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Electrical engineering
Course: Electrical engineering > Unit 7
Lesson 5: Bit-zee Bot- Bit-zeeeeeeeeeee
- Bit-zeeeeeeeeeee (long version)
- Parts for Bit-zee and It-zee
- Tools for Bit-zee and It-zee
- Introduction
- Planning and propulsion
- Parts
- Chassis/frame
- Wheel mounts and fenders
- Component mounting holes
- Batteries/power
- Battery wires
- Power wires and on/off switch
- Motors/propulsion
- Motor controller functions
- Motor controller
- Motor controller connections
- Arduino connections
- Digital camera connections
- Digital camera connections II
- 5 volt power distribution board
- Digital recorder/player connections
- Power connector for the Arduino
- Prototype board
- Motor controller connection to Arduino
- Camera connection to the Arduino
- Bumper switches
- LED eyes
- IR sensor
- Chassis modifications
- Camera wiring update
- Programming
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Wheel mounts and fenders
In this video we show you how to create Bit-zee's fenders out of hair dryer motor mounts and we also take you through how to mount the hair dryer motors in Bit-zee's frame. Created by Karl Wendt.
Want to join the conversation?
- One of the wires on the motor was black and the other was red. When I mount the other motor, would I need to have its red wire opposite the red wire on the first motor? If so, why?(17 votes)
- No, you do not. The motors are wired to a motor controller later.(1 vote)
- Would it still work if I covered the wheels with rubber treads or could you file down the blades so it would have a blunt edge so it wouldn't scratch(because my parents have wood floors and I would get in big trouble if I scratched it)? Also, where can you get zip ties?(5 votes)
- Rubber treads would work. (thats a good idea)
you can probably get zip ties at walmart or home depot(4 votes)
- Is it safe for a 13 year old kid to do this alone?(3 votes)
- Yeah, just be careful with voltage. Too high voltage might be dangerous.(3 votes)
- Karl, where do you buy these brands of items because every chip board has different stuff and although i cannot afford them, there are something I can get my parents to do for me(2 votes)
- Here's a list of where Karl purchased the items for this project:
https://www.khanacademy.org/science/discoveries-projects/robots/Bit-zee/a/parts-for-bit-zee-and-it-zee
And the tools: https://www.khanacademy.org/science/discoveries-projects/robots/Bit-zee/a/tools-for-bit-zee-and-it-zee
I hope this helped.(3 votes)
- do you have to have medal ruler; or can you have another ruler ?(2 votes)
- It doesn't matter. Just make sure it's straight. :D(2 votes)
- At,what is a screw boss? 1:05(1 vote)
- That's the end you stick the screw drive in.(1 vote)
- That's so cool and complicated!(1 vote)
- Shouldn't he have some protection on his hands while using the hacksaw?(1 vote)
- As long as you know what you're doing, you don't need to wear gloves when you're working with a fine-tooth hand saw.(1 vote)
- Is he cutting with a ruler?(1 vote)
- no, its a hacksaw, though it looks like a ruler from a bird's eye view(1 vote)
- Do you have to be really really really super exact to were you put your holes in the plastic and were you put your fan blades?(1 vote)
Video transcript
In this video, we're going
to take our motor that's going to be our wheel
from our hair dryer, and we're going to find a way
to connect it to our tap light housing. So we're marking the screw boss
locations on our tap light. And that's where the
screws from the tap light connected to the bottom
of the tap light housing. And we're going to
measure between those. And so we've got about nine
centimeters between those, so four and a half centimeters
will be right in the center. And we're going to
mark that because we don't have a direct
line connecting it. We're going to double
check those measurements with our ruler on both sides. And it's important that the
mark is right in the center so that our wheels line
up when we put them in. So we're going to do the
same on the other side. Again, it's about nine
centimeters across, so four and a half between. And then we're going to just
drop that mark down the side. And we're going to use the
inside of our tape roll to create the arc that we
need for our wheel well. And we're going to measure off
of the boss, the screw boss, to the bottom. And that'll be 1.5 centimeters. And we're going to
measure off of that. And then we'll transfer that
1.5 centimeters to the outside, and that'll be
the top of the arc that we're going to
create with our tape roll. So we're going to just line
it up with the mark there. And then we'll take our
Sharpie, and we'll draw our arc. So once we have
our arc drawn, we can begin removing
the material that we need to remove so that
the motors fit inside of the tap light housing. And now we're going to
put on safety gloves. And we're going to use
a break off blade knife. The break off blade is
probably not the best knife to use for this. I'd probably use an X-Acto
knife or another kind of carving knife, but it's
the one I happen to have. You can see the blade
just snap there, so make sure if you do
use this kind of knife that you wear safety glasses. But right now, we're just
whittling away at the material. And it's very soft, very
easy to cut with a knife. You can just trim it down. You want to just
take the material away just a little
bit at a time. And then, obviously,
you want to try and make sure they stay inside
that black line. You don't want to
cut too far away. Otherwise your wheel well will
not line up with the wheel just perfectly. Of course if you do go a
little over, it's fine. It won't hurt anything,
but it definitely won't look quite as good. So we're just trimming up the
inside edge of that wheel well now and cleaning it
up with the knife. And we'll do this on
both sides, so it's the exact same process
on the other side. So we're lining it up to see
if it fits with the motor and it looks like
it's pretty well. So we're just lining our
motor up with housing, making sure that the
opening is the right size. You see the vanes
here on the motor, that connects the inner motor
surround to the outer motor surround, the surround
that basically protects you from the fan blades? We're going to have to
remove some of those in order to get the fan to
contact the floor. Now the fan is acting
like our wheel, and in order for it to
move the craft forward, we have to remove the bottom
part of that outer housing around the fan, the
clear plastic housing. So we're going to
remove two of the vanes on the bottom and
