It's an interesting question about the strength of the top section in a crank up, so I looked at the UST calcs for the HDX589, 85mph 3 sec gust, 71mph fastest mile (EIA-222-F). I'm not a PE so this n
Anecdote follows: Frank Clement, W6KPC (SK), who owned Tri-Ex for many years, told me in personal conversation that their crankups were designed so that if a catastrophic failure were to occur with t
Regarding failure points: I've seen photos of two fallen US Tower retractable towers and both of them failed at the very bottom. The problem with designing a retractable tower such that it will fail
Sounds like a US Tower problem to me... :-) Chris KF7P (tri-ex owner...knock on wood) Regarding failure points: I've seen photos of two fallen US Tower retractable towers and both of them failed at t
On 2/8/13 7:54 PM, SPWoo wrote: Regarding failure points: I've seen photos of two fallen US Tower retractable towers and both of them failed at the very bottom. The problem with designing a retractab
Jim, With regard to your comments below, are you assuming laminar or turbulent flow? I just grabbed my copy of Leeson's "Physical Design of Yagi Antennas" and he discusses this same issue of a rapid
With regard to your comments below, are you assuming laminar or turbulent flow? I just grabbed my copy of Leeson's "Physical Design of Yagi Antennas" and he discusses this same issue of a rapid chang
With regard to your comments below, are you assuming laminar or turbulent flow? I just grabbed my copy of Leeson's "Physical Design of Yagi Antennas" and he discusses this same issue of a rapid chang
On 2/9/13 11:12 AM, K8RI wrote: On 2/9/2013 11:43 AM, Jim Lux wrote: On 2/9/13 8:21 AM, Michael Tope wrote: Jim, Laminar flow is when you have undisturbed air (e.g. clean airplane wings) and my own e
The drag coefficient may be 1/2, but when multiplied by 400% more face area is the drag not 2x? KM5VI And I'm not sure that specifying "round members" is valid. Members in the 1-4" range at 70mi/hr
The drag coefficient may be 1/2, but when multiplied by 400% more face area is the drag not 2x? Doh.. yes.. 4 times the diameter, twice the drag. _______________________________________________ _____
On 2/9/2013 8:43 AM, Jim Lux wrote: He then states "conservative design, however, dictates a less aggressive choice", referring to the choice between assuming turbulent flow or laminar flow when doin