Driling My Discs

[mason79]

I went to the mods page and the pdf and pictures won't load,help

can i drill without chamfering the holes and if i have to chamfer, what size do i chamfer it with and is it just to knock any burrs off?

what is the recommended size of the holes max size?

what are the benefits of drilling other that it looks bi-oching

if i do it i promise to upload some pictures

[papanovember]

Drilling the rotors will aid in cooling and help disperse water. I put the later slotted rotors on my 79F. Good luck!

[planedick]

Hard

You will find that the rotors are VERY hard and even using carbide drills you will have to have lots of them. The steel is nearly as hard as a carbide drill. Best way is to take them to a machine shop where they have a sinker type EDM. It will cost less and get much better results.

[rover]

I drilled mine with a HHS cobalt drill, not the nitride coated one, and I only had to sharpen after each disk. I used the pattern I found on this site. You need a drill press, preferably with auto feed, run a slow speed, and use thread cutting compound. I am thinking I could have drilled all three disks without sharpening, but I played safe. Stopped all the squealing probs I had on both ends. Oh, drill size 1/4" and I used a countersink to deburr. You could use a 5/16 to deburr, but watch for chatter. Only necessary to remove the burr

[xswilly]

I drilled this using 4 different size drills
and only 1 of each

trick is to use a drill press and use oil on the drill

[mason79]

Originally posted by xswilly
I drilled this using 4 different size drills
and only 1 of each

trick is to use a drill press and use oil on the drill

nice, heck i think i'm having an lsd flashback looking at those...

i want to do 12 columns will that weaken the disc too much?

and can anyone email me that pdf, the page's links are all dead as far a s the pictures and files, help!!

[Ken Talbot]

Mason, try the pdf template files on this link I just checked it out and did not have any trouble.

As you scan the article, you'll see I had no trouble drilling the rotors with plain, garden-variety cheap drill bits. Mind you, I did use a fairly decent sharpener to change the bits to a better split point, and ket the bits sharp. The the rotor material is not difficult to drill if you use a low feed speed, cutting fluid, and a freshly sharpened split-point drill bit.

[mason79]

Originally posted by rover
I drilled mine with a HHS cobalt drill, not the nitride coated one, and I only had to sharpen after each disk. I used the pattern I found on this site. You need a drill press, preferably with auto feed, run a slow speed, and use thread cutting compound. I am thinking I could have drilled all three disks without sharpening, but I played safe. Stopped all the squealing probs I had on both ends. Oh, drill size 1/4" and I used a countersink to deburr. You could use a 5/16 to deburr, but watch for chatter. Only necessary to remove the burr

does the 5/16 counter sink bit need to be hhs cobalt as well?

[mason79]

Originally posted by Ken Talbot
Mason, try the pdf template files on this link I just checked it out and did not have any trouble.

As you scan the article, you'll see I had no trouble drilling the rotors with plain, garden-variety cheap drill bits. Mind you, I did use a faialy decent sharpener to change the bits to a better split point, and ket the bits sharp. The the rotor material is not difficult to drill if you use a low feed speed, cutting fluid, and a freshly sharpened split-point drill bit.

yes ken , can i buy a cheap drill press, i see them going on ebay for 19.99, crazy man, or harbor freight, when i'm done it's done, right?

split point you mean angle? duh...

[planedick]

Split point

Split point is a type of drill sharpening that is 135 degree angle and an offset point that helps keep the drill from wandering when you start and is a little more aggressive in cutting and feed rate. I would be real interested in hearing how this went when you get done.

[mason79]

Re: Split point

Originally posted by planedick
Split point is a type of drill sharpening that is 135 degree angle and an offset point that helps keep the drill from wandering when you start and is a little more aggressive in cutting and feed rate. I would be real interested in hearing how this went when you get done.

i'm coming over to use your drill press dude...

and no complaining

[pggg]

Don't do what I did and 'burn' the disc with impatience coz the drill holes turn as hard as hell and get harder and harder with each attempt.

[mason79]

thanks everyone again roger wilco over... roger wilco over

[Ken Talbot]

Originally posted by mason79


yes ken , can i buy a cheap drill press, i see them going on ebay for 19.99, crazy man, or harbor freight, when i'm done it's done, right?

The drillpress I used for my rotors cost me a bit more than 19.99, but is still just one of the no-name brand, cheapo types that you can buy all over the place. I've been using it for years without any trouble. It's biggest drawback is the lack of the really slow speeds that you would want for large holes in steel, but it's slowest speed worked just great for the 1/4" diameter holes I put on my rotors. The counter-sink I used was also a garden-variety HSS unit.

pggg is right on when he advised not to get impatient and trying to drill too fast with too much pressure. With just the right feed speed, you get beautiful, long curly spirals all the way through each hole, and it feels like you're cutting through butter.

[TADracer]

When I drilled my rotors I used a simple bench top drill press I had from Home Depot for $99.00. The bit, lubrication and patience is the key.

I have two size holes, 1/4" and 5/16". I used Norseman cobalt bits. Bits you get at places like Home Depot or a hardware store will usually not last. You have to get professional bits from tool dealers. I bought three of each for the job (one for each rotor) but did all the work with one bit. The very best way to make the hole is to use steady pressure, low RPM (600-800) and constant oiling while the bit is cutting. It is a mess but oiling the bit constantly makes it cut through like butter. If your bit is cutting correctly you should be getting long spirals of metal. Then I used a 5/8" bit to slightly chamfer each hole. Then clean up very well with brake parts cleaner.

The 'hole' deal only took a few hours to do.