three on the top. And the two that we're
going to keep we just marked with our Sharpie. So the two that we're
removing on the bottom, we're using our nipper pliers. So we're snipping those off. And then we're going to
take our hacksaw blade, and we're going to clamp the
motor in place as best we can. And we're going to
take our hacksaw blade and trim off-- just
basically cut straight through the outer housing,
the outer clear plastic piece that goes
around the blades. We want to make sure that
we line the two propeller blades up in such
a way that when we cut through
the outer housing, we don't cut into
the propeller blades. Because we want to use
those as our wheel. Now this is time lapsed, so
it's going faster than normal. But I've already cut
through the other side. This side's almost cut through. I'm going to use the nipper
pliers to trim off the rest. Then we're going to
make sure that we've got enough blade exposed,
and it does look like it. We're going to clean up
the edges with a break off blade knife. And that's just to
clean off the burrs and the rough
edges of our motor. Make sure everything is clean
and exposed and ready to go. And we're just trimming
off the excess there. So now you can see the
motor spins freely and can connect with the floor. And on top of the motor,
there's a-- we're just checking to make sure it
still works and spins freely. So on top of the
motor, you can see there's a Sharpie marker mark. And that was drawn from
just taking the bezel and putting it over the motor. And so we want to see if
we can cut that mark out. And so we're going to
take our hacksaw blade, and we're going to cut the
plastic housing at an angle so we can try and get as close
to that line as possible. So it's at about
a 20 degree angle. And we're just cutting
straight down to try and cut along that line that we
drew with our Sharpie. And the point of this
is basically just to get that plastic surround
to sort of wrap around the tap light housing. And we're cutting through it. It takes a good bit of
work to get it lined up, but since we're doing it by
hand we can hold it like that. Now we're taking
our nipper pliers, and we're snapping
those connections. And we're just
going to cut right through the rest of the housing. Now we're pretty close
to where we need to be. So in order to get
it to fit just right, we're going to need to trim it. And we're going to
use our nipper pliers to finish the
trimming and make sure that we can get the kind
of fit that we want. It takes a fair bit
of patience, but I think it's better to take
a little bit off at a time than to try and
do it all at once and not get a nice, clean fit. So we're just snapping through
the different parts there. And you can see that
the motor fits nicely against the white
plastic housing. So we've got protection on
our motor, around our blades, and it fits nicely
against the outside. We're taking just a
little bit more material off now to make sure that
the motor fits pretty well. And again, this material
cuts very easily with our nipper pliers. So you could potentially cut
the whole thing with the nipper pliers and not use the
hacksaw if you wanted to, but I felt like it was a little
easier to use the hack saw. So we're just checking
our motor out, and making sure it fits,
and double checking the connection between
the motor and the housing. Giving it a close inspection. You can see that there's
a pretty good fit there. We're trying to find out if
there's any places where there may be an interference,
or the parts don't come together the
way we want them to. And we're also looking
at how we could fasten the motor to the housing and
making sure everything clears. So there are a couple of
little nibs, plastic nibs, left from when we cut off the
vanes using our nipper pliers. So we're just filing those
down so that the motor will sit flush with the Lexan. And the motor
needs to sit flush, because we're going to zip
tie the motor in place. We're going to hold it in place. And if the motor has
those bumps on it, it won't have quite
as good a fit. So right now, we're
just making marks. We made four little marks there. And those marks go on
either side of the motor. And we're going to use those
to run our zip tie through. So we'll run our zip tie through
from one side to the other. And we're just going to use
a quarter inch drill bit. All right, so now we're
just removing the screws from our polystyrene housing
and getting them out of the way. And we're going
to drill our holes that we marked for the motor. And that will allow us to
run our zip tie through. And we're just going to clean
the edges of the holes up with our break off
blade knife there, making sure that they
line up with our motor. And they do. And those holes are roughly a
quarter of an inch in diameter. Doesn't really matter
exactly the size, but as long as they're
just a little bigger than your zip tie, you're fine. So we're going to thread
the zip tie through. We want to make sure that the
bump on the end of the zip tie is on top of the Lexan
so that the zip tie holds tightly against the motor. And because the motor has
got two levels of plastic, we're putting a
little shim in there, just a little piece
of extra plastic. And that'll help
hold the motor flat. And now we're going to
pull the zip tie down. We'll pull it down all the
way and snap it in place. You can see now the motor's
pretty securely in place. We're going to go ahead
and grab another zip tie and do the other side. So we'll grab-- oh
we're just pushing the shim the rest of the way in. I forgot to mention that. We want to make sure the shim
is tightly secured in there. And the shim is just made out
of another-- it's same type of Lexan, same thickness. We just cut a little piece of
it that's about half an inch square and stuck it underneath
that part of the motor. All right, so one more
zip tie on this motor. And the other motor's
done exactly the same way, but we're going to run the zip
tie through and connect it. Again, the raised
portion of the zip tie needs to be above the Lexan. We'll feed the
bottom of the zip tie through and pull it
tight against the motor. This'll give us the ability to
adjust the motor if we need to. Make sure that it's lined
up along the imaginary axis between two, where the
two motors will be. And as we're
tightening that down, we may want to
grab a screwdriver to finish tightening
it the rest of the way. And we'll leave
the zip ties long so we can make
some changes later, if we need to undo the zip ties. So basically, that's
how to mount the motors for your Bit-zee Bot. The other one's done
exactly the same way. Thanks.