1st crash.

BigglesPiP

BigglesPiP

BigglesPiP

Soldato
Joined
8 Mar 2006
Posts
13,311
Location
Telemark
No, not the Alfa.

Today we tested the Formula Student car, I was the second to drive it after we made a large number of alterations. Half way round the second lap we did a Buemi, the rose joints holding the left front upright to the wishbones both failed. The wheel departed and I went sliding along the grass with the car on the floor. Getting out I noticed a drive shaft had snapped, so I actually had no brakes: Front circuit was open because the calliper was running away with the wheel, the rear was useless because it's a single disk on the diff, and the shaft had failed. Didn't hit so much as a cone, I have no desire to test the impact attenuator. :D

There are photos, which I will get hold of and post tomorrow.

Before the crash it was going quite well, there are niggles - such as it being almost impossible to change gear - but it handles really well, there's a lot of power which is delivered very smoothly (80bhp / 250Kg = 320bhp/ton), it's easy to control with a lot of power on too.

Oh, an it was wet. Lots of work to do this week now to get out and test again on Sunday. But it's better to find out it's too weak with 6 weeks left to the race. Gave the Golfists at Aintree a good scare too. :D
 
So I'm not the only one to crash one of these then. We use the CBR600RR motor with a custom intake and re-baffled sump, other than that it's a standard engine.

I'm with Liverpool John Moore's University. We were only a week later than we planned to test in January. We're actually quite happy with the amount we've learned and how little needs changing, just that one of the things is a bit fundamental and made a wheel fall off under me. I still feel like **** for breaking the car, the 2 other drivers who were about to be stuffed in for 3 laps each were a bit frustrated.
 
Apparently Oxford Brooks did the same thing in Detroit the other week. We had 10mm joints which had been subject to welding temperatures.

Anyway, as promised:

Teh car.


A wheel.


I take Jack through the startup.


The 1st time the car has moved under its own power, it's horrid to drive at this point, gearshifts are impossible.


After some alterations it's better, shifting is still hard, Jack seems to be having fun:
dsc0114b.jpg


Ignore the spin, the car is performing very well, it's hugely controllable on the power.


After a few modifications to the throttle I get in.


The thing can tripod at both ends it seems.


And then it all ends with a bang as I touch the brakes. I trundled onto the grass with no brakes at all.

-

-

-

-


So, yea, we're changing those for 3/4 imperial roses and we're going to re-make the arms so the top and bottom ball joints can have no thread exposed, we're not welding with them in and we're taking the Camber adjustment to the inside. Then we're letting the next driver who was just about to jump in after me do about 5 brake tests back to back. Must dash, car to mend.
 
A student who is now with the Oxford Brooks team. Jack and I spent most of November trying to stop his design leaking. Then we tackled making it less tall with that bend, so that would be hard to pin on him. It was designed by him with a lot of emphasis on CFD analysis to maximise airflow.

It fell off the head because none of the mountings were fitted, It's strong enough to manage the tests we have planned for this Sunday.
 
Last edited:
Hmmm, this is the sort of input we really do want. I take it with the intake you were referring to that the fuel rail and manifold needs to be fastened to the engine? We're doing that.

I can't find anything in the 2010 rules about not bending rod ends or wishbones.

Remember this is out 1st car, about 50% of the chassis design and a lot of the intake and suspension design is taken from the class 2 entry and done by students who aren't here now.

As for reading the rules, the whole team read all the rules and try to poke holes. We also have regular visits from one of the Judges.
 
kaiowas said:
Any idea how you managed to fail the suspension and the driveshaft in the same incident? Seems an odd combination that i'm struggling to get my head around.
Click to expand...

Us too, here's my theory:

1. I brake.
2. The front wheel runs away with the calliper.
3. I brake hard with the remaining rear circuit.
4. The single rear brake being on the diff, the welds in the shortened shafts couldn't take it. One shaft failed and now there's no brakes at all.
 
Simon said:
The rod ends broke thats why the wheel fell off.

Some of them have over 2cm of thread under bending!

6mm bolts on double shear load paths are also against the rules I think.
Click to expand...

