UTAS build 2015

[CWA]

Sounds like you've learnt a lot chap.. and that's what it's all about

Some things from me:
- Didn't last year's UTAS car also have a high steering effort issue?
- What does "run the parts" mean?

[MCoach]

Oh boy... what have I started here. Maybe I should just say the 270kg was a typo! Relax, the car is not 270kg, but until recently we had not had an accurate weigh-in. I'm not going to add fuel to the fire here as most points have been made, but if I may, lets set some facts straight so people know a bit more of our story
- we are not one of the "big" uni's in Australia, and so we tend to attract a lot of local Tasmanian's who do engineering "because". Think of it like the African brain drain... most of our brightest students transfer over the mainland after 1st year. We get many of these joining our team, and we had 42 people back in January. We are now down to 18. 16 heading to comp. It makes it very difficult to judge where to spend resources, time, effort and place students in areas. Suspension is now a one man team, which leads me to my next point...
- all students complete honours, or a final year project, of which this year we HAD 4. The driveline guy decided to leave in June with unfinished designs. He was slightly ambitious, but had done plenty of analysis so we didn't have to do too much to finalise his designs and get them made. Our aero leader wanted to design a base-line aero kit that could be expanded upon in years to come. This was her passion, she worked INCREDIBLY hard, but has been let down by members of her team leaving (and perhaps lack of communication). Suspension was again a 4 man team in January, it's now a single guy who's final year project was to develop and analyse the same suspension system we had last year, and his decision after many many matlab & simulink calculations was to develop ARBs. It is VERY difficult to tell these guys that their projects cannot go ahead... and this is why we have some additional components on the car this year, vs simplifying old ones.

Now,

Z : I like your points, most are valid. I wouldn't say we have gone in the wrong direction, but we have certainly overshot what we could have done. Again, as I've said, this was due to an massive influx of students in January (way more than we had in 2014) and so we thought we had to capability to complete what we set out to achieve.

Claude : Some just criticism, some unhelpful comments. As Menisk mentioned, you have no idea of our budget, facilities, experience, knowledge transfer. I think we have a major team management problem, and is something I will be asking around the teams at competition to fix for next year. Our faculty advisor loves the bureaucracy of several team leaders, each with team members that report upwards in the chain etc. But also, the only comment he could make when i designed our 2.8kg engine bulkhead (with extensive ANSYS FEA) was that "[he] would be happier if it weighed closer to 5kg". So I guess we're lucky the car only weighs 270, as it might've weighed 272.2 if I'd followed his advice!

To ritwikdas18 & P^squared; thanks for you criticism, not very constructive or supportive, but anyway. We do not have many of the benefits of mainland unis, mainly a lack of major industry support (though we do have a nice workshop). Also very poor university funding. But we manage without.

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A separate point;

Having been lurking on these forums since the end of 2013, I was surprised to see a lack of 'build threads'. I thought it would be a common thing (as you would see on many car enthusiast forums), but oddly not. Looking at many of the comments in this thread, it's pretty obvious why.

Utas has put itself out there for critcism, as have Jon and I. It's a good thing, else we would not bother! But there is a serious problem with the community here as Menisk has mentioned, intrigued students are treated as inferiors and their ideas often shunned.

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I'm gonna back out for a bit, and grab some more popcorn.

If there is anything I've learned, it's do not to be afraid to be wrong. I've spent my entire life being wrong with very few select moments of being correct. The criticism that many have given, especially Z with his fundamental questions has constantly challenged us to go back and make sure we understand the basics, able to form individual thoughts, and provide goals for ourselves (however unrealistic some of them may be). Now, not everyone needs to be shouting, nor interacting in a condescending way, because we are all students. Students study the materials, teachers study the students.

If anyone told me where the FSAE community level of expertise and competitiveness would be in 5 years when I joined, I wouldn't believe them. Flat out, would not believe.

I guess the only thing else that I have to add to UTAS is that software and simulation are cheap compared to making physical objects. Carrying concepts from year to year that are considered "acceptable for now" can allow you to spend more time using and building analysis tools to decide what systems/parts are too heavy, what is too compliant, what doesn't fall under the team philosophy of building the best car you can muster. Simulation tools can allow you to make the decisions of what areas to tackle first and what you're limiting features are. Aero? Chassis weight? Suspension geometry? Component selection? As powerful as these tools can become, their accuracy is always limited by their assumptions and their usefulness is always limited by "time cost" of using the software.

