HU baja

[Nick]

Hello everyone!

Over a year ago I posted on here that I was joining the SAE Baja team at my university... but I didn't... well now I have!!

This is only Hardings second year with a Baja team but last year the team came in 27th (not completely positive on that but it was close) over all in our final competition.

SAE Baja is a college level build competition similar to the build of on this site (excellent work to all those who competed this year by the way).

At this point Im not sure what part of the cart Ill be working on but im sure ill have questions when I do so ill keep you guys posted on our progress and problems!

 

[souperman000]

SWEET!

I'm in the process of applying for schools and Baja is a big factor in my decision. That or the F1.I'm really looking forward to your progress.

 

[landuse]

Hey, great!. Remember to post lots of pics if you can

 

[Nick]

Second meeting was today. I was placed in charge of steering, which was the area I was most afraid of but hey I didn't want to learn how to build a proper steering assembly! haha Ill have to do a bit of research on the best way to do steering so any info you have will be much appreciated!

At the meeting we drove last years cart (in the pic) a little just to get a feel of what were doing. Have to say its a little different than driving Poj (my cart) and I think I actually like driving Poj more but thats just cause theres nothing like driving your own work!!

Ill keep you guys up to date and am looking forward to any advice you have on our build.

 

[landuse]

Have a look at THIS thread

 

[Nick]

Thank you landuse that was exactly the kind of thread I was looking for.

So just after a quick look at that Im thinking I need positive caster (leaning back) of around 10*, 0 camber, 1/16"-1/4" toe out, tie rods that angle forward from the steering wheel connection, and the King pin should lean towards the back of the cart slightly and in 10* with the spindle 10* the other direction. Im pretty sure the assembly will be rack and pinion since it seems to be the best option for this set up.

I know that was a lot of stuff in little detail but how does it sound so far? Any more thoughts on how to improve this set up? Are there any things I need to look out for since this has full front suspension?

 

[Nick]

Just talked to the team leader, Ive been reassigned to drive line so thanks for the steering help but know I need drive line help! haha

 

[souperman000]

I think that may be easier and maybe even more fun...

I know Baja has a lot of specific rules. Have you researched them in detail yet? That being said, if you could enlighten other members on the site of the specific rules it will help us help you.

Now, I know the basics is a briggs Intek 10hp with some sort of CVT right?

 

[Nick]

I believe the only restrictions on this area are that you cant do anything to the engine they give you which includes changing the governor, changing piston rings, and a bunch of other stuff. The rule document is pretty long and wordy so it is possible that I've missed some thing about drive train but from the couple of times ive looked at it and from what I've heard about other teams we can change the rest of the drive train as much as we want.

I haven't gotten to take a good look at the drive system on last years car yet (were taking it apart tomorrow to see our systems) what I do know is that last years has a CVT in it some where and it also has a made in house gear box (I don't have a whole lot of knowledge on that part yet so im looking forward to getting it apart.)

My main concerns on this sub system is getting it to deliver power reliably with as little wear and tear as possible with the full suspension. We've talked about the possibility of making a live differential to improve our handling but were concerned about added weight and loss of acceleration due to one drive wheel taking most the torque.

 

[OzFab]

IMO, live axle drive is the better option (that's assuming the guy on steering does his job properly), unless you can lay your hands on a small LSD centre & CV axles...

Have a look at some of mysteryboy28's builds for ideas...

Just a quick not on overall design (perhaps you can give some input to the team), wide & low is the way to go. Obviously, allow for sufficient ground clearance but, keep the overall height to a minimum with the driver seated as low as possible; a high CoG (centre of gravity) will affect suspension, steering & overall performance

 

[souperman000]

As I said, post some basic rules.

Fab, The baja in the picture (last year's baja) is basically what this one will look like (please correct me if I'm wrong, you are more involved in the program than I).

There are very specific rules on height, width, frame design etc. You take part in challenges to find which buggy is the best.

If anyone feels so inclined, here is the official rulebook, all 62 pages of it. Perhaps we can use it for reference for this thread.

http://www.sae.org/students/mbrules.pdf

*Please correct me if I'm wrong, you are more involved in the program than I. I don't wish to hijack your thread or take over your project. Let me know if you want me to back off a bit. But I am extremely interested in the program.*

 

[Nick]

souperman000 no need to apologize, I appreciate the enthusiasm! I have only browsed through all the rules and from what I know they aren't as strict as I originally thought. There are some size regulations but since we will be mainly using last years design we should be fine on those regulations.

Fabroman we will be using CV axles since it has full independent suspension.

Is a CVT with a single reduction gearbox what we should stick with or is there another system we should look into? Remember the plan is to reduce weight and maintain a high amount of torque/power. If anyone has a page like the one that landuse referenced but for drive train that would be much appreciated! Thanks

 

[ed1380]

CVT is your best bet. I've thought about a bicycle drivetrain or building a simple gearbox, but when it comes down to simplicity and ease for the driver CVT all the way. I was going to start a baja chapter at my uni, but personal life got in the way

 

[souperman000]

Have you guys gotten any sponsorships? From some of the youtube videos I've watched, Polaris sponsored some teams. They got a bunch of parts like CV axles, wheels, etc donated.

 

[Nick]

I'm not sure if we have any sponsorship lined up yet but I know we have talked about looking into it. One of the guys on the team did mention a family member of his who has a company that makes carbon fiber parts (He mentioned carbon fiber axles made on a lathe but I'm not sure how that works...) so we may be talking to them sometime. Other than that well probably elect some one to be in charge of that stuff soon. I do know that a few of the guys from last year were offered jobs and internships with Polaris at one of the competitions last year though.

 

[Nick]

Ok so I've just started looking at torque converters can some one explain the difference in a torque converter and a CVT? From the small amount of research I've done they seem to be about the same in this kind of application.

 

[OzFab]

A torque converter is one type of CVT.

CVT = Constantly Variable Transmission which is what a torque converter is...

 

[loud1]

A torque converter is about the simplest of cvt's. I know that some cvt's use a torque converter as well as an automatic gear box.

 

[itsid]

A torque converter is about the simplest of cvt's. I know that some cvt's use a torque converter as well as an automatic gear box.

Careful loud1,
A car torque converter has nothing in common with a kart torque converter (except for the name)

A kart TC is a cvt almost all cvts work on exactly the same principle like a karts torque converter.
(two variable pulleys and a belt or chain to connect)

Not all automatic gear boxes are cvts, some have a number of fixed ratios, thus are neither continuous nor variable

'sid

 

[OzFab]

Which is why I usually refer to a go kart torque converter as a CVT