Know How... 139 (Transcript)
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Today on Know How we will be
bringing new life into old electronics. We are going to be doing something with
this mysterious blob of stuff and finding the best motor for your quad.
Father
Robert Ballecer: Welcome to Know How, it is the Twit show where we
build, bend, break and upgrade. I’m Father Robert Ballecer.
Bryan
Burnett: And I’m
Bryan Burnett.
Fr.
Robert: And this
under the sheet here is… who knows? Probably a quad copter.
Bryan: Definitely something to do with
Quad Copters right?
Fr.
Robert: Because
that is all we do on this show.
Bryan: It is probably something like a
mobile platform from DJI.
Fr.
Robert: We are
going to ignore that for now because we have something more pressing to talk
about.
Bryan: Very easily ignored right here.
Fr.
Robert: Pay no
attention to that being behind the curtain. Now Bryan, we are kind of in a
drought huh?
Bryan: Yes, California has been suffering
for the last few years.
Fr.
Robert: It is funny
because we have been having droughts on and off since I was a kid.
Bryan: This one seems to be sticking
though.
Fr.
Robert: This is
sticking and it is kind of scary because when you drive the 152 it goes past
this huge reservoir. And when I was a kid, there were years where the water
would come up over the roadway and it would shut that thing down. That was how
high the water was. Now I can barely see the water it is so far receded and so
many hundreds of feet down that it goes nowhere near the roadway.
Bryan: It is very scary and it is not just
drinking water that is affected. It is the recreational stuff that we like to
do. Like going to Tahoe and enjoying the snow, which the snow is kind of where
we get a lot of water over the summer.
Fr.
Robert: That is the
other part of it. Which is, we depend on the snowpack. No snowpack, means we don't get water throughout most
of the year. And the snowpack doesn’t really exist anymore. Snowpack is kind of
gone, but, skiing and resorts are still a multimillion dollar industry in
California. So we thought we might want to talk about the technology that goes
into making snow. We have all seen snow makers, but the more advanced ones are
actually far more complicated than you might think they are.
Bryan: Yeah. I guess I just always
imagined you get a refrigerator, you shave some ice and you just shoot it out.
Fr.
Robert: That is
what most people think.
Brian: You do it consistently so it
doesn’t all melt.
Fr.
Robert: But we know
that is not true. Because real snow you get powder.
Bryan: Yes. It is much nicer to ski in
power than hard pack ice. That is when you get hurt.
Fr.
Robert: Anyone who
has skied knows that skiing on ice is not fun. It is hard on your feet and you
just don’t have that much control. Too fast sometimes, too slow other times. You
actually do need snow and because it is more than just shopping up ice for more
than just spring water in the air and hoping it freezes, well Alex, make it
snow.
Bryan: Make it snow. Make it snow. Despite
the best efforts by Disney, it still has not snowed.
Fr.
Robert: Specifically I want to talk about this multi-step process that some of the
bigger resorts are using with multimillion dollar pieces of machinery.
Bryan: This is their industry. They've got
to figure out a way around us.
Fr.
Robert: So the
first part has to do with spring water. The it is not
just like opening the tap and turning on the sprinkler. You divide your water
into multiple planes. So you might have one plane going this way, one plane
going this way and one plane going across it. The idea is to have the planes
intersect with each other because when the planes intersects as the water is
sprang out, it breaks them up into tiny little droplets. The more droplets you
have, the more surface area you have which means the faster they will freeze.
Because remember you need these things to turn into snow before they get the
ground. Otherwise you…
Bryan: Are just icing the ground.
Fr.
Robert: Huge
icicles. But that is not it. That will give you part of the solution. The other
solution is something that we figured out when we were trying to make rain.
Have you ever heard of ceding clouds? They you is a process called nucleation
which is, you need something that either the water droplet or the snowflake
will form around. If you give it something it will actually glom and then it
will form. Have you ever done the quick freezing beer?
Bryan: Where you put it in the freezer for
a little while and then…
Fr.
Robert: You tap it?
That is super nucleation and all the liquid is really cold. It is cold enough
to freeze but it doesn’t have anything to form around so it doesn’t. Then if
you tap that you disturb it enough that you get bubbles and the bubbles become
nucleus and then it just spreads.
Bryan: And that is what they can glom
onto?
Fr.
Robert: So you’ve
got the spray, breaking up the planes, the nucleation so they have something to
form around, and there we go. This is what it looks like. This actually shows
you the last step which is pressurization and compression. Have you ever used a
bottle of compressed air?
Bryan: Yes.
Fr.
