Hybrid Wincharger Update (photo)

[Dave B]

  Well it's been a while but my 18' Wincharger Hybrid has been modified and is very close to ready to fly again. As some may know back late last Summer I purposely let it run in extreme winds of 50-60 MPH and had a blade strike the tower at upwards of 6-8 KW output. I learned a lot and after lowering it and a detailed inspection I decided more than just replacing the blade set was the correct thing to do so I took it all apart and here's what was done :

  Wound and cast a new stator, cut and re-welded a lesser furling angle, replaced and re-packed new front and rear hub bearings, carved a new blade set changing the rotation to CCW., designed a new hub mount and shortened the blades to a 16' diameter, shortened the tail assembly to 8', installed a heavier mechanical brake cable and return springs, wired a 50A receptacle disconnect / shorting switch outdoor panel at the tower base.

  Bottom line is that the blades profile and diameter over powered my alternator after about 3-4 KW and the furling was set too "hot". I'd like to hold this alternator to about 3 KW and I think shortening the blades and adjusting the furling angle should allow for a more safe adjustment of the furling and RPM thus limiting it's max. output.

  All that's left to do is balance the blades and pull it up and wait for the wind to start testing. I pre-heat water with the wild AC (about 90-100 VAC unloaded at 200 RPM. Updates to follow soon.  Dave B.  

[richhagen]

It is nice to see it going back up. :-)  Rich

[jmk]

 I was wondering when you were going to post that it's going up. Looks nice! I can't wait to here how it performs.

[Dave B]

Thanks for the replies. I took advantage of the beautiful weather today and balanced my blades and winched it up, here's a couple photos. So far so good, saw 23 MPH wind today with it consistanly starting to furl at 20 MPH and fully furling by the 23 MPH mark.

This was approx. 3 KW total from my hot water heating elements. Time to connect the logger for my Davis Weather Wizard and my RS RS232 DVM for logging volts and current. Updates to follow, it's fun to have it back up flying and heating water again besides.  Dave B.

[blueyonder]

  it looks like you had fair weather to do your tower raising .

   a verry nice bit of work i must say dave.  the gen looks great.

   i thank you for the great pics with the blue sky's  

  you must be going about with  a smile from ear to ear .

[jmk]

Looks like you put some leading edge tape on the tips? What was the mark you wanted to be furled by?

[Dave B]

Very little wind so far today but that gives me the chance to see how well the blades are balanced. They don't seem to favor any one stop position so I believe they are close. I want to adjust to fully furled under 25 MPH wind and it was great to see it happening yesterday around 20 MPH so I'm on the safe side for now and like it that way. I installed stainless tape for 2 feet on the leading edge of the blades. This really does protect from abrasion over time and it looks sharp when the sun is just right. With 3 coats of gloss enamel and a coat of good old car hard paste wax these blades really look super and I know from before the performance will be great. Dave Moller carves these blades here at :http://royalfabrication.com/index.htm Updates to follow, thank you for your comments.  Dave B.

[jmk]

My blades can get a bit out of balance and still not favor any certain position. I can tell by a slight wiggle in the tail, and a slight vibration on the tower. This usually happens after ice - snow. I am glade to see it all worked out.  

[Dave B]

I like to balance everything with it all together on the tower and know I can get it close, (no load of course) I do use the rear grease seal but remove the spring that tensions the rubber and also just slightly cut a bit of the lip of the seal to lessen the drag, I'm glad it's on there. On my previous I used low temp (snow mobile grease) which seemed to work well in sub zero temps. to help it start up a bit easier but at 18' I don't think I could have really known how much it helped. I have bronze bushings at the top of the yaw bearing and tail pivot that I hole saw cut from 1/2" plate to fit (ain't cheap) and are greased besides. After inspecting these from before I think they will last forever. Waiting on the wind,  Dave B.

[jmk]

All I was trying to say was that after all you can do is done you can tell how well you did by looking at the tail and feeling the tower. I don't think that the dust cap thing  matters after ten foot. I greased mine booth ways and couldn't tell the difference. If there is it isn't worth worrying about, so you might just as well grease it. To tell you the truth the balance changes with the weather. You have experienced more than I with wind turbines anyway. I am just trying to give my two cents. You are well on your way.

[dalibor]

Dave B,forgive me if i have missed it somewhere while reading it before.

what is the closest distance between blades and tower?

[Dave B]

Hello dalibor,

  At present it is 1 foot. My previous blades were 18' and of Poplar, these are 16' and are of Ash. My previous blades were at 1 foot also but the blade striking the tower was caused by my own decision to push beyond the limits of it's design in severe winds. The plan worked perfect, the furling was not set properly, the blades over powered the alternator and went into overspeed. In winds of 50-60+ MPH one quick gust to yaw at over 350 RPM and smack, it was over. Plenty of modifications this time to control the speed and better match the blades to the alternator.  Dave B.