Mini-Baja & Building a transmission... from scratch!
- Thread starter cruiseroutfit
- Start date
- Location
- Sandy, Ut
BioNuke1 said:
Nope.. we have to have it governed at 3800rpms, an we can make zero mods. Briggs has engineers at the event to do inspections and winning teams get a tear-down inspection post race.
Mother Deuce
Registered User
- Location
- Somewhere North of Ogden
Cool pic, Kurt. Your seat looks like ours. We laid up the first part of on Saturday in the weld shop. Are you guys putting any kind of a core between your layers? We're adding some foam for shock absorption then we'll put another layor or two on top (bottom?) of that.cruiseroutfit said: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 $$$
How did you decide whose butt to fit?
- Location
- Sandy, Ut
Mother Deuce said:
We put a layer of "roafoam" in between the 2nd & 3rd layer to add some rigidity to the seat, however for absorbtion we will use a seat cover. All of has driven the 04' car, we all seem to fit in it pretty easily, luckily we don't have the weight & size constraints your team does. (For those that don't know Mother Deuce is the team leader for the SAE Formula team, basically building a 600cc race car
)We used the same mold as used for the 04' & 05' car, saved us a bit of time over making our own mold... we have plenty of other things to spend out time on
Can't wait to get these projects DONE, I can't help but be frusterated when I watch what other senior projects have accomplished...
We have completed 10x as much, worked on it 10x as much, and we all get the same grade... :-\
Mother Deuce
Registered User
- Location
- Somewhere North of Ogden
We also re-used an old seat mold. But we have a pretty big differential between the largest (6'4") and the smallest (5'8") team members so getting dimensions right is an issue. We're also padding the top of the seat, as much to adjust the size as anything.cruiseroutfit said:We put a layer of "roafoam" in between the 2nd & 3rd layer to add some rigidity to the seat, however for absorbtion we will use a seat cover. All of has driven the 04' car, we all seem to fit in it pretty easily, luckily we don't have the weight & size constraints your team does. (For those that don't know Mother Deuce is the team leader for the SAE Formula team, basically building a 600cc race car
We used the same mold as used for the 04' & 05' car, saved us a bit of time over making our own mold... we have plenty of other things to spend out time on
Can't wait to get these projects DONE, I can't help but be frusterated when I watch what other senior projects have accomplished...
I am frustrated like you, but feeling much better now that I know why I get cold. I been up nights wondering about that.
Get your team cracking NOW, and you'll have a much better finals week later. I was on the team at the U, cant remember which year, but we made the crappy red car that I dont think ever drove. The last month before the competition, and during the competition was hell, way too much to do, with way to little time, and only personal money to be used!
- Location
- Sandy, Ut
jgw50 said:
Good advice!
What problems specifically did your team run into? We feel like we are running smooth but I am sure there are hidden time killers ahead... suggestions?
- Location
- Sandy, Ut
way2nosty said:
You can have as many as you please, but weight and reliability rule the race, not top speed...
- Location
- Sandy, Ut
BioNuke1 said:
We are running a Comet/Hoffco torque converter (~5:1-.75:1 ratio range) connected to our 10:1 final drive unit. The only gear change is forward to reverse... The transmission we are working on is also a "quick change" system, allowing us to go to say 7:1 if we feel we are too low. But I feel pretty confident in our numbers now...
Complex drivetrain systems have been employeed in the past, but in the end reliability makes the winners. The endurance race will wipe over half of the competitors out...
Mother Deuce
Registered User
- Location
- Somewhere North of Ogden
You mean you were on the Baja team or the Formula team? Gotta know the year, can't leave me hangin' like that.jgw50 said:
way2nosty
Registered User
cruiseroutfit said:
My original question was directed towards the limited RPM range of the B&S, WIth the variable ratio Torque converter I'm sure it'll do fine, A friend of mine has an early Score truck It amazed me the amount of forces they take. Pure and simple is the way to go in my book. You're probabbly CNCing the case out of like T6. Have you thought of doing a Heavy Chain/Chain drive to save weight and rotating mass?( I'm sure you have I was just curious about the process that lead to the case) I started on the engineer track, it just wasn't for me, It takes a lot of moxy to stay in the game, my compliments.