Robert: And you know that when you spray it, it gets cold. Well that is
actually the law of thermodynamics. You are decreasing the pressure so
therefore the heat is exothermically escaping. Well, what you do is you shoot
high pressure air into these things and because there is such a pressure
difference it actually drops the temperature. So these things can work up to
10° above the freezing point of water. When you think about it, it really is a
science. And it is really different now than it was even when I was a kid. When I was a kid, though snow machines really made ice. But
now, you’ve got an advanced snow machine and it feels like snow.
Bryan: Look at the powder. That little mound that they had built up? It looked like it
had just snowed overnight.
Fr.
Robert: So, yes we
may be in a drought but we will still ski. Because of
technology.
Bryan: Yeah. If only we had technology to
make more water. Or do we?
Fr.
Robert: Maybe that
is what is under this curtain. Wait. Bryan, magic revealed. It’s a quad copter
right? No? Wait for it. Boom. That’s right folks. We
are getting into 3-D printing. This is not a quad copter, it is not as snow
machine, it is not a rotisserie. We promised you that
we would start getting into 3-D printing and this is actually a brand-new
printer. This was just released yesterday. We got this a month in advance from
the folks at XYZ. We first took a look of this at CES. This is the da Vinci
Junior.
Bryan: Isn’t the appeal that this isn’t
that expensive compared to others?
Fr.
Robert: $349. So I
am actually going to have the full review of this tomorrow on Before You Buy, so
make sure you watch so that you get to see the whole rundown. Now the whole
idea is they had a very successful product called the da Vinci. Which was nice,
but it was a little expensive. Even now it is still $500. Back then it was 700
or $800. Which was affordable, for a 3-D printer but still…
Bryan: A little out of the range of your
average hobbyist.
Fr.
Robert: If you are
just looking to play with 3-D printing you are probably not going to pay $500,
$600 or $800 for it.
Bryan: That is a pretty big investment.
Fr.
Robert: That $349?
That is not bad actually. Very tempting. And the nice
thing about this is the way that they built it. We are going to go over this
in-depth in Before You Buy. But things like the removable head. One button and
I can take the head off. That has been one of the biggest problems with the 3-D
printers because they jam and then you have to disassemble the entire machine
to get at it. With this I push one button, look this up and I literally turn
the head over here and I push a button and I can slide this whole thing out.
Bryan: I like that. It is kind of modular.
Fr.
Robert: It also
does PLA only. There are two types of plastics that we use, called filament. So
when we talk about filament we are talking about these spools of what looks
like plastic. This is just plastic that has been rolled up. This is PLA which
is actually an organic product, it is polymeric acid
or something…
Bryan: So there is this one and then the
other one which is?
Fr.
Robert: ABS is a
bit stronger because it is actually more flexible. PLA will tend to fracture
before it really starts to bend. But PLA is an excellent material to start
with. So once again this is a starter printer. This is what you would just kick
off your 3-D printing career with.
Bryan: You have a few examples here that
you built right? This is a little structure that you made for the quad copter.
This feels really solid. This is a fairly complex little shape that you built
and it is not very thick and you can kind of squeeze it but it feels solid.
Fr.
Robert: And then
you got everything from these, this is the rear mount for a tri-copter. I don’t
even have this set at maximum resolution. Maximum resolution for this is .1 mm.
That is the height of the layer that it can lay down. .1 mm is actually pretty
good and this when will go to .5 if you really don’t need that much definition.
The cool thing about a printer like this is you can manufacture these parts,
and then bolt them together and you can do all this and change it within hours
rather than days. Your design can really be a fast prototype. One of the other
things that I like about this, is this bed. This is a
non-heated bed. Right here the way that this works is this head just goes back
and forth. This kind of motion is actually handled by the bed. So, I get all
degrees of motion but I don’t have to worry about a multi-dimensional arm on
top. This is actually a really good combination. One of the other features I
really like about this, it is a stand out I think, is the ability to put your
designs on a card. This is just a standard SD card. And I loaded up and now I
can select from the front, I can build from card and I can selected design that
I want to build and it does it completely isolated from the computer.
Bryan: That is cool. That makes it really
easy to use then.
Fr.
Robert: It is good
for a workshop because you don’t want to have to have your computer hooked up
to the 3-D printer for everything. You know, three or
four hours or however long it takes to run it.
Bryan: That seems very well thought out.
Fr.
Robert: It will
print up to 5.9 x 5.9 x 5.9. So you get a cube of what you can build in here.
