My Hiatus

[redsox985]

We should be there this year. Our plans are for Michigan, Lincoln, and Formula North (Barrie, ON).

 

[redsox985]

Recently, our team held a car show on campus. I just wanted to drop off some photos and show everyone some of the awesome cars that came by. Below is one preview picture and a link to a small album of pictures my friend touched up in photoshop.


Album

 

[Doc Sprocket]

Let me know when you're going to Barrie. It's 30 minutes from me and if it's open to the public, I wouldn't mind checking it out!

 

[redsox985]

Doc, the event date in Barrie is set for May 22-25 and the page for Formula North has more info, too. It's at the Barrie Molson Centre and is open to the public. FN was much more lax than FSAE Michigan, so I feel you'll be able to wander just about anywhere you wish. I don't think they had anyone really monitoring who went where aside from the "dynamics areas".

 

[redsox985]

Just came across this in studying for my materials class. I wonder how close of an approximation this can get to when a fly wheel would actually fail? I think the biggest issue would be finding exactly what material the flywheel is to get its yield strength.

 

[itsid]

I think the biggest issue would be finding exactly what material the flywheel is to get its yield strength.

Not really, since what you need is the density of the material

So, get a scale and weigh it (metric!!);
then submerge in water and measure it's volume (again metric!!)...
you end up with rho being mass(kg)/Volume(m³)

say it's volume is 0.6 liter (0.0006 m³)
and it weighs 1.7 kg

so it's density is ~2833 kg/m³ or 2.83 g/cm³ whichever you prefere
that'd be aluminium of some sort.
And now you can check your alloy tables for the density and you'll find the yield strength
(hopefully)
like...
Aluminium alloy 2014-T6:
yield strength (MPa) 414
ultimate strength (MPa) 483
density (g/cm³) 2.8

that should be close enough


'sid

 

[redsox985]

Good call! I wasn't thinking of doing all that extra, but it surely gives exactly what you'd be looking for. I want to spin up a fly wheel and see where it bursts... For SCIENCE!

 

[itsid]

Good call! I wasn't thinking of doing all that extra, but it surely gives exactly what you'd be looking for. I want to spin up a fly wheel and see where it bursts... For SCIENCE!

And I want to see the video of that

No, unfortunately it's not too exact, since some aluminium cast flywheel come with a steel centerpiece, the magnet itself might not be removeable so it also has to be weighted...
So you end up with a slightly bigger number than you need.

And, if you're unlucky enough you'll find two alloys with the exact same density but completely different yield strength

But if you assume the smaller strength material you still know how to run it safely.

'sid

 

[OzFab]

I want to spin up a fly wheel and see where it bursts... For SCIENCE!

This just got interesting

 

[itsid]

Thinking about it a little...
that calculation is worthless, isn't it?

I mean honestly, this doesn't seem to be a matter of material,
but quality of the cast when it comes to flywheels.
breaks, cracks, bubbles and things like that.
You don't change volume, weight or material if you whack a flywheel with a hammer, but it will fail really soon if you do...
Or if it got dropped by a packing gorilla on the way to your door.

just a thought.

'sid

 

[landuse]

I want to spin up a fly wheel and see where it bursts... For SCIENCE!

This just got interesting

Thinking about it a little...
that calculation is worthless, isn't it?

It looks to me that if you want to do this scientifically, you are going to have to spin and explode several flywheels, just to get an average

FOR SCIENCE.......

 

[itsid]

It looks to me that if you want to do this scientifically, you are going to have to spin and explode several flywheels, just to get an average

FOR SCIENCE.......

I'm totally fine with that

as long as I don't have to pay the flywheels that is

Go ahead, video; HD and super slow motion please,
well basically "Mythbusters style"...



'sid

 

[redsox985]

Obviously, quality is everything, but a billet one will be da** near perfect, aside from grain imperfections at an atomic level. Let's find a GrabCad model, write some GCode, and CNC them...