- Location
- Sandy, Ut
way2nosty said:
Chain drives have been used extensively in the past, but we wanted something with reverse (can be done with chain), we also wanted a quick change gear ratio option (easier to do with a gearbox).
The best feature of cloesed gear train design is the closed lube system and safety. SAE requires any drive belts/chains (including our TC) to be covered, gets kind've truicky & awkward with a chain system. In addition this vehicle will be driven in mud, rocks, motocross track, etc, a sealed gearbox should hold up better than a chain drive...
The gearbox is surprisingly light... ~ 10lbs, not a huge increase over a complete chain drive system...
Here is an older final drive unit built by the U, no reverse, no locking differential, just a solid drive.
And last years unit that featured toroidal variation & reverse...
RedBull_RockIt
Registered User
This project looks like fun. Is there a budget limit on this and how is that covered...or by who?
Also, how far do you race in this cool rig?...II guess a simple link to somewhere might answer those questions if you don't have the time. I'd love to see more on this one.
Also, how far do you race in this cool rig?...II guess a simple link to somewhere might answer those questions if you don't have the time. I'd love to see more on this one.
- Location
- Sandy, Ut
RedBull_RockIt said:
There is no actual budget, however we have to convince companies to donate...
The U of U kicked in ~$2k and several local companies helped us out big time too! As for the race, there are actually several different events, hillclimb, rockcrawl (NOT NAMED ROC in any way
), acceleration race, then the endurance race (~80 lap race). Can't wait I will get some updated pics soon, our front chassis is complete, A-Arms are underway, and our transmission is coming along nicely...
Our deadline as of now is April 25th (Engineering Design Day) in which it will be displayed along with a couple of other Mini-Baja cars in front of many peers & industry members.
Here is the SAE link:
http://students.sae.org/competitions/minibaja/west/
Here is our team website (though we havn't had much time to update it)
http://www2.eng.utah.edu/me4000wiki/index.php/MiniBaja1/
:greg:
Sorry for taking so long, I was on the team 2003-2004. We didnt race our car, but raced the previous years black car (the last one with 10" rims). We bought 8 14" fox air shocks for our cars, I really wish I could get my hands on those now!
Anyway, we spent WAY to long brainstorming and not building. We got 2 atv detroit gearless lockers donated and wanted to put those in, we wanted to do offset axles too.
After all the planning, we didnt have our frame built until Feb, and then had to mount the suspension components. We were integrating up to the last night. The last two weeks we took turns staying until 1:00 in the morning trying to get it done. We thought the chassis would be the hard part, but re re-designed the brakes, uprights front and rear, and Drake needed a lot of support for working on those too.
In the end, we cobbed the chassis together, but had no front hubs. The CNC lathe was burning parts up and Drake was burned out from working a ton, and it came time to leave. The last night we decided to focus on the previous years car. We went till 3:00am the night before we left at 8:00 am and finally got it running. (there arent many campus police around at 3:00am, and that car definilty got its taste of campus stairways!)
Annnyway, we didnt bring any spare parts with us to the competition, and they had a whole bunch of new rules for things like throttle cables, brake lines and such. We spent the first two days of the competition trying to pass safety inspection. One of our brake calipers had a crack in it, and would not hold pressure. We had 3 spare calipers in the senior design room but that did us no good up in washugal moto park in oregon.
Soo, we somehow got the girls running the brake test to pass us (crack still in the caliper) and actually got to compete in the endurance race until I snapped the steering tie rod off. The set screw that holds the steel insert into the steering knuckle never got set at 3:00am, so the insert slowly threaded down. Then I hit a woop dee woop, and the suspension flexed enough to snap the rod end off because there was not enough clearance. Drake reminded us 2 days before to tighten all of the set screws!
We actually cobbed the car back together after that and got a few more laps in.
