Tractor mounted generator? (Kubota G5200HST)

Posted by: MacTech

Tractor mounted generator? (Kubota G5200HST) - 08/06/09 11:22 PM

I've been lurking around ETS for a while, and finally got around to registering, great website and forum here smile

anyway, I've had an idea that I've been kicking around in the back of my mind for a while, I was reminded even more during the New England Ice Storm of 2008, back around Dec 15, 2008, we were slammed by a massive ice storm, 30,000 homes without power in Coastal Maine alone, New Hampshire was even harder hit

anyway, it took six days to get the power back on, we didn't see a single Central Maine Power (worst power company in the universe, IMHO) line truck until late evening on day 5 and 6

thankfully, we had plenty of wood for heat (the house has three fireplaces and a woodstove in the sunroom), water set aside, plenty of cold weather clothing, heavy blankets on the beds, oil lamps and battery powered flashlights, the only real inconvenience was the lack of gray water for washing up and flushing

I had some containers in the sunroom growing lettuce and tomatoes, so in the depths of January, we had fresh veggies available for snacks as well

anyway, on to my point....

We have an old Kubota G5200HST diesel garden tractor (3-cyl diesel) that we use to plow the driveway in winter and mow the lawn in the summer, it sees a lot of heavy use year round, it's easily 20+ years old and runs just as good as the day it rolled off the assembly line

I was thinking, if there was a way to rig up a generator to the PTO (the front will have the snowblower in the winter, the rear PTO will have the mower in the summer) we could have a highly-mobile electric generator for those numerous times when CMP drops the ball and sends us another power outage

how would I build a PTO powered generator that runs off the tractor's engine, I'm assuming the easiest way would be to find someone selling a small generator with a dead petroleum motor, remove the generator components and hook them up to the tractor

I figure, we have half of the neccesary generator components already, building up the other half shouldn't be *too* hard...
Posted by: dougwalkabout

Re: Tractor mounted generator? (Kubota G5200HST) - 08/06/09 11:45 PM

Sounds like you're pretty well prepared already. Good job.

I concur with the Kubota diesels ... they just won't quit.

In theory, there's no reason why the PTO (power take-off) wouldn't run a small generator. (I assume it would be a pulley-and-belt system?)

But: the challenge IMO is maintaining a constant voltage. Integrated motor + generator units (gensets) have a governor that throttles up the engine when the electrical load increases. I suspect good ones would have some sort of electronic voltage regulation as well.

All of this protects the equipment it's powering. Most stuff today is engineered for nice, clean, stable grid power. It will suffer overheating and/or failure from undervoltage or overvoltage conditions, especially for an extended period.

If you were powering stuff that's expendable, I suppose you could run the RPMs up to the maximum, apply loads, and adjust RPM (and thus voltage) using a pro-quality multimeter (cheap ones don't always read true RMS).

My 0.02.


Posted by: Todd W

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 12:25 AM

You can get the generator head from harbor freight then you would need some steel working knowledge but you could weld up some brackets, and pulleys and get the RPM range you need, you could then make the whole unit a "Bolt Up" to your tractor and use a drive-shaft for the PTO to the generator setup you built.

That's a very simplified version but it's doable smile


There's no reason to idle down or up... figure out the right pulleys and the "Sweet Spot" for that engine for fuel consumption and power required to turn the head and match the pulleys accordingly. That will run fine.

What you won't have is variable output you will essentially be running at "full throttle" on the gen head...

You could of coarse vary the output by varying the RPM of the engine, but you just make sure your pulley can support "full throttle engine (or sweet spot)" = full power.

Basically it depends on the engine and the genhead requirements... Shouldn't be hard to test / exp with!
Posted by: scafool

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 12:34 AM

Hi Mac, and welcome.
There are quite a few older PTO generator units around. You might be able to find them at auctions. I have seen them as units on trailers, as stationary plants you back the tractor up to an connect a shaft and as units that mount on a three point hitch.
I have seen therm in almost every size, from small units to power a few lights and skill saws to units meant for emergency power to hog barns.
They are still being made new too, but are not a common item in the stores.

Here is a small unit somebody put on a garden tractor.
http://www.mytractorforum.com/showthread.php?t=64583

Here is a fact sheet on PTO units from the Ontario ministry of Agriculture.
http://www.omafra.gov.on.ca/english/engineer/facts/00-059.htm

Here is a catalog page from a manufacturer.
http://www.wikco.com/generator.html

As you see, they are not cheap units to buy new and the fact that you need to be have a tractor available to run them makes them less attractive than units with their own motors for most people. (It means they command a lower price when sold used)
This means that tractor powered units sold at farm auctions are usually in pretty good condition, at least as long as they have received any reasonable care at all.

If you decide to build your own you need to think about how to get the right number of RPM on your PTO. You might be able to use a gear transmission or belt pulley transmission.

Remember the generator set has to be secured to the hitch or the ground well enough that the PTO does not simply start flipping the whole thing over. It takes quite a bit of torque to generate power.

edit:
Variable power should be about the same as most other gensets with the tractor's governor controlling the motor rpm and the field strengths in the generator controlled by the load.

Posted by: Yuccahead

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 12:57 AM

I have also seen PTO generators at Northern Tool. For example http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200308467_200308467

They require a trailer as well....
Posted by: KenK

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 01:57 AM

I'd suggest you ask the folks at this forum: http://www.tractorbynet.com/ .

They have a wealth of information and experience about tractors. I'm sure you're not alone in your thinking.
Posted by: RayW

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 10:22 AM

+1 on tractorbynet.com. It's been a while since i looked into getting a pto generator for my kubota. New the units are expensive and it can be difficult to find a deal on a used one. Or at least i never found one that was small enough for my tractor to run at a price i wanted to spend. But if you keep looking i'm sure you can find one.

Posted by: williamlatham

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 11:27 AM

Try Northern Tool and Equipment. The last time I checked they had at least one PTO generator and even a PTO welder/generator.

Bill
Posted by: ponder

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 11:51 AM

I've got an Onan 25KW PTO generator. It is on a small trailer with a short PTO shaft. They have a voltage meter on the generator. Just run the RPM's up until the voltage is correct and you have 110v or 220v.

Posted by: falcon5000

Re: Tractor mounted generator? (Kubota G5200HST) - 08/07/09 09:52 PM

MacTech, your definitely on the right track, I would go with a 15KW or higher generator. 15K will run your whole house fine, I have a 12.5 KW gas portable and it runs everything fine but wish I had a 15KW. My old supervisor has a 15 KW generator that he ran during the hurricane session and he definitely made out cost wise by using farm diesel in his tractor (dyed fuel) and If I had the land, I would have gone that route as well. If you have a good tractor you have a great power source a lot cheaper than gas or propane/natural gas.

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