 

[itsid]

Where's the video :toetap05:

'sid

 

[Orange Krate]

Where's the video :toetap05:

'sid

A video of this exists! I'll be danged if I can find it though. Believe me I've tried...as much as we've had the exploding flywheel debate on here

I saw it on a website when my nephew was racing 1/4 midgets in 2005. It was a race billet flywheel mfg that did it to show their "superior quality". The ones they blew up might have been cast aluminum.

 

[redsox985]

Time for another update as I sit in the library procrastinating by any means possible. This past week, I finished up TIG'ing our test stainless headers... (pictures to come, thread where I got advice on how to do it -> http://www.diygokarts.com/vb/showthread.php?t=23898)

With a whopping half hour of stainless TIG experience under my belt, I still more than anyone else. We had always made our headers from .065 4130 since we had a bunch of it, it was cheap, and easy to weld. They came out pretty good I feel. On some practice parts, I figured that running the machine at about 50A and keeping the bead on top of the tube, while still getting ample penetration gave the best results. This stainless set is about 4lb lighter (I was told) since we were able to use .035 tube. The chromium and nickel help it preform at higher temps, so they don't need to be .065. Once I cleaned them up with the wire wheel on our pedestal grinder, they looked absolutely awesome. We pressure tested them by sealing the ends and submerging them in a big tub of water for about 20 minutes while checking for bubbles.

This weekend, we started machining our wheel studs from some grade 5 titanium. If we were to buy them, they'd be $20 each and only come in on size and set of dimensions. We opted to get a 4' length of Ti for $100, learn to machine it ourselves, and modify the design we would have purahased. Below is a photo of one of the studs, yet to be knurled for the press-fit. Also, we finalized the design and analysis of our front hubs. The rears will be a lightened version of the fronts, but we're looking to machine them soon. Alcoa gave us a 2' section of 6" 7075 aluminum which we're going to use. They'll be roughed out on a CNC lathe and have a lot of features finished up as 2.5 axis jobs on our CNC mill.

 

[redsox985]

I just realized I never updated after procrastinating during finals week. Anyways, as I said, pictures of our stainless headers are attached. We finished up our two competitions and suffered disappointing ends to both, but we're a very young team (70-80% sophomores), so we're optimistic and about to get started on our newest car.

For this year, I'll likely be our manufacturing lead, so a lot of welding, machining, and composites layups fall on me. I'm most excited for the composites and really looking forward to making some gorgeous carbon fiber bodywork and wings for the car.

We had wings this year, but they just weren't up to par, so we ended up not using them at competition.

So, the photos are as follows:
1 - Our car's custom intake. It's SLA 3D printed then coated via vacuum metalization. The resin used isn't UV stable, so it needs to be coated somehow, and we got this done for the cost of shipping, so why no up the cool-factor? And it's also lighter than a coat of paint. IT's a .002" layer of aluminum.

2 - The car.

3 > 5 - Our exhaust and new CF bodied muffler. It's a pound lighter than the stainless bodied one and Yoshimura offers significant discounts for college teams.

6 - Our car with wings during testing. The unfortunately broke shortly thereafter, so we were skeptical of running them in a competition setting. Also, you can see the slight warp to the rear. The mold (mould? mold? whatever) was a bit off and the profile came out warped. Next year we're planning on using a ShopBot table router at the nearby TechShop to make female molds (I'm sticking with mold) and then making them in two halves instead of the "taco shell" we did over male molds this year.

7 & 8 - An update into my personal life. I found a 2004 BMW 330ci ZHP at a reasonable price and in IMMACULATE condition, so I sold my oh so fun 2003 Honda CR-V and put a bit of money towards the huge upgrade. Oddly enough, these are about the only two decent photos I have of it. I guess I've been having too much difficulty getting out of the driver's seat.

 

[J_Walker]

2 - The car.

3 > 5 - Our exhaust and new CF bodied muffler. It's a pound lighter than the stainless bodied one and Yoshimura offers significant discounts for college teams.

that's because two brothers has a better sound then a yoshi... they gotta sell something!