What you will find in a lot of designs is you can break up the designs into the
pieces that don’t get bolted together. This is one that I actually created. Because I started out with this. This I downloaded from the
Internet. This was an FPV for a camera. So it actually has slots here so the
camera will fit in the front. And then the battery will fit in here and you put
the little transmitter in. So you have an FPV pod that is like a self-contained
transmitter if you want to fly first-person view. You just stick it onto your
quad copter and you are good to go. But I wanted something else since that
didn't quite do what I wanted it to do. So I took that design and I used
AutoCAD and I shortened it a little bit. I reduce the width and the height and
I gave at this cool little channel so now the camera is actually just slotted
in there. There is a little hole in the bottom for me to get the wire out of
the camera and then the battery actually fits on the sled. Now all this wiring
is messy right now but ultimately there is going to be another piece that snaps
over the top and it will literally be a pod.
Bryan: See? That is what I love about the
idea of 3-D printing. You can take something that someone else built and then
modify it to your own needs. What is the speed like?
Fr.
Robert: Okay. Speed
will depend on resolution. Like I said, you can print as small as .1 mm. So
that gives you really fine resolution. It gives you something like this. A very nice look to it. But that takes longer because it has
to make more and more layers of really small layers. Well, versus something
like this. This was printed very rough. I used .5 mm on this. And you can kind
of see it. It is a little rough. But I didn’t need something that was pretty.
Bryan: You just needed it to be solid.
Fr.
Robert: Exactly. So
it depends on what you choose. Something like this, this pod right here took me
about an hour and a half to print.
Bryan: That’s not bad. That is quicker
than if you had to ship yourself a pod.
Fr.
Robert: Like these.
This takes like 10 minutes. For a set of four, because they
are tiny. And then you’ve got things like this. Does this look familiar
at all?
Bryan: That looks like one of the panels
that would hold the camera.
Fr.
Robert: Exactly. Wait
a minute they actually have a template for this.
Bryan: That one looks a lot nicer.
Fr.
Robert: It looks a
lot nicer and it is a lot more sturdy. The other nice
thing about this is once you dial it in, you can always print. You don’t have
to order parts. I am always breaking things and I don’t have to worry about
that anymore. I have a bag full of spares. You really are only limited by what
you can imagine.
Bryan: One of the biggest pains though is
that we got a 3-D printer may be a year ago and you
always had to calibrate it. So I guess this one is all self-contained?
Fr.
Robert: That is one
of the other things I really like. There is no calibration on this whatsoever.
You will never have to calibrate unless you break it. You physically jolt this
thing. There are controls where you can set the offset so you can have the head
lower. As long as you don’t mess with anything inside you are never going to
have to calibrate it. The only thing you have to worry about is running out of
filament and the head. Sometimes you will have to clean the head. Although,
I've only had to do it once and I didn’t really have to do it I just wanted to
see what the process was.
Bryan: And what is the process?
Fr.
Robert: You let it
heat up and then basically it is a fuzzy pipe cleaner that you put up into the
head and you tear out any debris that might have stuck. Speaking of that, there
is one thing about the XYZ printers that some people are not going to like.
Bryan: Yeah, you were telling me about
that. This feels a lot like a regular ink printer.
Fr.
Robert: I get what
they are going with. So, I don’t want to open this because we are going to be
talking about a lot of tips for the 3-D printing. One thing is when you get
filament it is only stored in a bag, don’t open it unless you are going to use
it. Filament will, by nature, absorb humidity. And if it absorbs humidity it
actually affects the way that it prints. So you only want to break it out of it’s bad when you are about ready
to print.
Bryan: So, say you hooked up a filament to
your 3-D printer and you wait a few months to use it again, you have to replace
your filament?
Fr.
Robert: Not replace
it, but if you are going to let it sit for a while…. oh look, this is another
thing I really like this. It is one touch load. Loading and unloading a printer
is normally a pain in the butt. It is not fun. This actually gives you a load
that will heat up the head, hold back the filament and then you unload it. Then
take it and put it in an airtight bad and it is good to store. But, each of
these spools has an NFC card.
Bryan: I knew there was a catch.
Fr.
Robert: People are
going to cry foul. Because it sounds like you have just DRM’d the filament. You can by this filament cheaply on the inter-web. It is about $22
per 2 kilograms. The XYZ stuff is like 20-40% more. you might think you could just load more filament on the spool but unfortunately in
the school right here and right here there is an NFC card system. So that when
you put a spool on, it knows exactly what you have loaded and it knows the
temperature that it should be setting the extruder for, it knows how many
meters of filament you have left so it won’t start a job if you don’t have
enough filament to complete it. But it also means once
that counter gets to zero it won’t continue to print.
Bryan: Right. So…
Fr.
Robert: It is a sad
trombone.
Bryan: You did make some good points about
why they would want to do this.
