Instructables
Picture of Homebuilt Generator (Riding Lawn Mower) 1Kw
Well like most of us, I was looking to find a way to minimize expenses in creating an alternate energy power source.

The easiest way to perform this task was to re-use existing equipment installed in my home, & power toys to minimize costs.

My favourite expression to utilize cross functional synergies.

Well, I was able to put together the following items

At Home items


a) 2 Batteries (Used for my Motor Boat) 140AH

b) Lawnboy lawn tractor 10 HP (1980s vintage)



Sale Items


a) Xantrex 1000 power inverter ($89.00) Cdn Tire



Regular Priced Items


a) Fan Belt 4L44 Cdn Tire $ 11.00

b) 12V Car Led Lamp Cdn Tire $ 2.50

c) AC Power Monitor (UPM Em100) Cdn Tire $ 25.95

d) Battery clamps Cdn Tire $ 5.95

e) Booster Cables Cdn Tire $ 20.00


Optional: Siemens Generator Panel Box (and Circuit Breakers) $280.00

Note: Extensions cords will do in a pinch!

Scrap (Yard) Items

a) Cadillac Alternator (120amp) with Built in Regulator $ 35.00

b) 4 Position Switch (Scrap from old Battery Charger)

c) 6 Gauge Wire (Old Battery Booster Cables)

d) Panel Mount (For Switch and light)

e) Tie Wraps (Keep all loose wires tight and away from Belts)

Total Cost *Including Electrical Panel $ 469.40
Without Electrical Panel $ 189.40



 
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Step 1: Alternators

Picture of Alternators
Of special note, when assembling this conglomeration of items special care needs to be taken to research the specific products selected.(I.E.)

Alternators

The cheapest way to connect an automobile alternator is to select one that has a built in regulator. In many instances they are denoted as a single wire connect. If you have external sense lines coming from the alternator (As Below) , wiring can become a little more difficult as you may need a resistor value of approx 35 ohms leading from the Generator Light wire on the alternator to + DC voltage. You also have to have a Power Switch to disable the charging of the stator at initial power up time. I.E. The resistance of the alternator can generate enough force feedback to make it too difficult to start you engine.

cemb4 years ago
cemb: asks; at what rpm does an alternator need to spin in order to produce its max output
Maximum power is usually controlled by the regulator; it is more rpms and efficiency, usually 2 to 2.5 idle speed of the vehicle the alternator is for.
An example a Mack truck’s idle speed is 400 to 500 rpm and max rpm is 1800 you might want to run the alternator at 1000 to 1200.
A Chevy Sprint’s idle speed is 1100 and max rpm is 10000 rpm its alternator you might want to run at 3000 rpm.
NightLord3 years ago
So, is there any good solution how to connect inverter directly to home power?
This is the kiind of inverter you are looking for http://www.dcacpower.com/product/6000psw.html
In reality house wiring has 220 across two live lines that go to ground at the neutral making 110 per side. Another little known fact is home hydro can fluctuate from 90v to 135v depending on where you are on the line and how modern the service is. If you are getting voltage from the neutral it is probably feed back in the lines finding a shorter rout to ground, I was shocked by a house circuit with the circuit breaker off that way.
To connect to house wiring you need a 220 110-volt power inverter with a pure sine wave signal synchronised to the service. The output is kind of like a centre tap transformer. Service transformers have the windings hooked up in ether delta or Y configurations they’re essentially a centre tap transformer. This is a simplified explanation.
I hope this helps.
kflack (author)  Josehf Murchison3 years ago
Absolutely Correct Josehf !

My reference to using a (Non Bonded Neutral) for the switch panel is a non standard approach to temporarily use (During a power failure) for key switched circuits. By using a non bonded Neutral it is possible to use a less expensive inverter (Square Wave) versus True Sine wave as you mentioned above.They in reality do not use the same methodology for power generation (Center Tap transformer) and hence the need to have the Neutral (NOT Bonded) to the ground line. It is not an accepted standard for household wiring to have the neutral unbonded from the ground line, but is the only way possible to use a square wave inverter on household wiring via a switched panel.

