[TowerTalk] Metal Thermal Rate of Expansion

[Gedas]

Thank you grant. I was not sure how to interpret that linear expansion 
as my situation is using round tubing. Not sure if the diameter would 
change at the same rate as in a linear strip of metal. 73

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.

On 10/3/2021 5:19 PM, Grant Saviers wrote:
> 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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