Vanagon – boring steel wheels

Old Simon, yes the guy who has the hi top 91 Westy and recently the syncro double cab, bought another vanagon a month or so ago. I haven’t posted about it yet, I’ve been waiting for some of the little improvements to it to be finished.

One of the improvements is better wheels to replace the stock 14″ that the van came with. Simon found four 15″ steel wheels but the dolt went ahead and had tires mounted before the centre holes were opened up. I’m still cursing him for that. Without the tires I could have mounted the rims on the big lathe and the job would have been a snap.

The original bore hole size was something around 56 mm diameter. We needed to have them opened up to at least 66.4 mm. I fussed around with making a dedicated boring tool to use in the mill, but I ended up using a roughing endmill and the big rotary table.

I should mention that I haven’t done this job before, take my technique and approach with a hefty grain of salt.

As big (and darned heavy) as the rotary table is, the tire and wheel is bigger. Wheel on the table with inside face up, and the outside face sitting on blocks on the table so that the tire is taken out of the clamping set up. Not a great shot here, but you get the idea.

Oops, I skipped a step, the rotary table has to be centred directly under the spindle of the mill. This particular table has a #4 Morse taper hole and I stuck a little lathe live centre in there and indicated off that. Ok, I have to state right now that this entire boring process does not need to have super precise set up. The wheel is lug centric, the centre hole is just a clearance hole. Still, it was worth it to go through the motions to be semi precise. I centred the table to within about 1-2 thou. Good enough.

Then the wheel is humped up onto the table, on blocks, and loosely clamped. I discovered that the collet holder bevelled end fit into the unbored wheel well enough to get a rough centre alignment.

Clamped the wheel down onto the table just lightly and then I indicated the hole, got it pretty well centered ( again, around 1-2 thou) and, as the British would say, nipped the cramps down firmly.

Ok, endmill inserted, it’s a 7/8″ HSS roughing endmill. Moved the mill table over until the cutter touched the side of the hole, set my dial on zero. Yeah, no DRO on this mill yet. I had calculated a total depth of cut of 0.217″/5.51mm on the radius. That would give a diameter increase of 11mm, making the enlarged hole nominally 67mm.

So once touched off, I cranked in a depth of cut ( that varied between 0.070″ and 0.020″, I did a finishing climb cut at the smaller value). I cranked the rotary table and the wheel rotated and the cutter cut. I have a shaky video of that.

Exciting stuff eh?

In the end, the wheels turned out pretty good. The surface finish with the roughing endmill was acceptable. How about before and after shots?

Unbored

Bored (aren’t we all?)


This was one of those jobs where the set up took far longer than the actual machining.