Waoouu awsome work, congratulation. Just an idea if you don't already have thought of it. As the generator shaft seems long enough, you could add a second pulley and a second belt , both pulley are mounted on a one-way bearing. So the generator rotate always in the same direction, and you get a DC current (to smooth with a capacitor) and you avoid the inertial losses of the rotation inversion. And perhaps you could add a flywheel. Keep up the fantastic work laurent

great work.

GREAT JOB......wind generator as the generator would be more eff when charging.....I have 1 400 watts in perfect condition I could send it to you Fedex if you want. It is brush less with strong magnets inside very low torque.

The back and forward motion has to increase its speed, and then decreases. Some sort of sinus wave. If you want to charge a capacitor with AC (as that is what your DC generator creates), and even if you rectify it, not all (electrical) power is transferred. You can visualize this by drawing the rectified sinus wave, and draw a line at (lets say) 9 Volts if that is what the capacitor holds. This means all power from zero to nine volts is unused. I have this problem myself! I have 2 solar panels, one is 80W 16 Volt, the other is 120 Watt 22 Volt. These are in parallel. So at clouded days the MPPT will drop the voltage to round about 11 or 12 volts, so that both solar cells can deliver power (which is more power than if only one cell would deliver it at 18 or more volts). It is as if you are looking at a bucket which is being topped continuously. The voltage is the 'height' where there is an opening in the bucket to have its water poor out. To get 100% all power, the hole would be at the bottom for the best performance. How do you get this done electrically? This is how I do it: I have no MPPT for real! I am just using a DC2DC booster. It boosts up to 36 volts, which then goes into my inverter (sending power back to the grid). I hope this helps. On the other hand, this design will probably be better off all mechanically build. Perhaps you can use the stroke movement to pump up water, and have that fall down with a constant speed?

Magnets can also be used in driving the generator, eliminating more friction from mechanical transfer. Also magnetic levitation instead of conventional bearings.

have you tried playing with BITTS transformer?

Your setup's begging for a Scotch Yoke.

Luc, any more testing on this? Further changes? Etc... Seems you disappear? 3 yrs ago?

Brushed DC motors with gear reduction won't approach 80% efficiency... more like 75% direct drive, and 65% with multi-stage gear reduction. Only in brushless DC motors can you approach efficiencies of 85% and higher... even up to 95%. With modern brushless DC motors from radio control applications, you would see much higher performance on both sides. Very low Kv (RPM/volt) rated motors (large outruners, like used for camera gimbals - 90mm and larger) would be about the right speed for this - without any gear reduction losses. For the generator/alternator motor, you gain a lot of efficiency by it being many poles/rotation for a higher frequency output, then with 3-phase low-loss Schottky bridge rectification, you get much more usable DC output. An interesting mod would be to convert the reciprocating output into a one-way rotation, driving a flywheel on the shaft of the BLDC motor/generator. With a pair of one-way bearings attached to identical gears, driving the opposite sides of a mating (smaller) gear mounted on the 'generator' shaft (along with a couple of idler bearings to get adequate timing belt wrap), you would have a more continuous output speed/voltage. Reason? When you allow ANY motor/generator approach Zero speed, you lose TONS of efficiency... you have to maintain a constant shaft speed, and well within the efficiency curve of the motor/generator (alternator really) being used. I sure wish KZfaq allowed attaching images... I could post a scribbled-up drawing... www.dropbox.com/s/8uqag76cw1df3zm/lucgotoluc-oneway.jpg?dl=0

are you counting that your measurements were on the outside diameter of the wheel...now the torque of moving the wheel from the center is hi than moving tangential

very impressive. Ever thought also using magnets to mechanically convert linear to rotary movement like in kundel motor? good demo here: kzfaq.info/get/bejne/m7SXl5SLu8DYo40.html could it be possible to close the loop with this kind of system. it would minimize losses by not converting to electricity. Keep up the great work Luciano