Simple method of redrilling discs

[takai]

On the AE86 and MA61 ive commonly had to redrill discs from one stud pattern to another, which commonly can be a lot of mucking around with drill presses and dividing heads. But here is a simpler way to do it.
Firstly machine down a chunk of metal (2011 in my case) to the outside diameter of the new disc, and then the old disc, in my case 72 and 60mm respectively:


Should look something like that

Then stack the discs ontop with each one being a tight fit with the location ring as so:



Finally, after lining up two of the holes (and using something to dowel them, not pictured here) use a transfer punch of the correct size to mark the disc below:


Then all you have to do is drill at the markings. Truely a piece of piss.

[oldcorollas]

thats rather backyardingly awesome

[Duk]

Firstly machine down a chunk of metal (2011 in my case) to the outside diameter of the new disc, and then the old disc, in my case 72 and 60mm respectively:

And you have access to this size and amount of material how often, where from and at what price?

Oh, that and, nice job

[takai]

Cost under a tenner from Capral. offcuts ftw.

However as a bonus you normally need to machine up locator rings for these things, so you can reuse the plug as the basis for the locator rings after you are done.

[allencr]

Backyard.
Couldn't you use some of those 'hub-centric ring' things that people are always writing about?
Braze, solder or glue them together.
******************************************
Also, drill a pilot hole first, starting with something about 1/4 the final size & don't try to drill it in one shot with a large bit.
A drill press is just about a necessity for a clean & straight hole
A center punch with tape wrapped around it will work OK for finding the centers.

[takai]

Yup, that is the other option, and a pretty good one if you dont have a lathe.
In my case ill simply machine off the 60mm nub at the front and then machine up a spacer ring for the disc onto the hub

[YLD-16L]

Yup, that is the other option, and a pretty good one if you dont have a lathe.

You can also use your hub as a template by removing the studs (if mounting disc over hub).

Thats what I did as I was replacing the studs anyway so they had to come out.

Of course the disc still needs to be hub centric to get a good result.

[takai]

Yeah, thats the problem for me, my discs arnt hubcentric currently, i had to machine down the alu to make a locating ring anyway, so figured i would do that.

You do make a good point, youll need a locating ring in the end if you have non-located discs, so you may as well put that on the hub first then use the hub as a template. Just leave one stud in to locate it.

[neal]

Can any one explain the drilling process? My conflict as such is will you be introducing a weak point by doing a back yard drilling.

[gixer]

cool, will definately use this in the future.

[takai]

Weak point sure, but the actual forces are being dissipated through frictional force of the surface of the disc against the surface of the hub and the wheel, there should be no impacts between the disc holes and the wheel studs.

[oldcorollas]

in addition that, for it to really be a problem, you would have to be in fear of the standard holes in the disc being flogged/chewed out by the forces on the disc from the brakes.. and usually, it is not a problem.

[neal]

Thanks for clearing that up.
Another quick question. Is it important to drill at low speeds mainly to not heat the disk?

[Hen]

^^ No. Drill as you normally would at the proper speed (which of course can be quite slow with a 12mm drill)

I've done a few sets of discs by an even simpler method using a set of verniers and some maths. Then measuring from the existing stud holes and centre bore before marking with a punch. Once I had to file a hole slightly to fit, but if you take your time it is accurate.

Hen

[andrew_mx83]

u should be using a cutting lube for big diameter holes like that anyway unless u want to be buying a new drill bit for each disc. and yes cutting slow for big holes is always a good idea


offcuts are awesome for stuff like this