Home Brew Hydro : MK II & III

A small hydroelectric project. (see MK I)

Home Brew Hydro Saga

MK I: Early turbine and generator

MK II & III: New alternator and couplers

MK IV: shaft bearing and real world use

Coanda Effect water intake (New Rain Update!)

New Penstock and Nozzles WOW

Home Brew Hydro Video

Bob's Water Wheel Project

alt.energy.homepower discussion

Useful links

Contact Me

hh 1

Here is MK II -- a short lived version that did not produce the desired RPM and it had issues with the shaft coupler. Way too much spin washer effect when it got up to speed. The coupler had been bored out but didn't really fit all that well on the alternator, so it introduced a lot of side to side variability. Also there were too many right angles in the plumbing so I was losing power. Then it froze and broke one of the pipes so I changed everything.


To solve the shaft coupler issue I eventually ordered three piece coupler from The Epicenter of Eugene.

shaft couplerA

'Special-threaded and counter bored for GM alternators' & 1/2" Direct Drive Coupler mated together with a rubber spider. It made a much better connection to the DC-500 Wind Blue PMA

Following very informative advice from alt.energy.homepower I replumbed the system trying to minimize hard angles and I used flexible clear poly 1 1/4 inch pipe to make the connection to the 3/4 inch nozzle fittings. The only right angles are a T that comes off the 1- 1/2 inch main feed



The new coupler makes the shaft slightly longer but that was fine since I wanted to have a slight downward angle on the jets, in order to push the splashing away from the alternator. I also bored out both nozzles to 1/8th inch and then use a dremel tool to smooth and polish them, always trying to eliminate resistance and turbulence at the tip.

wheel 1


Here is the setup with the xantrex controller and the wiring. Its not pretty but I keep tearing it back apart and changing things, so this is a work in progress. Special thanks goes to the people who make Hamms

Keep Hamms Alive


So I fired it up and got it producing between 11.5 and 12.5 volts at probably around 1000-1200 RPM. But man .. it was shaking like a mofo. I wasn't able to get the shaft coupler to mate very well since it wasn't designed to grip the shaft without some kind of support structure. I had just tried gorilla tape and a hose clamp but that didn't cut it at high RPM.

When I can I'll drill and tap both couplers so I can make a solid connection between the two.

I made power today!. The xantrex c35 was blinking so it was charging. The battery I had in there was fully charged so i'll have to test with a dead one and see how it does. But first, drill and tap the coupler ..

coupler 2
Yesterday we finally got my buddy Erics shop un tarped after his roof was blown off in the last big storm. The roofers took their time, but what we had was access to his very nice drill press. We drilled and tapped the coupler so three equidistant stainless screws would mate the two parts together. Hopefully no more wobbly wobbly.


Yup! that was the ticket. The shaft is stable at around 1000 RPM and its making around 12 volts. Still getting the jets just right. You can move those jets a few mm and get a pretty dramatic change in voltage, so its difficult to get them spot on. I've ordered a brass and teflon bearing that will go onto the shaft at some point in order to relieve some of the pressure on the alternator (hopefully making it last longer), but it doesn't need it to operate. I'd just be smart to do I think.