Drilling rotors

[kvanderploeg]

I finally got around to drilling my rear rotor. I drilled the front one about 5 days before my son was born, so things have been on the back burner. For the rear rotor, I used a progressive drill patter. The holes get smaller as you move from the inside edge to the outside edge of the rotor. Nothing terribly complicated here, but I thought some guys might like to see just how easy it is.

It does help to box up around your drill press with some cardboard to keep the metal chips from flying all over. I drill smaller pilot holes first, then come back to enlarge them. As with drilling any metal, slow on the drill press and plenty of lube.

Kent

 

[leggers]

Thanks for posting this. I've been thinking about drilling my rotors too, but I'm unsure if my old press can handle it. Did you use any special bits for this? How or where did you create/get your pattern?

Thanks for sharing

 

[racerdave]

Ploeg, I like that clamp. Did you make that, or store bought?

 

[kvanderploeg]

I got my original template from "thelowlife" came from this thread:

http://www.xs650.com/forum/showthread.php?t=12671

I just resized his original template to 90% for the rear rotor, but I did as him if he could make an official template for the rear as well. He has a rear drum, so he didn't originally create one. I didn't use any special bits. Just a good set of Craftsman black oxide bits. I will add that this drill press certainly isn't great, and was a $60 garage sale special, according to my buddy that is letting me borrow it. Unfortunately, it's only a 5 speed, and 700 RPM is as slow as it goes.

Kent

 

[kvanderploeg]

The drill press is actually borrowed from a buddy of mine. He has no real garage to use, so I get use of his press. That said, he had the clamp with it, but I think it's just a Harbor Freight special. Works quite well!

http://www.harborfreight.com/9-inch-drill-press-locking-clamp-36221.html

Kent

 

[3Deuces]

Are you going back and chamfering the holes after you drill?

 

[kvanderploeg]

Are you going back and chamfering the holes after you drill?

I didn't on the front. I've found a few rotations of the wheel with light pressure on the brake pads seem to do the trick.

Kent

 

[3Deuces]

Cool, that saves 90 operations!

 

[kvanderploeg]

Cool, that saves 90 operations!

Per rotor!

Kent

 

[gggGary]

Vice grip makes a clamp like that. It has a stud and eye nut on the bottom so it's easy to move around in the table slots, Mine is always on the drill press.
IIRC the recommendation is don't chamfer rotor holes.

 

[kvanderploeg]

IIRC the recommendation is don't chamfer rotor holes.

I thought I had heard or read that somewhere before, but I couldn't remember the reasoning.

Kent

 

[3Deuces]

Hmm, seems like a chamfer would reduce the chance
of the rotor cracking between the holes.

 

[gggGary]

Quick guess is you want to scrape off any crud as it goes by the hole, not wedge it between the rotor and pad.

 

[kvanderploeg]

Quick guess is you want to scrape off any crud as it goes by the hole, not wedge it between the rotor and pad.

That's a good enough theory for me.

Kent

 

[3Deuces]

Good point. I just went and looked at the rear rotor on my dirty bike and there's no chamfer. It does have 40 hrs and on it's second set of rear pads, though.

 

[racerdave]

Ploeg, what do you mean you resized it to 90%?

 

[kvanderploeg]

At the time, I didn't have a pattern for the rear rotor, so I downsized the front pattern to 90% to make it work. Since then, "thelowlife" posted a proper pattern for the rear rotor. I haven't actually used it, but his front pattern worked great.

http://www.xs650.com/forum/showpost.php?p=174457&postcount=24

Kent

 

[jchrisk1]

I tried that with the five hole pattern and couldn't get it below 91%(I don't know how to use these things very well) unless it was a lot less than that. Which made it too big for the rotor. I couldn't get it lined up properly on the rotor. I wish he would have made a new one for the five hole.

 

[racerdave]

Kent, I guess I'm just dumb, but I don't understand how you downsized the front pattern to 90%? Anyway the 5 hole sweeping style like on your rotor is what I want, only with all holes the same size, like your small hole. 3/16 I think. Want a side job? Or maybe send me your resized template pattern? I'm in joliet.

 

[kvanderploeg]

I just downsized it from the printer properties before hitting the print button. Do you need both front and rear rotors done? What are you up to today?

Kent