Fr.
Robert: I don’t
think this… I get what they are doing. In trying to make a beginner’s printer
they are trying to cut down on things like people buying bad filament. And then
suddenly you are breaking the head because there is a bunch of debris.
Bryan: When you start a project, the
printer will know how much filament you have so that it can say that you need
to add more if you are going to do this project.
Fr.
Robert: I can go
right here to information and it will tell me if I go to schools that what I
started with. So I had 100 m to start and I have 26 m left. So it will tell me
in the beginning because the programming that I used to create the STL files
and turned them to EW files, it will say this will use approximately 6.2 m. So
I know in advance if I should load up a new spool.
Bryan: I know. It just…
Fr.
Robert: I will say
this. I love the guys at XYZ and thank you very much for sending me this
printer. I may have already hacked it. I know.
Bryan: We’ll see what we can do.
Fr.
Robert: Will see
what we can do about that.
Bryan: There are a lot of places to give
filament.
Fr.
Robert: This was
just a quick demonstration. We wanted to show you what we are going to be using
over the next couple of weeks. We are going to be bringing you a lot of 3-D
printer projects. Next week we are actually going to show you the first print.
Once you get one of these, and you will be able to get it now. Literally this
was released less than 24 hours ago. You will be able to get one of these
things and we will show you the entire process. And the
advanced process. Everything from how do you load it up, how do you
prepare the bed so you can print on it, how do you get the print off. And then
the week after that we are actually going to show you how you can modify some
of those STL files so you can customize your builds to what you want to see.
Bryan: We were talking about this earlier
but I am going to have to start dusting off my old AutoCAD skills. To make the models.
Fr.
Robert: This will
do STL, it also does EW which is the data format for
XYZ. And they include a program that will convert STL to EW. You don’t have to,
but I like it because their software even though it is very rudimentary it will
let you do things like flip and rescale. It is good for people to start
thinking about how with 3-D printer has to print. It prints from the bottom up
so if you’ve got a structure that is a single plane and then it breaks out,
you’ve got to flip that out because the big breakout should be at the bottom.
So you have to printed upside down.
Bryan: You have to start thinking in 3-D
printer dimensions. And you have to plan your project and decide if you have to
compartmentalize it.
Fr.
Robert: So folks,
the future in 3-D printing. Speaking of the future, let’s go ahead and take a
moment to think the sponsor of this episode of Know How. Now Bryan, we are
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Bryan: Or fix McDonalds toys. Or an old Game Boy?
Fr.
Robert: Now Alex
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Bryan: One of these lives at my desk
downstairs.
Fr.
Robert: You know, I
think six of them live at Burke’s desk.
Bryan: I don’t know if you would be able
to put any of them back together. Keep your kits organized.
Fr.
Robert: We might
need an iFixit guide to fix the iFixit kits at Burke's desk.
Bryan: Maybe that should be one of our
Know How segments.
Fr.
Robert: Okay folks
we did want to move on to something that is near and dear to our heart. That is
taking electronics that you may already have an breathing some life back into them. Bryan, tell me what is in the box?
Bryan: What is in this sound box that I
found?
Fr. Robert: That is a cranky hippo
box.
Bryan: Well you know there was a few weeks back that Nintendo release their new DS. And
I picked it up and I had a lot of fun playing it, there are a lot of great
games on that platform. But, it didn’t scratch the nostalgia itch that I was
hoping it would. And, low and behold I was rooting around in my closet and I
found my old Game Boy.
Fr.
Robert: You never
forget your first Game Boy.
Bryan: It is kind of got that iconic look
to it. I pulled out the old Game Boy.
Fr.
Robert: It’s not
the old original because all the old originals were plain Vanilla White. This
is a colored one.
Bryan: This is a colored case, but that
one was released in 1990. The very early ones in the first release were gray.
And they had different buttons. You had one of the legit ones?
Fr.
Robert: Seriously,
my serial number is in the low thousands.
Bryan: Yeah, I believe it. You should
bring it in sometime. Are you afraid that I will break it? Well anyway. The
whole reason I busted this out is because I wanted to play some of the old
games. I’m going to put Pokemon gold in now.
Fr.
Robert: I had Pokemon gold but it was yellow.
Bryan: That is not Pokémon Gold then. That
is yellow. You have the one where Pikachu follows you around. Anyway, this was
first released in 1989 and I don’t think I picked it up until a few years
later. But, one of the common things that happens with
these poor guys is that they get these vertical lines.
Fr.
Robert: Yes, I had
that happen. Now, on mine I could hit it a couple of times and they would go
away.
