Homebuilt stuff (generator)

[nonhog]

I am not as cheap as it seems I love making stuff from **** I've got laying around.
I would love a nice new Honda generator but not in the cards right yet.
check out this site I found when looking for homemade mufflers (look for another post)

http://theepicenter.com/cgi/order.c...erters_and_inverters.html&cart_id=%%cart_id%%


My big question would be refridgerators , how much does it take to keep one going and be able to handle the start up spike.
Could care less about lights , candles work just fine.

I'll probably build one even if it only powers lights . It would be a kick .

 

[Junkman]

Depends on the refrigerator. Some will work on a 900 watt generator, and others will require a 6000 watt generator. The details are the important factor when asking a question. How big a bus do I need to transport my whole family???? How many in your whole family????? got the idea?????

 

[Tom2]

Id love to build a generator.. Has anyone made on from scratch? Something like a 5-10hp engine with an alternator? Is it possible?

I especially need on here. Very cold, and if the power goes out, Ill freeze to death. No wood stove. And Im on well water.
Something to power the gas furnace, fridge, freezer, and water pump would be ideal. Likely I wouldnt be able to power all once though, unless it was quite a large setup.

 

[nonhog]

Depends on the refrigerator. Some will work on a 900 watt generator, and others will require a 6000 watt generator. The details are the important factor when asking a question. How big a bus do I need to transport my whole family???? How many in your whole family????? got the idea?????

Good point ! . Its good sized for a home kitchen but not huge.
I'll get out the paperwork tonite

 

[nonhog]

Id love to build a generator.. Has anyone made on from scratch? Something like a 5-10hp engine with an alternator? Is it possible?
QUOTE]

You didn't click on that link did you ?

 

[Tom2]

Id love to build a generator.. Has anyone made on from scratch? Something like a 5-10hp engine with an alternator? Is it possible?
QUOTE]

You didn't click on that link did you ?

Isnt that just an inverter you hook to your car?

Ill look at it with more detail later..

 

[Junkman]

We have a Sub Zero in the kitchen, and the 8000 watt generator that I bought in 1982 had to be specially made to have the "ability to handle the start up draw".... per the factory guy that I was using. I don't believe that it was "bull", because they did have some 8 kw gen-sets in the warehouse at the time, and he could have just as easily sold me one of those. My well pump is also a 220 volt 2 HP unit. It also has to run that..

 

[Tom2]

Ah..Here we go:
http://theepicenter.com/tow02077.html

Im defintely building one.

 

[nonhog]

Ah..Here we go:
http://theepicenter.com/tow02077.html

Im defintely building one.

Sorry my bad I thought thats what I copied . DOH ! (link)
I have an extra lawn mower among other stuff sitting around waiting to be converted .

Tom be sure to post pics !

 

[Tom2]

Yep..I have a 6hp horizontal shaft Tecumseh I can use.. I can get an alternator for $14. Can find a high amp unit probably. The only thing I would really have to buy would be the inverter..Thats the downside. A good inverter costs about as much as a new generator.
Maybe I could find a deal on eBay etc..(no sense buying one new) Maybe truckers have even higher watt stuff?

 

[HOTFR8]

Very interesting. I wonder how they would go providing power via a battery and an Invertor ?

 

[Tom2]

Something I cant figure out.. What kind of inverters do store bought generators use? I cant imagine how they can sell a 3500W unit for $400, when the inverter alone can cost that much.
Theres gotta be another way to get an inverter besides the automotive ones.
Or something other than an alternator. Something that creates AC from the get-go.

 

[nonhog]

Maybe we need a homebuilt inverter thread

 

[kbs2244]

One of the projects that has been on my “to do” list is to get a RV or marine generator to rebuild. They are somewhat common when owners upgrade. They should come with a “quiet kit.”

Most of the RV generators are gasoline and air cooled and the marine are diesel and water cooled.

The big ones (over 5KW) will put out both 120 and 240 VAC.

The big problem with the plans that have been shown is that they generate 12 VDC. Then that has to be stored and converted to 120VAC.