Good luck and looking forward to what you may produce next year.

[Adman]

Sounds like you've learnt a lot chap.. and that's what it's all about

Some things from me:
- Didn't last year's UTAS car also have a high steering effort issue?
- What does "run the parts" mean?

You are correct regarding steering. For some reason or another, the same problem has occurred again. It is better mind you, but compared to driving other cars we are still behind. There may have been a miscommunication between myself on chassis and our suspension leader, as we are still not making full use of our steering rack travel which we purchased on a slower ratio to improve the effort.

"Run the parts" refers to the front and rear wings that we could not get mounted in time. GTS gave our faculty advisor a good flogging for it (which the team somewhat enjoyed) but in reality our aero leader hadn't fully considered how to mount it. It was always a "she'll be right" attitude. There was no cross bracing on front and rear wings (so it would just flop side to side) and little consideration was taking for the space taken by the bodywork and exhaust routing. Admittedly some things got in her way unexpectedly (like our CAD model for the tyres not being accurate).

We've learnt a lot, and aim to get the most knowledge retention we can over the summer to give our 2016 car the best shot it can.

GTS, thanks for your comments. It's awesome to have a judge that can back up their comments with feedback!

MCoach, again thanks for you comments. We have a solid idea about where we want to go this year, it's more about how we manage ourselves that we know has to change.

[GTS]

- What does "run the parts" mean?

It means stick them on a car, get some data and experience. The excuse given for not running the parts was... not good (it didn't come from the student involved). Simple application of Logic Sticks and Reality Helmets, ~20 odd students with a copy of SolidWorks (I'll assume all are legal installations!), some steel, welder and fasteners would have made for a directionally-correct solution. The other concerns mentioned are fixable... every project starts thus. Time, cost and quality, you can pick any two in any instant etc...

GTS, thanks for your comments. It's awesome to have a judge that can back up their comments with feedback!

Anytime. (Bonus points for correct spelling on your previous post).

In life in general and in racing in particular there are two categories of people: one that makes winning and the one that makes excuses. We have to decide which category we want to belong to.

A bit interesting to read further up.

Claude, I get this, having worked in racing, 'life in general' and the like. But I've also been faculty and, many moons ago, a Formula SAE student.

I sympathize with the notion that many efforts simply set poor targets. There are many reasons for this, some to lack of knowledge, most to lack of confidence. Some of the latter goes far deeper than just the students involved and well into faculty that, for better or worse, don't believe the collective efforts of their students and resource network are capable of winning (those present last year might remember a few of us having a rather memorable argument to this end). Whilst your science is in the right place, I'd suggest that where the issue can be confidence, tearing it apart in an open forum won't build it.

Nor is the ultimate goal of everyone's FSAE career winning. There's motorsport for that, and this isn't it.

[Claude Rouelle]

GTS,

More than confidence it is the lack of ability to understand and measure what is necessary to make a winning car and a winning team.

That you do not have the resource, the time,the budget, the education, the labs, the teacher, the software etc....to make a wining team and car, especially the the first year, is understandable: you need to start somewhere.

But not having a bit of imagination and search skills and take the time to create that list of winning criteria is an insult to your own intelligence and the people who have invested in you. (I mean "you" in general, not GTS in particular)

[GTS]

GTS,

More than confidence it is the lack of ability to understand and measure what is necessary to make a winning car and a winning team.

That you do not have the resource, the time,the budget, the education, the labs, the teacher, the software etc....to make a wining team and car, especially the the first year, is understandable: you need to start somewhere.

But not having a bit of imagination and search skills and take the time to create that list of winning criteria is an insult to your own intelligence and the people who have invested in you. (I mean "you" in general, not GTS in particular)

Claude;

I'll go the other way.

Whether in racing or in FSAE (which certainly isn't racing), self-belief is everything. Whilst agreeing winning isn't chance, citing 'lack of ability' reads poorly. These students were each smart enough to get into an engineering degree program, to which admission isn't free. They've all a basic command of Newton's 2nd and get the basics just fine. The number of students I've met that set goals behind the ultimate is staggering, but it's very little to do with not being able to identify winning criteria. In many cases the 'we set our targets mid-pack' statements really boil down to 'we're not confident we can do better', not 'we're not sure what better is'. Often the very attitude you cite is endorsed by the very faculty and stakeholders that students look to for guidance and endorsement. No student wants to come into FSAE, give up a good amount of free time, put their name to a prominent piece of work all in the name of targeting mediocrity at best - if that's an assertion it's a silly one.

