Posted by Solar Flare on February 21, 2007, 9:43 pm
Forget all the gin pole and counter weight crap. I have been through
it with a 150 pound unit on a 4" pipe pole. Hook up the top to your
ATV and have somebody back it up to take up the slack. Get two strong
men to lift the pole up and walk their hands down the shaft as the ATV
backs up to take up the slack. Safety is all you really need for this
tiny unit not to falll on your heads. If you base it fastened with a
hinge you can raise it in five minutes.
Make sure your tensioners are not open hooked and/or your guy cables
are looped back through a solid part of the ground anchors. A few have
been dropped because the guys disconnect themselves on open hooks as
the unit is raised and the tensions slacken and tighten. The same two
men can hold the unit vertical as the fourth tighten and adjust
guys.One or two long 2x4s can aid in the balancing for safety also if
you can find a "notch" or joint to hook them under.
> wmbjk said the following on 2/21/2007 6:38 AM:
>> On Tue, 20 Feb 2007 18:12:43 -0800, 'Captain' Kirk DeHaan
>>
>>> wmbjk said the following on 2/20/2007 4:43 PM:
>>>> On Tue, 20 Feb 2007 14:42:31 -0800, 'Captain' Kirk DeHaan
>>>>
>>>>> I have an Air 303 wind turbine. Still working fine. My issue
>>>>> is it is not high enough. It's only 15' off the ground although
>>>>> we are a few hundred feet off the valley floor on the side of a
>>>>> mountain and have decent wind flow. The actual "good" wind
>>>>> stream is about 15' higher. I plan to build a single pole tower
>>>>> of nested/stacked sched 40 steel pipe with a pivot arrangement
>>>>> at the bottom. The bottom will start at 3" and end up at the
>>>>> required 1.5 inch pipe. 3 to 2.5 to 2 to 1.5. I am looking for
>>>>> information on lateral forces I may encounter so I make sure I
>>>>> have enough concrete at the bottom and a stiff enough pole that
>>>>> will hold up to the gusts. My current thinking is a 15' section
>>>>> of sched 40 1.5 inch as the last step with the remaining steps
>>>>> in 5' sections. Overlaps at the welds will be 1.5 feet. I'm
>>>>> looking at about 800 lbs of concrete for the base set 5 feet
>>>>> deep. I have a C band satellite dish that has not moved in 12
>>>>> years with this amount of weight at the base and a huge surface
>>>>> area even though it is mesh. Do you have any pointers to
>>>>> tech/engineering data that might help and what do you think of
>>>>> the plan?
>>>>>
>>>>> Any help appreciated
>>>>>
>>>>> Kirk
>>>> A 303 is a pretty light load, I've seen quite a few on un-guyed
>>>> towers
>>>> of 20 -30', most of lighter construction than you have in mind.
>>>> Your
>>>> plan sounds fine to me, although I'd probably simplify it with
>>>> fewer
>>>> steps in the pole. I posted some info previously that might give
>>>> you
>>>> an additional data point - "Here's a photo of a similarly
>>>> constructed
>>>> windsock tower.
>>>> http://citlink.net/~wmbjk/images/windsock.JPG Sock is 18"X96",
>>>> pole is
>>>> close to 30' tall. It only bends a little in a stiff wind. The
>>>> brace
>>>> at the bottom doesn't hold anything up, it's attached to a
>>>> counterweight so that I can raise and lower the pole by myself.
>>>> Concrete is about 18" in diameter, 36" deep. I dug most of the
>>>> hole
>>>> using a powered chisel, which should give you some idea of the
>>>> ground
>>>> hardness."
>>>>
>>>> Wayne
>>> Hadn't thought of a counter weight. Using that my plan should
>>> work fine with some changes in the steps. I'll stick with the
>>> overkill on the concrete since we have some wet spring thaws.
>>> Thanks!
>>
>> My original plan was to use a chain as a link between the
>> counterweight end and the tower. That way the tower could lower
>> perhaps 30% of the way before picking up the counterweight, and
>> more
>> of the effect of the counterweight would be available when the
>> tower
>> was in the lowered position. But since the windsock is mounted on a
>> 10% slope, folds uphill, and is lowered onto a crutch, the
>> counterweight worked well enough with a fixed link. It's a bear to
>> get
>> the tower started down, but after that it's easy to handle. If
>> you're
>> on level ground, you might use the chain, and perhaps even dig a
>> pit
>> for the counterweight to maximize its effective range. What are you
>> planning to use for hoisting power?
>>
>> Wayne
> My original plan was to use a gin pole with the winch from my ATV
> with the ATV anchored to a car or truck for "ballast".
> --
> Kirk
> "Screw the planes, take a train", Me
Posted by nicksanspam on February 21, 2007, 3:04 am
>I have an Air 303 wind turbine. Still working fine. My issue is it is
>not high enough. It's only 15' off the ground although we are a few
>hundred feet off the valley floor on the side of a mountain and have
>decent wind flow. The actual "good" wind stream is about 15' higher. I
>plan to build a single pole tower of nested/stacked sched 40 steel pipe
>with a pivot arrangement at the bottom. The bottom will start at 3" and
>end up at the required 1.5 inch pipe. 3 to 2.5 to 2 to 1.5. I am
>looking for information on lateral forces I may encounter so I make sure
>I have enough concrete at the bottom and a stiff enough pole that will
>hold up to the gusts. My current thinking is a 15' section of sched 40
>1.5 inch as the last step with the remaining steps in 5' sections.