 

[rickairmedic]

Ok if your building anyways why go to all the trouble of a power inverter and all the other mess . I plan to use one of these I am linking to and a good old 1600CC VW pancake motor ( aka bug motor) .


http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45416


Rick

 

[D KRAGER]

I was thinking about using that very model Rick to make a PTO version for my 25 hp kubota tractor...

 

[nonhog]

HF Hmmmmmm they have variety . Chicago Electric ? Wonder how there track record is ?

http://search.harborfreight.com/cpisearch/web/search.do?keyword=inverter&Submit=Go

 

[UnionWelder]

read more into generator heads before buying one. most of these heads dont last long.
also here is some other issues gas engines require a 3600 rpm generator head and diesels require a 1800 rpm head. The other problem is the regulation of the engine speed all electric stuff in your house is rated at 60 hz "60 cycles per second" the faster or slower the engine spins the lower or higher the hz go. most modern electronics are rated for 55-60hz however I have seen someone with a home made generator who blew up everything in his house that was electronic I tested the volts and they were perfect when I tested the Hz it was at almost 67.

 

[Tom2]

Bah..Screw the whole thing. Maybe if I found a good inverter for cheap Id consider it.. Otherwise theres just no sense in it. The AC heads are too expensive and like mentioned, can be hard to tune-in.
I dont want to fry the house..

 

[Major Ramifications]

My old 1960's Mongomery Ward Powr Kraft 1KW generator (nickname Ol' Sparky) had no problem powering any refrigerator we've had. It would also do a TV and a fan at the same time.

Generators don't NEED an inverter. Most generators use an alternator wound to make 120VAC.

 

[nonhog]

Bah..Screw the whole thing. Maybe if I found a good inverter for cheap Id consider it.. Otherwise theres just no sense in it. The AC heads are too expensive and like mentioned, can be hard to tune-in.
I dont want to fry the house..

Think as your house is smoking and the wife pulls in the driveway
Uh, well, I, uh ...................

I'm still building one but maybe just for outdoor lights like out in my woods .
Have about 1/4-1/3 acre of brush and trees that I could fight blackberry bushes into the night

 

[HOTFR8]

I would believe it is better to by a decent generator that provide 110v or in my case 240v than make one this way.

 

[boulderbean]

check around this site, there are instructions for building an AC generator using permanent magnets, you would need to gear it down to the speed of a wind generator or adjust the design for the speed of you drive
http://www.otherpower.com/otherpower_wind_alternators.html

 

[rinny_tin_tin]

I am not as cheap as it seems I love making stuff from **** I've got laying around.
I would love a nice new Honda generator but not in the cards right yet.
check out this site I found when looking for homemade mufflers (look for another post)

http://theepicenter.com/cgi/order.c...erters_and_inverters.html&cart_id=%%cart_id%%


My big question would be refridgerators , how much does it take to keep one going and be able to handle the start up spike.
Could care less about lights , candles work just fine.

I'll probably build one even if it only powers lights . It would be a kick .

Loads like refrigerators and any positive displacement pump like well pumps use motors that engage the load as soon as they turn (start) So, the inrush current for these motors are larger than the 5x usually ascribed for motors used for applications with centrifugal clutches, for example. A rule of thumb, make sure the capacity of the generator/inverter can withstand at least 5 x the continuous current of the motor. You can look up the nameplate rating on the fridge and that should tell you the continuous current, but if you are planning to use one of those solid-state inverters, you will likely need to at least triple the rating of the inverter if you are going to get any respectable life. For generators, find out the instantaneous and 10 minute ratings, and you will likely have to ask the manufacturer as often this data is not published on consumer products.

 

[kbs2244]

I have used scrap treadmill motors to convert my drill press and some other stuff to vari-speed.
I understand they can be used as DC generators, good for charging batteries, but I haven't any source for plans.
I would expect voltage to vary with speed.

 

[nadogail]

I too am putting together a generator set. Like the OP, I am doing this on the cheap because I enjoy the challange. I am using the High Power AC/DC Generator as a model. Look at the Epicenenter.Com website.

