imma DImyself slotted rotors

[88accordalltheway]

hey guys....even tho i dont have a 3rd gen anymore, maybe someone can help me...

I am going to slot my own rotors for my car. I have the tools to do it (aka milling machine/multiple drill presses) and the knowledge of HOW to drill and do a good job. Thats not my problem.

i have two questions:

what kind of rotors should i get?(brand/type)

are there patterns i can copy?(or even equations i can use to make my own pattern?)

i know this can be a kind of far out subject seeing that i have a totally different kind of car(04 vw Jetta Gli) but im hoping someone can point me in the right direction.

I am extremely afraid of warping, thats why i only want to slot(and maybe dimple), and why i am asking what kind i should get, and why i ask about patterns. I dont want to mess with the structure of the rotor too much, but i do want better performance.

thanks to anyone that can help!!

[2ndGenGuy]

I don't think that there are many "patterns" you can follow. I think you have to follow the directional vents and go between them. At least thats how the slots are on just about every rotor I've ever seen. Could be because of structure, or just how they fit between the drill holes... Hell without holes, It might not matter at all... Just food for thought I guess.

[paso100]

You're going to do this by hand? I don't think that'll be such a good idea. If you don't use a jig and micrometer, how are you going to be sure you're rotors are balanced? How are you going to make sure you take out precisely the same amount and spacing, etc. Your gonna take a chance on something like brakes??? I'd be worried about overheating, warping, and ultimate rotor failure. Imagine this happening at 80 mph down the highway w/ traffic coming at you. Hmmm. If you do it, good luck.

[Pico]

If you can wait I can check on Monday at work and see how I can get them for your VW, and you can even pick them up at my orange co. warehouse

[Ichiban]

Do you have access to a dividing head or a rotary table? I've heard of people using a dividing head set up on a vertical milling machine with a ball end mill to machine in the spiral slots, although I don't believe they went through on the slots, just a 2-3mm relief. For drilling the holes, I would use the dividing head, and probably countersink the holes slightly to relieve any stress. I'm unsure of any heat treatment you could do to facilitate machining/toughness of the material.

[MessyHonda]

you got to make sure you take out enought material on both sides and still keep it balanced....i paid 160 for the front rotors....dimped and sloted with zinc coating so they wont rust.

[Oldblueaccord]

I have slotted mine myself for years. I used to use a rotab and mill but now I just bolt them straight to the table. I laid out a brake pad and decided that two slots should always touch the pad and went from there. I think I came out with 7 slots. I just cut down to the minimiun thickness of the rotor although Power slots are much deeper then that I have learned.

For the record I cut my slots going foward (to the front of the car ) I think it works better. But in all honsety I copied a picture from SCC years ago and they must have had the negative flipped so i really cut my first set opposite of how they sell them


wp

[88accordalltheway]

I do have access to a rotary table and all the tools i will ever need...like i said, the actual drilling part im not concerned with.

as for the heat treating, no i dont have access to it, but i will definitely look into it. I might be my only solution to the prevention of cracking/warping...

messy, my rotors are going to cost a little more than 160...no matter where i go... haha...god bless the inventor of the high price for German car parts!

yea see i know i could come up with a pattern by myself, but i really want to see if theres a "best" pattern. Obviously this can lead to a great argument over drilled vs slotted vs drilled & slotted vs...blah blah blah... which will lead to nothing more than a thread with a bunch of funny cat pictures...

taking it down to the minimum thickness sounds like a good idea on the rotor, but still im kinda skeptical cause of warping.

Another thing that concerns me is that if i do do this, can the rotor handle the rapid change in temp(if i decide to drive it really hard, or even absolutely need to in an emergency)? Thats why im concerned with which one i decide to go with. I mean, if i buy some good rotors, i don't know if they can handle the drilling, or are even meant to be drilled on(probably not). If i do get rotors that are meant to be drilled on, they would probably cost me just as much as the ones that are already drilled.

to be totally honest, im doing this mostly for looks( i hate to say it) and the fact that i can say that i did my own rotors. Im not planning on driving my car like a maniac.

these brakes are a lot bigger than the ones on the accords so im sorry if this is making some of you think too hard...i just dont think id get the kind of help on the vwvortex forum as i would here.

[Oldblueaccord]

unLess the drilled holes is cast in I have trouble with it myself. As far as the slots not warping I say mine did. It was the reason I went with slots in the first place back when I had 10.3" brakes. The only way I can keep my fronts from not warping is I went to 11.1" fronts ...so far.

As far as rehardning I dont think I'd worry about it since the rotor's wear surface might be affectted. You could have them cyro treated that seems to be popular option now days.

Ill see if i can find some pictures of mine. I currently do not have slots on this set on my car. I think I have done amybe 6-8 sets of slots without problems.I have had my car since the mid 90's and did my first set in I think 98.

The biggest and really only benefit of slots that I can confirm is that you have great brakes in the rain on first application.


wp