Bryan: So, the fun thing about working on
some of these old electronics is that they are really easy to take apart as
long as you have the right tools. The iFixit kit
helped a lot because you have the tri-wing screws on the back. But once you are
in there, all the components are spaced out. It is not like when I have done a
tear-down on a new cell phone or something like that. This was meant to be
taken apart by human hands and you can actually get in there and do some stuff.
Now that I am almost 30 this thing is 20 something years old now too. There has
been kind of a resurgence of people modding these and
stuff. To fix the screen lines was super easy. And, to many of these have been tossed in the garbage because people think they are
broken. When, in this next video that I made you can fix this within 10 minutes
and it will be back to brand-new.
Fr.
Robert: Well there
you have it. Why don’t we see how hippo fixes the screen.
Bryan: So this little break of nostalgia
is the original Game Boy. If you are not familiar with it, well you should be.
This is the predecessor to all the mobile games that you enjoy now. It was
released way back in July 1989. In the first day is sold over 40,000 units and
we are going to breathe some new life into this old Game Boy. The nice thing
about the game boy is that it is really easy to disassemble if you have the
right tools. And they have tri-wing screws in the back of the Game Boy and as
long as you have an iFixit case or a tri-wing screwdriver
you will be able to get these out in a jiffy. There are six of them, for on the
back and two behind the batteries. Once you’ve got those screws out you can
flip the back of the Game Boy around. And you've got yourself a pretty easy
access to the board, compared to modern electronics. This was built in the day
that you could actually work on it. The problem with this game boy is that it
had vertical lines missing on the screen. Which, some people might think was a
death sentence for these little guys. Once the screen started
to die. But it is really easy to fix. So, we will take out all the
Philips screw heads that attach the front board to the front of the case. And
just pop those out real quick and flip the front board around so you have
access to the screen. What we are going to need to do now, is heat up our
soldering iron and there is this little black piece of tape that runs along the
front of the screen. That is where the soldering is attached to the LCD screen.
And by just heating up your soldering iron and running it over that tape, which
is very heat resistant so don’t worry too much, you can reflow the solder and
have the LCD screen come back on. And retrieve those missing bars. So just take
your time, I would recommend leaving the screen plugged in so you can watch
what you are doing. Heat up your soldering iron, and leave it on the adage for
no more than 3 to 5 seconds and watch as the LCD screen starts to come back to
life. Just work your way up and down the length of the board and eventually if
you take your time, you will have brought back all the little remnants of the
LCD screen. And bringing this Game Boy back to working order. Which is awesome. And super easy. This took me about 15 minutes to complete. Also, there is a little black piece
of rubber that you have to pull off to get access to where you are going to be
putting the soldering iron. Make sure to hang onto that and put it back on and
maybe put a little tape to hold it there or some glue. This is going to help
protect those soldering joints that you just re-flowed by giving it a little
cushion against the case. Not only did you have a little fun and learn a little
bit about this old piece of tech, but you brought it back to life and
definitely scratch that nostalgia itch that I had. Put everything back in the
reverse order that you took it apart and put back on the front screen and
you’ve got yourself a fully functioning piece of hardware from 1989, 25 years
old. But we are not done. We are going to keep adding stuff to this Game Boy in
later episodes to stick around.
Bryan: So now that you have done your
screen fix with the vertical lines, I didn’t want to end there.
Fr.
Robert: This is a
good geek. Because you are just never happy to be done. As long as I am in here how else can I fix it?
Bryan: I wanted to add…
Fr.
Robert: Wait. What?
Bryan: Yeah. There are these really easy,
cheap kits that you can get to backlight this. These are nearly impossible to
see unless you are in broad daylight.
Fr.
Robert: I had an
attachment with a little game port here that was like a LED light over the top.
Bryan: It was kind of janky.
Fr.
Robert: Janky, but
it worked. That backlight would be much better.
Bryan: So, it is not too difficult to do.
The kit is pretty cheap and next week I will show you how to do that. A little
bit of soldering, but if you have done any soldering where you did the project
that I did about two episodes with the watch, this is not difficult at all.
Fr.
Robert: As long as
you are can it be poking around your Game Boy, why not make it better?
Bryan: So, I am having a lot of fun
playing around with it.
Fr.
Robert: Now,
speaking of improving things. We know that we have gone a little quad copter
crazy so we wanted to back off a little bit and give you a different kind of
quad copter knowledge. Still very much quad copter technology, but we wanted to
show you how we choose motors here on Know How. This is a Thrust Bench. It is a
standard thrust bench measuring stand and all you need is the bench itself, you
need some blocks to hold it down. The idea is you need a way to be able to
measure how much the thrust a motor and prop will develop. The reason this is
important is because that will vary depending on the motor you use, the prop,
the angle of the prop, what type of battery you use, even the ESC’s. This is
the scientific way to choose what parts you want in your quad copter.