I have the 13 hp, electric start gas engine from Harbor Freight (got a discount from the sale price because they had lost the ignition key) and expect to receive the 10 KW alternator this coming week.

I am welding together a frame, I have some husky casters to add.

I do not expect to get a full 10 KW because I do not have 20 horsepower to turn it with; I am expecting to see an honest 6 KW output. It takes about 2horsepower to generate 1 KW.

I will eventualy add a 12 Volt, high output (100 or 150 Amp) alternator to recharge the battery and feed an inverter. Fair Radio Sales is running a special on 800 Watt inverters for about $50.

The custom shop that installs major electronics in vehicles has told me that all the inverters are alike "under the hood", just the ratings and brand names are different. My work van has a 400 watt K-Mart inverter for interior lights and exterior lighting. 8 years with no problems.

My plan is that the engine with an appropriate belt drive will spin the 12 Volt alternator fast enough to develop full output while running at half speed. When I want full AC power, I will speed the engine to 3600 RPM to make 60 Hertz from the 2 pole alternator.

If I wanted an inexpensive large sized plant, I would buy a used Generator Set from a wrecked motor home. But, I could not say that I built it in my garage.

Epicenter.com is a good resource

 

[trainer]

checkout the gen set that this guy built
http://www.f1-rocketboy.com/lister.html

 

[Blown71X]

Ah....BAH...alternators and 3-5 HP engines are sissy stuff

Being out in the middle of nothing and totally electric with heat pumps I quickly figured out that a few hours to a few days (4 days this last spring) without water and HVAC sucked.....A 2.2 liter EFI engine out of a Dodge Omni (yea i`m a mopar guy) and a PTO gen set later, This mess came to be, While looking back I wish I had went with a small diesel rather than gas, it does it`s job although I am on the hunt for a diesel still.

25 KW continous with 30 KW for 5 minutes surge

The downside is it goes thru a gallon and a half a hour or so at a moderate load, this last spring (the 4 day deal) was starting to hurt with 4 dollar a gallon gas and I had to cry foul and go hunt down some triplex to run a temp to the house from the shop...yea the shop had power and house didn`t and they are 100 feet apart ...yet another story in itself.

While this engine is rated at 105 HP the big problem is that at 1800RPM it is barely making the necessary 55`ish (roughly 2.2 HP per KW) to maintain an acceptable recovery to a large surge load so the heat pump tends to hit it pretty hard especially if the resistance heat is needed...Yea yea yea, I underestimated that when looking for engine, hence the prowl for a cheap diesel.
It really works decent even slightly underpowered as it is we just have to keep an eye on the loads, IE no stove or clothes dryer if the furnace is on, but other than that we function like nothing is wrong...it really makes the couple of neighbors down the road wonder WTH when everything is dark and we are lit up as normal

Rick

 

[HOTFR8]

Blown 71x A suggestion for you - Convert the motor to run on LPG or what you call Propane.

 

[BooUrns!]

I just don't see the point in trying to patch something together to generate power. Most electrical devices can be damaged by power drop and unreliable voltage.

I picked up a 6500W silent diesel generator for $600 at a heavy equipment auction (Ritchie Bros). Thee are always generators at these auctions and they have a lot of different locations throughout the year.

 

[Blown71X]

I just don't see the point in trying to patch something together to generate power. Most electrical devices can be damaged by power drop and unreliable voltage.

I picked up a 6500W silent diesel generator for $600 at a heavy equipment auction (Ritchie Bros). Thee are always generators at these auctions and they have a lot of different locations throughout the year.

That greatly depends on the "patched together" design, In my case the needed 20+ KW gen sets just aren`t that common place to find used, nor cheap new or used,
While it is really irrelevant,At the time (11 years ago) we were still struggling from a 3+ times increase in mortgage payments for the new house and a 8000 dollar plus generator just wasn`t in the cards and I enjoy making stuff.
That whole deal is a tick under 1000 dollars and with the exception of a broken timing belt a couple of years ago has never failed me.
The main thing to keep in mind when building engine powered power generation from scratch is a good quick reacting governor, it took a couple of trys to get one that would hold, but this will hold 1 1/2 hz from an immediate switch from full load to no load which is fine, and I have a ton of somewhat sensitive electronics: 2 servers, a couple of PC`s that are on 24/7, multiple Sat receivers, fiber optic hub, a complete inhouse cable system, multiple security cameras and related recording equipment, 2 plasma TV`s and alot of Ham radio gear that I regularly run while on standby and while you might once in a great while get a beep from one of the UPS`s on one of the servers, all of this has well into 200 hours of running on the generator with no issues ever.


