Hi Grant,
Here are a few sites that I keep on tap that others may find of interest:
http://www.boatoutfitters.com/cut-to-size-white-white-king-starboard
http://www.tapplastics.com/product/plastics/cut_to_size_plastic/king_starboard/526
https://www.interstateplastics.com/Uhmw-Natural-Virgin-Sheet-UHMNV~~SH.php?vid=201312282312-9p
http://www.mcmaster.com/#uhmw-polyethylene-sheets/=zmvqqd
Jon Pearl - W4ABC
On 11/1/2015 9:16 PM, Grant Saviers wrote:
Agree. Rulon and TFE filled or plain polyamides (e.g. Vespel) are
indeed "crazy expensive" and not at all needed for radial or thrust.
UHMW is a small fraction of their costs and works just fine at the
PV's (pressure x velocity) that is found in tower/mast rotation
systems. UHMW will creep more but that makes little difference in a
tower thrust or radial bearing. My 3" x 22' mast thrust + radial
bearing is a 5" diameter 1/4" SS disk screwed with flat head screws to
an aluminum sleeve with 8 grub screws to secure it to the mast. The
disk rests on a 6x6x4" UHMW block bored 3.040" for a 3" mast. I think
the parts cost was $50 for UHMW, plus $40 for the 6061 and SS and
bolts (I did the machining).
I designed a 10.5' tall swing arm assembly for mounting two large
yagis and it has a UHMW bearing as I described at the top but then
decided to use individual ring rotators.
Grant KZ1W
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