Messing around with the metal 3d printer, are you? Yeah. Yeah, so I'm a wall. I'm a student testing analyst at the lab and
I'm actually metal 3d printing some parts for a student team that I'm on
Linus tech tips is nice enough to sponsor us for these parts
I'm gonna tell you guys all about what the parts are what they do and
Why it's so useful to have a machine like this a metal 3d printer versus a traditional five-axis CNC or
Other manufacturing processes. It's a student team called McMaster Baja Racing
What we do is we build an off-road single seat race car and it's completely student designed
It's student manufactured is only a few parts on the car that we have to outsource
Such as these parts and there are more complicated parts that need the complicated geometries
so everything is built by the students designed by the students and
Raced by the students what you're telling me you guys jumped over a car. Yeah, so our car is an off-road car with
But like seven inches of suspension travel, so it's meant to go over rocks jumps crazy things
So at competition we go over like massive pieces of wood
There's sometimes six-foot drops that our car has to survive
So doing things like this pretty routine for our team and we have to build super strong parts that can
Last a competition like that. So if you look at these parts
The angle on these ramps is actually a compound angle
So if you were to look at it from this perspective and kind of rotate it
This line stays on you such that if there was a bearing riding on this
It would ride with a line contact throughout the whole ramp
so because of this there's a compound angle here it curves in two planes and
Because of that the only way to manufacture this with a traditional
Machining process is a five-axis CNC that can rotate in two directions at once and cut and that part costs us
$60 in material and a hundred and thirty five dollars from our
Student machine shop at the University and because of this metal 3d printer we can print
This part for about twenty dollars and have it ready the next day
So this machine is really great and allows us to get
Super difficult geometries that are either expensive or impossible in other manufacturing processes
So how many of these parts do you need for your car? So if you look we've already printed two
And these have different ramps. So this one is a much steeper ramp. It's a progressive ramp
It starts off pretty slow at 30 degrees and ramps all the way up to 45
Well, this one is a linear 30 degree so it's a 30 degree across the entire ramp and
These different ramp geometries actually have a very different
Tune in our transmission. So these parts are for the secondary CVT in our transmission
So a CVT is a continuously variable transmission and essentially what it is is we have a rubber belt on
Pulleys and those pulleys can expand and contract
So as they expand or contract the belt falls or
Rises within the pulley and because of that the gear ratio changes
So between our most closed state and our most open state we have a continuously variable
Transmission ratio that we can go between and what these do is these provide a feedback for the secondary the output shaft of this
transmission and the ramp geometry the
Tan of the angle is equal to the
Side the belt clamping force given in this direction
So I actually have the assembly here This is where the engine mounts and that is the output shaft of our engine here and then from this it goes out to our
Secondary CVT, which is what we're looking at right here. And if I just
You can see this is right here. This is that this is what we printed that ramp geometry is right there
so those bearings ride and What they do is they provide clamping on the belt and you need to clamp this rubber belt so that the torque can be transferred
These rubber belts work in a pulling fashion the primary
Squeezes and pulls and the secondary squeezes and grabs because of that. We have different geometries and you can think of it
Kind of like a hill for these bearings to ride on so as the hill gets steeper
It's harder for it to ride on and it'll provide
More clamping and because of that we might want more clamping right as we start accelerating
And then as we're done accelerating at the end of our shift all the way in sixth gear in a manual
Which would be the top here you want less clamping because you want less
Efficiency losses so that you can get to those higher speeds. It's a really really simple
But really really intricate part that kind of
Characterizes where we can go in our transmission what this metal 3d printer allows us to do and the reason we were so excited to use it
Was because it's $20 per part we can print a whole ton of parts and we don't have to worry
About how possible the geometry is to make on a CNC the printer will just print it and any layer lines
We can just sand away so Yeah, that's kind of most of the information about the part
And the team and how does the process of taking something from this cad right here into the middle of 3d printer work?
So that's actually super simple so here I have the cad for the for this helix is what we call it because it's like a helical angle and
We actually have Equations here and we can change these starting and ending angles. So I can go from
A starting angle of 30 in an angle ending angle of 46 to a 46 to 30 and this cad will actually
Hopefully automatically rebuild No breaking
Yay So you can see that the cad updated and now we have different angles super easily and we can try different things
From that all we do is we save it As an stl just like you would for any 3d printing process
Uh, and then we bring it into a rapidius version of kira. So kira is a metal three or a 3d printing slicer
Very common and all we do is we bring our part in
and We don't want to print it like that
So, uh, we just place it down. We can arrange it. So it's in the center
We can change all of our settings here, but um, the
Uh, settings that were already on seem to work pretty well
All we do really is we hit slice
That'll make this part into, um, a whole ton of different slices
Uh, layer by layer just like every other Uh, fdm 3d printing process
We save this file to, uh
To our disc and then there's a online tool by rapidia that's hosted by the machine
And uh, all we do is we give it the gcode
We let it render it'll load up the gcode now. It says ready to print all we do
We hit start Uh, you can see the bed is going to warm up pretty soon. It's still at zero
But so once that gets up to 40 degrees the printer will just start printing
And is this guy right here the only thing that you have to 3d metal print?