Bryan: Would this be a good way of
diagnosing if one of your motors is failing?
Fr.
Robert: Actually
yes. You can put all four of your motors on a bench and you can figure that
this one is only half the output of the others. It is somehow damaged. Because
when it is in the air, you can’t tell.
Bryan: It is a little hard to tell. You
can tell that it is not flying well.
Fr.
Robert: I would
consider this an essential piece of technology. Something
that you need in your toolkit if you are going to be doing some serious
aircraft building. Not necessarily only quad copters because this will
work for anything that you have to test the thrust on. I have been able to use
this for airplanes that I have been flying around.
Bryan: This is cool. How much is this
little kit?
Fr.
Robert: Like $50.
You can make it a lot cheaper. We are going to show you in a future episode how
you can make an inexpensive one for about $10.
Bryan: It feels really solid.
Fr.
Robert: This one is
solid. I made a janky one and I wanted to see what a real one looks like. And now
that I have a real one I am not going back to the janky one. Let’s talk a
little bit about those questions about the motor and the prof. For example,
we’ve got two different motors here. This is one of the Emax,
the 2213’s that I recommended for Alien X. I kind of favor these. They are very
durable, not that expensive, you can get them as low as $14 a pop if you buy
them in for. Versus this. This is a Hobby King motor
that I got on this thrust bench right now. It is technically rated the same
but, we are going to see that it is not the same.
Bryan: When you look at the specifications
on the page it says the same numbers and everything?
Fr.
Robert: It says the
same numbers. And that is the problem. Those numbers can be total lies. I can
tell you right now the operation of this is not nearly
as nice. You hear a little bit of a rattle. You don’t get that on this one. It
is just the quality of the bearings.
Bryan: How much was this one?
Fr.
Robert: Like $10. $10 versus $14. Pay the extra four dollars and get yourself
something with quality. We want to look at the size of the motor, we want to
look at the size of the prop and we want to look at the rating of the battery.
How fast can it supply power through the ESC to the motor. Those will all affect how much thrust I can generate for any particular prop
and motor combo. Remember we always talk about the combo because you can buy a
really good motor and put a bad prop on it. You can get a great prop and put a
bad motor on it and it is just not going to work right.
Bryan: Or by a great prop and a great
motor and then buy a crummy ESC.
Fr.
Robert: Exactly.
Now let's start with shooting your motors. We have talked about this before but
it is worth repeating. When you choose your motors, remember that you’ve
typically got two numbers. There is a rating like 2213, and so a 2213 is a
bigger and more powerful motor than a 2208 period that just refers to how many
windings you have inside of the engine. I don’t want to give you an exact
definition because it actually changes from manufacturer to manufacturer. But
on a whole, the bigger that number the more power it will be. The more
important number is the one next to it, like this one is a 2213, 1100 KV. Remember
we know from KV that KV is the number of times that this thing will spin, the
number of revolutions per volt that I give it. So this is an 1100 KV motor,
which means if I give it 10 V it is going to spin 11,000 times a minute. That
is my rotation. Now we also remember from way back when, motors that spin faster
typically offer you less torque. Motors that spin more slowly offer you more
torque.
Bryan: Which is better for
bigger props.
Fr.
Robert: Right. Exactly. So, if I have a motor that spins at 2300 KB but it
is rated 2213, it means that it needs to use a smaller prop. It is just going
to spin it more quickly. Something like this which is
an 1100 KV. There are motors since then at 600 or 680 KV. Those are designed
for those huge props. Which, theoretically, is more
efficient. When I spin my bigger prop more slowly I will get more flight
time out of it. Because I am not spinning it so fast.
Bryan: But that is less of a performance
or aerobatic squad.
Fr.
Robert: When I was
building my 250 class I used the 2300 KV motors because I want that motor to be
able to spin up-and-down really fast because that is what gives me all the
crazy acrobatics. But, if I am shooting I want to be able to use a big profit
because it is going to spin more slowly, less vibrations and it is going to be
more stable and give me more flight time. Because I am not going for acrobatics
I am going for film quality and time in the air. Now that we
know that, that is choosing our motors. Next is choosing the props. We
kind of led into this and we talked about this before. This is a nylon prop.
You can see that. Boing, boing. This, is a carbon fiber prop. There is no boing in this. This is stiff. Now, people
will debate this. You have to balance all your props it doesn’t matter if it is
nylon or carbon fiber. Carbon fiber props tend to be lighter. Lighter props
will spin up and down more quickly. And spinning up and down more quickly gives
you more acrobatics.
