PDA

View Full Version : Building a generator



DirtyOldMan
08-29-2007, 02:39 PM
Hello folks,

I usually just lurk around on this site, hope it's not considered rude to just pop in and ask a question. If so just pitch me out.
Anyway I have aquired what I believe is a "belt driven generator" It is a Dayton but apparently old enough that the model numbers don't coincide with anything at Graingers.
It's specs are 20000 watts. 83.3 amps and is to be driven at 3600 RPM.
The tag on it indicates that it was tested/rebuilt in 1983 and the plastic put on the shaft to mask for painting is still there. I've toyed with the idea of running a generator off my tractor PTO so I grabbed this thing when it was offered.We live out in the country and power outages are not uncommon. Thought maybe I could build this thing into a little shed and just back the tractor up, hook up and get the lights back on.
I have seen PTO generators that seem to have some type of transmission. I'm thinking I'd have to build some sort of gear drive to get from 540 rpm to the 3600 needed.
The tractor has 26.9 HP at the pto shaft.
I know this isn't a direct machining topic but I've seen similar projects posted here and you folks seem to be in the know about this type of thing.
So I'm hoping some of you will help an old carpenter out and comment on how you'd approach a project like this.

Thanks
http://img.photobucket.com/albums/v24/sjnkc/P8280001.jpg

tattoomike68
08-29-2007, 03:01 PM
You could make a chain driven set up with some large sprockets and chain, some plate and bearings.

knowing how Inventive farmers can be you might already have the stuff sitting around to use now.

Make a trip to the junk yard and find the more expensize parts as cheap as possible and build down from there.

Your Old Dog
08-29-2007, 03:05 PM
Get your neighbors to help you! When they see your place lit up like Christmas they'll all be over to borrow some power :D Make'em earn it up front...

agrip
08-29-2007, 03:16 PM
Look around for a gearbox specifically designed to do the step up. Graninger and others sold em.

If you can find such, I suggest you run with a timing belt drive. I believe you will have a practical machine.

Step the 540 up to 3600 with a 6.666/ ratio, - - -
Well, whatever you can find slightly over that.

Just a SWAG but you may get 18 kw plus or minus a bit.

Suggest you use a minimum of two stage step up.

Avoid a wild over-hung load moment on the input shaft.

Good luck Ag

Willy
08-29-2007, 03:45 PM
Agrip has some good advice, a timing belt has many advantages. Long life, no chain case, no lube, light weight.
Have a look at the generator section at this (http://www.listerengine.com/) site for more info on setting up your gen head.
Welcome aboard I'm sure you will enjoy the circus.

Mad Scientist
08-29-2007, 06:29 PM
I just finished building an emergency generator a couple weeks ago. It has a 10KW generator head (Harbor Freight) that supposedly wants to see 20HP to run at maximum output. If you only have about 27HP you might not be able to run yours at full power, but you still will have a whole bunch of power that you would not otherwise have.

In my case I am running it with an engine from an 87 Honda CRX. Welded up a frame to mount engine, gas tank, generator and other assorted parts. Threw away the transmission but saved the input shaft. Turned off the case hardened gear teeth :eek: so as to mount a dual “V” belt pulley to drive the generator. Probably would have been easier to make a new shaft from scratch, but at least it had the “correct” splines to match the clutch. Got the pulleys from “Surplus Center” and they give about a 2:1 setup. Thus engine runs at a quiet 2000 RPM.


Got a change to test it last Thursday. Had the dogs out for what they consider to be their mandatory afternoon walk, it was overcast and just starting to rain. Get them back in the house and sit down for about 5 maybe 10 minutes before noticing “boy” its really dark outside. About then I also noticed that we had lost power. So I step into the garage to have a look, and its raining like hell leaves and small branches everywhere, across the street the neighbor has three trees down. Well not quite down one was resting on the roof of his front porch. These were 12-14” diameter and broken off at the base. Behind him more trees are down. The neighbor to the right of me also has two trees down. I lost one branch on one tree. :confused:

With heavy rain and no power to run the sump pumps my basement will flood rather quickly, as my shop is in the basement this is not acceptable. Start generator and connect to sump pumps, freezers, and refrigerator. Neighbor to left of me brings over an extension cord to run his sump pumps.

Rained on and off for the next couple days, flooding and downed trees taking out power line all over the area, the power company was totally overwhelmed. Power was not restored until Sunday morning.

With the exception of a minor tweaking to the speed control governor the generator ran flawlessly the whole time. :) :)

tattoomike68
08-29-2007, 06:46 PM
Mad Scientist it sounds like it has already saved you from losing your shop and food in the freezer.

If my power went down I would be screwed, I would have to go buy dry ice to keep the freezer cold. A half a beef rotting away would piss me off.

