I believe that it is also important that the pulley have a large enough
wheel diameter and the groove have a radius which fits the rope diameter.
Otherwise the rope will be flattened as it rolls over the pulley. A local
ham, W7BUD (SK) used Dacron rope to guy a 120 ft tower with 2 full size 4el
20m beams on it. The upper beam used a pipe shaft to the ground mounted
rotator and a TIC ring for the lower one. It was up for at least 10 years at
his hill top location until he passed on. I helped take it down. Needless to
say, none of the locals would climb it but he did frequently.
73, Dan, N5AR
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of Craig Clark
Sent: Wednesday, February 22, 2006 6:32 AM
To: towertalk@contesting.com
Subject: [TowerTalk] rope
>
> >The black dacron covering wears through and once that happens the
> >polyester seems to go pretty quickly.
>
>I've had similar bad experience with the dacron rope from the following
>link. I was using it with pulleys to suspend dipoles from the tall tower
>at W6BX. It lasted about a year.
>
>http://www.radio-ware.com/products/dr316.htm
Wear is a function of abrasion and if you have something that is
hostile to the rope, it is going to break! All too often poor quality
or undersized pulleys are used: I know because I have made this
mistake. I also had a triangle antenna in a quaking aspen that stayed
up long enough for the tree to grow over the rope......and then it failed.
Marine grade pulleys are by far the best to use but pricey. I found a
better grade of hardware pulley with a bronze axle at my local hardware
store.
If you have the rope going over a tree branch, the mechanical motion
of the tree is going to abrade any rope. Another potential problem is
using a small sized rope in a too large pulley. The rope could slip
off the wheel and jam between the axle and the housing.
No rope product is perfect.
73, Craig Clark, K1QX
PLEASE NOTE NEW EMAIL ADDRESS
JCCLARK@WILDBLUE.NET
RADIOWARE AND RADIO BOOKSTORE
PO BOX 209
RINDGE NH 03461
603 899 6957
WWW.RADIO-WARE.COM
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.15.12/265 - Release Date: 2/20/2006
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|