Author Topic: Tims Tower Project  (Read 4566 times)

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DanB

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Tims Tower Project
« on: October 25, 2007, 02:42:45 PM »


TimS posted a bit about this before.  I thought I'd get a posting about his tower project on here with some additional comments about what we did, what went smoothly and what didn't.  Some of these pics I've posted before but I wanted to get all that I have in one place.  The tower is 63' tall built from 10" tubing.  Pictured above are some of the parts.  Down the tower we're running 10 gage wire (a bit light but it's good /flexible stuff) and then from there to the batteries we're running about 160' of 4 gage (the big red roll of wire pictured above).  This tower is being built on the very top of ridge on what appears to be an excellent wind site.  Most of the trees are leaning and the ones that stand alone show some pretty serious flagging.


Here is what we built the tower from:



  1. ' of 10" tubing (60' for the tower, 34' for the gin pole, and 6' for couplers)
  2. ' 6" of 12" seemless pipe (12" for the tower top, 6" for the end of the gin pole and 2 6" pieces for the pivot)


Some angle iron and misc pipe/flat steel for fabricating the tower base.


  1. " of 3" sched. 40 pipe for the stub at the very top of the tower.
  2. 1/2" turnbuckles.  I got them here - they have reasonable prices on all the 'rigging'


http://www.webriggingsupply.com/pages/catalog/hardware/turnbuckles.html

Part #   50032X9EE x4

50040X9JJ x 4


and the rest....



  1. /4" steel cable: 180'
  2. /8" steel cable: 360'
  3. /4" thimbles: 10
  4. /8" thimbles: 12
  5. /4" cable clamps: 35
  6. 8" cable clamps: 40


shackles (1/2"?) 10


We used 3 12" long 'red heads' which we hammered 12" down into solid granite for anchors.  On the west side we didn't have good rock to work with so Tim used his backhoe to dig a 4' trench and we buried a 'dead man' for that anchor.



Rich drilling 12" deep holes (1" diameter) into granite.  These hammer drill bits are expensive and granite really dulls them quickly.  It pays to sharpen them frequently -  a nice tool for that is a diamond burr on a dremel tool.



The coupler on the gin pole.  When we assemble these we lightly clamp it to one of the pipes, then slide the other one in.  We used a hi-lift jack to get everything  pretty much perfectly straight before we tighten all the bolts.



We fixed this large pulley to the back of the gin pole to double the mechanical advantage while raising the tower.  It also makes things happen more slowly /safely.  Beneath this (attached at the ground but not shown in the picture) is another similar pulley to keep all the force pulling 'down' - it assures that we never are pulling too hard against the tower base.



There is the tower base - Tim put down some mesh and poured concrete around it the day after we got it in place.



We used a backhoe to raise the gin pole.  In the picture above he's just raising it enough so we can do some work at the anchor under the end of it - he had to reposition to actually raise it.  It all went smoothly - but I get scared using such powerful tools to do this stuff, it would be very easy to make a tiny mistake and pull the tower base out of position.



There is the tower mostly assembled.  Once the gin pole is in the air this all goes pretty quickly.



We had a good team and things were organized Saturday morning.  Rich and Tom measured out guy wire's/turned lots of nuts on cable clamps - other people double checked bolts/tightened couplers.  I assembled the blades with Marys help.



First test raise.  It was starting to get a bit windy and a bit scary.  We did just about get the guy wire lengths right but we were a bit off and on the first raise things were a bit loose/blowing around.  This is when we realized we'd made one big mistake.  After they'd welded up the tower base a few weeks ago we notice that the gin pole was going to be about 91 deg to the tower!  I always prefer to make it less than 90 deg....  we thought it'd be OK though because Tim said the ground dropped off.  But   - since then, we'd decided to move the tower slightly and forgot that the ground really didn't drop off so much.  So we got the gin pole right down to the ground and the tower was quite a ways off of vertical.  At this point I had a pretty strong feeling that we'd not get finished and some serious re-fabrication was required.  Our only hope was to see if Tim could dig a trench for the gin pole with his back hoe - I thought that was unlikely because of all the large granite around but it worked out.  (lucky)



By about 3 Oclock Saturday it was getting very windy (gusting perhaps to 40 or 50 mph).  And - they were calling for a blizzard to roll in by about dark.  By this time we had raised/lowered the tower 3 times and everything was working very well.  The clouds to the west looked ominous.  I stood on this ladder for a long time waiting for brief moments of calm so I could balance the blades.  I got it 'close' I felt...


