[TowerTalk] FW: FW: Thrust Bearing Installation

[Peter Voelpel]

Yes, the black UHMW will be the best for that purpose and 5% cheaper then
POM (Delrin), POM-C should be used black only as well.

73
Peter


-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Grant
Saviers
Sent: Sonntag, 27. Dezember 2020 19:36
To: 'Tower Talk'
Subject: Re: [TowerTalk] FW: FW: Thrust Bearing Installation

When I need a top plate radial bearing, I use black UHMW which is UV 
resistant.  1, 2 or 4" thick depending on the load & 6" sq, bored 0.030" 
oversize for the mast.  HDG masts get a touch with a file to remove Zn 
lumps & high spots.  No thrust bearings are used, although the largest 
has a collar in case PP rotator work is needed.

UHMW is the cheapest, is very slippery, and has decent PV and yield 
specs.  Whatever polymer is your favorite, make sure it is UV resistant.

Grant KZ1W

On 12/27/2020 10:12, Peter Voelpel wrote:
> Yes, that´s what I use, Nylon or POM plates with a hole cut for the mast.
> I also still use a thick bronze bearing on one tower.
> All weight is on the rotator and I use another shelf above the rotator
with
> a temporarily muffler clamp above it if I need to remove the rotator.
> 
> https://pbase.com/df3kv/image/128881498
> 
> 73
> Peter
> 
> 
> 
> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of
> Charles Gallo
> Sent: Sonntag, 27. Dezember 2020 18:42
> To: Grant Saviers
> Cc: Tower Talk
> Subject: Re: [TowerTalk] FW: FW: Thrust Bearing Installation
> 
> Every time this topic comes up, I alway think about “why are we doing
this”?
> “Thrust bearings” (agree, most are used as a second axial load bearing,
not
> thrust) in ham applications are, frankly low rotational speed, low
> rotational duty application.
> Always makes me think of the lessons learned when shipping cars by train
> (fretting caused by vibration during non rotational times)
> Frankly, what we have is the perfect place for solid bearings. In the old
> days, bronze, today, plastic
> I think a T shaped bearing, made of say a filled nylon, or filled acetal
> would deal with 99% of the issues (never mind torlon/rulon etc). Industry
> has gone to plastic bearings for low speed/low duty/ high load bearings
for
> a reason.
> 
> I don’t know how the Yaesu “thrust bearing” is made, but rotating one by
> hand, they FEEL like plastic
> 
> 
> 
> --
> 73 de KG2V
> Charlie
> 
>> On Dec 27, 2020, at 12:02 PM, Grant Saviers <grants2 at pacbell.net> wrote:
>>
>> ?Matt,
>>
>> Got the image, thanks and nice work.  Very informative about some of the
> issues.  The three bearing study would also help settle a lot of debates.
> Were real bearing models developed?  The design that was developed for
> radial float (done in some machine tooling to float reamers) of the
rotator
> would be interesting.
> 
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