Posted by
ARDUJENSKI on
Aug 10, 2006; 5:46pm
URL: http://elecraft.85.s1.nabble.com/Re-60-foot-fiberglass-pole-Pole-Strength-tp392858.html
SUGGESTION
Use of fiberglass poles for end supports WITHOUT GUYING would indicate a
lack of understanding of strength and stiffness of an end loaded beam. Most
people however do not deal with this type of engineering so a simpler approach
may be warranted
As was presented about 6 weeks ago on QRP-L, there needs to be a deflection
test applied for comparative technical details. A simple approach would be:
1. Mount pole horizontally about 4 ft above ground
2. Add with to the tip in 1/2 lb amounts and measure deflection
3. Record results for comparison
By knowing the load you will place on the mast tip you can know what the
deflection will be beforehand. If unacceptable you can look at another support
or check to see if guying would remedy the problem.
To simulate guying, you take the horizontal pole and move a support along
the horizontal pole to check if this remedies the deflection problem.
If you guy at say the 20ft point, depending upon the pole design you may
also need to guy every 10ft for heavier loading
NOW you can approach the question of what will be an adequate SUPPORT in a
more professional manner.
For guying I generally use cheap Phillip screwdrivers as anchor points for
my masts pushed in at a 45 degree angle.
Alan KB7MBI
Woodinville, WA
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