TowerPlan Fred Hopengarten K1VR Eric Scace K3NA
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TowerPlan
Fred Hopengarten K1VR
Eric Scace K3NA
Typical questions when buildingor changing antennas
• Is it safe to guy at a different spot than the catalog drawing?
• Can I go higher than the manufacturer recommends if I use this “smaller” antenna?
• Can another antenna be added to this tower?
• Is my mast strong enough?
• What problems have I overlooked?
Answers are expensive…or uncertain
• Hire Professional Engineer.
• Over-design.
• “Frank, Tim and Matt do it this way, so it must be OK.”
• “It hasn’t fallen over yet, so I can add some more.”
Sneak preview:TowerPlan software & services
• Color graphics, text reports:
– Safety margins for all parts of system.
– Deflections, loads, and torques*.
• Construction drawings.
• Bill of Materials.
• P.E. “dry” and “wet” seal documents (when required).
* Important for rotators!
How TowerPlan works:Step 1: Description
• Base & guy anchors.
• Tower:
– Pick from library of manufactured towers.
• Guy wires & insulators.
• Antennas.
– Pick from library of manufactured antennas.
– Describe homebrew antennas.
• Antenna mounts & rotators.
• Miscellaneous: cable runs, boxes, etc.
Extensive dialogs.
Continuous view of system.
Easy to use
How TowerPlan works:Step 2: environment
• Select conditions:
– Choose the industry standard for the location.
– Select custom wind and ice loads.
• Multiple sets of environmental conditions may be included in each analysis.
– Example:
80 mph wind + no ice
65 mph wind + ¼” radial ice
How TowerPlan works:Step 3: safety factors
• Separate safety factors for each major part of system:
– Rotators.
– Antennas.
– Mounts.
– Tower.
– Guys and anchors.
• Allows for “progressive failure” under extreme conditions.
How TowerPlan works:Step 4: analysis
• Calculating engine:finite element analysis (FEA).
– Strain, shear, torque and displacements on each element.
– Compare to failure point to determine margin of safety.
– Compare margin to target safety margin.
•Wind directions around each antenna tested for worst orientation.
•Rotatable antennas aligned to the most severe combination for system.
•Wind directions around entire system tested for different failure modes.
How TowerPlan works:Step 5: results
• Graphic display:
– Stress, shear, torque, displacement.
– Safety margin relative to target.
– Points of failure.
• Detailed and summary text reports.
How TowerPlan works:Step 6+: iterate
• Modify design:
– Correct for failures.
– Optimize choice of materials.
• Re-run analysis.
• Print final design:
– Construction diagrams & report summary.
– Bill of Materials.
Making life easier:Tower & antenna libraries
– “Pre-described” tower sections.
– “Pre-described” antennas.
• Homebrew antennas can be described and added to personal library.
– “Black box” to the user.
• User picks from list of manufacturer products.
• Product details are not available to user.
• Manufacturer may provide both current and historical variations of products.
How TowerPlan works:Need dry- or wet-seal drawings?
• Finalize design with TowerPlan.
• Request sealed drawings on-line.
– Dry seal: PDF file e-mailed to you.
– Wet seal: TowerPlan prints and ships drawings with wet seal.
– P.E. seal chosen appropriate to jurisdiction.
Observations
• Most hams will work intensively to design a system…
… but, after design is done, do not make changes for months or years.
Will software be current then?
Not available in stores!(and don’t call 1-800-…)
• Web-based service:
– Register on-line.
– Description may be done off-line.
– Analysis calculations occur on-line.
– Results may be reviewed off-line.
Not available in stores!(and don’t call 1-800-…)
• Benefits:
– Current software features & bug fixes.
– Current library antennas and towers.
– Not constrained by user’s CPU speed or memory.
– Eliminates complexity of multi-platform software design & maintenance.
– Reduces distribution expense.
Release schedule
• Release 1 software and libraries in development.
– 3Q: beta testing.
– 4Q: general availability.
• Release 1 will likely contain:
– The most popular tower models.
– As many antenna models as we can practically gather!
You can help!Tower or antenna manufacturer?
• Contact us NOW to:
– Include your products in the TowerPlan libraries.
– Post links to your web-site.
eric @ k3na.org
You can help!Professional Engineer?
• Contact us to:
– Provide seal services for your jurisdiction.
– Receive referrals for custom design work.
– Post links to your web-site.
eric @ k3na.org
You can help!Planning antenna project soon?
• Remind your tower and antenna manufacturer:
“Please arrange for your towers/antennas to be included in TowerPlan libraries!”
• Contact us:
– What kind of tower & antennas?
eric @ k3na.org
www.TowerPlan.com
• Sleep soundly during storms.
• Build.
• Optimize.
• Analyze.
• Don’t guess!
eric @ k3na.org
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