Hello

I'm projecting the brakes for a Formula FSAE car and we wanted to use floating discs, but it's hard to find floating discs with 220mm diameter.

Can anyone tell me where did you get your brake discs?

And what are the problems in buying a normal disc, and cutting the inside of the rotor to adapt them to floating?

Thank you,
Luís Monteiro.

This message has been edited. Last edited by: Luís Monteiro,

you get them from the same place as everything else: stock material

In India at least 220 mm rotors are really on almost all motorcycles available. Maybe you could check out the motorcycles available in your market.

I've always had a tough time having 220mm disks inside 13"rims. Make sure you have place to squeeze the calliper between the rim and disk.

Lasercutting a steel plate always works.

quote:

Originally posted by EPMAl:
Lasercutting a steel plate always works.

Not if you want flat rotors.

quote:

Originally posted by Kirby:

quote:

Originally posted by EPMAl:
Lasercutting a steel plate always works.

Not if you want flat rotors.

Perhaps you need a better laser-cutter! Ours have always been flat.

quote:

Not if you want flat rotors.

Beg to differ. Have done it in our teams for tha last few years and has always worked. Thick plate though(1/4"i fmymemory serves me well)

quote:

Originally posted by Luís Monteiro:
Hello

I'm projecting the brakes for a Formula FSAE car and we wanted to use floating discs, but it's hard to find floating discs with 220mm diameter.

Can anyone tell me where did you get your brake discs?

And what are the problems in buying a normal disc, and cutting the inside of the hub to adapt them to floating?

Thank you,
Luís Monteiro.

Usually the floating discs you would find on the market are for front motorbike brakes. They dont sell the disc but only the whole assembly (rotor and mounting plate). There is an article by Brembo about floating discs if you could find it. Best quick option is to modify a normal disc.

quote:

Originally posted by Kirby:

quote:

Originally posted by EPMAl:
Lasercutting a steel plate always works.

Not if you want flat rotors.

We always used Marting Custom Products (http://www.mcpbrakes.com/). Sent them a CAD drawing of our brake design. They would laser cut them and then Blanchard grind them to our desired thickness. Never had any problems.

quote:

Originally posted by Pi­co:

quote:

Originally posted by Luís Monteiro:
Hello

I'm projecting the brakes for a Formula FSAE car and we wanted to use floating discs, but it's hard to find floating discs with 220mm diameter.

Can anyone tell me where did you get your brake discs?

And what are the problems in buying a normal disc, and cutting the inside of the rotor to adapt them to floating?

Thank you,
Luís Monteiro.

Usually the floating discs you would find on the market are for front motorbike brakes. They don't sell the disc but only the whole assembly (rotor and mounting plate). There is an article by Brembo about floating discs if you could find it. Best quick option is to modify a normal disc.

When you say Brembo has an article on modify a normal disc to floating do you mean cut the rotors? Because that was the kind of adaptation I was thinking of.

I've tried to contact several motorcycle brake manufacturers, but most of them only have discs models displayed by motorcycle models. The brand I found that displayed a catalogue with dimensions of the disc models was Galfer, and they aren't answering to my emails...

Thank you for your reply,
Luís Monteiro.

This message has been edited. Last edited by: Luís Monteiro,

quote:

Originally posted by Kirby:

quote:

Originally posted by EPMAl:
Lasercutting a steel plate always works.

Not if you want flat rotors.

Thicker plate and blanchard grinding to size works well....

quote:

Originally posted by RacingManiac:

quote:

Originally posted by Kirby:

quote:

Originally posted by EPMAl:
Lasercutting a steel plate always works.

Not if you want flat rotors.

Thicker plate and blanchard grinding to size works well....

Iowa Laser can cut them 1/8" without any warping that I can measure.

220mm disks are easy to fit inside a 13" rim - standard Formula Ford, Formula Continental, and F1000 disks are 254mm, and 263 can be fitted, depending on the caliper used.

220mm disks inside 10 inch rims could be a hassle, however.

For decent, low-cost rotors, stick with Ductile cast iron. Grey CI will work fine if you are not heating them too much (thermal cracking resistance of grey CI is not as good as for Ductile). The vast majority of cars come equipped with grey CI rotors, so finding an aftermarket rotor shouldn't be very hard, unless you are using a too-small inside diameter (anything under 5 to 5.5 inches, most likely).

