[TowerTalk] US Tower Crank-Up Tower Thrust Bearing

[Mac]

Thank you Grant for the much improved answer than i was trying to cough 
up...  mac/mc

On 7/28/2019 7:07 PM, Grant Saviers wrote:
> If it is truly a thrust bearing then it must have grub screws or a 
> collar above with grub screws.  For the former the ID - OD mismatch 
> could be large and still be ok.  For the latter you could get a collar 
> machined with an 0.030" extension, but I would think that is overkill.
>
> If it is a radial bearing then 1/16" really won't matter.  I machine 
> plastic radial bearings with 0.030" clearance. I think that is the ID 
> of the "2" inch tube on larger UST crankups.
>
> While all masts are not equal, those of real DOM (drawn over mandrel) 
> alloy (4130, A513, etc) are usually pretty round and very close on 
> ID/OD diameters.  If you are using pipe then all bets are off re round 
> and generous diameter tolerances. (plus not a good idea unless of a 
> known quality source). (specs are published for both). Galvanizing 
> adds a bit, on the order of 0.008 to 0.015" diameter plus some 
> droplets etc to file off.
>
> Grant KZ1W
>
> On 7/28/2019 2:02 PM, Mac wrote:
>> This measurement is near insignificant, it needs or should comport 
>> with the mast size O.D. not all mast are equal in size by a long shot.
>>
>> By its self is not enuff answer.?? The mast and thrust bearing are 
>> near symbiotic in their relationship.
>>
>> best:?? mac/mc?? w5mc
>>
>> On 7/28/2019 1:06 PM, W3OA wrote:
>>> A buddy and I are doing some work on a US Tower crank-up with an 
>>> unknown history.?? He measured the inside diameter of the thrust 
>>> bearing as 2 1/16 inches.?? Does this sound right or is it possible 
>>> the bearing has been replaced with one that is not the same size as 
>>> the original?
>>>
>>> 73 - Dick, W3OA
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>