[TowerTalk] Metal Thermal Rate of Expansion

[Grant Saviers]

The materials difference in thermal expansion is 1.7e-6 per degree C.

So 2" x 1.7e-6 x 100d C temperature range = 0.00034"

You will never notice at any place on earth.

Grant KZ1W

On 10/3/2021 11:45, Gedas wrote:
> It is has been WAY too many decades since my last ME classes to be 
> confident in my estimations so I am wondering if someone can give me 
> their opinion if I am going to run into trouble.
> 
> The YT video (URL below) shows a new 10 GHz elevation mount I am making. 
> For a bearing I chose to use 6061-T6, ~2" OD tubing rotating inside a 2" 
> ID brass collar. I had to turn down the aluminum tubing a bit to fit 
> nicely inside the brass collar which now allows it to turn freely w/o 
> slop but this is at room temperature.
> 
> My fear is that on a very cold day or a very hot day my home made 
> bearing may seize up on me.
> 
> Can someone run a quick calculation? I see that my aluminum and brass 
> have 13.0 and 11.3 (for yellow brass which is a WAG for what I have). I 
> am leaving off the units and exponents etc.
> 
> https://www.engineeringtoolbox.com/thermal-expansion-metals-d_859.html
> 
> Here is the URL that shows the homemade bearing:
> 
> https://www.youtube.com/watch?v=Ps_PRXaByz4
> 
> 
> Gedas, W8BYA EN70JT
> 
> Gallery at http://w8bya.com (under repair)
> Light travels faster than sound....
> This is why some people appear bright until you hear them speak.
> 
> 
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