Vibrating wheel hub puller - GIF

**Altair** · Oct 7, 2022, 11:27 AM

Vibrating wheel hub puller.

Previously:

Improvised wheel puller - photo
Haul truck wheel hub - photo
Wheel rim straightening machine - GIF
Wheel winch - video
Formula One wheel guns - photo

**WorkerB** · Oct 7, 2022, 08:34 PM

Seeing the heating that’s going on reminded me of something thats always puzzled me.
Leaving aside potential damage to the ‘wanted’ bits, is it more logical to heat the outer component or the inner component of a frozen coaxial apparatus?

Heating the outer component would make it expand (in all directions) making its internal diameter smaller thereby binding even tighter.

Heating the inner component (again expanding in all directions) would increase its outer diameter thereby binding even tighter.

Does anyone have a logical explanation of which is better?

**nova_robotics** · Oct 7, 2022, 10:45 PM

Originally Posted by WorkerB

is it more logical to heat the outer component or the inner component of a frozen coaxial apparatus?

I think it's just a perspective issue with the camera. You definitely want to heat the hub and not the spindle.

**tonyfoale** · Oct 8, 2022, 01:48 AM

Originally Posted by WorkerB

Heating the outer component would make it expand (in all directions) making its internal diameter smaller thereby binding even tighter.

Heating the inner component (again expanding in all directions) would increase its outer diameter thereby binding even tighter.

Does anyone have a logical explanation of which is better?

Heating the outer component makes it expand as you say but its inner diameter expands away from the centre not towards it. If the hole expanded inward and the outside expanded outward as you propose then there would have to be a ring between those two extremes that did not expand. This is not the reality.

Imagine the circumference of the hole, if that circumference expanded then its diameter also has to expand not close up.

Imagine the hub as being a set of concentric rings, each ring will expand such that inner and outer diameters will expand outward, therefore the whole object will expand outward.

So you need to heat the outer part.

I recall asking my school teacher a similar question close to 70 years ago. He was unable to provide an answer.

**tonyfoale** · Oct 8, 2022, 01:52 AM

Originally Posted by Altair

Vibrating wheel hub puller.

Am I going blind? I do not see the source of the vibration, that would be the only interesting thing in that video.

**WorkerB** · Oct 8, 2022, 01:52 AM

Thank you so much Tony.
It makes sense now. Like a doughnut (or is that donut in the US) increasing in size. The hole gets enlarged too. Brilliant!!

**tonyfoale** · Oct 8, 2022, 02:06 AM

Originally Posted by WorkerB

Thank you so much Tony.
It makes sense now. Like a doughnut (or is that donut in the US) increasing in size. The hole gets enlarged too. Brilliant!!

Make mine a doughnut.

**olderdan** · Oct 8, 2022, 05:11 AM

I used to repair Salsbury axles on Scimitars and the method which worked every time was to pour two kettles of boiling water over the hub which would then fall of the taper with a couple of blows of a copper mallet. Trick is to expand the hub before the heat gets to the shaft. Hydraulic puller methods can be a bit scary when they let go.