Centering A Vw Hub To Drill Lug Bolt Holes

[hotrats]

Complete newbie here.
Project is adapting VW axles to a old Lotus Europa. The hubs need to be turned down to a smaller diameter, the center part of the hub turned down a bit so to fit thru the wheel center opening. and new lug holes drilled.
Questions are:
1 - Would it be better to locktite some threaded rod into the holes for the VW lugs before turning down the diameter, just leave open? Suggestions other than that?
2- What/Where to zero off of for centering? Splines for the axle?
Photo is of hubs. I ended up with a free set, so, the 1st one is sacrificial.
Thanks in advance
Andyh

 

[Bob Korves]

1. Just leave them open if you have no further need for them.
2. Indicate on the O.D. of the flange to center the work in the lathe.

3. Remember that you are the engineer, designer, quality control, and quality assurance as well as the machinist. Don't do anything that you are not completely comfortable with while wearing any of those hats, even if they do not quite fit your head. Lives may be at stake...

 

[Tony Wells]

It would be good if we knew a little about your shop in terms of what kind of equipment you have to work with. Any chance you can get your hands on a splined portion of axle that fits the hubs properly? That is, one that you could cut off short enough to be used as a tooling aid. It would be a great help for what you describe needing to do, provided I understand correctly.

 

[hotrats]

Thanks for the replies.
I used a cut off piece of axle in the chuck to hold the hub, tightened the axle nut to force hub against chuck. Didn't know which spot would be better to zero off of - the outside of the hub flange, or the spline portion.
as far as equipment, lathe is a old Taiwan 9x24, Winchester branded, I think. Mill is a PM 940 w/ dro.
This is a sacrificial parts/learning test for me, I have a experienced machinist to carry the parts to if I get stuck.
I'm always a bit apprehensive when doing something I've not done before. This drive train modification is not a complete unknown -
it has been done before.
I just wanted to try it myself, since I've bought the equipment, and basically got the parts for free. (And I need to be able to show the wife it was a worthwhile expenditure buying a mill and lathe, lol)

 

[Billh50]

I would indicate the axle splines in the chuck. Mount the hub to the axle and indicate the face to make sure it is square with the axle. It should now be running the same as it would be on the vehicle. Turn the center to fit the wheel and the diameter to size needed. Now when you put it on the mill you can indicate the center or the outside diameter as they were turned together.

I do have one question though. Is there a shoulder on the axle for the hub to stop against? I only ask as you mention tightening against the chuck. There is no chuck on the vehicle and the hub should tighten to the axle.

 

[hotrats]

Thanks for the reply.
Yes, there is a shoulder. I cut the CV joint flange off the axle to be able to use it in the chuck. I tightened the hub to the axle, ran a live center tight against the axle.

 

[Billh50]

well if you indicate the axle true it will be running the same as if it was on the vehicle. Then just make sure the face it square by indicating that. You should then be ready to do your turning. Once turned just lay it flat on the milling machine and indicate center. You can either use a rotary table or trig out the holes for the lug holes.

 

[hotrats]

Thank you all for your help.
I've done as has been suggested, and turned each rotor. Chamfered each edge a bit too. the Honda disk brake rotor slip fits on the center of the hub. Decided to wait to drill for the lugs, as I don't have the correct size bit.
Cut off VW axle a bottom of pic, original Lotus hub at top left, other 2 are turned VW hubs.