
into that, which will keep it totally straight all the way up. It’ll make more sense when
you see it done.
Now with that pressed in, we can position this over the top and press it in the rest
of the way. Now we have the coupling pressed into the joint. And we can take the coupling,
put it onto the steering module, and bolt it down to the steering gear. And figure out
where this slips through the firewall. Steering gear...firewall. Eventually we will weld around
the edges of this, but with the press that we have currently, it’s not going anywhere.
So we’ll position everything without welding it first. There’s a flat portion along the
splines of the universal joint that can just slip onto the steering gear. Then the steering
assist slips down into place and we can line up on the firewall where we need to start
cutting things.
Removing the rubber boot for the old steering shaft is easy enough, just four bolts and
I can pull it out from the inside of the firewall where the driver sits. We’ll have to make
our own boot for the custom shaft after we’re done. As we’re lining the motor up along
the steering shaft, it needs to sit inside of the firewall, which means that we have
to drill out a little bit of that firewall to make room for the motor.
[Drilling sounds]
Woo!
[Drilling sounds]
Alright. We found that using a hole saw tends to make the best looking cuts. Drilling in
a few different spots, lining up the motor, seeing if it fits, and drilling out some more.
Next time let’s work on a smaller car.
So remember how back in the day I said that with the original military humvees, they don’t
have a key, they just have a switch that they turn on. In order to lock them up they have
something that was pretty unique. Underneath here on the steering wheel is this guy. See
this tube that runs all the way down? This is a metal cable that just wraps around the
steering wheel and locks, if you want to lock things up for a long period of time. The only
problem is as we are cutting a hole for that power steering module, it’s kind of getting
in our way. So we had to unscrew two bolts down there at the bottom which should let
it slide enough that we can line the shaft of the steering wheel up with the motor and
get our power steering back.
As far as the wiring goes, there are three wires. One is a signal wire to turn the thing
on. The other is the positive wire that can handle 30 amps, and a negative wire to complete
the circuit. And like always, I’m using my 12 volt control panel from the battery
to the 30 amp fuse, and from that fuse to the relay. Using 10 gauge wire because 30
amps is quite a bit. So when we took the shaft out from behind the steering wheel and cut
it, it comes in multiple parts. This is where we cut it down here. And this piece slides
up into this piece, which heads up to the steering wheel. Now what we have to do is
cut out the exact length of this part because this is going to sit in the shaft. So I think
we’re sitting at like seven and three quarters, and we will chop this as well at seven and
three quarters.
[Sawing sounds]
[Sanding sounds]
[Welding sounds]
We found the best way to stick the couplings to the shaft is just by welding them in place.
During this whole process we’ve taken very special care to keep the shaft as straight
as possible so there’s no weird kinks or angles as we’re turning the steering wheel.
Even though this system isn’t particularly load bearing and not under a whole lot of
stress, it’s still not something we want to mess up or mess around with. Quick overview,
we have steering wheel, we have the steering shaft, this tucks up inside of there. These
are the welds we’ve fabricated. This is the coupling. We cut out a portion of the
shaft where the motor’s going to sit. And then we have this going down to the steering
gear box. The only thing left to do is put it in place and see if it works.
Okay so we have everything wired up, temporarily of course. We still need, like, a big mounting
plate right here. But, we are connected to the steering wheel as well as the steering
gear. Now Jacob’s going to flip the switch. See if we have any steering assist. It’s
working?!
-Easy.
-Good. Okay. When we spin it back the other way the motor might flip up a little bit.
Oh yeah. But we can go one direction, right? Sweet.
We need to get a new hose because the power steering is just leaking. Basically what we’re
going to do is just loop it from one side all the way to the other just so the power
steering fluid stays inside. Trying it for myself. Everything is on. I’m able to turn
the tires with one finger. That’s a lot of steering assist. I’m very pleased with
that motor so far. But the more important thing is is we need a metal bracket that will
hold that motor steady while we’re turning left and right. And we’re going to do that
with lasers. We’ll be making this out of one eighth inch thick aluminum so it’ll
aesthetically match all of the rest of the silver components we have underneath the hood.
