[TowerTalk] For Chrome Moly and tower/wind load experts out there - Mountain top tower installation

jimlux jimlux at earthlink.net
Sat Aug 15 15:15:52 PDT 2009

Roger (K8RI) wrote:
> trappaport at austin.rr.com wrote:
>>  Some tower comanies have recommended I get 5" OD steel mast pipes, which will not work for my rotors that take a maximum of 2.5" OD mast!
> How about having an adapter machined to get from the 5" tube to the 2.5" 
> rotator mount? It might be kinda heavy but should meet the strength 
> requirements.

how about a toothed belt drive between rotator and mast. I'm assuming 
that the 5" OD pipe is very thin wall (either that, it's literally going 
to weigh a ton).  But this is getting pretty non-standard.  Maybe taking 
a step back and saying: do I really want to use a ham rotator for a 5" 
diameter pipe, with all the improvising and cobbling I'm going to do? 
If you're going to cobble, getting some other sort of industrial motion 
control drive might be a better plan. Perhaps a worm and ring gear? 
Toothed belt to gear motor? There's an enormous number of ways to turn 
moderate speed motors into heavy duty vertical axis rotation. How about 
an inexpensive rotary table as used on a vertical mill? Or a modified 
auto rear end (as is popular for hot-walkers for horses)?

Or, some sort of spring loaded idler wheel friction drive between motor 
shaft and mast (like the old record players used to use). Has the 
advantage of a sort of "breakaway clutch" if something jams. Put the 
azimuth sensor on the mast, and use a programmmable controller like a 
green heron (or any of dozens of industrial motion control boxes). 
You're already talking thousands of dollars for the rest of the system, 
so saving a few hundred bucks on the rotator may be a unwise economy.

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