New turbine, a few questions

[1951mgtd]

Hi to all--I'm Curt, new to the board, Located in NE Missouri.  I currently have a 860 watt solar array with 560 amphours of battery (next upgrade), an Outback 3048 invertor and MX-60 controller.  I have been lurking here and trying to post to no avail--board admin can't seem to figure out why after registering as a user and logging in, I continually get a "Permission Denied" when attempting to post.  We are still working on it and in the meantime, maybe admin will be so kind as to post this for me.  Any user with suggestions on board access could email me direct at xpag@nemr.net.

I have scratch built the 10' Windpower mill in 48 volt configuration (complete at this point-except for tail vane) I purchased the set of three fiberglass blades off ebay from an outfit in Texas.  They are 10'5" swept area and cost me $118.00 with shipping.  A couple questions on the mill.

1. My Kill switch stops the blades, but does not hold them firm--I suspect this is due to virtually no resistance in the  5' of 10ga wire, as mounted on my test stand.  Any thoughts?
   
2. Using the fiberglass blades and I'll put a 1/4" sheet of PVC on for a tail vane--How do I determine if I need to add tail weight for proper furling.  Every other aspect of the mill is virtually to specifications in the online directions.  (And I complement Otherpower for the explicit, easy to follow instructions--a little interpolation needed in places, but outstanding)
   
   

Next a couple questions on my tower.

I purchased this used free standing radio antenna tower from the local hospital when they installed a new taller tower.  I paid $255.00 for it.   It has some vry minor surface rust, but is structurally like new.  It is 5' across the 3 leg base and would be 98 feet tall if completely assembled.  However I have decided to use only the lower two sections with a 7" stub of 2 1/2" schedule 80 pipe for mounting the generator on.  This will put the generator at 80 feet.  I have bolted on my stub at the top and if I ever feel the need, I could put the 3rd section (25 feet) on with out any problem.  

I've configured the base as a tilt up--the tower secured along one section with "pipe in pipe" hinges and a hold down on the opposing leg.  All hardware is 3/4" grade 8 and hinge components are schedule 80 pipe.  At the base of the tower is a gin pole receptacle.  I plan on using a 30' gin pole and raise with my tractor using 3/8" 1/7 strand utility pole guy wire.  All guys will be single length--no splices.  (Bought a bunch of it from the local electric plant here in town--dirt cheap--with hardware.

My base for the tower is 10" I beam, welded into a "T" configuration.  This will be imbedded in 2' of concrete with three (one at each corner) 4' deep concrete pylons with rebar.

I will guy the tower at 65/70 feet with the same 3/8' utility pole 1/7 strand guy wire.  Being a triangle base with one side hinged --side guy wires (as in a four guy system) will not be possible---I intend on raising the tower with guys attached near the top and then connecting them via turnbuckles to the the guy anchor points, once it is standing--about 40' from the base in a triangular pattern off of each leg.

Am I being over concerned with the guying of the free standing tower?  It was free standing design with it's original mast radio antenna on it--however with a 105 pound wind generator mounted on it, I feel guys are necessary.

I will be test raising the tower lower section (41 feet), then again testing (two lower sections and stub (80 feet), prior to raising with the wind genny on it.

Sorry for the long dialog and many pictures--If I could get board access--this would have been sequencially done in smaller posts.  Any suggestions/comments/criticisims woul;d be appreciated.  I've only been into RE for a few months, but as you can see--not afraid to get my feet wet.  Iv'e done a lot of reading on the net, but i'm still wet behind the ears.

Curt B.

[ADMIN]

Another question Curt had, that I don't think I can answer --

Do I need to watch the blades themselves for fatique or fatigue to the generator frame et cetera?   RE Raising tower--Being on a 5 foot wide hinge (one side of the tower base) do you think side guys on the tower are necessary during raising?  I don't see how that's feasible if my guy wires are at 120 degrees(one on each leg).     Are you suggesting side guys (90 degrees off the line of pull) for the raising.   Curt

[Flux]

No form of electrodynamic brake will hold the blades fixed, they will crawl round slowly. You have to turn the alternator to generate power so there must be a crawl to produce a braking torque. This is perfectly normal.

Just try the tail and if it furls too early at least you are safe. Most err on the too heavy side and that is not safe. If it is well furled and you are below the expected output then add a couple of pounds near the vane centre and try again.