If they were completely able to guide, research, self-endorse and actuate, they'd not be students, Claude, they'd be professionals. The role of this project is to accelerate this journey, not to critique that it is, in fact, a journey. The message needs to be you can do it, not you're an idiot for not having done it. It's a learning experience the first time, a mistake when made the second time - and there's plenty of career for the latter.

Teams - complete teams, not just individuals within - need to believe they can win and want it too, and that's not easy within the student FSAE environment. Nor is it the point of it.

Modern FSAE doesn't make it any easier, we give students industry-grade CAE tools and wonder how they can't deliver when in reality, these things are very complex and require a level of commitment and proficiency not possible in what remains a part-time student project. They don't actually know better that to drop complexity in execution increases reliance on their heads, which given free reign are particularly powerful things.

Our local competition has a few elements of it's own which remain a bit shitty to deal with. Some are political. On aero particularly it took a rule change to force free thinking. Nothing's perfect.

When individuals in the FSAE environment buck the trend enough to commit to their potential beyond any self-doubt and end up delivering something special, then it's a real achievement. To this end, UTAS FSAE achieved.

[Kevin Hayward]

Well said GTS

[Jonny Rochester]

Some things from me:
- Didn't last year's UTAS car also have a high steering effort issue?

Yes. I even measured the steering torque required when stationary, made note of the steering wheel diameter, steering rack ratio, and upright toe base. I/we listed all the possible contributions to steering effort, then tryed to change a few. I think the main one is the steering rack ratio combined with the toe-base length, but I also looked at the wheel alignment angles. After talking to another team I chose some very low numbers for KPI, caster and scrub, and our suspension guy went along with this after doing his own calcs. I would have increased toe-base also but it would seam now the suspension guy thought the wheel alignment angles were enough, and I guess it's his job to calculate the Mz contribution of each change. We bought a different rack with a slower ratio, (not because it was a slower ratio, but because it was gold in colour and price). however I find later the suspension guy had actually decreased the toe-base significantly (from 70mm to ~63mm) to match the rack so we maintain the same overall steering ratio. It seams fair, but not surprisingly we had quick steering with similar feel to last year. Some spacer plates where made to increase the toe-base by 15mm which worked very well and the car is drivable, however people still comment the steering is quick with high effort.

I had planned to make a new steering wheel that is 5mm larger in radius ( I agree with incremental changes and keeping things simple). We made the steering wheel but a local business that was to trim the wheel went out of business and out steering wheel went in trash with the rest of the company. So we used last years steering wheel.

A solution now would be to remake our spacer plates to again increase toe-base further. We also have a mild steering lock issue. The inner rim just about touches the wishbones and we struggle to get around some cones.

[Z]

Jonny,

After talking to another team I chose some very low numbers for KPI, caster and scrub,...

I sent a PM to Adam about the heavy steering issue.

But for now can you give your numbers for,
1. KPI (aka SAI = Steering-Angle-Inclination, from vertical, in end-view),
2. Castor (angle in side-view),
3. Offset (aka "scrub radius" = end-view distance between SAI-ground-intersection and nominal-centre-of-wheelprint),
4. Trail (side-view distance ...),
5. Degrees of full hand-wheel movement (lock-to-lock),
6. Corresponding degrees of front-wheel movement (lock-to-lock).

By FSAE standards you have more than average weight on the front wheels, plus biggish sticky tyres, but once the car is rolling a good steering geometry should give very light steering feel.

Z

[BillCobb]

A useful procedure to employ is called a "Friction Breakdown Test". It can be very revealing. Use a torque wrench on the steering wheel to measure the scrub torque with the car stationary. Then place the steered wheels on grease plates and measure once more. Then disconnect the tierods and measure again. Finally disconnect the column from the rack and get a value.

You maybe quite surprised to find some unexpected steering loads coming from ball joints, rack internals, swivel joints, u joints, whatever, under actual loading conditions. The grease plate test is where the eyeballs usually start coming out. "Ain't supposed to be that way" is a commonly heard expression. If your rack is tight, the rack pushaway mechanism (to prevent tooth separation) can be a problem, but if you modify it there is a chance you will jump a tooth during fast turning maneuvers.

There's always air pressure. If the cause of high effort is your tire MZ output, chances are you also have a problem with compliance understeer in the front end if your restraint structure is undersized. The car changes character when the MZ runs out at high cornering levels and becomes bi-polar. That's usually not a preferred driving situation.