This is a 500 watt power generator big enough to power tools, and home electronics. If you try plugging in kitchen appliances, heaters, window AC units etc....it will shut down, you need a 2k-3k watt power converter for large power comsumption appliances..
It's not difficult to build this project, if you know how to wrench things apart and have a basic understanding of how things work with engines and electrical components then you'll do just fine. If you want to save money on the build, go to junkyards, recycling centers, and landfills which is where I got most of the parts. You'll be surprised the stuff you can find for pennies or better yet FREE. I spent $40 for all the parts needed for this project.
There are a few optional parts not needed to run this little power jewel. The lawnmower tires, enclosure, vehicle battery, handle, voltage meter, 120VAC outlet, light, and on/off switch for light. I decided to go all out with this one by adding all those extra features, just took me longer to make, 3 months exactly. A schematic diagram will show how to wire everything up. The AC outlet you see on the panel is tapping from the power converter which already has AC outlets. I just wanted to make an extension of it so I wouldn't reach around the back to plug in things....
Step 1: Parts, Where, Tools, How Much$$
Here are some links for the power tools I used.....http://www.sears.com/shc/s/p_10153_12605_00921914000P?blockNo=2&blockType=G2&prdNo=2&i_cntr=1292168781911, http://www.sears.com/shc/s/p_10153_12605_00928223000P?prdNo=1&blockNo=1&blockType=G1, http://www.sears.com/shc/s/p_10153_12605_00911543000P?prdNo=10&blockNo=10&blockType=G10, (1) WOODEN or METAL platform- Helps bolt down the Alternator, Engine, and DC to AC power converter. I used aluminum sheet metal with L-frame bars for a sturdy frame. Got the sheet metal and L-bars for FREE from recycling center. I used a JIGSAW with a metal cutting blade to get the job done easy.(NOTE)..Do Not Try Using the jigsaw to cut IRON or STEEL...The blade will kick back and will break sending pieces flying...If you have better cutting tools for that kind of material then by all means use it.
Other tools include a drill press, vise grip, portable hand held drill, hacksaw, and a hand held file. If you have better tools to get the job done quicker and safer don't hesitate....It took me three months to build the crazy thing, and a few busted knuckles.
The platform size varies with how many components you want to throw on it, the one I made is a 2'x3' with a top shelf to hold vehicle battery. more details about that later.
(2) LAWNMOWER ENGINE- Vertical or Horizontal, 3.5HP or bigger. I got it for FREE from landfill (vertical shaft) with a key way slot, or you can buy a new one for $100+....
(3) ALTERNATOR- It's a delco part# CTBBB-7127-12 rebuilt, with internal voltage regulator, 65amp, two wire connector harness. paid $23, auto parts store. This is the heart of the system, I recommend using this one, it's simple to setup and comes with an internal voltage regulator.
(4) DC to AC POWER CONVERTER- The one I used is a 500 watt converter, got for FREE from recycling center. The bigger the better, pure sine wave is the best.
(5) VARIABLE RESISTOR- Also know as a Rotory Switch or POT. You can get one from an auto junkyard for $2... look for an older vehicle, 70's through late 80's any model, also known as a light dimmer switch or dashboard, panel lights dimmer....you just turn the knob in one direction and the lights dim or brighten....you need a 2 wire pin switch....this part is used to control the amps coming from the alternator.....
(6) ON/OFF Switch- There are a few different kinds...rotory, toggle, rocker, and push. I used a toggle with a built in green light.
(7) PULLEY- 3" or 4" diameter, IRON or STEEL, $3 from junkyard, Make sure it has a key way to help prevent it from slipping on the engine shaft. (NOTE) make sure the pulley is equal the weight of the cutting blade or greater, if not the engine will not hold it's spin cycle. Got mine for FREE from recycling center.
(8) BELT- $12 at lawnmower repair shop or auto parts store. If you want cheap try the landfill which I got from, or recycling center, auto junkyard or neighbor throwing it away. I recommend a belt from a self propelled lawnmower, makes a perfect fit.....which I used on this project.
(9) BOLTS with NUTS & WASHERS- Paid $12 for nuts, bolts, and washers from home depot. Try to get rust proof hardware.
Other parts are optional like the voltage meter, light, on/off toggle switch for light, and extra 120VAC outlet, which are not required to operate a fully functional generator.
Step 2: The Frame
The frame is what took me the longest to make for lack of tools, I used a jigsaw with a metal cutting blade which was kicking my butt, the blade would sometimes kick back so I had to take it slow. To smooth out the rough edges I used a hand file, also used a drill press, hand drill, and hack saw for the L -bars. I recommend using a band saw to cut the sheet metal and L-bars, that would have saved me alot of time.
