Build Your Own Generator From A Lawn Mower

Motor Selection

Horizontal motors can be used but are not as standardized, so expertise in fabrication of your mounting plates could be necessary.

Vertical motors are usually more prone to be mounted to even a piece of plywood, though the vibrations would eventually wear through you mounting holes. Building a base similar to the old mower base would be ideal. Though most of the mower bodies themselves are constructed wrong for using for this project, unless using an old power deck style that used a v-belt to run the blades. You could also use an old riding mower as a platform. One of those Briggs and Stratton V-twin motors could come in handy for producing consistent power in an emergency.

This would also remove the mounting of wheels to make the generator mobile, and you could leave the push handles intact as well to use for mounting the inverter and power boxes. You would only be left with mounting the alternator and battery(s). The riding mower could still be completely mobile and the generator parts could go under the mower where the original mower deck was, using the PTO of the blades to power the generator.

Mounting the canisters for the Brown's Gas system would be easier with the riding mower as well. One of my projects was on an old commercial Yazoo unit with an 8-horse motor. I just added the part about the riding mower because I recently picked up and old Ford farm and yard tractor with a rebuilt Briggs and Stratton 16 horse V-twin. It is currently in the parts gathering stage. Photos will be added when I start building it. It is a horizontal motor so there will be some use of the original pulley systems that powered the mower deck for building the alternator system.

The Alternator

A GM style automotive alternator. The alternator will fall into one of three categories:

A) External voltage regulator type.
This type of alternator does not have an internal regulator and must have one connected externally to control the alternator field intensity and thus the output voltage and current of the alternator. The disadvantage in using this type of alternator is that connection is a bit more complicated and the regulator is an added component that must be mounted and connected properly. This type of alternator is typically less expensive than the other options shown below, but like the model with an internal regulator, it too requires an external on / off switch or the alternator and regulator pair can discharge batteries when it is not charging and the switch is left on.

B) Single wire connection type with internal regulator.
The single wire connection type alternator automatically starts producing output power when the RPM of the input shaft reaches a minimum speed. And, when the RPM drops below a preset speed the output stops. A big advantage is that it does not require a switch to isolate the alternator from the battery source to keep the alternator from draining the battery when not in use. The disadvantage in using this type of alternator is that the alternator will start to charge the batteries as soon as the minimum speed is reached, and will place a load on the engine as soon as the minimum RPM is achieved. In some cases, you might need to throttle through this minimum RPM range to insure that the motor does not bog down at low RPM when the alternator begins to produce power. Another disadvantage is that these alternators are more expensive than other options, but it provides a very simple connection method.

C) Internal regulator type with external control switch.
This alternator has an internal voltage regulator but requires an external switch to start or stop power production. The advantage in using this model is that the alternator can be switched off while the motor is still running and power output stops. This aids in connecting and disconnecting batteries or other loads.

Warning You must use a regulator type alternator. Failure to so will over charge the battery and cause a meltdown at the very least!

My new riding mower system will be powering four GM 220 amp alternators from Nations Auto Electric .com. The system will have a drive pulley pulled from an auto air conditioner so that if the motor throws any kind of warnings (overheat, power loss, over charge, emergency shut down) the alternators will quit spinning before the motor does. More details on this system at a later date!

Battery
While a deep cycle battery like a marine or a car audio specialty battery like a StreetWires, PhoenixGold, or Optima battery would work best but aren't necessary.

A basic car battery of a medium CCA (cold cranking ampere) rating should suffice. If you are looking for more amperage you can always add more batteries in parallel. But be sure to check the ratings on your inverter!

My new riding mower system will actually have lots of room for batteries, so I am in the process of designing a system that will handle several thousand kW, complete with a dummy load so that the system can shut down safely without over charging the batteries and the motor can stay running.

Inverter
This is going to completely depend on your application. There are basic 350 to 500 watt units that can easily power a TV or laptop, or ham radio equipment. Then there are monster watt+ units that while pricey could power a refrigerator, lights, well pump, or small heater during a black out. Check around for for the best unit for your application.

OR you clever hackers could find the initiative to wire up a couple of old computer UPS systems (yeah those battery backup thingies) for a cheap inverter. I will discuss that later! My system will have a purpose built inverter from an RV.

