Skystream 3.7

[russ]

What is the acceptable allowance from vertical?

[BillF]

I'm not sure of an "offical" number beyond "as close as possible". However some time ago we were asked to look at a 45' monopole that was installed by a now out of business SS3.7 dealer and the client was complaining of the turbine always wanting to orient in one direction. Using an elevating transit we noted the tower top off by roughly 2.5" to 3", consistent with the wayward orientation of the turbine. We adjusted the foundation bolts to get the tower top within a 1/2" of plumb. A noticeable improvement was seen in performance.

[ggunn]

Why wouldn't the designers of these things make them balanced at their pivot point so that a little bit of tilt wouldn't make them favor an orientation?

[65DegN]

BillF, thats the ticket, an elevating transit. I used one when I put up my guyed rohn tower 25 years ago. Got it within 1/2" from top to bottom (85').
I have an old 2 KW Whirlwind that was built by Elliot Bayly (now of Ventera Energy and designer of the Whisper series of turbines now owned by SWWP). The Whirlwind, generally considered the laughing stock of wind turbines, with some modifications has worked great for 25 years.