Mini-Baja & Building a transmission... from scratch!

[cruiseroutfit]

OK, so its not really 4x4 related, but it is still cool.

As many of you know I am a senior Mechanical Engineering student at the U. As part of my degree I have to participate in a school sponsored Senior Design Project. There are many different projects that we can choose from, in addition to making up on of our own.

I am the team leader for the SAE Mini-Baja team. Our goal is to build a race ready, engineered chassis & Vehicle to compete in a baja style event against 100+ engineering schools this coming May.

We have been designing (solid modeling, prototyping, testing, benchmarking, etc) the vehicle since last June and we are just getting started on the build. I figured I would show you guys some pics of the progress thusfar, and more importantly the project I in personal in charge of, the final drive unit transmission.

Testing the chassis in ANSYS, a FEA software that lets us determine the weakspots under given loads.

Our chassis design

With front A-arms & rims

2004 U of U vehicle

2005 U of U vehicle

Close up of A-arm design (thusfar)

Specs:
All 4130 chromo, TIG welded
HT PTFE Lined Rod Ends
4130 Rod end inserts
Carbon fiber seat (to be formed by our team)
10 Brigss & Stratton motor (spec, can't go bigger )
Custom Tranny (thats my baby...)

 

[cruiseroutfit]

The transmission I am working with Dr Samuel Drake to design and machine (all by our team & Dr. Drake)

The case (for dimensions & interference) in Solidworks

Input gears (by Sam Drake in Alpha1)

Input & Idler gears (by Sam Drake in Alpha1)

Input, idler & output gears (by Sam Drake in Alpha1)

More pics to come...

Specs on the transmission:
4140HT gears (we are machining & splining them this week)
Hardened shafts, gears, etc.
Detroit Locker
~11:1 ratio
Reverse!!!

 

[Hickey]

That's kick ass.

 

[muleskinner]

Wow, thats sweet!

 

[James K]

very cool Kurt :greg:

 

[Jay5.9L]

Nice, I was on the team in 2000. We just used the same CVT and gear box from the previous year

 

[rjmax]

I was on the team at Utah State University back in 1998 and 1999. It was a ton of work but the best project. It was a lot of fun and I learned a ton. I was actually able to get my hands on the one I built and it is sitting in my backyard if you want to take a looksy.

Here are a couple of sites I have found recently that might help with sub-components.

http://www.desertkarts.com/

and of course,

http://www.hoffcocomet.com/comet/index.asp

There are quite a few resources online if you do some searching. Where is the competition this year? I went and checked it out a couple years ago when they did it up in Logan. Good luck!

 

[Shawn]

Looks like fun!!

 

[cruiseroutfit]

Got the material for the tranny gears, 4140HT (28-32 Rock C.)... not cheap

~$200 worth of steel right there!

 

[cruiseroutfit]

For a trained eye... the cage may look a bit "awkward" to some degree...

We have a set of rules that complicates the chassis construction, "only x amount of bends in the rear roll hoop", "6 inches of head clearance", "3 inches of leg clearance at side impact members", etc. I wish we could make the chassis any way we want, but we have to not only adhere to their rules/specs, but be able to justify the construction of it if questioned. Cars in the past have showed up to the event and failed the tech inspection, so they get to spend the day fixing their chassis.

BTW, chassis is 1.25" .065wall DOM Chromo (4130).

Not sure what we are going to do with the bends we already plan. I am afraid that the industry standard benders may kink that thin of tube? Any signs of distortion or collapsing in the bends can disqualify your chassis...

Any ideas? Know someone with a mandrel?

 

[Milner]

For a trained eye... the cage may look a bit "awkward" to some degree...

We have a set of rules that complicates the chassis construction, "only x amount of bends in the rear roll hoop", "6 inches of head clearance", "3 inches of leg clearance at side impact members", etc. I wish we could make the chassis any way we want, but we have to not only adhere to their rules/specs, but be able to justify the construction of it if questioned. Cars in the past have showed up to the event and failed the tech inspection, so they get to spend the day fixing their chassis.

BTW, chassis is 1.25" .065wall DOM Chromo (4130).

Not sure what we are going to do with the bends we already plan. I am afraid that the industry standard benders may kink that thin of tube? Any signs of distortion or collapsing in the bends can disqualify your chassis...

Any ideas? Know someone with a mandrel?

I was wondering why there were only 2 bends.
Maybe a "standard" bender would work if you packed the tube with sand????
Might be worth a try, a 3' piece would be enough to test it....

 

[cruiseroutfit]

I was wondering why there were only 2 bends.
Maybe a "standard" bender would work if you packed the tube with sand????
Might be worth a try, a 3' piece would be enough to test it....

Sand is on our list, as is freezing water in the bend section of the pipe (a little harder to do but supposedly works). There are a couple places in SL that have a mandrel setup, in years past they have done the bends for free too.. (tax write-off I'm sure )

We have a couple hundred feet of steel showing up ASAP... I'll update you on the progress!

 

[I Lean]

Most "standard" benders will bend that thin fine, but only in the larger radius dies. I'd venture that most people choose a smaller radius since they don't care about being able to bend the thin wall stuff.

Might check with Russ Fullmer to see what his 1.25" radius is....he's got a lot of dies.

 

[mbryson]

I was on the team at Utah State University back in 1998 and 1999. It was a ton of work but the best project. It was a lot of fun and I learned a ton. I was actually able to get my hands on the one I built and it is sitting in my backyard if you want to take a looksy.

Here are a couple of sites I have found recently that might help with sub-components.

http://www.desertkarts.com/

and of course,

http://www.hoffcocomet.com/comet/index.asp

There are quite a few resources online if you do some searching. Where is the competition this year? I went and checked it out a couple years ago when they did it up in Logan. Good luck!

Did you work with Lane Nielson on that? He graduated about then.


Oh, and KEWL project Kurt.

 

[Jay5.9L]

We had a Lane on our team.... Iforgot his last name but it sounds familiar. Are yousure he did not go to the U?

 

[solidfrontaxle]

I wanted to do the mini baja this year so bad at USU, but I graduate in the fall, so I couldn't be on the team. I had to design a planetary speed reducer instead. Next semester they are having a transfer case design project for aftermarket off road applications. I'm pissed that I'll be gone...

 

[Cherokeester]

Hey Kurt, my wife is the team leader for the Formula car program. She says hey! Thanks for posting what you are doing there, very cool!

 

[tv_larsen]

I was on the '98 and '99 USU teams with rjmax. For the '99 year I was in charge of the transmission. It was a lot of fun, and I learned a lot.

Cool looking trans Kurt.

 

[cruiseroutfit]

I have been meaning to update some pics...

The front half of our chassis as of a couple weeks ago...

1.25", .095" 4130

 

[cruiseroutfit]

Carbon Fiber seat mold & me molding a seat with the help of Advanced Composits in SLC

Only one layer of carbon fiber for the bling, the other layers were standard glass to ensure weight savings and save $$$