Custom Wheels

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Originally Posted by Claude Rouelle

Benashcroft,

Apologies accepted though it is not about me but about all the readers of this forum and there are a lot of them

Newcastle where? The is a University of Newcastle in the UK and one in Australia.... Come on guys, can't you be just a bit more worldly and fully introduce yourself?

Speaking about your wheels, (I guess you mean rims) what are in your opinion the characteristics of a rim which make it a "good" rim? Can you present them in a priority list? That will open a useful (and hopefully not too long) debate.

Let me give a start (without priority): weight, inertia, stiffness, price (or cost of manufacturing), availability, ....

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It's The University of Newcastle Upon Tyne, UK. Newcastle racing are now on our 10th design, which we have christened NRX.

With regards to the rims, our priorities at the moment are to have as little unsprung mass as possible, with inertia and stiffness a close second. Cost/price are a consideration, but not too great at the moment as we are only submitting a Class 2 entry (although obviously we can't say we'll spend a fortune on wheels!).

The main issue we are having is finding a wheel that's currently manufactured that we can mount our gearbox design onto. It's looking more likely that we'll have to design a bracket to go between the gearbox output and the wheel. I was merely curious to see if anyone had any experience with custom wheel manufacture.

Ben,
Custom wheels for FSAE have ranged all the way from off the shelf shells with student made centers to full custom cast mag wheels or custom laid up carbon jobs. The early end of the range is cheap and pretty easy to pull off but you'll find that some of the manufacturers have fairly inconsistent weight and stiffness characteristics.

The custom wheels I've worked with tended to be a lot lighter and stiffer than the Keizer, etc. setups but a lot of work went into them. The mag wheels Akron was running a couple years ago for example were a two year project. They found a sponsor that helped them out with the rough casting, but the final machine work was pretty involved. I've also noticed that some of the student built wheels tended to screw up the rim to tire interface. I saw at least one team at Michigan running silicone on the rim in order to get their tires to hold air. I also heard about one German school having to run their tires with an innertube because their carbon wheels wouldn't hold air.

There are probably some really good threads on the topic here if you dig around a bit.[/QUOTE]

Thanks for the reply Zac.

It's our first year of looking at custom wheels, so our current knowledge is pretty basic, hence I came here to ask for advice. I saw the Delft custom carbon wheel last year at the UK event and this is where our idea for a custom wheel came from. I think I also read about the issue of sealing against the wheel.

A custom wheel currently seems to be the better option from a performance point of view, but trickier in terms of design and manufacture. I have been in touch with one company here in the UK but our design lies outside their current scope. It's sounding more and more like adapting our current design may be the best bet.

Thanks for the response

This is FSAE, in my opinion, if you want to customize a part especially for your car / your needs, you should do it yourself as far as it is possible. Otherwise you pay a professionell engineer to design a part - your job.

Customized rims and even CFRP rims are in the competition for far more than 5 years and dozens of teams have done it and you don't need special tools for it. A workstation will be enough. So there is no real excuss for paying (or get sponsorship from) a company that does your customized rims.

Julian, we are trying to make as much of the car as possible ourselves; just last week we visited a local foundry to produce our own design of cast Upright pieces. However, as we are a relatively small team, only reaching 20-25 this year, with a relatively small budget I was merely seeking advice. Of course, any solution will be of our own design, I was curious to see if anyone had any pointers, that is all

Quote:

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Originally Posted by benashcroft

It's The University of Newcastle Upon Tyne, UK. Newcastle racing are now on our 10th design, which we have christened NRX.

With regards to the rims, our priorities at the moment are to have as little unsprung mass as possible, with inertia and stiffness a close second. Cost/price are a consideration, but not too great at the moment as we are only submitting a Class 2 entry (although obviously we can't say we'll spend a fortune on wheels!).

The main issue we are having is finding a wheel that's currently manufactured that we can mount our gearbox design onto. It's looking more likely that we'll have to design a bracket to go between the gearbox output and the wheel. I was merely curious to see if anyone had any experience with custom wheel manufacture.

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Quote:

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Originally Posted by benashcroft

However, as we are a relatively small team, only reaching 20-25 this year, with a relatively small budget I was merely seeking advice. Of course, any solution will be of our own design, I was curious to see if anyone had any pointers, that is all

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Hello my name is Craig Kellermann. I am the Project Manager at the University of Texas-San Antonio(Roadrunner Racing).

