Rear five lug hubs, machining steps. Options

[Aaron Cox]

i have just discovered that my uncle has had a machine shop in his warehouse for many a year. i thinl im going to let drill my hubs and stud them. (save me some $$$) my uncle is a mini cooper guy, and has been making stainless brake pistons for aftermarket calipers i guess lately.

so what do i need to have him do?

to go from 4 x 130 to 5 x 130
spotface the area where the stud goes. do i need to have him put a boss on it? (eric shea? i believe did this)

give me a rundown on what is required please.

[davep]

You have the basics correct. Many people start with a very early hub that has the both sets of bosses cast in. It would likely be useful to have bosses made where the studs will go, but I don't know the risks involved with building up the cast iron. Get the studs before you start to ensure you know the exact size hole to drill.

[skline]

Aaron, if you need an extra set to play with let me know as I just replaced mine on the Chalon and these are just sitting here doing nothing. You can take them and practice with them.

[Aaron Cox]

skline, pm sent.

ill take them.

[Eric_Shea]

Simple way. Yes, 5x130. Spot face everything down to 5mm thickness. Stud them and go. You will use one of your existing bosses. You'll need to spot face it an additional 5mm (I believe) to bring it down to the level of the other faces. because they use lug bolts 914 hubs are slightly thicker than 911 hubs.

By facing down to 5mm the outside edge of the seat just cuts into the flange. When I did mine I used a set of 911 hubs as reference since the studs most people use are for 911's. I spot faced my original boss slightly down to 8mm and used 3mm ring bosses/spacers to bring the remaining 4 holes in the hub back to the 8mm 911 spec.

WTFA for most folk including myself. Just spot everything down to 5mm and stud'em.

[Aaron Cox]

okay, my school has a bazillion dollar mill that i can use for this project. the thing accepts "mastercam" files. otherwise id have to do it all by hand (dila gauge, etc etc)

can anyone draw up a 5 x 130 rear hub file for me? i dunno how to do that, is "mastercam" a widely used file type? the mill accepts these on a floppy disk.

also, does anyone have a diagram of the rear hub (blueprint)

thanks.

mucho appreciated. if this can get done, i can run a couple of sets of hubs for basically free.

does autocad turn things into mastercam?

[peridotian]

Autocad can export files in various formats. You need to find out what format Mastercam wants. I suspect DXF format will be fine.