The moral of the story? Get the car done early. If you shoot for 2 months early, you'll probably be right on time, it sux to work that much sometimes, but its worth it in the end. Then, once you get the car complete, take it out and beat the piss out of it. Find out the weak spots and hope you have enough time to solve the problem. I took that black car out and rolled it, snapped two drive shafts, busted a shock nipple off (200 psi of nitrogen propelled oil, right in the eye) and completely busted the front upright. All from going into one ditch!
The courses are rough and SOOOOO much fun to drive in, but it takes a good car. So have fun, its pretty sweet having all the resources at your fingertips there at the U
Also, get your travel stuff figured out before. Find a tow truck, and a trailor way in advance. We had to last minute rent a truck from budget, and had no trailor!
Is that enough?
Sorry so long!
Seriously though, get me a set of those air shocks, they would work very well on my new TJ, who needs coils?
Anyway, we spent WAY to long brainstorming and not building. We got 2 atv detroit gearless lockers donated and wanted to put those in, we wanted to do offset axles too.
After all the planning, we didnt have our frame built until Feb, and then had to mount the suspension components. We were integrating up to the last night. The last two weeks we took turns staying until 1:00 in the morning trying to get it done. We thought the chassis would be the hard part, but re re-designed the brakes, uprights front and rear, and Drake needed a lot of support for working on those too.
In the end, we cobbed the chassis together, but had no front hubs. The CNC lathe was burning parts up and Drake was burned out from working a ton, and it came time to leave. The last night we decided to focus on the previous years car. We went till 3:00am the night before we left at 8:00 am and finally got it running. (there arent many campus police around at 3:00am, and that car definilty got its taste of campus stairways!)
Annnyway, we didnt bring any spare parts with us to the competition, and they had a whole bunch of new rules for things like throttle cables, brake lines and such. We spent the first two days of the competition trying to pass safety inspection. One of our brake calipers had a crack in it, and would not hold pressure. We had 3 spare calipers in the senior design room but that did us no good up in washugal moto park in oregon.
Soo, we somehow got the girls running the brake test to pass us (crack still in the caliper) and actually got to compete in the endurance race until I snapped the steering tie rod off. The set screw that holds the steel insert into the steering knuckle never got set at 3:00am, so the insert slowly threaded down. Then I hit a woop dee woop, and the suspension flexed enough to snap the rod end off because there was not enough clearance. Drake reminded us 2 days before to tighten all of the set screws!
We actually cobbed the car back together after that and got a few more laps in.
The moral of the story? Get the car done early. If you shoot for 2 months early, you'll probably be right on time, it sux to work that much sometimes, but its worth it in the end. Then, once you get the car complete, take it out and beat the piss out of it. Find out the weak spots and hope you have enough time to solve the problem. I took that black car out and rolled it, snapped two drive shafts, busted a shock nipple off (200 psi of nitrogen propelled oil, right in the eye) and completely busted the front upright. All from going into one ditch!
The courses are rough and SOOOOO much fun to drive in, but it takes a good car. So have fun, its pretty sweet having all the resources at your fingertips there at the U
Also, get your travel stuff figured out before. Find a tow truck, and a trailor way in advance. We had to last minute rent a truck from budget, and had no trailor!
Is that enough?
Sorry so long!
Seriously though, get me a set of those air shocks, they would work very well on my new TJ, who needs coils?
- Location
- Sandy, Ut
jgw50 said:
They are gone... last years team SOLD of them to get some $$$ for their car
, we are using the Bilstein coilovers that they bought. They too never ran their car.We are way further ahead of the norm, our chassis is complete, and we hope to test fitting all our suspension components next week. We made a carbon fiber seat a few weeks back, and only need to order a couple of minor parts.
We are using the Detroit lockers in our transmission... Both teams (the U is sending two cars this year) is also using one.
We still take the Black car for spins on the campus... for as much use & abuse that thing has taken, it still works great. Thanks for the insight!
- Location
- Sandy, Ut
jgw50 said:
Tell me about it... We had another kid "offer" to sell us one of the Detroit Lockers that was donated to the U. He wanted a $100 for it, sequential number to the existing one...