Benashcroft, I personally feel that you are falling into the common engineering mistake. I see this as looking for something with the best specs on paper but not what is the be utilitarian approach for your project.

1.We here use pugh matrix for making decisions like this during our design phase. You and your team may want to do this for your wheels/rims.

2.Also if you are going on the custom route vs. bought I would suggest you need to look at the amount of time it takes to manufacture and the human resources needed.

3.You stated that your team has "20-25 members with a moderate budget", If you want to consider Claude's motto "C-Car, A-Team First" Look at What choice would get the team the most successful the fastest.(I have a feeling that it maybe just buying an offshelf wheel)
~Reasoning Behind Statement above:
1. Most likely the lowest on resources(Time, money, and Knowledge)(Time being the hardest to gain back)
2. If they fail you can buy more
3. Why reinvent the wheel unless you know you can make it better( haha that's a pun)
4. Can you validate your decision with Engineering Data( In may cases a Pugh Matrix is engineering Data)(If you make something you validate it works with data)

We here at UTSA hold Time and Money as the highest Values on our team with weight fallowing it cause we have a team with 10 members. the less time we spend building the more time we have to test and tune our bad engineering mistakes.

You don't have to be defensive, I'm just stating my opinion, I'm not attacking you ;)

To your points: If you have a small budget, I even more urge you to do the design of your parts by yourself. Your work is for free (moneywise...), if you pay(!) someone to do your design, you reduce your budget even more.

About the team size: 20-25 is not soo small. Zurich is always in that range of active people and it is enough to be a front-runner in Class 1 ;) (Before I joined, the 2009 team consisted out of 9 people and they won Dynamics Overall and placed 3rd overall at FS UK 2009, so it even works with fewer people ;)).

One point, I am suggesting:
Search for a sponsor that can manufacture such parts. I heard that this is more complicated in the UK compared to the "continent" but if you have someone that offers you time on their CNC machine, that's way more valuable than a large monetary budget.
If you have that you can customize basically all parts on your car.
Start searching for a manufacturing sponsor, they don't care if those are going to be rim moulds, uprights or hubs. Just call everyone around Newcastle ;)

With What JulianH said"Sponsorship=free"They also Free up team members. So in many cases its a double win the team.

Sweet Parts and A team member working on manufacturing another part of the car.

Hi Craig, thanks for the response. The more I look into this, the more it's looking like an "off the shelf" wheel may be better. It will likely mean we can spend more time on other areas of the car, and I'd feel more confident in an external wheel over one we'd made; at this moment in time anyway! If we go for an off the shelf, it should just require a small redesign on the gearbox output to attach the wheel to the gearbox.

Hi Julian. I have contacted as many UK based companies as I can find with regards to wheels. We do have a CNC machining sponsor already, I sent some parts to them yesterday, so they can help with any machining. It does seem more difficult to find large companies here, especially with regards to custom wheels; a lot of companies focus on wheels for classic cars such as the original Mini. Our current main issue is lack of knowledge on wheel manufacture. I am looking into this, but obviously companies who design wheels will know a great deal more than me !

Ben,

I'm not sure if I understand you correctly. But from what I am reading, you are searching for someone in the UK, that can manufacture rims and only find guys that manufacture rims for old Minis?

If that is true, then you are making a big mistake: Don't search for someone who can do rims. Search for someone that can produce parts. It doesn't matter what they are producing. You give them your files and technical drawings and then they can produce it.

For example:
Our moulds for the CFRP rims were manufactured by the physics laboratory of the university. The centers for our last aluminium rims were manufactured by the guys that maintain the aircrafts of "Swiss" airlines.
Both have no ideas about rims or even cars.


Of course, Craig is right. Rims don't make your car a winner. It is just a small part. If you have trouble getting a good car to competition, you can use the person responsible for the rims for something else, something more valuable.

If you are planning to go Class 1 in 2016, make sure you get your top-level decisions right.

Cheers

Thanks Julian.

Yes, we're not short of people who can manufacture the wheels. I'm looking to find a company who makes wheels in order to help us eliminate any simple errors when it comes to wheel design. This is the first time we've considered producing our own wheels so it's a completely new area for all of us.

From a meeting we had today it's looking likely that we're going to go for an "off the shelf" solution for this year's design.