2-piece Floating rotor set-up design
2-piece Floating rotor set-up design
(OP)
Hi everybody,
I am working on designing a 2-piece floating set-up for a road car (that will also see some track time).
I understand the fundamentals of the floating rotor design.
I have the rotor material (G3000 Grey C.I)
I have the Hat material (6061 Alu)
I have seen rotor temperatures on a very similar set-up approach the 1100F mark on track, so I am using 1200F as my upper limit for operation temperature.
There are two dimensions for float: Radial and Axial
Given the thermal expansion coefficients, you can easily calculate the amount of radial float that must at least be present.
My question is: How to control the axial float?
I understand most race car set ups are not concerned with the noise that is generated with a floating set-up, however I need to have spring preload and still allow for axial thermal expansion.
I have experience using a set-up that uses belleville washers in between the bolt head and rotor flange. This allows me to torque the hat to the rotor without having relative movement.
How should I determine the amount of float needed in the axial direction? We are accounting for both thermal expansion and movement in the suspension/braking components bolted to the uprights.
This seems a little open ended, but I am looking for advice. If there is anything missing from this post that may be needed to pose an answer, please let me know.
I appreciate it, thank you.
I am working on designing a 2-piece floating set-up for a road car (that will also see some track time).
I understand the fundamentals of the floating rotor design.
I have the rotor material (G3000 Grey C.I)
I have the Hat material (6061 Alu)
I have seen rotor temperatures on a very similar set-up approach the 1100F mark on track, so I am using 1200F as my upper limit for operation temperature.
There are two dimensions for float: Radial and Axial
Given the thermal expansion coefficients, you can easily calculate the amount of radial float that must at least be present.
My question is: How to control the axial float?
I understand most race car set ups are not concerned with the noise that is generated with a floating set-up, however I need to have spring preload and still allow for axial thermal expansion.
I have experience using a set-up that uses belleville washers in between the bolt head and rotor flange. This allows me to torque the hat to the rotor without having relative movement.
How should I determine the amount of float needed in the axial direction? We are accounting for both thermal expansion and movement in the suspension/braking components bolted to the uprights.
This seems a little open ended, but I am looking for advice. If there is anything missing from this post that may be needed to pose an answer, please let me know.
I appreciate it, thank you.





RE: 2-piece Floating rotor set-up design
RE: 2-piece Floating rotor set-up design
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: 2-piece Floating rotor set-up design
I was able to figure this out. Calculate the force generated to move a given amount due to thermal expansion at your operating temperature. From there you can select your spring rates.
RE: 2-piece Floating rotor set-up design
RE: 2-piece Floating rotor set-up design
With disc brakes you can use axial float of the rotor or axial float of the caliper. Racing disc brake systems usually allow radial and axial float at the rotor-to-hat attachment and use rigid caliper attachments. Most automotive disc brakes use a rigid radial/axial rotor attachment, and an axial float of all/part of the caliper.
Racing disc brake rotors are attached to the hat using "hat bushings" like this: http://www.apracing.com/drawings/CP2872_1000CD.pdf