Re: ON-Topic...For Cliff even...

On Sun, 20 Aug 2006 19:55:32 GMT, (DaveB) wrote:

On Sun, 20 Aug 2006 19:50:23 GMT, "Gary H. Lucas"
<gary.lucas@xxxxxxxxxxx> wrote:


"Cliff" <Clhuprich@xxxxxxx> wrote in message
news:pvbge2tdfhg0i6r8phefir7tur56va6g36@xxxxxxxxxx
On Sat, 19 Aug 2006 23:12:53 GMT, "Gary H. Lucas" <gary.lucas@xxxxxxxxxxx>
wrote:

Getting it off with heat might be possible, IF you can keep the shaft
cool, relative to the bushing.

You need to heat it fairly fast.
There's actually not much metal to metal contact where the bits mate
so conduction across the (mating area) gap is low.

Cliff,
did you read the whole thing? Can you suggest a FASTER heat source than a
#12 rosebud on an acetylene torch?

Gary H. Lucas



Cliff Says,

"There's actually not much metal to metal contact where the bits mate
so conduction across the (mating area) gap is low".

Can you explain this to me? If the "Bits" are 2 " wide how much
surface contact is there?

What kind of crap is this?

Regards


Daveb

Dave,
While most metals conduct heat fairly well there is not
really a great deal of actual metal to metal contact to
do thermal conduction in the contact area between
the shaft & the collar (or whatever you are fitting). Just
a few "high spots" here & there in decent contact (and
any oxides make it worse).
Hence much more heat will be conducted around the
collar *in the collar* than conducted to the shaft if
you don't allow it time to conduct much to the shaft at low
heat flow rates (collar to shaft).
It's not a really good thermal junction (such
as a full weld or 100% solid metal might be).

This makes it possible to heat the collar without also
getting that shaft nice & warm too (thus making the entire
process rather ineffective) <G>.
--
Cliff
.

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