HHO unit
Everybody by now has been over run by Ozzie Freedom's Water4Gas units. Well, you know me, I reverse engineer everything, and his little windings of stainless mean nothing to me. I use perforated stainless plates made from upcycled kitchen appliances like sinks and refrigerator panels.

I do use the parallel canisters though. I will get into a more in depth with my ongoing unit as we continue. I will discuss the different parts of my unit in detail later.

The riding mower project will feature a double six pack. For information on the designs let me know if you are interested. I am considering drawing up a full plan and selling the ebook.

My design I like to think goes a bit further than Mr Freedom's units by offering more surface area for the water molecules to break under the electrolysis. It really still isn't efficient enough for more than just a few pennies of gas savings for an automobile, but for a single or twin piston engine, an expanded and more efficient system can be the sole source of fuel.

Instead of using an elaborate plexiglass tower with a few strand of expensive stainless wire wrapped around, I am working with a cylindrical wrap of an 8 inch by 30 inch piece of stainless steel cut from the bottom of a kitchen sink that was discarded. The sound deadening material was a pain to remove, and I drilled thousands, well hundreds of holes in it.

Then wrapping the coiled sheet I kept it from shorting against itself by making stand offs of simple neoprene tubing. Once finished, the coil was dropped into a canister that my former employer sells in their catalog. The canister I use is actually a water purifier container. I just don't need to buy the filters.

The units will be detailed on a later page. For now email me keystone045(at)hotmail(dot)com or twitter me @sirkeystone for more details.

Using the updated Water4Gas system using a six pack of canisters set up in parallel meaning each canister feed a mainfold, rather than Ozzie's original design that had each canister feeding the next one in line in a series circuit, I built a system using another of my former employers parts: a pex pipe manifold, which is actually a water pipe manifold for branching water into a hotel, an apartment complex or such other application.

This manifold has check valves before the HHO gets to it, and check valves after the HHO leaves it. It also has a pressure valve so that at a set pressure, the valve lets off the excess rather than forcing it's way into the carburetor, causing who knows what kind of carnage. Of course, you have to buy the valves. The manifold doesn't come with them...

Of course I will be expanding this part as I get time so check back or leave a question at the guest book or @sirkeystone on twitter.

Working with a lawn mower engine can be risky, because they put out a decent amount of power. Be careful of spilling fuel and oil onto the motor when lifting and setting it onto the base. Beware of the danger of overheating, and do not rely on this type of machine for all your emergency power.

Building a generator like this probably will save money over buying one at a hardware store, however, it will take up a lot of time, and may not work reliably in case of an emergency, depending on your knowledge of engineering this project.

Working with the insides of a breaker box of any other power center, or working with your own UPS storage device is very risky. Some of the batteries and capacitors can store high levels of electricity even with out being plugged into a outside source. In some cases the shock could be as bad as working with a fly-back transformer on a television, which of course, would make a worthwhile addition to this project for doubling your power output.

HHO can be very dangerous, make sure all check valves are installed properly. Oxygen and Hydrogen are explosive, that is the point. It is best not to let the gases build up too much pressure, otherwise if you are lucky all it will do is pop the lid off of your canisters. At worst your neighbors could have you hauled away for some kind of act of terrorism, and you'll have a big hole in your back yard.

By the way you aren't experimenting with this stuff inside the garage are you?

Temperatures: The motor and the exhaust should run at considerably lower temperatures because of the implosive nature of HHO, but it still produces heat. The alternator generates heat. The UPS device generates heat, ANY inverter generates heat. The HHO canisters work by generating heat. Some of your devices may need to be fan cooled. Simple 12V fans can be wired into the 12V side of the system.

This entire system is a "Your Own Risk" project. If you build this generator or something similar, you must build it at Your Own Risk, and assume all risks related to it's construction and subsequent use. This tutorial is intended for educational purposes only. No guarantees are expressed or implied as to the accuracy of the information presented here. If you have any doubts consult with the experts you purchase your parts from, before attempting to carry out any of the procedures mentioned here.

Some of the parts mentioned in this build were not built for this purpose. Some of these "experts" you consult will tell you explicitly that these procedures are not going to work, or at least not properly.