Drilled Rotors- 1st attempt.

Finally got around to drilling a couple thick 7mm  KZ900-KZ1000 front rotors. Pain in the butt. Plus I separated the aluminum carriers. That was the hardest. 1 rotor was all corroded at the pressed rivets. But cleaned the carriers up, de-burred the casting marks, glass beaded them. drilled the 9 holes to 1/4" I am going to surface grind the discs to smooth out and make sure they are flat. One of our machinist guys who does flywheels and engine blocks for the race car, gonna do it for $40 a piece. $80 for all 4 sides. But 108  5/16" holes. takes awhile. Gave me lots of time to use my Dad's old Craftsman Drill press. It looked old when I was 5-6 yrs. old.
I love that old thing, you can not buy that quality today, no matter how much you spend. Very sentimental, lost my Dad in 1972. I always think of him when I use his tools to this day.
But they look good, Simple design. I paint the button heads black, stainless ny-loks and flat washers. Took 8 new bits, and a spray bottle of ice water,

Nice job but with the rotors off their carriers you could have saved a lot of time by bolting them together and drilling them both at the same time with only 54 holes and got exact mirror images in with the deal too.
I use cobalt drills for that with a bit of cutting oil.
You just have to go easy when the bit breaks through the first disc as it can sometimes snag the bit if you go too quick but you only make that mistake once.

I had 3 rotors for my Z1-R surface ground by Tom at True Disk ( truedisk.net/ ).  He did all 3 for $135.   This was in 2015, so it may have gone up.  If your machinist doesn't come thru, I would highly recommend giving Tom a try.  The turn around was quick and the quality was 1st rate.  

MDZ1rider wrote: I had 3 rotors for my Z1-R surface ground by Tom at True Disk ( truedisk.net/ ).  He did all 3 for $135.   This was in 2015, so it may have gone up.  If your machinist doesn't come thru, I would highly recommend giving Tom a try.  The turn around was quick and the quality was 1st rate.  

Truedisk's  website still says  $45.00 Dollars per rotor to resurface and a additional  $45.00 Dollars per rotor to drill  if  desired.
     Met him at a Bike show . Nice guy
           Dave

Hey Zed, was a learning experience! I was just playing around. I did not plan it through? I did not reverse the opposite side
direction. I was going to grind them down to the 5mm / 4.5mm and have a dual disc set. But it would look goofy to me the rotation pattern.
So now I am going to just clean the surface on both sides just to true and smooth them.
I'll probably sell them as a single disc on ebay in the future.
I have a set of Z1R's on my dust collector project. Which I countersunk the 4 bolt holes in order to use flat head machine screws