Drilling Your Own Brake Rotors

[eagleeye]

These are the discs that I drilled last Sat. from my 80xs.
I used a template my friend made for me with his CAD program. 72 holes per disc, 5/16" holes and ever so slightly debured. Lots of oil and 540 rpm. Center drilled first, sharpened once before starting.

Steve

[Göran Persson]

Hello Eagleeye,

Did you drill your holes offset or in 4 straight rows?
5/16 Holes = 8mm. 4 rows with 8mm holes = 32mm.
The Brake Surface Area on the XS650 is about 40mm.

I believe that to sweep the entire brake pad
you need 5 rows if drilled with 8mm.

Best Regards
Göran Persson
New Zealand

[eagleeye]

Offset, slightly overlapping.
Thanks for asking,

Steve

[Machi]

All you cad experts out there - Would you like to design me a pattern for the rear disc rotor of my 80 SG?
I have one of those alloy rotors from Mikes on the front and I need a template to match it, only for a 10.5 inch rear rotor.
The measurements on the picture (cm) are for scale. The holes are 0.6 cm. PM me if you are willing.
Thanks!

[Göran Persson]

Machi,

I have sent you a PM with my email address.
Contact me.

Best Regards
Göran Persson
New Zealand

[tomterrific]

The last set of disks I drilled was for my autocross car. I bought a drill press because the money for new drilled rotors was the same as the drill press on sale. I carefully drew out the disk on paper and practiced the hole pattern. When I finally got the pattern perfect I was able to cut the paper and glue it to the disk surface and center punch the holes.

Now this is where I discovered something interesting. While setting up the disk I used the drill bit on the edge of the disk to perfectly center it on the press table. What I discovered is the press table rotates on a large pin with a pinch bolt securing it in position. By cleaning and lubing the pin I was able to set the pinch bolt snug but still was able to turn the table. This turned the table with the disk centered and secured into a rotary table. By spining the table I was able to drill holes percisely on a circle from the center.

My next disk will be drilled not with a pattern on the disk itself but to indexes around the outside edge of the rotating table. The table can be loosened bumped to the next circle of holes and the pattern continued. Planning will still be the most important step in this experiment.

Tom Graham

[Göran Persson]

Hello All,

I have posted Drill Patterns for the Front and Rear Discs on:
smg.photobucket.com/albums/v463/GoranXS650/
Go To: Brake Disc Drill Pattern.

I have posted the "Classic" 90 of 8mm Holes and
a number of Universal Patterns.
Print Out and make your own pattern by selecting holes.

Contact me via email if you want a print out on A3 Plastic Film.
(I will have to charge for the A3 Plastic Film and Mail Costs).

Best Regards
Göran Persson
New Zealand

[Machi]

Those sound like good tips, Tom. A friend has a basic machine shop and sometime this winter I hope to learn how to operate the drill press. Haven't seen it yet so I don't know if it will allow rotating the disc as I drill.
I sent Goran a pm - before I checked out his universal patterns. Seems like I would have to use two of those to get the pattern I want. (?)

[eric123]

goran said:

Hello All,

I have posted Drill Patterns for the Front and Rear Discs on:
smg.photobucket.com/albums/v463/GoranXS650/
Go To: Brake Disc Drill Pattern.

I have posted the "Classic" 90 of 8mm Holes and
a number of Universal Patterns.
Print Out and make your own pattern by selecting holes.

Contact me via email if you want a print out on A3 Plastic Film.
(I will have to charge for the A3 Plastic Film and Mail Costs).

Best Regards
Göran Persson
New Zealand

You sent me a template years ago...It worked great...Just wanted to say thanks again. eric

[xcbullet]

Larrybart
I would like to do this on a CNC at work .I was wondering if you had the numbers for X & Y cordenates for that first swirled pattern all I would need is the first 4 holes in that pattern then I can rotate to get the rest.This would be a easy on this machine as I am familar with the speeds & feeds,but most of all it would be dead tru

[xsleo]

i just shopped on ebay until a set of slotted rotors came up and my bid won. now i have two slotted front rotors an a slotted rear rotor. i whole lot less work than drilling your rotors and i think they look better. i know they work great.

[xcbullet]

I have the X Y coordinates now for this drill pattern,its almost the same as larrybart's but with a 5 hole swirl repeat 6 times I used a .335In. drill its actaully 8.5 mm.
If somebody wants them I will get them from work they are in the pc & have to be put on mill to read them.

[LarryBart]

kcbullet

---

Sorry I missed your first posting June 7,2008. I too bought a drill press to do my own front disk. Needed one anyway for other shopwork. That benign said One of our members BigharryRalph came through with Two sets Swirl cut one for my sons 1981Special duel set front,. In addition he also came up with a Rear swingarm and disk setup my son will put on his bike. Great to deal with, good prices, anything you are ready to buy as far as parts go he may vary well have it. Just pm him with your request he has helped many more members than me. Must have gone through a crapload of 650's.

Regards Larry Bart

[petesponies]

I drilled these . . .