[TowerTalk] Metal Thermal Rate of Expansion

[Gedas]

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

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