[pp7]

Does anybody know the easiest way for me to make an aluminum brake rotor 11" diameter, 3/8" thick to bolt onto a custom wheel hub ? I never made these before. I have some 6061 rectangular aluminum plate. I was thinking something similar to the attached picture. I've got a ZX45 mill and G0602 lathe.

[SCzEngrgGroup]

Is this for a car??? If so, 6061 is a HORRIBLE choice of material - it'll last a few good stops before getting horribly gouged up, if not simply breaking. Brake rotors are typically made of cast iron, and for a good reason....

Regards,
Ray L.

[pp7]

It's for a light car, about 1100 lbs. I was hoping to get away with aluminum for the weight savings. Maybe it's not such a good idea?

[SCzEngrgGroup]

It's for a light car, about 1100 lbs. I was hoping to get away with aluminum for the weight savings. Maybe it's not such a good idea?

That would be and understatement.... And when they did fail, if you caused an accident, you'd be in a world of hurt legally.

Regards,
Ray L.

[shogun1940]

why not look to nascar suppliers if you really want light parts for a brake system

[pp7]

I did consider just bolting one of these to my hub. Speedway Motors - Product Summary

Maybe that's a better idea?

[mwood3]

most of those look to be for racing gokarts or fourwheelers...for a car you need the ones made with internal cooling fins (double row rotor)

[307startup]

There are aluminum brake rotors on the market, but they are an AL-MMC...aluminum metal-matrix composite. They are made from 6061 with silicon carbide suspended in the alloy. Not something that can be done at home, unless you have access to the material and that will be exceedingly expensive and wasteful.

Lotus Elise and Plymouth Prowler are two examples of vehicles that used these rotors.

Look up MMC rotors.

Here is an example:
Rel, Inc. - Advanced Lightweight Metal Matrix Composites, -- Lightweight Matrix Brakes

[mwood3]

What type of car will this be going on? while unsprung weight reduction can vastly improve handling 2:1 over sprung weight reduction there may be other area to reduce first or to point your money at...

[pp7]

Thanks for the responses. I guess I didn't realize the aluminum rotors on the market were 6061 aluminum composites. Does anyone know if it's possible for me to machine a stainless steel rotor on my equipment? It sounds like the double row brake rotor is better for cooling but I don't think my setup will allow rotors that thick. I need to keep rotor width to 0.38" or less so I can use narrow calipers.

[Flenser]

I've cut T-303 on a G0602 and on a ZX-45 without much trouble. Not sure if that kind of stainless is best for brake applications, though.

I also trimmed some stainless mountain bike rotors on the G0602 using a ceramic insert - they were a lot harder than T-303. To prevent them from warping I had to bolt them to a hardwood fixture, but these were thinner than what you want to make.

[pp7]

I've cut T-303 on a G0602 and on a ZX-45 without much trouble. Not sure if that kind of stainless is best for brake applications, though.

I also trimmed some stainless mountain bike rotors on the G0602 using a ceramic insert - they were a lot harder than T-303. To prevent them from warping I had to bolt them to a hardwood fixture, but these were thinner than what you want to make.

What is the best way to cut the rotor on a zx45? Should I use a rotary table? How can I clamp it to the table? Can I cut the entire circumference using an end mill set? Which type of end mill is best for steel?

[kawazuki]

I'd be looking at using motorcycle discs - perfectly suitable for an 1100lb car - most are stainless these days so they don't rust and the calipers are ltwt too - no contest!

[Flenser]

What is the best way to cut the rotor on a zx45? Should I use a rotary table? How can I clamp it to the table? Can I cut the entire circumference using an end mill set? Which type of end mill is best for steel?

There are a lot of people on here way more experienced at this stuff than me. But if I were going to cut a brake disc, I would rough cut it with the band saw, drill the holes on the mill, then use the holes to bolt the disc to a lathe fixture for finishing. Not sure if you would need to grind the surface to get it completely flat, but that would add some additional steps.

I like the motorcycle disc idea, too. That's a much simpler solution.

[Fastest1]

Put it on the rotary table clamping it by the ID. Center it under the spindle, offset the radius you want. Then spin the table slowly as you are milling it. Due to its hardness, a few passes might be in order. The best way would be in a lathe though, Should be able to use a 4 jaw and hold it from the inside. Ever consider relocating the caliper rather than trimming a rotor? 2 things bad brakes do, make you much faster in the turns or kill you. You wont get faster in the corners if you dont turn though! LOL

What is the best way to cut the rotor on a zx45? Should I use a rotary table? How can I clamp it to the table? Can I cut the entire circumference using an end mill set? Which type of end mill is best for steel?

[nofx]

I would vote it could be done. I believe you would have to heat treat and then grind the rotors. If not it would turn in to scrap thinking about the physics. Older auto shops use to grind brake parts, before the throwaway economy took hold. If you made your parts, heat treated them then grind them at a shop that still has that equipment.

[nofx]

From what I have learned in school and thoery class about heat treating steel. If you properly heat treat a part, you can do the following things.
A> Stress relief surfaces stresses you could create cutting.
B> Using a cylindercal grinder on said parts would put them within 0.0002 of in all axises which maybe useful for when your spining said rotors at highway speeds. You may beabout to hit 0.001 with a 4jaw and carefull setup.
C> anywhere the said brakepad didn't touch would not get ground.
D> A ****ty toolsteel would contain enough chromimum to make them pretty corrison resistance.
Really the size of the rotor in which you want to make is the major consideration.