Author Topic: rotor drill patterns (Read 22939 times)

goon 1492 · « **on:** January 17, 2009, 10:36:41 AM »

I have done several fo these now for 750's, 500/550's, now low and behold 400's too. I wanted to share them with all the fellow members here and your on you own on these I claim no responsability for you actions, I have a hard enough time with myself....

goon 1492 · « **Reply #1 on:** January 17, 2009, 10:39:45 AM »

I only have one spiral pattern for the 500 right now but I will add more when I can.

goon 1492 · « **Reply #2 on:** January 17, 2009, 10:41:33 AM »

and last but not least here is the 400 pattern, thank loopsandlogic for the sizes on this one. I couldn' have completed it with out him

goon 1492 · « **Reply #3 on:** January 17, 2009, 10:43:03 AM »

the fast spiral pattern I described is like the ones I have done here is a pic.

goon 1492 · « **Reply #4 on:** January 17, 2009, 11:01:24 AM »

Your welcome.

for all those in lurk mode.....

LoopsAndLogic · « **Reply #5 on:** January 17, 2009, 01:41:00 PM »

We will no by tonight if the 400F measurements are tight!!!

Yipeeee, I'm the first to thank you.....I am so honored....I'd like to thank my parents and the....

Cheers

LL

billybobobrain · « **Reply #6 on:** January 17, 2009, 01:51:25 PM »

Just downloaded the fast spiral for the 750, MANY THANKS!

GammaFlat · « **Reply #7 on:** January 17, 2009, 03:25:24 PM »

Is this too many holes? The patterns you have are really awesome looking. This one certainly isn't aesthetic but is it functionally ok?

Bouncer · « **Reply #8 on:** January 17, 2009, 03:42:58 PM »

Truly appreciated goon.

One question:

How do you go about printing if you have a normal home printer? Any tips? Also what do you print these on to stick on the rotors, I assume there is some sort of special sticky paper?

Sorry that was actually 3 questions.....

mbrown67 · « **Reply #9 on:** January 17, 2009, 04:25:06 PM »

Goon, thanks for the posts! Any tips on how you have drilled the holes? Are you using a tabletop drill press?

- Matt

LoopsAndLogic · « **Reply #10 on:** January 18, 2009, 01:24:18 PM »

Simply open up the attatchments in Adobe, and split the image in half, then print the 1 half twice.

Now you have an exact copy that is perfectly even.

I would use some rubber cement to hold the paper down like they would use in pre-school.....

Hope this helps....I just found out my drill press is toast!!!

The shank is bent

How in the hack did that happen

Cheers

LL

HondaMan · « **Reply #11 on:** January 18, 2009, 01:45:41 PM »

Quote from: GammaFlat on January 17, 2009, 03:25:24 PM

Is this too many holes? The patterns you have are really awesome looking. This one certainly isn't aesthetic but is it functionally ok?

Functionally speaking, it's OK, it just has less swept area. It will stop better than a stock disc in the wet, though. It looks like one that someone wanted to reduce the weight, like maybe a drag bike or someone who just doesn't ride at severely. Be sure to bevel the edges of the brake pucks when installing new ones, to prevent chunking of the new pads while they burnish in.

While I can't tell to well from this picture: are the holes countersunk? They should be, at least 1mm in on both sides. This can be done with a good, hard (i.e., US made) multi-flute countersink.

And, it won't squeak, ever!

goon 1492 · « **Reply #12 on:** January 19, 2009, 09:34:45 AM »

LL that sucks the shank is bent.
When I did mine I made a 1mm plastic template on the machine I run and used double faced(sided) tape to stick it onto the rotor.
I then used a center punch, I have a nice spring loaded one I use.
I went onto using a .125" (1/8") drill bit to make pilot holes in all the center punched holes.
I then went onto setup three and drilled out the holes to .188" , I used this size primairly for the venting properties more than the weight reduction.
Last but not least I used a multiflute 45 deg. bevel bit to chamfer the holes so I wouldn't play cheese grater with my pads everytime I hit the brakes.
below is a pic of the bits I used. Good grade cobalt bits are the best but I had good luck with the titanium coated bits, about 3-5 bucks a bit. I had to resharpen them all once, except for the bevel bit.

I would say go slow with the down pressure with slow rpm's or you will smoke your drill bit, I have a trick that Terry in Australia said and that was to use some cheap dishwashing detergent and it will work great for cutting oil. I haven't tried this yet and still have to drill my second rotor if I can get the time this week.
Hondamans tip about beveling the pucks sounds like a good tip too and I will have to try that.

Bodi · « **Reply #13 on:** January 19, 2009, 07:38:41 PM »

I disagree on the countersinking. I want a sharp edge on the holes to slice water off the disc surface, some race mechanic years ago told me not to countersink. I remove any burrs or raised edges on the holes using a fine flat India oilstone, doing a circular motion over the disc surface using light oil as lubrication. I can really feel when the burrs are gone, they are very obviously being ground down if present during this "lapping". Final result is very sharp edges on the holes. This does not seem to wear the pads more than normal. The stoned surface looks really nice at first as well, but gets polished smooth fairly quickly with spirited braking.

goon 1492 · « **Reply #14 on:** January 20, 2009, 09:46:00 AM »

Quote from: Bodi on January 19, 2009, 07:38:41 PM

I disagree on the countersinking. I want a sharp edge on the holes to slice water off the disc surface, some race mechanic years ago told me not to countersink. I remove any burrs or raised edges on the holes using a fine flat India oilstone, doing a circular motion over the disc surface using light oil as lubrication. I can really feel when the burrs are gone, they are very obviously being ground down if present during this "lapping". Final result is very sharp edges on the holes. This does not seem to wear the pads more than normal. The stoned surface looks really nice at first as well, but gets polished smooth fairly quickly with spirited braking.

