The self-timer group photo session.
On this year’s course we built a 2F machine but with 16 magnets instead of the usual 12. I have a cheap source of these smaller magnets. The 2F is a “2 metre diameter Ferrite magnet wind turbine” which is documented in my 2F wind turbine construction manual.
The rpm is a little higher than the 12-pole version. We played with adding an extra layer of magnets to one rotor, and got about 15% higher flux density (hence lower rpm) but I don’t think I will build any serious alternators stacked like that.
Most of the blade carving was done with drawknives but I did not get any pics of that. It’s an easier procedure than the one in my Recipe Book and seems to give good results for this size of turbine.
I am very grateful to Kostas Latoufis for coming to help, and for putting up with me so patiently. Also grateful to the five participants for their hard work and good company.
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- Welding practice
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- Owain welds the stub axle in
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- Theo welds the yaw bearing
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- Annabel welding
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- Kostas sets up the tail hinge angle
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- Theo helps with the tail hinge angles
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- More angles
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- Using a 6mm drill bit as packing to check that the tail hinge is above the yaw axis
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- JP sets up a fence to cut the blade taper
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- Tapering the blade
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- Owaing kerfing his blade
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- and chopping out the waste wood
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- Using a chisel to smooth the triangular ramp.
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- Removing the tip in the end
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- Some blades came out a bit undersized
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- Sam building up his blade with epoxy
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- JP cuts the root of his blade to fit the hub.
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- Annabel checks the thickness of her blade root
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- Marking out the holes for the coil winder
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- Sam drills holes
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- Cutting notches for tape
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- One coil winder.
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- Winding coils
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- Taping a coil.
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- The stator mould
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- 12 coils the right shape and size ready.
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- Fixing in place to solder tails.
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- Owain checks polarity using a magnet with a current in the wires.
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- Kostas and Theo put coils in mould.
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- Out comes the stator
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- Hot glue gun to fix the stainless wires around the magnets
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- 16 pole magnet rotors in the moulds
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- Owain assembles the alternator
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- JP fits the second rotor.
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- Extra magnets on one rotor.
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- Playing with an extra set of magnets on one rotor.
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- Hub assembled in reverse so we can access the grease nipple.
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- Checking clearances
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- JP welding the tail
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- kostas helps JP with tail welding
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- Theo paints the tail (a leaf)
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- Assembling the blades
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- Stainless steel coach bolts this time
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- Drilling clearance holes
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- The blades did not need any balance weights!
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- Off to put up a windmill.
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- The self-timer group photo session.
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- Annabel cranks the rope hoist.
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- Up and running!
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- Another beautiful windmill spins.
Looks like a fun time.
just one question…Given that you are off-grid, did you use your system’s batteries to do the welding -I know that some people do that- or did you use a gas generator ?
hi David,
Yes we use the batteries and inverter to weld. Much better than a generator. Silent and smooth with instant power response. for many years I used a generator and it’s great to now have a big enough system to comfortably weld with it. A decent 48V battery and a 3kW inverter is all you need to run an inverter/welder (much more efficient than the old buzz box type). I have had many engine-based welders over the years but using renewables is by far better.
cheers
Hugh
Interesting…I use an inverter welder, myself, and I like it very much; small, light, DC output and it does a great job. When asking myself about welding with wind/solar, I’ve always considered the straight-off-the-battery approach but I like your approach more. It’s not as messy and, unlike an engine-welder, it’s not running even when you’re not striking an arc.
years ago when we were running on wind, I had rebuilt a two-cylinder Wisconsin engine and I teamed it up with a 200A, 24 v aircraft generator for welding. It worked very well but had I set it up to dump charge into the batteries when not actually striking an arc, I could have justified it a bit better. I definitely prefer your idea and I’ll file it away for future use.
Lovely to see that well done