Cheap and Light vented discs.....

[George_Of_The_Jungle]

Hi Guys and Gals,

I'm designing a one-off bike powered twin seat racing car to enter into the the 750mc bike-sport competition. Currently designing the uprights, and i'm looking for a suitable disc.

Requirements: Mass produced for a road car (to reduce cost and increase availability), preferably 4 stud, 250-280mm OD, and preferably to fit an offset of 18-30mm

Any Ideas?

[UweM3]

there you go

http://www.brembo.com/ENG/catalogo_AM/2007/index.html

[George_Of_The_Jungle]

I UseM3, thank-you for your comment, but could i re-emphasise the word cheap......

[N00b]

I UseM3, thank-you for your comment, but could i re-emphasise the word cheap......

How much is "Cheap"?

[George_Of_The_Jungle]

cheap as poss

[e21Jason]

Go onto APEC web and use solid disks if you have read carrol smith you know there is no need for vented on a sub 800kg car I would use ford so you have the choice of alloys and of the shelf hubs

Jason

[BadDave]

You say you're after 4 stud,but what PCD and centre bore

There's not much about in 4 stud with less than 30mm offset

Found some 280mm rover ones but they are 32mm offset(that is total offset from the outer hub face)
Inner face thickness isn't mentioned but they're normally about 8mm thick

[caneswell]

I UseM3, thank-you for your comment, but could i re-emphasise the word cheap......

I would imagine Uwe was pointing you in the direction of the "Search by Dimensions" option on that site.

Then at least you know what car to look at.

[UweM3]

I UseM3, thank-you for your comment, but could i re-emphasise the word cheap......

I would imagine Uwe was pointing you in the direction of the "Search by Dimensions" option on that site.

Then at least you know what car to look at.

sigh, where is my spoon.....

[George_Of_The_Jungle]

I haven't got a specific offset or PCD, as I will be making one off fabricated uprights and hubs.

I'm aiming for a kerb weight of 400kg, so even if I only save a few grams by using one less stud per wheel 'every little helps'

I haven't read Carol Smith's book, but I will add that to the list, probably just before Milliken and Milliken's Race car vehicle dynamics. Solid discs would save a fair bit of weight.

Has any one used MMC brakes - or even just know about the life of MMC rotors? (I know MMC rotors will cost and arm and a leg but the weight saving would be huge)

As far as wheels go - I'm going to be using Compomotive CRX-1370s, I have spoken to compomotive and they will machine one off PCD and stud pattern to predefined offsets.


The next question is bodywork....... Any idea how much it would cost to make a one off mould?

[UweM3]

The next question is bodywork....... Any idea how much it would cost to make a one off mould?

£2456,45!

holy crap, who is designing the car? You or E30zone.net?

Seriously, you need to be a bit more active. How will anybody here know how much matting, resin, gel coat is required to make a mold for a car which doesn't even exist?

If you want to make a career in design, you will have to learn to RESEARCH. I spend a fair amount of time browsing through cataloges, list etc to find the stuff I need when designing a new product/project.
And without a drawing/sketch or any sort of guesstimate you will not be able to work a meaningful cost out.

So get on the phone, mail, fax and get some prices in for material and work it out.

Not that difficult really.


I am sure if your question would be "where can I buy resin etc at a good price" people would actually be able to help you.

[caneswell]

I haven't got a specific offset or PCD, as I will be making one off fabricated uprights and hubs.

You had some preliminary dimensions, stick those in and see what comes up, then find out which is the lightest.

Has any one used MMC brakes - or even just know about the life of MMC rotors? (I know MMC rotors will cost and arm and a leg but the weight saving would be huge)

Lotus!

The next question is bodywork....... Any idea how much it would cost to make a one off mould?

>£50

[George_Of_The_Jungle]

The next question is bodywork....... Any idea how much it would cost to make a one off mould?

£2456,45!

holy crap, who is designing the car? You or E30zone.net?

Seriously, you need to be a bit more active. How will anybody here know how much matting, resin, gel coat is required to make a mold for a car which doesn't even exist?

