New Tower Project

[ruddycrazy]

Hiya Guy's,

           Well with my last tower failure I've decided to use my 12 metre comms tower I picked up from the scrap yard for only $200. Scoop is a pain in the butt so I'll just do links to the pic's

http://www.anotherpower.com/gallery/album63/new_tower

Today I made a winch pad and set it in concrete. it's made from 8" I beam with a 3"x1/4" angle iron brace and I welded a heap of braces so it will key into the cement. I only got 800mm down and went thru solid rock to get there, so I drilled into the rock and chemset some anchors in to key into the rock.

http://www.anotherpower.com/gallery/album63/winch_pad

Now this comms tower can extend to 12 metres buy I'm worried about the winch on it so I'd prefer to raise it fully extended. Now as I've never made a gin pole before I'm thinking 4 metres should do which is 1/4 of the tower length.

The genny will be a Fisher & Paykel 80 series rewired to 7 pole x 3 which is the best rewire for this size, we've been testing using non-polarised caps and found the extra current at low speeds (240rpm) provides 3 amps of current where without caps theirs no current.

The blades are made from curved plywood and aren't really standard per say, but with my last tower they proved better than any piggot design so I'll use them again.

Cheers Bryan

[SparWeb]

You're right to keep it in its fully extended size.  In fact I'd rather have the tower rigidly set at one size.  Maybe just weld it up full height and leave it there so that you don't have to tighten 4 cables against one winch cable that holds it up.  You want guy wires up near the top, but if a cable keeps the tower up at maximum height, then tightening your guy wires will shorten your tower slightly.  You will be running around and around every time you tighten the fourth guy, because the first one you started with loosened a little...

The gin pole could be longer, but 4 meters may be okay as a minimum.  That's 1/3 the tower height, btw.  The forces involved in raising the tower shoot up quickly with a short gin pole.  Whatever cable size you are comfortable with on a gin pole that is 1/2 the tower size - use a size or two larger with a gin pole 1/3 the tower size.