Rick

 

[IDASHO]

Something I cant figure out.. What kind of inverters do store bought generators use? I cant imagine how they can sell a 3500W unit for $400, when the inverter alone can cost that much.
Theres gotta be another way to get an inverter besides the automotive ones.
Or something other than an alternator. Something that creates AC from the get-go.

They do not use an inverter.

They use a generator head.

 

[nadogail]

I have run my "Homebrew Generator" under a load. The load was a pair of portable space heaters and 500 Watts of incandesant lights. I am pleased with it. The frequency held between 59.7 HZ and 60.5 HZ under various load and no load conditions.

I used the 13 HP, Electric Start 1 cylinder Harbor Freight 99856 gas engine and the 10 KW Harbor Freight 45416 Generator. They were both on sale and I used the 20% coupons on both of them.

I expect to see an honest 6 KW output, using the formula of 2 HP per Kilowatt. The engine is directly coupled to the generator by an L-110 Lovejoy Coupling. Everything is mounted to a piece of 1" plywood that is covered with laminate. I made a pair of blocks from hardwood to raise the generator shaft to match the engine shaft.

I purchased the coupling from Federal Sales in PA. I used a flap wheel to sand the ID of the 1" coupling the .003" to fit the 25.5 MM shaft diameters, of the engine and the generator. They were advertised as 1" diameter, and 25.5 MM is almost exactly an inch.

A marine battery from Walmart cranks the engine.

A commercial setup would have a larger fuel tank, but I bought a engine intended for a generic industrial use, not a generator.

The whole thing is on a frame I welded from steel I scrounged and rolls on 6" casters from a retired tool box.

Eventually I plan to add an automotive alternator to charge the starting battery and an inverter for small amounts of quiet power.

I could have bought a ready made commercial genset for a couple hundred $ more than I have invested; but I couldn't say that I made it.

 

[HOTFR8]

I posted a topic http://www.garagejournal.com/forum/showthread.php?t=31145
and also posted this link how to work out what size Gen set will work best http://www.cumminsonan.com/portable/select/ . This link was alos interesting reading http://www.f1-rocketboy.com/lister.html

 

[brockanderson]

Something I cant figure out.. What kind of inverters do store bought generators use? I cant imagine how they can sell a 3500W unit for $400, when the inverter alone can cost that much.
Theres gotta be another way to get an inverter besides the automotive ones.
Or something other than an alternator. Something that creates AC from the get-go.

aslternators put out ac voltage
an alternator has rectifer diodes and resistors to smooth the ac ripple
the rectifer diodes and battery smooth the ac ripple

not that the alternator will put out enough ac voltage to run anything other than a toaster

 

[nonhog]

thought I would wake up this thread as i just got a call from my wife saying
"Dang camera phone, can't figure it out, Oh too late it just sold, was going
to send you a picture of a really nice compressor but some guy just bought it for 30 bucks. Sorry " "But she has another generator that doesnt work as well " ...... Did you say generator ? "Ya that other guy just bought the nice one for 30 bucks" O.K. buy the other one less than 30 right ? ......."o.k."

5 $ for a generator that needs work of some sort, cant go wrong if its just for parts.

Trying to be happy about the 5 $ find and forget about the one that got away
anxious to see it tonight!

 

[nonhog]

Another project ! that makes about 56

 

[nadogail]

Information about inverters: http://www.aaroncake.net/circuits/inverter.asp

This looks like it will answer questions from a lot of garage folks about inverters and how you may be able to build your own. I, for one, do not plan to build my own inverter.