I am not a computer genius but make sure you have cookies enabled, I had trouble from that initially.

Flux

[SparWeb]

Hi,

...Any suggestions/comments/criticisims... OK I've got a few of each.

Firstly, great start!  I like meeting new members that are so resourceful.

I don't think any electrical kill switch can prevent rotation.  It has to move to create the current, and the current has to go wayyy up fast to work.  My kill switch works okay on 8' blades, but it could be better.  With 10' blades, just 10 gauge wire, I don't think you have a problem.

The tower is a nice find, but I want to ask about some of its bracing members: how thin are they?  It also looks pretty rusty.  Have you inspected EVERY joint for cracking?

Your tilt-up mechanism looks like it will work.  80' tower with a 30' gin pole - how heavy is your tractor?  I have a 25 HP garden tractor and my 45' tower can't out-pull the brakes.  You'll probably be fine.  When you start experimenting with tower lifts, start with no windmill, raise the tower a few feet, stop, put the parking brake on, and wait and see what happens.  Then later do the same with the weight of the windmill on the tower.  You will also notice the difference in power required to get moving.  

The pipe joint at the top doesn't appear to have a lot of spacing.  Do diagonals connect the pipe joint members?  It doesn't look like they do.  The windmill will load the legs of the tower between diagonals, potentially bending them.

For tilt-up gin-pole raising, nothing works as well as 4 FOUR guy wires in a diamond pattern.  I know you have a 3-leg tower.  Put your welder to use and make a few Y-brackets that can grab 2 legs and join the fourth guy wire.

Good luck.  Hope the admin sorts out your posting problems because I look forward to seeing your success!

[redneck power co]

have you thought about servicing your wind mill? Are you going to have to lower it if something small like a blade breaks off or can you just tilt the top section down it might be easier?

[electronbaby]

Everything you show looks very nice. I would say that tower looks great for a 10' turbine, BUT I would follow the advice, and check carefully for stress cracks. I also would be a little scared to raise and lower on those hinges you made. I hope that you will run some solid rod through the pipe. I fear the pipe would not be strong enough. It looks pretty small diameter. Also, I would have placed more distance between the top section mast supports.  There is a lot of force placed here under normal and extreme wind conditions. The legs of the tower are solid steel Im assuming. It looks like three top sections of an SSV Rohn. Maybe a clone. I dont remember the SSV sections being greater than 20'.

Good luck :-)

[DanG]

I also think the tower base is a little on the light side - it may raise a bunch of times with no problems yet over time the tolerances may take a jump for the worse just when you start taking it for granted. Block hinge sleeves instead of those dinky pipe tubes, 4-bolts per side, solid hinge pins, and a collar and some strut webbing on that ' T ' section AND on the jin cable attachments just to keep the gray hair count down?

That is a lot of tower, add in the stub and all cables & hardware, alternator and power drop lines I hope you see four guy line cables are definitely required to keep sway near zero every time, and larger hinges for when that tractor is snatching all that weight around ...

[DanG]

We scared him off?

[TomW]

Not at all.

If you read carefully, you will see he has an issue with his account not working.

Tom

[1951mgtd]

Thank you to all board users for your comments & suggestions. I can't post yet, but check the board often and appreciate your responses.  

I have beefed up the pivot points on the base as suggested and will add web reinforncement to the gin pole receptacle, the top stub and guy wire attachment points.  Also, upgraded to 4 guy wires as suggested.  I will insert a solid bar into the hinge pipe, even thought it is schedule 80 pipe already.

I am giving the tower a good inspection, as I wire brush it and paint it.  No heavy rust or cracks have been found yet.

Excavated and poured the concrete for the base today.  4 1/2 yards of 6 bag bag (4000 lb mix) for the base.  Two six feet deep reinforced poured pylons extend down from the center of the base.   Wire mesh added in the center of the concrete.  The base is nearly 9 ft by 9 ft (abbreviated triangle) and concrete is  36" deep.

Thanks again for the input.  I will check the board for further responses--or if anyone would like to email me direct--xpag@nemr.net.  Curt

 

[vfarrell]

Curt,

 Great start and a good looking genny, thinking you must be close to where I live (Glenwood, mo) going by your email addy.

Vic