My 3d printed generator

[karlb]

Thanks.
What diameter would you recommend for the wind mill section?

design the transmission system in such a way as to keep your gear ratio options open.

Definitely! If theres one thing I've learned from this so far, its to design things in a way that keeps your options open later on .
Thinking about enclosing the alternator in its own unit with only the shaft and wires coming out. Then 3d printing some gears, and mounting the alternator on some type of 'sliding rails' so that it can accommodate different gear sizes. Ideally the alternator slides along the rails until the gears mesh and then its held in place by some screws. To change the gear you just undo the screws and slide it out

[electrondady1]

my vawt design  uses 5/8 cold rolled steel for axles
it's only 20"x 54" sweeping 7.5 sq.ft.
that's as tall as i feel comfortable going with a single mounting point at the bottom.
any taller and you will need another bearing point at the top

gathering pieces now for the next step 4'x6' sweeping 24' sq.ft.
and for that i will use 1'dia c.r. shaft.

[fabricator]

If you use chain and sprockets you can change ratios simply by swapping sprockets, it's a lot easier than trying to get perfect gear mesh.

[karlb]

Thanks, I'll consider adding another bearing point at the top and or using a thicker axle.
Thanks for your advice fabricator, I am still working out the design for a gearing mechanism as I go along. Whether it is gear mesh or chain and sprocket will depend on how easily I can get hold of a chain, and how well either design fits my current setup.

Quick question whilst I have the alternator apart:
Will adding some steel wedges in between the magnets as shown give me a higher volt/rpm? I'm thinking this will help conduct the flux even better. If so then how many layers / how far up the magnets should I go?


Cheers.

[karlb]

Sorry about the double post, couldn't find a way to delete it

[Flux]

No don't do that it will be a disaster.

You will divert the flux between adjacent magnets on the discs, you want it to cross the air gap .

The only conceivable way it might help is if the steel discs are way too thin and you keep the wedges less than about 1/3 magnet thickness. If the discs are far too thin then your wedges would be more use at the back of the discs, but it is not the right way to go.

Flux

[karlb]

Thanks for your advice Flux, I won't add those wedges 

I've done a lot over the past few days, Here I am drawing around the 3d printed blade holders to cut out wooden ones. They will be a lot stronger made out of wood, and also I can get loads of wood for free whereas 3d printing filament is expensive.
I made the arms coming out of the hub slightly longer so that the wings are further out which should give me a bit more power.

I scavenged an old bicycle chain that my local bike repair shop were going to throw away, then 3d printed some gears for it. I'm gearing at a ratio of 3:1 (21 teeth to 7 teeth) which seems to be working well from my initial tests, but I can easily change this.
Here is a pic of what it looks like so far:

More in the video: https://www.youtube.com/watch?v=8ofceH45qyY
In the video you can see me turning the blades by hand with my 3-phase rectifier and multimeter all hooked up. You can see I get up to about 19v.
To get the torque I need I'm going to have to stack more blades to increase the height. All I need to do is cut out some more wooden blade holders and put blades in them. This should be easy compared to the rest.

[electrondady1]

nice to see the lights come on
your machine makes electricity
congratulations.
now your gonna be hooked just like all of us !