That sounds good bro but alot more work than most shade tree mechanics are willing to do. It takes some skill to pull this off too without takeing all day anyhoo. Good point though

Flashman1965 · « **Reply #15 on:** January 20, 2009, 10:09:43 AM »

Here is a pattern that I used on my 75 CB550Four.

I printed the pattern out on 11x17 paper and then cut it out and taped it to my rotor. I used a caliper to check the distance from the outer edge of the rotor to the first ring in the pattern to ensure that I got the pattern centered on the rotor.

Next I used a center punch to mark all of the intersecting lines on the pattern.

After that I used a centering drill bit to drill my initial holes in the rotor. The centering bit puts about a 1mm hole in the rotor and finds the center punched marks without wandering. It also cuts a chamfer into the rotor so that when you drill the hole out with the desired drill bit it centers right up to your mark and drills exactly where you want each of the holes drilled.

After drilling all the holes I used a chamfering bit to deburr and chamfer each of the holes on the front and back of each hole about 1mm.

I used 7/32 drill bit for all the holes except for every second hole on the outer ring and they were drilled with a 9/32 bit.

Flashman1965 · « **Reply #16 on:** January 20, 2009, 10:19:14 AM »

The pattern in the previous post was drilled on the right side rotor of my CB550. I attached the pattern to the back side of the rotor and drilled the holes from the back surface through the front surface. This allowed me to have the rotor flat on the table of my drill press.

I am converting my 550 to a Dual disc setup and now I will bolt the left rotor to this rotor with the outside surface facing each other and drill the holes through the holes in my right rotor and then through my left side rotor. This will ensure that my patterns match identically on both rotors.

If you use the pattern from the previous post make sure that you have the spirals going in the direction you want by either attaching the pattern to the front or back of the rotor and drilling your holes from the front or back side depending on what fork leg your brake is mounted on.

cben750f0 · « **Reply #17 on:** January 20, 2009, 12:17:56 PM »

i have an autocad drawing of my set up, its taken from a cbr disc pattern, 2/3 swirl look.

let me know if you want me to post or mail it to you

peace

tygrant · « **Reply #18 on:** January 20, 2009, 12:23:54 PM »

I used goons template on my 550 rotor with fantastic results. at the 600 rpm setting I used the same bit for the whole project. i used the drill doctor one time to sharpen it up, I have the smallest drill press sold at sears and it worked wonerfully. just two drops of 3in1 oil for each hole. couldnt be more happy. thanks again goon!

goon 1492 · « **Reply #19 on:** January 20, 2009, 01:18:45 PM »

Thats pretty cool fella's just remember if you do the dual setup make sure you line up the rotors together with the spokes of the rotor so it all lines up upon assembly.

LoopsAndLogic · « **Reply #20 on:** January 20, 2009, 04:37:38 PM »

I'm actually having some trouble centering my pattern on the 400f rotor.....

Measurements that I gave you Goon are spot on, but I'm trying to find the most accurate way of
making sure this pattern is centered....

Someone told me it could throw your tire out of balance, but how??

The rotor is pretty close to the hub...I'd say yeah, it could throw it out of balance if the extra weight on
one side was closer to the outside of the tire....I'm I right??

This is a good topic to talk about

LL

tygrant · « **Reply #21 on:** January 20, 2009, 07:25:30 PM »

i dont know what you mean by centering it? as long as the patern is even and the template fits the disc corectly you dont need to start the patern here or there, it doesnt matter. when i used goons template i used scissors and cut the center of it out very carefully then once it fits over the hub of the disc snugggly your good to go... hope that helps

goon 1492 · « **Reply #22 on:** January 21, 2009, 06:41:13 AM »

It shouldn't matter that much with it being that close to center like you stated, I noticed when I started my second disc that the diameter of the rotor itself was about .04 smaller than the first one. I just centered it on the rotor surface and went with it. If you are worried about balance make sure they(the discs') are all bolted up to the wheel when you get it balanced, or plan on getting it balanced after the rotors are both reassembled at least. I stated something similar a few pages ago because i thought too I wonder how much it will throw it off when I cut the notches in my front wheel, mine is off a k8 wheel and it doesn't have those notches in it for the speedo drive plate mod.
The patterns should be even and mirrored, when I drew them up I flipped a copied version of it ontop of the original and it all was symmetrical.

Soos · « **Reply #23 on:** January 21, 2009, 07:12:10 AM »

Quote from: GammaFlat on January 17, 2009, 03:25:24 PM

Is this too many holes? The patterns you have are really awesome looking. This one certainly isn't aesthetic but is it functionally ok?

Kinda how mine is, function, but visually almost too busy.

That is the same pattern I have on the dual disks on my '79cb650.
Pictured there is the '80 cb650 I sold last year to a good friend.

The second picture had lines drawn to help "visualize" how the pattern is supposed to look.

l8r

LoopsAndLogic · « **Reply #24 on:** January 21, 2009, 09:47:26 AM »

I see!!!

Thanks guys...I guess my scissor skills need improving....he he he he

*Darn you 1st grade!!!!*

Cheers

LL

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Author Topic: rotor drill patterns (Read 22939 times)

billybobobrain

mbrown67

Flashman1965

Flashman1965