Nylatron is a very interesting material but there are MANY variations of the
product. See this site for about 20 or so different "Nylatrons". It is NOT
a variation of UHMW--but rather something completely different. Looks
like a version good for bearings may be superior to UHMW in some significant
properties--although it is not as good a dielectric and it tends to absorb
water in
varying degrees.
To see many different kinds of Nylatron
http://nylon-plastic-resin.com/dsm-nylatron.htm
Comparison of Nylatron, UHMW, and other things.
http://www.machinist-materials.com/comparison_table_for_plastics.htm
43 page tutorial on engineering with plastics. This booklet looks pretty
interesting. I am downloading it and will read it on my next flight to
somewhere. http://www.tstar.com/pdf/quadrant-DF.pdf
73--John W0UN
At 05:04 PM 2/11/2003 -0600, Robin Midgett wrote:
>I use a material referred to as "Nylatron" for the bushing in the
>Sidewinder; works great! It may be the same as what John refers to; it is
>black; it has graphite in it to make it slick, and it is UV stabilized. It
>is specialized UHMW for bushing use.
>Use a nice, slow RPM on the drill press to avoid melting the material
>whilst you bore it out to size. Fastening it to a piece of wood or metal
>to secure it while boring on the drill press is a very good idea.
>
>At 03:02 PM 7/29/2002 -0500, W0UN--John Brosnahan wrote:
>
>>The proper material to use for mast/tower bearings is UHMW polyethylene
>>Ultra High Molecular Weight Polyethylene is used for all kinds of
>>bearings. The white version appears similar to Teflon although not
>>as slick. And it doesn't cold flow like Teflon.
>>
>>There are gray and black versions that are UV stabilized. But I just made
>>my bearing brackets in such a way that they are out of the direct sunlight
>>and have had no problems with the white bearings (made with 1 inch thick
>>UHMW) in over ten years of service with a number of large antennas. Such
>>as 8 element 15 meter beams on 60 ft, 3 inch diameter, booms. Never needs
>>to be lubricated and is CHEAP. And doesn't rust of course.
>>
>>The mast hole on UHMW can be "drilled" using a hole saw in a drill press.
>>Pretty easy going and makes for a cheap machining job.
>>
>>Good Luck--John W0UN
>>
>>BTW I would never use any material that I wasn't sure of. And I wouldn't
>>use Teflon in any case. W7RM was an early adopter of the UHMW bearings
>>and has had very good service over MANY years.
>>
>>
>>At 03:13 PM 7/29/2002 -0400, Jim White wrote:
>>
>>
>>>share with us Toddles...on a related matter...
>>>
>>>I am considering using some scrap pieces of what I think is Teflon
>>>picked up at a flea market. I want to use them as horizontal thrust
>>>bearings on a tall rotating mast...seems like these should be a good low
>>>rpm choice...
>>>
>>>The mast would be aluminum and these would have a hole in the "plastic"
>>>slightly large than the mast...the stock is about a half inch thick and
>>>in turn would be bolted to an aluminum plate with a slightly large hole
>>>than is in the "plastic"...should take care of lateral movement it seems
>>>and at the same time would not chafe the aluminum mast during rotation.
>>>
>>>Is there a concern I should have for ability of Teflon (this might be
>>>something else but lets assume is what the guy selling it said it was)
>>>and its exposure to UV - a crucial problem here in FL.
>>
>>_______________________________________________
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>
>Thank you,
>Robin Midgett KB4IDC
>IDC Technology
>rmidgett@bellsouth.net
>www.idctechnology.com
>615-322-5836 days - rolls to pager
>
>3232 Beckwith Road
>Mt. Juliet, TN 37122-5215
>God Bless America; in God we trust.
>
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