> >I would expect either
>>tapered roller bearings, or today, do what most of industry does, and use
>>an engineering plastic bearing.
>
> And, in fact, that's what I do. One mast has a brass shaft collar that
> rides on a slab of Nylatron (GS grade I think), and the other mast uses a
> scrap TB-3 that was machined to replace the ball assembly with a Nylatron
> sleeve insert for axial and radial thrust. I expect both of them to
> outlive
> the towers they're sitting on... ;-).
>
> 73,
>
> geo - n4ua
Yeah, I suspect they will
I'm sort of surprised however that they aren't made that way, although by
FEEL, that may be how the Yaesu thrust bearing is made. Heck, a piece of
UMHW PE would probably work too. As I said, not a real high load
situation. You have room for LOTS of square inches of plastic, which will
prevent any creep so you don't need the high bucks stuff like rulon or
vespil (shudder when you price vespil), it'll never rust, it never needs
lube, doesn't matter if it gets wet
Looking at the design of the DXE bearing, and the TB3 - the DXE is a true
THRUST bearing - aka designed for a load along the axis of rotation (aka
carry weight off the rotor), where the TB3 is really just a regular
bearing for side to side loads. To be BOTH, they would really need to be
angular contact, or use a flanged plastic bearing, so it has bearing
surfaces in BOTH directions, and get the best of BOTH worlds
Heck, if I was designing a rotor today, or say updating the Ham V series
(including the TX2), I'd use plastic there too, with the added advantage
of it tending to act as at least a partial water seal. Never did the math
for what plastics you'd need keeping the contact size the same
I mean nylatron is practically begging for that use. No elevated temps
(folks reading - elevated temps here means greater than 50C on a
continuous basis aka 20 hours at a time - and even then, if we go
reinforces with either glass or Molly, you can go 75c - just in case you
want to paint your bearing black and put in in the sun in the Mideast),
"moderate" loads per square inch, low rotational speeds, no seriously
significant shock loads. Never have to worry about the balls indenting
the races like the Ham IV, never have to worry about rust etc. MFJ could
get rid of the two steel races, the balls, the retaining rings etc, and
have a better product for probably less money
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