Your assessment above is absolutely correct and is a superior configuration (True Sine Wave Inverter) that meets existing legal wiring codes. In your instance above, with a True Sine wave inverter, the Neutral Line would remain bonded to the Household ground
mpandersen3 years ago
Great article !!! My step-daughter REFUSES to turn off the computer when she is done, SO I want to make a pedal powered generator to get back at her. (If this seems cruel, I REALLY do need to lose my Molson Muscle !!! LOL) My wifes' car quite working right after I replaced the alternator :-(, so now I have a nice new shiny Delco Remy CS 130 series alternator I can't return. Would anyone be so kind to email me a wiring diagram of the circuit ? I'd hate to wire it up incorrectly and destroy it ! I've also stripped all of the relevant wiring & battery out of the car. Many thanks in advance. My eMail is : mpandersen@live.com
Oh, Hey! I made one of these last week!!! Min is made from a vintage 1980 Lawn Chief ride-on mower. The engine died, so i tore the whole thing apart and put in a 5hp honda engine. the new engine connects to the transmission, and also a 55-amp alternator. (I couldnt afford a more powerful one) it generatoe loads o power that run it's seven 55W halogen lights. i havent hooked an inverter to it yet, but i was planning on doing the exact same thing as you. I have it on youtube: http://www.youtube.com/watch?v=vK7WSZER9yI
I was half thinking of rigging  an alternator on a treadmill type of devise and just chaining the  yard tractor up on it.  this makes much more sense 
cchubb4 years ago
 One other little comment I would make would be to put one or two 12V biscuit fans on the brackets and aim them at the alternator. Those 100+ amp alternators run hot and heat is the major killers of the diodes inside. On a car they are usually cooled by the airflow over the engine, but on your genset here they won't get the same cooling airflow. 
Gen-set5 years ago
I have a Craftsman lawn tractor with a 19.5 B&S Twin-II I/C engine, that would work perfectly for the reasons that kflack stated. Driving a Delco CS-144 140A alternator should be NO problem!! Last year, I built a 1.5kW gen-set using a 6hp B&S Lawnmower engine, another Delco CS144, a Xantrex Prosine 1800 Inverter and up to 300Ah of batteries, for up to 5 hours of silent runtime before I have to re-start the engine.
Sandisk1duo5 years ago
A little bit inneficient, AC motors would work better
An AC MOTOR?? I assume you mean an AC alternator? The car alternator is an AC alternator that rectifies the AC to DC. You could remove the regulator I suppose to get straight AC but then the frequency of the AC would vary all over the place as the speed of the motor changes not to mention it would never be 60HZ or that you couldn't regulate the output voltage.
I'm sure the cost of a purpose built alternator designed to 120V would well exceed the intent of an instructible. You'd be better off buying a cheap generator!
Remember most electric motors are generators when driven. And generators become motors when plugged in. Or so I have been lead to believe, that is the premise of using a 3 phase idler motor to turn single phase into 3 phase on the cheap (generating the 3rd leg).
kflack (author)  darkride5 years ago
Hi In reality its a standard Cadillac Alternator with built in DC voltage regulator. The output is connected to a gang (2) of batteries for charging. To the batteries I have connected a Xantrex DC to AC Converter (Modified Sine Wave Generator). Simple ,functional, and the Lawn mower gets used every week (Summer) so the gas never goes stale. Tank also lasts almost 12 hours of use so I can sleep through the night, even during power failures (winter) as it keep our oil furnace going.
kflack (author)  Sandisk1duo5 years ago
Hi Alex You are correct, as this is typically what is used for standard generator(s) and they run at a constant speed to maintain frequency. Also as darkride mentioned, the speed control would not be available to ensure constant speed control or current control for that matter. The key here was to use as much available resources and get the "cheapest" possible way to charge the batery bank. It would be difficult to beat a $35 (cdn)alternator, both for price or endurance. The inverter is also so portable that it could, in a pinch be hooked up to your car battery and be used as a generator.
This is a great idea! It would combine with another project I found years ago that uses an alternator for arc welding (driven by an electric motor). this makes it more portable!
falconsabre5 years ago
great idea, easy and effective, i like it
Nice N' easy. I like it. Whats the added resistance like at startup without load? Is it worth adding an electromagnetic clutch like the one on the deck or not so much?
kflack (author)  Hands Without Shadows5 years ago
Interestingly enough even without a load attached the armature inside the alternator is generating its initial electric field and it takes quite the kick to get it started. That's the reason for the "Generator Light" resistor. These creatures are actually built to get their initial charge from the initial current from the generator light...to create this field. I highly recommend a bypass (Off Switch) disabling the light (Sense Line) until the motor has been started and is at a reasonable rpm before engaging. Still possible to start without it, but in cold winters where battery starting power is at a minimum I wouldn't want to take the risk when you have no alternative sources of power to start up you homemade genny.