A generator is on the TO DO list now.

Evan
08-29-2007, 07:22 PM
I'm just finishing putting together a small one right now. I'll post some pics when I have it running.

As for running that monster alternator the original poster has, run it through a standard automotive transmission backward. Transmissions have to work in both directions. To get the 6.6 to 1 ratio a truck transmission will be needed. Current Chrysler six speed manual light truck transmissions are around 6.3 to 1 in first gear which should be close enough.

zukIzzy
08-29-2007, 07:49 PM
An NV 4500 has a 6.34 to 1 first gear and can be found in 1 ton chevy and dodge trucks. You could also find a 4x4 with a low range transfercase. using the t-case and engine you could get well below 6.6 to 1 and you can probly find something pretty cheap complete and running. S10 blazer, Bronco II, sidekick, Samurai. any would work.

Wayne

Guido
08-29-2007, 08:44 PM
Power losses are sky high for any speed inducer, plus to rig a heavy transmission backwards, connecting your generator to a PTO or whatever, might be a real eyesore. LOL. For PTO operation, power band belt would require a 20 inch or so pully, driving a 3 incher on the input to the generator. Old Onan 6.5 KW generators utilized 11 HP, so your PTO would be maxed out at probably less than 12 KW of load.

Homebuilt aircraft builders prefer Subaru liquid cooled boxer engines over VW aircooled engines. Plenty available, and cheap, from the pickapart yards. Standard of 4,000 rpms for the homebuilts, into a vbelt reducer for a sensible prop speed. Only requirement would be to fab a flex connector to the Subaru flywheel, connecting it to your generator input shaft. Add radiator, muffler and fuel tank, and make popcorn. Subaru: Less than 166 lbs weight, up to continuous 170 HP. Parts available at NAPA.

G

timcasbolt
08-29-2007, 08:59 PM
I built several of those using the Harbor Freight 10kw. Pictures are posted in the completed projects section at machinebuilders.net.

DirtyOldMan
08-29-2007, 09:12 PM
Wow! Didn't expect this much response.
You guys have planted many seeds in my noggin.
Car motors, truck trannys.
I'm off to see these pictures you've sent me to
Many Thanks

darryl
08-29-2007, 10:16 PM
What rpm does the tractor engine run at? If the pto is spec'd for 540 rpm, it must be related to a typical engine operating rpm. Could it he 3600- if so I'd be looking for a way to rig up a direct drive, even if it had to come from the front of the engine. Another way of looking at it is to check the operating parameters of the engine. At what rpm is the rated power achieved? If the direct drive rpm can be about right, you can avoid the hassles that come with that much of a step up that is required off your pto.

I'd have to say that realistically, you'd be able to get 10-12 kw from that generator if run from the tractor engine. I don't think you'd be wanting to run it steadily at much more than half its power rating,

My next thought on this is to rig up some kind of governer so the system can come close to maintaining frequency. I don't mean close enough to keep a clock running in perfect time, just good enough to avoid having trouble with 60 Hz motors, etc.

dp
08-29-2007, 10:32 PM
I have to agree with the Subaru boxer engine idea and it is one I've also seriously considered. It has the additional advantage of providing a lot of waste heat to warm the building as well as providing electrical power. Get one with a cruise control and you can manage the engine speed, too. A Mazda rotary engine is also one to consider. An optional natural gas conversion might be a plus, too.

They have enough HP to drive twin generators so you can sell your excess to your neighbors :)

tattoomike68
08-29-2007, 10:36 PM
I'm just finishing putting together a small one right now. I'll post some pics when I have it running.

As for running that monster alternator the original poster has, run it through a standard automotive transmission backward. Transmissions have to work in both directions. To get the 6.6 to 1 ratio a truck transmission will be needed. Current Chrysler six speed manual light truck transmissions are around 6.3 to 1 in first gear which should be close enough.

Thats why a trip though the junk yard should be first and engineer around that, A truck tyranny would be a solid and reliable way to do exactly what he needs at a low cost.

Evan
08-29-2007, 11:31 PM
Speaking of junkyard, I just got mine running. I still have to build a power panel for it but the rest is done. I am using a 3.5 hp lawnmower engine that has been retired from mowing service because of a very slightly bent crank. It vibrates a lot with a big heavy blade on it but with just a pulley it's acceptable. I might even try balancing it out.

The generator is a 2000 watt Winco unit that I picked up for next to nothing because the field was burned out. I rewound it for a cost of about 20 bucks for the wire. That was some years ago when copper was cheap. I looked up the unit online and they still sell the exact same unit, $399 for just the generator. It's rated to start a 1/2 hp motor so it will do just fine for keeping the freezer running. We keep a couple month supply of food on hand and having it rot would be irritating.