Ah, yes, we have a plan regarding that. There will be new uprights designed to take larger rose joints (3/8 imperial instead of M8, I think) with no threads exposed. The inner end of the wishbones will point the roses directly at the chassis, so they can do the camber adjust. The wishbones will also be made to a finer tolerance, the current ones are rubbish.
 
That was also mentioned today. We've been looking through hundreds of photos of other entries and racing car design books.

I should make it clear, I'm no suspension expert, I'm the electrical guy (loom #1 worked 1st time by the way, #2 is being done with all new connectors, Deutsch where possible), I have a reasonable level of understanding of other areas of the car, I've done a bit of engine work for example. But when you say "spherical bearing", I need to go and read a book.
 
That's some sweet bodywork.

We have all the parts for 8 new wishbones now, the lower ball joints are spherical bearings. We've tested a couple of times since the crash and we're consistently bending rear lower roses. Welding the new ones up tomorrow.

Also; we all hate Percy, when we're done we're going to burn him. Our headrest now looks a lot more like yours, position I mean.
 
griffo_001 said:
I just noticed something: You're using a re-baffled sump? Is it still the wet sump as per the bike? Back when we used the CBR (And now with the Aprilla) we had to switch to a dry sump to avoid oil starvation during cornering.
Click to expand...

We've just re-baffled it, the way we've done it it's almost a tank. The pick-up has been lowered and a plate installed above that, the pressure valve return squirts excess oil below the baffle. We've copied what a Side-car racer using the CBR600 does.
 
griffo_001 said:
I wouldn't go that far :p

One of the main problems was that it never ran enough for the alternator to recharge the battery so we've knackered a series of batteries trying to start it, but now we're doing longer runs that seems to allow time to recharge :)
Click to expand...

Varley gave us their smallest Red Top for free, that thing can crank our Honda till the cows come home and then go to the shops for some milk.
 
Rod end issue is solved I think, all the bottom ball joints have been replaced with spherical bearings now. I'll try and get a photo.

The mad Vicar was with us at our last test, he was quite surprised we managed to bend them as we re-built the rear suspension after each run. For some reason - just before we made the new arms - we were consistently bending rears, but not touching the fronts. I think the front two I broke in the very 1st test had been in place near a lot of welding.
 
:D

We're all ecstatic with the results. For those that don't know:
-21st overall, it's a bit of a who's who ahead of us.
-6th UK team.
-18th in the Enduro.
-2nd in the Economy, using 2.5 litres of fuel. Lord knows how we did this, we ran out of fuel in a mock enduro in test then extended the tank from 5.7 to 7.7 litres. Adam Lowe - now of Oxford Brooks - who designed the intake doesn't think that's even possible.
-And the bit we really wanted; we passed scrutineering without having to re-queue, then finished every event.
-16th in the sprint.

Nice to have met griffo_001 in the camp site last night too, I tried to find you in the pit sooner but only found the car.

I'll try and get hold of some photos, we had a media team. :D


Edit:
Oh, and I can do the accel. faster than the egress.


Another edit:
Our neighbours of Liverpool University managed to produce a nice looking car by Sunday, I was very impressed with the students and the car, particularly the bodywork, just a shame it only made it to the enduro. Could stand to loose your faculty advisor though, he's a complete arse head. Rocked up late with a bare-ish chassis and immediately announced he was there to beat us, then tried to say that's how all the good teams do it, except the 2009 winners followed us through scrutineering with a tested car on Thursday morning.


Yet another edit:
I just noticed the set-up bars in your photo are the exact set we borrowed, I was wondering who we scrounged them from.
 
Last edited:
22k isn't it? Was slightly more because each lap was 1.003k. We could have done 2 more enduros with our tank.

The solid(ish) 90 and a bit of work on the map really did help. Also Aled driving like my grandmother might :p.


Edit:
The Gratz 1A crash was a bit strange, does anyone know why he just plowed on through the fence in a straight line? Good job that Jag got in the way else he'd have landed in the fuel tent.
 
Last edited:
There's like 50ft of run off after the box, and a choice of loads of soft(ish) hay bails to hit, yet he chose to park it upside down on the bonnet of a Jag over a fence directly on from the box. Either the steering also failed or the driver did.

We were waiting to go in the play pen when it happened. A swarm of photographers were on the scene in seconds.
 
You must log in or register to reply here.
Back
Top Bottom