Bryan: Would it then make it more
efficient? Because there is less work for the motor to spin
up and down?
Fr.
Robert: Yeah. It
does. But, some people like the nylon because they will flex and to a certain
extent props that flex will take some of the vibrations that would otherwise be
transferred into the frame. It doesn’t always work that way. In fact I have
found I just would rather have carbon fiber all the time. Unless it is a
trainer craft and I am worried about it because if you hit something with
carbon fiber props it will cut you. Nylon will not cut me. Carbon fiber will
first snap off and then it will leave a jagged edge will cut to my skin. But,
if you notice this is a ten inch prop and this is an 8 inch prop. You can have
multiple types of 10 inch props that the angle is slightly different. This is a
more aggressive prop, it has a higher angle which
means it is going to pull forward more. But it also means that it will pull
more power from the motor. Sometimes you just want a slow fly because a slow
flight prop will give you that nice smooth, long-lasting flight.
Bryan: The angle of the pitch.
Fr.
Robert: So
increasing the size of the product increases the amount of power that it will
draw. But it also means you can run the motor more slowly. The practical use on
the Alien 450’s that we just built, those motors can be used for both 3S and 4S
batteries. That is the 11.1 V with a 14.8 V battery. If you are going to use it
with the 14.8 V battery, you would go from these 10
inch props down to an 8 inch prop. Because if you try to put a 10 inch prop on
a motor that is supplied by a 14.8 volt battery, it will burn out the motor.
Bryan: Because it is just so much on the
motor.
Fr.
Robert: It is just
demanding too much wattage from the motor. It will burn it out. So, I can get a
big prop spinning slowly or I can get a small prop spinning very quickly and
the nice thing about that is I can change depending on how I want to fly. If I
want to get daring, like my quad flying over the water, I used 8 inch props
because if I wanted to punch out if I was getting too close, I didn’t want to
wait for my props. I wanted to throttle it up and get it out of there. But if I
wanted to do a shot located at the beach in Hawaii with that super smooth shot,
those are 10 inch props because I knew I was just going to pass slowly. And I
didn’t need a whole lot of performance.
Bryan: And so, now testing these on the
bench?
Fr.
Robert: So, this is
a very basic thrust tester. All it’s got is a way to mount the motor, a scale which is right here will allow me to figure
out how hard this thing is pulling. I am using a 3S battery so this is 11.1 V. So
what I do is I've got a servo tester here and I am going to go ahead and
slowly….
Bryan: Padre! There is dust everywhere. Did
you keep track of the numbers?
Fr.
Robert: I did. This
went up to 809 grams. So at it’s maximum this motor with this prop and that battery will pull 809 grams of
thrust. I’ve got four of them so I know I can get 3.2 kg worth of thrust out of
my motors. Which is decent payload especially since the frame is only going to be
300 g. It is a good power to weight ratio. Now, let’s go ahead and take a look
add a motor that has a same rating as this. It is our wonderful little Emax, 2213.
Bryan: You changed that motor quick.
Fr.
Robert: What we
have done is gone ahead and replace this Hobby King
multi-star motor, which has the same rating as this, with the Emax 2213. Now, we should note that we are using the ESC. this is not my personal favorite ESC. This probably robs you
of maybe 5% of thrust. But we want to use it as a baseline.
Bryan: That way we can compare the two
motors.
Fr.
Robert: Precisely. I’ve
got the set up rotating the proper weight. One thing you should know, if you ever have a motor that is spinning the wrong way
all you have to do is reverse to the leads. Just any too. Just flop them around and it will spin the right way. So
now, we've got the same set up. This is actually the same battery. We are at a
disadvantage because we have already been draining this battery testing the
other motor. What I have at home is a bigger battery that can withstand drains
much better. We know the other one, at its max was able to pull 809 g of
thrust. This is the exact same rating, the exact same speed with the exact same
prop. Let’s see if it does any better.
Bryan: Stand back. It’s all over the
place.
Fr.
Robert: At its peak this actually pulled 830 g of thrust. And leveled off around 790. Versus the other motor which
pulled at its peak 809 g of thrust and then it leveled off somewhere around 760
or 770. You are going to see that because whenever you see that pushback it
actually means the battery can’t supply enough power to the motor. Which we will address, because next week I am actually going to
show you my super advanced build. This is a decent thrust tester but it
only gives you one metric. It gives you how much thrust am I generating. The
better kind of thrust tester will also show you how much thrust are you
generating, how much power are you using, how much wattage and where it is being
used in the curve. And it will also tell you whether or not you are starting to
exceed the power limits of any part of your system.
