Two threads projecting from lock nut

[tiffany]

The image shows the rear hub design of our car. It is fixed to the wheels with 4 lugs. Moreover the axle of the hub has external threads on its outer end for a lock nut to be fixed (which is not shown in the design) on the axle. Since the lug bolts do follow the rule T11.2.2 regarding projection of minimum 2 threads out of the lock nut, I have a doubt whether this rule should also be followed for axle lock nut as well ? https://dl.dropbox.com/u/62269760/Rear_hub.jpg ?

[Jay Lawrence]

I'm not 100% on that rule but you shouldn't be limited on space on that side of the hub so why not add enough material for the extra threads?

While you're at it, I'd probably redesign the entire thing so that someone can make it.

[MUsusp72]

A very curious design indeed. What were the thoughts behind it?

[Kirk Feldkamp]

I think they're trying to combine the wheel hub and a brake hat into the same piece... just in a rather non-standard and complex to fabricate way. http://fsae.com/groupee_common/emoticons/icon_smile.gif

-Kirk

[Drew Price]

Originally posted by Kirk Feldkamp:
I think they're trying to combine the wheel hub and a brake hat into the same piece... just in a rather non-standard and complex to fabricate way. http://fsae.com/groupee_common/emoticons/icon_smile.gif



^^^ That.

[MCoach]

Originally posted by Kirk Feldkamp:
I think they're trying to combine the wheel hub and a brake hat into the same piece... just in a rather non-standard and complex to fabricate way. http://fsae.com/groupee_common/emoticons/icon_smile.gif

-Kirk

"Because CATIA said it would work" seems to be something I've seen from time to time.

[Kirk Feldkamp]

Originally posted by MCoach:

"Because CATIA said it would work" seems to be something I've seen from time to time.
Haha. Indeed. Looks like Solidworks in this case! http://fsae.com/groupee_common/emoticons/icon_wink.gif

-Kirk

[Charles Kaneb]

Depends on how many you're making.

That driveplate looks like a reasonable forging. The dies won't be too bad with the right equipment (4-axis CNC mill pretty much req'd, 5 possibly preferable). If you need a few dozen of them...

[coleasterling]

Neglecting that tiny radius at where the flange meets shaft, it is a stupid simple 2-op, 3-axis mill part. It looks like there aren't any internal radii on the back side of the flange either, but I'm assuming the actual part would have them instead of sharp corners.

I would punch a hole in the ID, helically bore the ID, rough the OD of the shaft, then helix the OD of the shaft to the top of the flange, thread mill the threads on the OD, surface the entire top of the flange, and finally punch holes and counter bores. Pull it out, flop it over, then surface the back side to finish it off.

[MCoach]

Originally posted by coleasterling:
Neglecting that tiny radius at where the flange meets shaft, it is a stupid simple 2-op, 3-axis mill part. It looks like there aren't any internal radii on the back side of the flange either, but I'm assuming the actual part would have them instead of sharp corners.

I would punch a hole in the ID, helically bore the ID, rough the OD of the shaft, then helix the OD of the shaft to the top of the flange, thread mill the threads on the OD, surface the entire top of the flange, and finally punch holes and counter bores. Pull it out, flop it over, then surface the back side to finish it off.

The only tricky part of the whole thing is that small radius and it could probably technically be done from the top with a long lollipop tool. If you were really worried about the mill tolerances on a round shaft, then I'd stick it our lathe with live tooling and substitute turning for the helical boring and thread milling.

-Cole


I'm tired of popping out parts like this on our 2-axis ProtoTrak.

Please feel free to send some machinery our way. http://fsae.com/groupee_common/emoticons/icon_razz.gif