>Overlaps at the welds will be 1.5 feet. I'm looking at about 800 lbs of
>concrete for the base set 5 feet deep. I have a C band satellite dish
>that has not moved in 12 years with this amount of weight at the base
>and a huge surface area even though it is mesh. Do you have any pointers
>to tech/engineering data that might help and what do you think of the plan?
V mph makes 0.00256V^2 lb/ft^2, eg 6.4 psf at 60 mph. If a 4' prop with
12.6 ft^2 of swept area pushes 80 pounds max (less, given Betz) with
guy wires every 10' up to 10' below the top, it needs to resist about
10x80 = 800 ft-lb = M = fI/C = 25KPir^4/(4r) = 19635r^3, so r = 0.34",
for solid pipe... 3/4" schedule 40 galvanized pipe with 1.05" OD makes
I = Pi/4((1.05/2)^4-(3/4/2)^4) = 0.044 in^4, so M = 25Kx0.044/(1.05/2)
= 2101 ft-lb, over twice the requirement.
The lower guy wires might have spreaders, with no ground connection.
Nick
Posted by Solar Flare on February 21, 2007, 9:45 pm
Wayne is instructing him to not use any guys. Figure that one into
your calcs...LOL
A disaster waiting to happen.
> V mph makes 0.00256V^2 lb/ft^2, eg 6.4 psf at 60 mph. If a 4' prop
> with
> 12.6 ft^2 of swept area pushes 80 pounds max (less, given Betz) with
> guy wires every 10' up to 10' below the top, it needs to resist
> about
> 10x80 = 800 ft-lb = M = fI/C = 25KPir^4/(4r) = 19635r^3, so r =
> 0.34",
> for solid pipe... 3/4" schedule 40 galvanized pipe with 1.05" OD
> makes
> I = Pi/4((1.05/2)^4-(3/4/2)^4) = 0.044 in^4, so M =
> 25Kx0.044/(1.05/2)
> = 2101 ft-lb, over twice the requirement.
> The lower guy wires might have spreaders, with no ground connection.
> Nick
>
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>> On Tue, 20 Feb 2007 18:12:43 -0800, 'Captain' Kirk DeHaan
>>
>>> wmbjk said the following on 2/20/2007 4:43 PM:
>>>> On Tue, 20 Feb 2007 14:42:31 -0800, 'Captain' Kirk DeHaan
>>>>
>>>>> I have an Air 303 wind turbine. Still working fine. My issue
>>>>> is it is not high enough. It's only 15' off the ground although
>>>>> we are a few hundred feet off the valley floor on the side of a
>>>>> mountain and have decent wind flow. The actual "good" wind
>>>>> stream is about 15' higher. I plan to build a single pole tower
>>>>> of nested/stacked sched 40 steel pipe with a pivot arrangement
>>>>> at the bottom. The bottom will start at 3" and end up at the
>>>>> required 1.5 inch pipe. 3 to 2.5 to 2 to 1.5. I am looking for
>>>>> information on lateral forces I may encounter so I make sure I
>>>>> have enough concrete at the bottom and a stiff enough pole that
>>>>> will hold up to the gusts. My current thinking is a 15' section
>>>>> of sched 40 1.5 inch as the last step with the remaining steps
>>>>> in 5' sections. Overlaps at the welds will be 1.5 feet. I'm
>>>>> looking at about 800 lbs of concrete for the base set 5 feet
>>>>> deep. I have a C band satellite dish that has not moved in 12
>>>>> years with this amount of weight at the base and a huge surface
>>>>> area even though it is mesh. Do you have any pointers to
>>>>> tech/engineering data that might help and what do you think of
>>>>> the plan?
>>>>>
>>>>> Any help appreciated
>>>>>
>>>>> Kirk
>>>> A 303 is a pretty light load, I've seen quite a few on un-guyed
>>>> towers
>>>> of 20 -30', most of lighter construction than you have in mind.
>>>> Your
>>>> plan sounds fine to me, although I'd probably simplify it with
>>>> fewer
>>>> steps in the pole. I posted some info previously that might give
>>>> you
>>>> an additional data point - "Here's a photo of a similarly
>>>> constructed
>>>> windsock tower.
>>>> http://citlink.net/~wmbjk/images/windsock.JPG Sock is 18"X96",
>>>> pole is
>>>> close to 30' tall. It only bends a little in a stiff wind. The
>>>> brace
>>>> at the bottom doesn't hold anything up, it's attached to a
>>>> counterweight so that I can raise and lower the pole by myself.
>>>> Concrete is about 18" in diameter, 36" deep. I dug most of the
>>>> hole
>>>> using a powered chisel, which should give you some idea of the
>>>> ground
>>>> hardness."
>>>>
>>>> Wayne
>>> Hadn't thought of a counter weight. Using that my plan should
>>> work fine with some changes in the steps. I'll stick with the
>>> overkill on the concrete since we have some wet spring thaws.
>>> Thanks!
>>
>> My original plan was to use a chain as a link between the
>> counterweight end and the tower. That way the tower could lower
>> perhaps 30% of the way before picking up the counterweight, and
>> more
>> of the effect of the counterweight would be available when the
>> tower
>> was in the lowered position. But since the windsock is mounted on a
>> 10% slope, folds uphill, and is lowered onto a crutch, the
>> counterweight worked well enough with a fixed link. It's a bear to
>> get
>> the tower started down, but after that it's easy to handle. If
>> you're
>> on level ground, you might use the chain, and perhaps even dig a
>> pit
>> for the counterweight to maximize its effective range. What are you
>> planning to use for hoisting power?
>>
>> Wayne
> My original plan was to use a gin pole with the winch from my ATV
> with the ATV anchored to a car or truck for "ballast".
> --
> Kirk
> "Screw the planes, take a train", Me