Bryan: That does sound like a lot more
information.
Fr.
Robert: And believe
it or not, you can do it with just $20 in parts. Not bad at all. So, I gotta tell you. I like flying quad copters but there is
part of that is really squeezed to build stuff and
this is a big old building toy.
Bryan: That is how I feel about the Game
Boy and that is why I liked playing with Legos. It was putting it together that
was fun. And then you get to have fun when it is built, but it wasn’t the main
part.
Fr.
Robert: Now folks
we know that this was a lot of material for you to handle. And which is why we
are going to give you detailed show notes. Now typically this is where we go.
This is where we would drop off, after telling you they could find our show
notes where?
Bryan: At twit.tv/KH. And not just show
notes but all of our previous episodes and ways to subscribe and download the
episodes.
Fr.
Robert: Speaking of
ways to download the episodes, there is no better way than participating in the
Google plus group. That is really the best way. Seriously. 8300 folks, a very active group, there is always someone there that is posting. If you have a question or if you have an answer. If
you are one of these people who want to contribute your knowledge to the group
of DIYers and makers it is a great place to join.
Just go to Google plus and look for the Know-How group. Join in and ask a
question. And more likely than not if you have a project that
you want to post we will use it on the show.
Bryan: And my favorite part? Is seeing other people’s projects. There have been plenty of
crash videos from the quad copters. There have been plenty of mods for some of
the other things that we have done. There is a lot of cool stuff to check out
in there.
Fr.
Robert: And it is
also a really good place for us to get ideas for future episodes. People wanted
to see Raspberry Pi, so last week we did Raspberry Pi OSMC. And we are going to
keep doing that. So suggest, ask, and we will answer. Don’t forget that you can
also find us on the other social media, specifically twitter. Just go to twitter.com/PadreSJ, that is me.
Bryan: And then me. @cranky_hippo.
Fr.
Robert: One last
thing before we go we do this thing every once in a while we call it a parting
shot. There is actually a special one. Something that… No, Alex. Bad Alex.
Bryan: Come on.
Alex: We’re a little early, we’ve
got time.
Fr.
Robert: I need to
do this thing. This thing, this Solar Dynamics Observatory is a space project
that I have just been peeking out over. And I have been containing my geek.
Have you heard me talk about SDO?
Bryan: No.
Fr.
Robert: Exactly. I
keep it to myself.
Bryan: Typically you have a very hard time
containing your excitement about things. So I am surprised I haven’t heard
anything about this.
Fr.
Robert: But this
thing is beautiful. It was launched five years ago and it has been orbiting the
sun. It has been taking high resolution images and videos once every second and
it has been absolutely gorgeous. I don’t want to talk anymore, Alex just play
this with the music. The amazing thing about that is you are actually seeing
the electromagnetic bands. That is the plasma that is traveling along the electromagnetic
bands that form on the sun. So it gives you visual representation to something
you wouldn’t otherwise be able to see. It is beautiful.
Bryan: That is so cool. And just the
immense amount of gravity for something that huge.
Fr.
Robert: In the
amount of power that you need to blow out that much material from a giant ball
of plasma. Awwww. I’ve watched this video maybe a hundred times in the last
month.
Bryan: I want an apartment next to the
sun.
Fr.
Robert: You need a
really good air conditioner and sunscreen. you got
burnt standing on a Segway. What you are seeing is the reason why sunspots
happen and it is because there are regular magnetic lines that flow through the sou just like through the earth, but the surface is
so turbulent and the inner workings of the sun are so turbulent that the lines
actually start to wobble. And then they cross and when they cross you get a short-circuit and it causes that expulsion of material in
the sun.
Bryan: That is crazy. Now if you wanted to
stop the reaction of the sun…
Fr.
Robert: All you
need is iron because iron actually kills fusion reactions. The sun is based around
fusing lighter elements into heavier elements but when he gets to iron, it
stops. So you have all this pressure that just keeps pushing and pushing on the
iron but it won’t use. And the sun, actually any star, is a balance between
wanting to explode from the reaction and the immense pressure is rapidly
pulling back in. So if you start to compress iron, which will not fuse,
therefore it will not create a plume of energy it no longer has that thing
pulling it back in and the star just blows itself apart.
Bryan: I could watch this all day.
Fr.
Robert: I know,
right? Okay we gotta go. I’m sorry I was just… awwww. That is it. I’m Father Robert Ballecer.
Bryan: And I’m Bryan Burnett.
Fr.
Robert: And now
that you know how…