Or is it more efficient to manufacture the other parts in a different way?
The point of the team is experience for the students, right? So, um
A lot of the parts Maybe could be metal 3d printed or it might even be cheaper
A lot of the times to send it out to a machine shop and have someone else do it
But getting those students the experience of
Machining of designing a part and being like, oh my god
I can't actually make this like if you design this and then brought it to a manual machine shop, which is all we have at university
They would look at you and say this is just impossible to make or
The setup will be insane and you need like three arms to be able to do it
It gives the students a real understanding of how to design parts not only for
For them to be working in their assemblies, but also designed for manufacture, which is a really big
Aspect of modern engineering So we can print a lot more parts in the metal 3d printer
But we would rather simplify our parts
Make them on a manual lathe or manual mill The other aspect is our team is based in ontario
So if a part breaks, we don't want to have to come back here
Especially if it's close to competition. We only have one week to go
Making simple easy to manufacture parts means if something breaks
We can go to the lathe remake it and it essentially doesn't cost us any money because we already bought some extra material that we can find lying around the shop
Yeah, the metal 3d printers are a really great tool for parts like this where you want a whole bunch of different parts to try out
Different things or you want to try like complicated features in different ways, but for most of the car
It's just simple cylinders or simple plates that are machined. So we'd rather the students manufacture that and when are you guys going to be building this?
So they're actually actively building the car. This is actually our first weld that we laid down
This last week. So this is our chassis
So we're actively manufacturing as we speak
So the goal is to get the car done for Laval University of Laval has a competition in Quebec City
And of January, February 1st to 2nd, I think is the date. So the goal is finished car running under its own power by that date
Uh We'll see how it goes. We did it last year in this timeline. Uh this year. I haven't been there. So I don't know
Uh, but yeah, that's kind of the goal and then in terms of the rest of the year
So that's a regional competition. That's not an official competition. So that's more just for fun
So that everyone can kind of test our car out in the snow. The official competitions are all during the summer
So our first one is end of april and then we have one sometime in may
That's where our car really matters and from February until then it's all testing
So we want to try out all these different helixes. We want to try out different, uh, suspension setups
We want to try out all these different little characteristics of our car and make them the best that we can
So that's only step one of the process. So these are called green parts and they are clay like, uh, very, uh, powdery
Uh parts and what we do is we take these parts and we sand down these layer lines for the bearing
May not look like it, but that feels super smooth to the touch and we put it in this machine here
Uh, we can't show you the inside of it But essentially you can think of it like a big oven and it'll get just close enough to the melting point
Of the steel such that the particles will attach together and kind of melt together into one solid part
And then it cools it down. It does this in an argon environment. So nothing really goes wrong
Uh, but out of this machine we get our finished part. So step one and step two
So it's the next day. Uh, we have our centered parts here, uh, ready for
Uh, putting it in the car. So you can see this is a green part before it's been centered and a centered part
Uh, you see the size difference. So rippitya one of the best things about it is it does all that shrinkage math for you
So there's multiple axes of shrinkage something that is
Wide and flat like the bottom of this versus these parts right here might shrink in different dimensions
But the software automatically calculates all that for you
So we have super accurate super clean parts ready to go
And these are all sanded down. So it's super nice for the bearings
And uh, hopefully in the next uh, little bit, I'm going to go back to the team and get this running in the car
So why did this one fail right here? That failed actually due to me
I put this outside the print volume of the printer and that's why the line is so straight
So it was just too far to the left on one of the sides
And physically the printer couldn't go there. So it was completely user error. Uh, it's my first time using the machine. So
Um, yeah overall this machine has been
Super good super easy to use once you get past a few little hurdles
Hopefully the next thing we can show you guys is this part actually running in the car
We have an engine uh and transmission dynamometer that we built ourselves that you might be able to see this in too
So, uh, can't wait to show you guys this part running in the car making it go real fast
Something else really interesting that the 3d printing process allows us to do and the reason we were so excited about it
Was trying all these different angles You can see each one has a label this one
You can see it starts at a super low angle and goes up to a really really steep angle
While this one starts at a steep angle and goes to a low angle
So this process allows us to try all these different types of angles very simply and very easily all those
Have different tunes on the transmission of the car due to the forces we talked about before
So we're really excited to be able to try Five different helixes, which we've never done before. We always just have one