That's about 1400 watts of lights there. The work lamps are 500 each and the photoflood is 375 watts. I set the pulley ratio to about 1.3 to 1 to keep the motor rpms down a bit.

http://vts.bc.ca/pics2/genset1.jpg

http://vts.bc.ca/pics2/genset2.jpg

justforfun
08-29-2007, 11:31 PM
IMHO, a trip to and or in the bone yard (tractor supply, equipment parts yard, junk yard, etc.) can be productive, if you know what you are looking for.

Learning to adapt what is available truly is inventiveness.

Tell the person (once you locate your source of parts) that runs the parts, salvage, equipment, yard, what you are trying to accomplish and they might possibly prove a great source of information.

Keep in mind, if you have to ask, then take the help a local source offers.

They might have been there an done that. :D

Roy

J Tiers
08-29-2007, 11:32 PM
That looks just like a bigger version of my 4kW Winco, right down to the mounting, the rear cover, and the control box. If so, you can probably get info from them on the generator itself, I got a manual for mine, cost a 10-spot. They'd know if they had made them for Dayton.

The 3600 is probably because it is a 2 pole generator, and 3600 RPM will give 60 Hz. If you want to run anything like motors, etc, then you DO want a pretty accurate 60 hz, or you may be frying (and buying) a fridge, etc.

Evan
08-29-2007, 11:51 PM
Most motors are fine if the frequency is within 10% either way.

If you want to frequency calibrate it here is a simple circuit to do that.

http://vts.bc.ca/pics/freq.jpg

You could also use two 12vac xformers and a couple of tail light bulbs in series. It compares the phase of the two sources. If they are far out of sync the bulb will glow dimly. As they approach synchronization it will begin to pulse bright and dim. The longer that takes the closer the frequency match. If it takes 1 second to go from bright to dim that's a 1/2 cycle per second difference, good enough for anything. In fact, if you can see it pulsing at all it's good enough.

J Tiers
08-29-2007, 11:53 PM
That is fine, and it works....

But the generator must hold that frequency under load..... which tends to slow the engine.

'Fridges are expensive to experiment on.

Evan
08-30-2007, 12:15 AM
It's a Winco alright. It's exactly the same design as this slightly smaller Winco unit, right down to the mounting bracket.

http://vts.bc.ca/pics2/winco1.jpg

justforfun
08-30-2007, 12:16 AM
Just wondering, what are "Fridges" ?


That is fine, and it works....

But the generator must hold that frequency under load..... which tends to slow the engine.

'Fridges are expensive to experiment on.

wierdscience
08-30-2007, 12:31 AM
Before I went to too much trouble I would spin it up for a test and make sure it's still an alternator and not a boat anchor.Nothing sucks worse then spending time and money building around something that later doesn't work(don't ask how I know)

Another thing to consider is fuel consumption.Diesel either tractor pto or old tractor engine is the way to go.If you have to run it any amount of time gasoline will cost a fortune and in a disaster maybe hard to find.An off road diesel engine won't need a seperate governor either.You just set the rack for the speed you want and that's it within 5%.

Herm Williams
08-30-2007, 01:05 AM
Would a hydraulic motor hooked to a tractor be better. Simple hookup easy to fabricate brackets quick coupling hoses, no mechanical shafts. Am I missing something?
re
Herm Williams

Mad Scientist
08-30-2007, 02:15 AM
Just got the pictures of my generator from the camera into the computer.

Made no attempt to try and make it pretty or see how small I could make it. For convenience the external engine parts are mounted in essentially the same location as they were in the car

http://i68.photobucket.com/albums/i17/mscientist/GEN1P.jpg

http://i68.photobucket.com/albums/i17/mscientist/GEN4P.jpg

It was running three freezers, a refrigerator, four sump pumps, and the water pump in my well. About 30 hours of running used about 20 gallons of fuel. It more then paid for itself by keeping the freezers and refrigerator cold. Also having running water for taking showers and flushing toilets was definitely at big plus.

Evan
08-30-2007, 03:06 AM
Would a hydraulic motor hooked to a tractor be better. Simple hookup easy to fabricate brackets quick coupling hoses, no mechanical shafts. Am I missing something?

Poor efficiency. That fluid would get pretty hot. A hydraulic pump/motor pair has a typical efficiency of only 75%. Fine for intermittent duty applications like operating cylinders but in this case the OP doesn't have a lot of hp to waste. You can figure about 2hp of IC engine output as input per 1 kilowatt of generator output. If you pump in 25 hp to make 10 kw then around 6 hp ends up as heat in the oil. That's the same as heating it with over 4000 watts of power.