The laser cutting we’re doing this time around is slightly more complicated than previous
designs. Yeah, OSHCut still has their 10 kilowatt lasers that can make short work of metal,
cutting out our entire design in seconds. Anyone can use this laser. Just drag and drop
your design onto OSHCut’s website and the machine can cut it out in seconds.
This video’s not sponsored, they just let me come tour the shop and I think it’s pretty
awesome.
[Laser sounds]
The finishing machine gets rid of any sharp burrs or edges on
the piece, as well as puts in a nice texture or grain to the metal. The difference between
this design and previous designs though is the center piece. The steering assist motor
has three little bolts that help mount it and hold it in place, and in order to get
that correct angle we’re going to use this machine here. This massive press brake can
take our design and bend the little flap out into a 3D piece that can then support the
motor exactly where we want it so it won’t rotate any time we turn the steering wheel
which is kind of important. It’s pretty awesome that OSHCut has all these machines
here in the same place so I don’t have to wait weeks or months for parts, I can literally
get them the next day. And they’ve been super supportive on this project. Now we’ve
successfully taken a 2D part and designed it to work in a 3D space. Let’s see if it
fits.
The purpose of this piece of laser cut aluminum is to sit along the firewall and hold the
motor in the correct position. The steering gear itself is also lubricated. We have a
stainless steel braided hose attached to the input and output so it’ll keep its own liquid
circulating inside. With the motor clipped in and bolted into place, we can bolt the
aluminum plate to the firewall of the humvee. And now that everything is connected there
is one more piece which is this guy right here. This is the brains of the operation,
kind of like what controls the motor, and I’m just going to tack it right up on the
firewall so that the wires running out of this can just run through the loom we already
have going. And there we have it. We have the brains of the motor connected up here,
the metal plate laser cut, as well as the motor connected to the steering shaft coming
from the steering wheel. And the hose that’s going to keep all the liquid inside of the
steering gear so that it doesn’t end up on our floor again.
Shall we try it out, Jacob?
-Let’s give it a shot.
-Key first. Nice. Nothing’s getting hot yet and the tires are turning. Let’s see
how many fingers it takes. So right now I’m using one finger on the steering wheel and
we are turning the tires. Yeah nice. And the best part about all of this is it’s completely
silent and it’s not running constantly in the background. As the other pump was constantly
running in the background at 20 amps, it would have decreased our range. But when these motors
aren’t being used, they’re not draining the battery. The good news is is that our
power steering can work at a complete standstill with the full on truck. Super happy about
that.
And there you have it. The power steering, the power brakes, and pretty much everything
else connected to the 12 volt system is now working. The only things we have left are
the high voltage, like the batteries, along with the cooling, the BMS, and you know, everything
that’s connected to those. We’ve posted every week for about 10 weeks now. This has
been the largest project I’ve ever done on my channel. And you might not have noticed,
but I’ve been filming these videos over the course of a year, but just publishing
them in the last 10 weeks. There’s quite a lot of work that goes on behind the scenes.
But as of right now, this video, we are 100% caught up and what you see behind me is where
we are at in real life. And now that we are caught up it’s time to take a short little
intermission. While I’ve been working on this project, my wife has been working on
a project as well. We are currently 9 months pregnant, which means that either this week
or next week Jerry Rig Junior will be joining our family. So I’m going to take some time
off to spend with them before continuing on this project. The goal is still to have this
thing moving before the end of the year. So make sure you hit that subscribe button with
the notifications on so you don’t miss any new developments. And thanks for joining me
this far on the project. It’s definitely one of the coolest things we’ve ever built.
If you have any questions leave them down in the comments. Come hang out with me on
Instagram and Twitter. And thanks a ton for watching. I’ll see you around.