In desperation a hill an nerves of steel can help for startups... Nice project - at best you'd be able to run a 5KW generator from that engine, though that's guessing it's still got 10HP then you'd be able to have a reasonable amount of electricity if it was for any length of time... I like the idea of the lawnmower having a generator though, I wonder what else it might benefit from? A stove on the back?
You could build a water heater that connected to the exhaust. The heat exchanger would act as a muffler too.
kflack (author)  Scubabubba5 years ago
Now your talking green energy.... Actually I do need a new muffler on the beast, thats a great idea,except I'll have to refill it, and it would need to be stainless steel (no rust)....getting complicated....
Saturn s-series cars ('92 thru '02) and maybe some others had stainless exhaust systems if you want to make a trip to the junkyard. If you treat it like a solar water heater you could have the heat exchanger in a small tank near ground level, then have a bigger tank (like an old water heater) elevated as a storage tank. Thermal expansion would drive the circulation through regular plumbing connections & you could get a hot gravity-fed shower or two in the morning when you have to run it all night. Put a toilet tank valve on a small side tank like a 5 gallon bucket (to keep it out of the heat) to automatically refill it from your regular plumbing system. How's THAT for complicated! LOL Great project you've got there -- there's a whole (very small) community of people who use the batteries in their '70s-era electric lawn tractors as power backup. Golf carts could work too. Anyways, nice ible, and it looks like it was fun.
kflack (author)  Scubabubba5 years ago
LOL Whoa ! Your not going to believe this but a) I own a Saturn SL2 (2000) b) I have 2 old (Non insulated) 30 gal ? Water tanks c) Just getting ready to replace my current hot water tank with a on Demand Electric. Was thinking of using the old tank as an exchanger for a Roof mounted solar Hot water heater panel. Man are we in sync or what...."Twilight Zone Music"
Ha! It gets freakier! My '95 SL went to 317,000 miles. Replaced it last year w/ a used '97 SL, my wife drives an '02 SL. And I have 2 water tanks in my back yard waiting for some type of solar project -- that's probably why I thought of it. I'd do on-demand but my electrical system won't handle it -- I've only got 200 amps (sadness).
kflack (author)  Scubabubba5 years ago
I also have a 200 amp circuit, but expect to be able to get the temp up about 30 deg + with a solar water heater. I also was thinking us using the old tanks (Uninsulated) as an internal heat exchanger to raise the water temp to room temperature.As I have a air based heat pump it would be a poor mans water pre-heater by using the ambient air temp to pre heat the uninsulated tank with air that was heated with the heat exchanger...Just trying to figure out what to do with the sweating tank.Apparently the 'Sweated water" is from the air and is relatively clean if it can be filtered and bottled.
So you've got ambient pre-heat, solar post-pre-heat, then the on-demand to top it off. I'll have to think if that'll work for me. There are comment threads on other projects where people talk about condensation water at painful length. Personally I'd water houseplants with it, but not drink it. If there's airflow over the tanks you'll get a bit of an air-cleaner effect, and the mostly pure, high-oxygen content water will slowly oxidize & dissolve the plating on the tank too. Eww!
kflack (author)  Scubabubba5 years ago
Element FourI guess a "Plastic Water" tank would be preferable to the "annodized?" aluminum (Yup, temporarily forgot how corrosive pure water is). There is a company that is working at bottling this stuff (From the Air Though)
Element Four
mabye i could install my old bolen gs 16
jongscx5 years ago
How many Amps does this output/would it be possible to scratch-build a decent welder with that size engine? Would be nice as it's self-propelled and self-contrained
kflack (author)  jongscx5 years ago
See Bradly CommentFound a link where someone actually did use it for a welder...
kflack (author)  jongscx5 years ago
Good Question....Keep in mind the current actually comes from the battery bank and the alternator is for charging the batteries. I have it running under my 100 amp rating (Fuse) and I figure its about 1000 watts charging, maybe 70 amps (DC @ 14+ volts)being pumped into the batteries under about 1/2 motor load or less.
dsandds20035 years ago
Is a good idea. Am wondering how this idea would work with a home made wind generator motor. Or a brushless DC motor??? I just might have to try something like this with a lawnmower engine, a wind turbine motor and run the small engine on home made fuel. I see LOTS of ideas generating from here!!!! Dave
Nice idea, however not that cost effective. I was able to buy a gas powered 1200w generator brand new at Canadian Tire for $119.00. But I guess if you have time to kill and money to burn this wouldn't be that bad.
kflack (author)  funinthefalls5 years ago
I probably wouldn't have built this 3 years ago if the cdn tire had existed at the time. I had already purchased the 1000watt (2000 surge)xantrex in the past and used it for quick power outages using the boat batteries (on trickle charge)I had. The generator (alternator) was only $35 (Scrap yard) so was the cheapest option to extend battery backup life... I bet your cdn tire generator will not run for 12hrs before refilling, and definately will not handle the same surge current that this baby can handle. Also, when you build one of these home gennies it becomes the talk of the neighbourhood....
You are right, I am sure mine would crap out long before 12 hrs. Your idea makes sense now that I know u already had the inverter, I thought u bought that to make this project. I applaud your ingenuity
natebug5 years ago
this is a very great idea!!!!!