If you use modified street car rotors, you will want to have them stress relieved before you cut them to the final thickness - cut them to about 1.5mm thicker then final, then get the sterss relieving done. Make sure that the heatreater lays them flat on a FLAT surface or they will relax to conform to the uneven surface once at temperature.

I can supply rotor blanks in Ductile if you need (have done so for lots of teams over the years) E-mail me at rpare@prodigy.net if you don't have any luck elsewhere.

quote:

Originally posted by Luís Monteiro:

quote:

Originally posted by Pi­co:

quote:

Originally posted by Luís Monteiro:
Hello

I'm projecting the brakes for a Formula FSAE car and we wanted to use floating discs, but it's hard to find floating discs with 220mm diameter.

Can anyone tell me where did you get your brake discs?

And what are the problems in buying a normal disc, and cutting the inside of the rotor to adapt them to floating?

Thank you,
Luís Monteiro.

Usually the floating discs you would find on the market are for front motorbike brakes. They don't sell the disc but only the whole assembly (rotor and mounting plate). There is an article by Brembo about floating discs if you could find it. Best quick option is to modify a normal disc.

When you say Brembo has an article on modify a normal disc to floating do you mean cut the rotors? Because that was the kind of adaptation I was thinking of.

I've tried to contact several motorcycle brake manufacturers, but most of them only have discs models displayed by motorcycle models. The brand I found that displayed a catalogue with dimensions of the disc models was Galfer, and they aren't answering to my emails...

Thank you for your reply,
Luís Monteiro.

It was an article about the floating mechanism.

Everything warps without exception. you could mill them (cnc?) out a thick plate then mill them down to thickness if you cant find an aftermarket equivalent.

Mill and grind. Or waterjet and grind. Or Lasercut and grind. Take your pick.

quote:

Can anyone tell me where did you get your brake discs?

And what are the problems in buying a normal disc, and cutting the inside of the rotor to adapt them to floating?

hi, this is my floating disc setup..


the hub is milled to accept the disc directly..
the disc is held by the hub on one side and a simple plate on the outside (held on by the wheel)
the disc is Alfa romeo alfasud unit, which is nice and flat 10m thick 257 mm diam, milled into final dimension (245 diam..)

this is the original brembo disc..
http://www.bremboaftermarket.c...?ModelIDMaster=11733

This message has been edited. Last edited by: Vlado,

quote:

Originally posted by Vlado:
[QUOTE] 10m thick 257 mm diam, milled into final dimension (245 diam..)

I think you mean 10mm which is still plenty thick, last year our fronts were less than half that thick, and the rears thinner yet. But just because we did that doesn't mean it's "right".

quote:

Originally posted by Vlado:

the disc is Alfa romeo alfasud unit, which is nice and flat 10m thick 257 mm diam, milled into final dimension (245 diam..)
this is the original brembo disc..

The disk does seem rather large.
Are you using 13" rims? How did you manage to package this inside them? What is the inside well diameter of you wheel where the disk is placed?
I am asking because I have always struggled to fit 220mm diameter disks in our 13" rims. I feel as if I am missing a trick.

quote:

I think you mean 10mm which is still plenty thick, last year our fronts were less than half that thick, and the rears thinner yet. But just because we did that doesn't mean it's "right".


Team Captain
Ryerson Formula SAE

yes, 10mm... of course..
but I am not building an FSAE car, but something with 180 HP, so want a bit more "disc"

I am using 13inch Compomotive CXR wheels, and with wilwood 4 pot calipers I can get a 255 mm disc inside, with no problems.



However, I have decided to push the discs outboard as much as I can, to ger a lower KPI, and had to reduce the disc to 245mm.


if you ask compomotive, they will send you a cross section of the wheel, with all the dimensions..

Laser- or watercutting a sheet metal with a milling procedure afterwards always worked very good.

In 2008 we had a brake disc failure on the rear axle 24h before the Baltic Open event.
With no time to grind new ones down anymore we lasered a substitute from a sheet metal with the desired 3mm thickness. Afterwards we bended them by hand (!!!) until no distortion was measureable any more. Russian style but it worked without any problems