Another concern I had...  Tim used a small bulldozer to raise this tower.  He had to drive backwards about 80' while raising and that put him well out of ear shot - and too far away to see what was going on.  We had to post somebody about halfway out to relay any messages (the only messages he need to know were 'stop' or 'go').  I much prefer a winch for this stuff - it's quiet and easy to control and you can tell how tight the cables are getting.  Even a truck makes me nervous but the bull dozer is quite loud - and - should things get tight he'd never know it.  Big power tools can do lots of damage very quickly.  In the future this will have a winch.



Up she goes!  I told Tim before this - I would never raise a tower in winds like this and I would never turn on a brand new wind turbine for the first time in such strong wind.  The trouble was - we were heading for really bad weather, and...  he planned a party, there were about 30 folks standing on his deck expecting a show.  We got everybody out of the fall zone and went for it.  Tims classic quote of the day came about this time 'it takes balls to have an erection'.



It really went very smoothly with no problems and nothing ever seemed scary along the way.



We secured the tower and turned it on - again, in pretty high winds.  It started right up - seemed to be well balanced (lucky), furled up about half way and immediately started making between 2500 - 3500 Watts steady.   The blades ran at a nice tame speed/you can barely hear them.   It did that for about 5 hours-  then the blizzard really hit hard and somebody noticed it making a 'different sound'.  I went out and I could hear the blades were over speeding and it was vibrating rather badly.  It was obviously running single phase.  I ran outside and shorted the machine at the base of the tower/shut it down.  I could tell when I shorted it that there was no damage to the machine (all 3 phases were hot).  The alternator in this is pretty efficient and it stopped quickly.


The problem....  when we made the rectifier (a 160 amp 3 phase rectifier bolted to a fairly large heat sink) we used pretty long screws to bolt it to the heat sink (and we used heat sink compound).  While it all seemed quite good and tight - upon later inspection it was clear that the rectifier was not in good contact with the aluminum.  Also -when it failed, the heat sink was sitting face down on Tims workbench.  Two rather silly mistakes.  That's all been fixed now and I expect the machine has a good chance of working fine now (hopefully for a long time).


Overall it went well!  Some things went more smoothly than others.  We learned some lessons/made some mistakes that won't be repeated.  A big thanks to all the helpers that day - lots of people chipped in and lots of other people brought good food.  Lots of fun!!!

« Last Edit: October 25, 2007, 02:42:45 PM by (unknown) »
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SparWeb

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Re: Tims Tower Project
« Reply #1 on: October 25, 2007, 12:42:34 PM »
[SERMON]

Calling a stop to a proccess that is going too hastily, especially with a weather-related time pressure is a hard thing to do.  Sometimes you have to steel your nerve and say "no".  It makes everyone mad, but when you're sure you are right, you have to act on it.  It happens all the time in the aviation bizness.


Seen from another point of view, it robs Tim of the opportunity to learn how to safely deal with the windmill and tower in the future, in a way that makes you comfortable.


You're the expert.  We respect your experience, particularly when it comes to the limits of safety.  If someone isn't listening to you, or risking too much, you can walk away.


[/SERMON]


It looks fantastic.  I would be as eager as anyone to see it go, myself!

« Last Edit: October 25, 2007, 12:42:34 PM by SparWeb »
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Volvo farmer

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Re: Tims Tower Project
« Reply #2 on: October 25, 2007, 08:30:35 PM »
As my neighbor would say... "Life's rough in the mountains" :-)


Dan, I know the wall thickness, or specification of that 10" tube has been posted in previous posts, but could you add it to this one as well? I've actually thought of calling the local steel place to see what this stuff costs in sections, but wanted some specifications before calling and looking like a dummy. Didn't someone up there make a similar 6" or 8" thin wall tower with those neat couplings you've been using too?

« Last Edit: October 25, 2007, 08:30:35 PM by Volvo farmer »
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bigdan

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Re: Tims Tower Project
« Reply #3 on: October 25, 2007, 10:04:00 PM »
Could you use 6" well casing? That should be a little cheaper than steel tubing.

Good luck and have fun, bigdan
« Last Edit: October 25, 2007, 10:04:00 PM by bigdan »