 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : 19th Nov, Another way to make blades?
| Author | Message | ||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5116 |
I'm trying a new way to make blades with Trev's help. I used the Warlock blade calculator to get the best figures for a 2.4m diameter 3 blade TSR6 turbine. After a lot of CAD work, I used the laser cutter to cut out 100 ribs from 12mm MDF. 
The ribs all have a 30 by 1.2mm slot, angled correctly to give the correct twist to the finished blade. The blade is designed to bolt to Trev's F&P hubs, with its mounting tabs at 34 deg. It took about 20 minutes to cut these ribs out. 
Then I cut a 30mm wide strip from 1.2mm stainless. 
Sorting out the ribs took a while. From biggest to smallest, each rib was unique. 
Then I fed the ribs onto the stainless steel strip. 
Finished. 
Now its up to Trev to see if we can make this thing work. Trev will glue the ribs together, smooth out the ridges with a little filler, and use the finished profile as a plug for a fibreglass mould. Technically, its a very accurate blade, but time will tell if this is a good way to make blade plugs. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| AllanS Regular Member  Joined: 05/06/2006 Location: Posts: 67 |
Hi Glen, All most impressive. However... if the simple blades you made from pvc pipe work well, where's the advantage in complicating things? Suppose fancy blades are 5% more efficient, hey, make the pvc blades a few centimeters longer to compensate. That laser cutter, tho. Magnificent. I want one. |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5116 |
Good point Allan, the PVC blades are easier and cheaper, but this plug is to make a set of fibreglass blades for one of Trev's customers. The finished blades have to look good, run quiet, and last many years. Yeah I would like to take the laser cutter home with me, but it weighs over 3 tonnes and cost about $250,000. Not to mention it needs 3 phase 415vac power at 60 amps per phase, I dont think my local country road power lines could supply that. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
Trev Guru  Joined: 15/07/2006 Location: AustraliaPosts: 676 |
Thanks Glenn for the excellent effort. For those following this development, my work will be in Trev's DiaryAerofoil 1.2m blade. Trev @ drivebynature.com |
||||
fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi Glen, The blade profile looks great , did you get some ridiculous width on the bottom cord from the blade caculator? Can the blade length be streched to 1.4mt? I think a proper airfoil blade would have a lot more than 5% efficiency over Pvc or the pipe I use..... PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5116 |
Oh yeah, the calculator wanted a 700mm wide chord near the center! I stopped at 300mm, rounded it off. Normally home carved blades would stop at 180mm or so, depending on the plank of timber. By doing it this way I had no limits on chord length, so could go bigger. There is little power in this region of the blade near the center, but the large chord and steep angle mean a turbine that will start very easily. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
GWatPE Senior Member  Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi Glenn, Wouldn't it be better for a prototype, considering the laser cutter is so fast, to just make 3 or 4 blade templates and mount each set on a SSteel strip. The rough plugs could be sanded and finished with epoxy glass and sanded back and painted. This would be a lot less work for a set of prototype blades that are of unknown performance. If the blades work well, then by all means make a mould for production of Carbon/glass blades. just a thought. Gordon. become more energy aware |
||||
| AllanS Regular Member Joined: 05/06/2006 Location: Posts: 67 |
Hi Glen, You've used 'proper' blades as well as the pvc blades on roughly the same sized set-up. Any idea of the difference in efficiency? |
||||
| Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 676 |
GWatPE, "less work" to do a set of 3 blades - epoxy glass etc. Can't agree. Have a look at the amount of work involved with the 2m aerofoil blade in Trev's Diary, I have spelled out in more detail the amount of work and time it takes with the 2m blade. And 3 blades of equal shape and weight...??? Trev @ drivebynature.com |
||||
 Print this page |
 |
The Back Shed's forum code is written, and hosted, in Australia. | © JAQ Software 2025 |
