Unless the fan itself is plastic, in which case it will be a mess.

A bit of oil down the grub hole and either end, then gentle tapping of the
spindle to see if it moves after a few hours. However if you have drilled
the grub screw hole, how are you going to re attach the fan to a new motor?
Brian

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The Sofa of Brian Gaff...

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"Clive Arthur" wrote in message
...
On 29/11/2019 13:07, Chris Green wrote:
I have a small fan motor that I need to replace, the fan is mounted on
an aluminium (I think) collar which is siezed on the shaft.

So, what's a good approach to getting it unstuck? I've drilled out
most of the grub screw that should be holding it, I doubt that's the
issue now. It's just that the collar is very firmly stuck on the
shaft.

snip

The coefficient of thermal expansion of Aluminium is about twice that of
steel, so I'd try heating it. Aluminium conducts much better too.

Hot oil might do it.

Cheers
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Clive