In comparison, the mechanical efficiency of an automotive manual transmission is around 90%.

John Stevenson
08-30-2007, 04:35 AM
One thing to note with driving a truck transmission the wrong way is the input shaft or primary shaft depending on what it's called is only supported on one rather small bearing compared to the output or main shaft.

They depend on high speed, medium torque from the flywheel and support from the same.
Running with just a coupling on the splines wouldn't be a good idea, they need some form of support or outrigger bearing even if it means belt driving at 1:1

By the time you have messed about with mounting and modifying it may be easier to go for a double reduction using off the shelf belts and pulleys. Chains at 3,600 will be noisy and demand attention.

.

Your Old Dog
08-30-2007, 09:38 AM
Just wondering, what are "Fridges" ?

Just abbreviated name for refrigerator !


Made no attempt to try and make it pretty or see how small I could make it. For convenience the external engine parts are mounted in essentially the same location as they were in the car


If I was able to do that I'd finish one hell of a lot more project. I get so damned hung up in minutia that nothing gets done in the end. I applaud your ambitious project!

Sir John, your post says 3:35AM. I assume it's near correct. Did the pubs just close? :D :D Watch out Gert don't lay a cricket bat over your head when you crawl into bed!

dirty old man
08-30-2007, 02:09 PM
Lot's of good ideas and info in this thread.
But my comment is directed at the original poster,DirtyOldMan:

I see that the start of your thread shows this post as your #2 post on this forum. I lurk far more than I post, and don't have a high number of posts here. But I do post here when I see fit, and have been using, and am registered here as: dirty old man for several years. I suppose that the upper letters and the no spaces allowed this to happen.

If you can live with it, so can I, but in the future it may cause some sort of problem.
Dave

Mad Scientist
08-30-2007, 02:43 PM
This all has to do with upper and lower case letters and spacing.
There is at least one other MadScientist on the forum. But I am the more spaced out one. :D

timcasbolt
08-30-2007, 08:13 PM
What rpm does the tractor engine run at? If the pto is spec'd for 540 rpm, it must be related to a typical engine operating rpm. Could it he 3600- if so I'd be looking for a way to rig up a direct drive, even if it had to come from the front of the engine. Another way of looking at it is to check the operating parameters of the engine. At what rpm is the rated power achieved? If the direct drive rpm can be about right, you can avoid the hassles that come with that much of a step up that is required off your pto.

I'd have to say that realistically, you'd be able to get 10-12 kw from that generator if run from the tractor engine. I don't think you'd be wanting to run it steadily at much more than half its power rating,

My next thought on this is to rig up some kind of governer so the system can come close to maintaining frequency. I don't mean close enough to keep a clock running in perfect time, just good enough to avoid having trouble with 60 Hz motors, etc.


Any tractor I've seen makes it's rated pto output at near full-throttle. The tractor's owner's manual would state the engine speed for a given pto speed.

Tractors come with a governor, and would tend to hold speed very well right up until you get to the point at which you are asking for more power than the engine has available. Then it would stall.

Tractor engines are designed and built to run at full-throttle for extended periods of time. Picture a farmer plowing his fields all day and all night until the job is done.

A neat trick for filtering generated power is to run it through an uninterruptible power supply (UPS). They can be had used on ebay for fairly cheap. You wouldn't care if the batteries were getting old.

BobC
08-30-2007, 09:22 PM
Any tractor I've seen makes it's rated pto output at near full-throttle. The tractor's owner's manual would state the engine speed for a given pto speed.

I agree about referring to owner's manual. However, I have two tractors and am familiar with others and believe the recommended pto speed (typically 535 rpm) for farm implements is achieved closer to 60-70% of full throttle.

Personally, I try never to run my machines at full throttle. If you must run the tractor at full throttle to get the required hp to drive the generator, I would be looking for another solution.

timcasbolt
08-30-2007, 11:01 PM
If you must run the tractor at full throttle to get the required hp to drive the generator, I would be looking for another solution.

You would never run the tractor at full throttle to get the required hp. The goal is to get the required rpm.

DirtyOldMan
08-31-2007, 10:14 PM
Lot's of good ideas and info in this thread.
But my comment is directed at the original poster,DirtyOldMan:

I see that the start of your thread shows this post as your #2 post on this forum. I lurk far more than I post, and don't have a high number of posts here. But I do post here when I see fit, and have been using, and am registered here as: dirty old man for several years. I suppose that the upper letters and the no spaces allowed this to happen.

If you can live with it, so can I, but in the future it may cause some sort of problem.
Dave

OOPS! Sorry my friend. It's the name I use on some other boards I belong to. Guess I shoulda checked.
I'll see if we can change mine.