If you want to make a career in design, you will have to learn to RESEARCH. I spend a fair amount of time browsing through cataloges, list etc to find the stuff I need when designing a new product/project.
And without a drawing/sketch or any sort of guesstimate you will not be able to work a meaningful cost out.

So get on the phone, mail, fax and get some prices in for material and work it out.

Not that difficult really.


I am sure if your question would be "where can I buy resin etc at a good price" people would actually be able to help you.

Thanks for your comments Uwe. In response I am researching into the questions I am asking, but I have found that discussion with others often produces new ideas and brings up problems I may have over looked.

I wasn't asking about how much it would cost for the glass, resin or gel coat, but how much it would cost to make the mould. I will rephrase my question. Does any one, who has more experience than my self in the processes of making a pattern or mould, know the name or a source of the foam, which is machined to the desired shape, to then layup into to make the mould or the component. Any suggestions would be appreciated, and I would just like to make extra sure that no one feels I am forcing them to respond or design components for me.

Once again thank-you for you input.

[UweM3]

If you can't make the mold yourself, it will be to costly. I know a company with a HUGE
5 axis milling machine who cuts boats etc in 1:1 for molds. But do you want to spend 3-4 grand?
Do you have a 3D CAD model of your bodywork?

[George_Of_The_Jungle]

I will need to get it milled. And yes I have a CAD model of the bodywork. I haven't yet finalised the bodywork and still need to add all the joggles and fixing locations but I trying to cost the project.

[UweM3]

try these people (never had any dealing with'em
http://www.polystyrenemodels.co.uk/poly ... odels.html

I have another contact if you are srious about it (cost wise)

if you want a scaled down model, I have a 3D printer

[George_Of_The_Jungle]

Thank-you Uwe I have emailed them to enquire about costs.

[caneswell]

Blimey, car sized milling machines would be rather expensive. I'd try and split it into as small sections as possible.

Or shaped the foam block by hand, like what they do with the clay models for production cars. I imagine that takes some skill and patience though!

I think you can also form the rough shape with 2D cross sections in ply/card built up into 3D. Then the gaps and details will be easier to sort by hand. Difficult to explain without a picture!

I take it you've seen this guy's site with the trials and tribulations building the "DP1": http://dpcars.net/
Worth a read.

[caneswell]

Better explanation: http://www.pistonheads.com/gassing/topi ... g%20method

[George_Of_The_Jungle]

I had totally forgotten about that method (it was used 3 times at uni to produce formula student bodywork) Similar to the balsa wood dinosaurs models, then fill in with foam, top coat of clay which you then smooth / sculpt, then wax or apply a releasing agent. That would reduce costs alot. As laser cutting the wood, would be much cheaper than machine time.

I will be splitting the bodywork up into a minimum of two pieces anyway but possibly 4 (nose / engine cover and sidpods, or nose / side pods x2 / and engine cover)

[e21Jason]

I would read smith before milken he does my head in defiantly more a book for the academic

To keep the cost down can you not buy some used Elise uprights or buy the ones from ADR

Jason

[George_Of_The_Jungle]

I can make my own uprights for about £30 each

[billgatese30]

as far keeping the brakes as light as possible can you not use a bell and rotor setup with some solid rotors. That way your bell can be Ali and therefore alot lighter than the steel, plus you can machine whatever offset and PCD works for you then. May not be the cheapest option though but it would solve alot of your problems.

[ross_jsy]

Another idea (and rather ghetto compared to all this talk of 5 axis milling machines) is how me and a friend made a fiberglass front for a mini.

We used blue expanded foam which I think was originally intended for insulation. Stuck it together to create a large block and then shaved/sanded it down to the desired shape and using that as the basis for the mold. Cost about £20 to do and came out really well.

[UweM3]

Another idea (and rather ghetto compared to all this talk of 5 axis milling machines) is how me and a friend made a fiberglass front for a mini.

We used blue expanded foam which I think was originally intended for insulation. Stuck it together to create a large block and then shaved/sanded it down to the desired shape and using that as the basis for the mold. Cost about £20 to do and came out really well.

well this is how students used to do it. Cheap and inventive.
But these days everybody is looking up to F1.....