Step 3: The Engine
You can use the same mounting bolts used to secure the engine to the lawnmower chassis..I used a jigsaw to cut out a hole big enough to have the pulley go through it, you first want to start a small hole with a large enough bit using a hand drill to fit the cutting blade through it
Step 4: The Alternator
How to connect the alternator. Here you want to the RED wire coming from the wire harness back into that positive nut. The purpose of that is to trick the alternator in pushing out a steady 14VDC at any RPM. The wire harness is included which consists of a two wire RED & WHITE. the WHITE wire has the dimmer switch connected in series which is used to control the AMPS coming from the alternator to charge a vehicle battery. more details about the dimmer later...it will probably make more sense looking at the schematics shown later.. Notice the two thickest wires RED & BLACK, they are for charging a vehicle battery which is optional, not required to connect on alternator if you don't want to charge batteries.
For a simple setup all you need to connect is 2 wires, 10 gauge size, Positive + (RED wire) connect it to the upper left nut on back of alternator, the other end of that wire goes to the positive(+) terminal of the converter box. The Negative - (BLACK wire) connect to the lower right nut(that is your negative) on back of alternator, the other end of that wire connects to the Negative(-) terminal of converter box.......That is it, just start the engine and turn on the converter box you should have 120VAC.......If you want to add meter gauges, lights, dials etc....I have more details with schematics...which will take longer to build...
To install the alternator just cut out a hole big enough to adjust the belt along with two bolts to secure the alternator....if it wobbles just add brackets to make it sturdy.. nothing to it.
Step 5: The Converter Box
Most converter boxes have built in 120VAC power outlets, just plug in directly to power up your home electronics or small power tools....you can also plug in a power strip directly into it like I did. GREY wire....Notice how I connected an outlet extending from the coverter box, that is so I wouldn't reach to the back end to plug in things...you can see the outlet showing in front of generator..
How to connect converter box to alternator. Simple, do you see that thick BLACK wire curving over, that is your NEGATIVE(-) wire coming from the NEGATIVE post(nut) from back of alternator. connect this wire to the NEGATIVE(-) terminal of converter box.
The POSITIVE(+) RED wire coming from POSITIVE(+) post(nut) of alternator connects to the POSITIVE(+) terminal of converter box...I ran out of red wire so had to use black wire....
You can custom make your own wire end terminals with a little bit of solder and heat shrink to have a custom professional look....You can secure the converter box with battery j-hooks, installed one on each corner....
Step 6: Variable Resistor(light Dimmer Switch)
Here is how you connect the dimmer. On the back side of alternator there is a connector with two wires sticking out of it, shown in step 4.....one RED and one WHITE, you can connect any one of the wires from the DIMMER to the WHITE wire, the other wire from DIMMER connects to the POSITIVE(+) nut on back of alternator nothing to it.
That's it, the dimmer is connected in series and now you can adjust the amps by twisting the knob on dimmer, you have to play with it to have at a proper setting. If you allow to much current to charge a battery, the alternator will slow down a bit and might cause the engine to stop.....You can install a bigger engine with more power.
Step 7: Main Power Switch
Here is how you connect it. This particular switch has 3 pins on the back for attaching wires....I will refer to them as pin1, pin2, pin3.
Step One: connect a RED(+) wire to the POSITIVE(+) terminal of converter box, then connect the other end of wire to pin2(NOTE: do not forget to attach a 10amp fuse in series) this wire will be the main wire carrying POSITIVE voltage.
Step Two: connect a RED(+) wire to the POSITIVE(+) terminal(nut) of alternator, then connect the other end of wire to pin1.
Step Three: connect a BLACK(-) wire to the NEGATIVE(-) terminal of converter box, then connect the other end of wire to pin3. Thats it. Keep in mind! you can solder wire terminal at the end of the wires to help secure them tight and clean.
Step 8: The Pulley
Step 9: The Belt
Before cutting a hole, measure the distance it will take to install the belt between the lawnmower pulley and the alternator pulley. You don't want to end up to tight where you won't be able to install the belt, or too loose where there won't be any rotation of pulleys....you can make a track to adjust the alternator to release the belt or tighten...
I recommend the belt from a self propelled lawn mower, that makes a perfect fit for it.
Step 10: The Bolts
Step 11: Optional Parts
I just added these components to add more features to it....not needed to run generator. included in schematics with details if interested in adding them....
Step 12: Labels
Step 13: Optional Meter Gauge
Step 14: Schematics
Step 15: Alternator Schematic
Step 16: LED Switch Schematic
Same here. each step will show how to connect each part, just follow the simple diagram and notes...
Step 17: Optional Meter,light,on/off Switch Schematic
Step 18: Final Step Optional Handle
This is the last part I put on, once again it's optional. Picked it out from recycling center and bolted it on...not much to it......That's pretty much it, took me 3-months to build this thing, what took the longest was building the frame because of lack of tools and finding parts at little to no cost. That alone was a bargain.
Good luck with this project, if you have any questions about the schematic let me know, some of the pics are far away. The battery is used for backup in case the motor runs out of fuel which is not being used indoors.....That would be to loud!