Ok, cool.
I was wondering if there was a preferred method (current vs. voltage) regulation. I will focus on the current then.
You guys are helping a lot.
If I install a current regulator, should it also be downstream of the LEDs?

 

Are you using the one from post 25?

 

If your generator output is ac then what do you expect the Vout of LM317 (dc ,ac) ?

Petkan:
Permanent magnet brushed motors when operating as generators produce DC.
The mechanical commutator acts as synchronous rectifier.

 

Ok, cool.
I was wondering if there was a preferred method (current vs. voltage) regulation. I will focus on the current then.
You guys are helping a lot.
If I install a current regulator, should it also be downstream of the LEDs?

Current regulation is definitely better for driving LEDs. It's just that you seemed further down the road of voltage regulation. Current regulators come in various guises, and where it is placed is dictated by the design of the regulator. There's been a few variations posted in this thread so far. ronv's two terminal solution does everything for you, and can go upstream or downstream (or even midstream!). Plamen's suggestion of turning your voltage regulator into a current regulator by adding a fixed load is neat and offers more customisation and experimentation potential that ronv's. It has to go downstream. The choice is up to you!