10Kw generator powered by JD332 garden tractor

[DanMc77]

My 6" pulley arrived and I put it on the generator. When I run the tractor engine at "full" throttle, I get 61 Hz with the Kill-a-watt plugged into the generator head. Remember, I tached the engine at 3220 rpm under no load at "full" throttle. So my throttle cable could be adjusted to get the engine up to it's rated 3600 rpm at "full" throttle, but this happens to be perfect. Now if I plug in the 2Hp compressor, it starts up just fine, even if there's pressure in the compressor. I also tried welding while the air compressor was running, and that worked fine too. At this point, I have no need for any more power than this. So this is perfect, I have 3 different operating points to run this: 3" pulley with engine running at a fast idle for small loads up to ~1500 watts. 4" pulley with engine running at mid-throttle for loads ~2500(?) watts. 6" pulley with engine running at full throttle for the heaviest loads. I can't really say with any accuracy what those "heaviest" loads are in terms of watts, but if I can weld while the generator is running the 2 hp air compressor, that's all I need.

Now as for engines running at full throttle: That's what tractors are designed for. I grew up on a farm and we would plow a field, or run an implement for days and days, and it was typically at full throttle the whole time. The tractor engines seemed to run forever and never showed any sign of wear. So in the case of this 332 with a 3 cyl Yanmar diesel, sure it's not a farm implement, but the diesel will still run for 1000's of hours. Maybe there's more wear at full throttle vs fast idle, but who knows? I prefer half-throttle mostly because it's quieter, the engine sounds "better" and it uses less fuel.

Now it's time to figure out a method for adding a bit of belt tension. Once that's done, a little bit of final cleanup and a few coats of paint.

 

[zzvyb6]

I would not use a spring loaded tensioner spring arm like what would be used on a mower deck because the bearings in those sheaves are questionable. Instead, I'd try to revamp your belt drive to use a tensioner from a modern car or truck, with the roller wheel on the back side of your belt. These devices are made to last a lot longer than the mower idler wheels.

 

[Tractor Seabee]

I would not use a spring loaded tensioner spring arm like what would be used on a mower deck because the bearings in those sheaves are questionable. Instead, I'd try to revamp your belt drive to use a tensioner from a modern car or truck, with the roller wheel on the back side of your belt. These devices are made to last a lot longer than the mower idler wheels.

ZZ is right on with that comment. Why not just have an adjustable bolted base for the generator and have 2 adjusting screws to keep belts tight. Have 3 bolt locations for the different sheave sizes. One less moving part to wear out. The belt sizes are broad enough that an idler would not cover the whole range. Just keep the 3 belts handy

Ron

 

[Industrial Toys]

I too, would hard bolt the belt tension. MAYBE, at certain loads, a spring tensioner could go into some resonance. You see it on mowers, a high rate of vibration on the tensioner.

 

[DanMc77]

Appreciate the input from everybody! Tractor Seebee has hit on what I have already done. The generator head is bolted to a wood base that is hinged on one end. The pulley end is then hanging on the belt. Up to now, the belt tension has been limited to the weight of the generator head (about 45 pounds). While testing, if I want more tension, I just put my foot on the generator.

I gave it some thought this weekend and here's the first approach I will try. I'll use the KISS approach. If I add a couple eye-bolts to the side rails, then I can simply take a ratchet-strap and run it from one bolt, over the top of the generator and down to the other bolt. I'll also add a spring in the middle there to add some compliance to the tension. I have it apart right now since I'm preparing to paint. Once I have it painted and back together, I'll post some pics.

Sometimes a project like this works, and maybe half the time they end up in the junk pile. Happily this is one project that goes into the "works" column. Posting it on this forum motivates me to push it to full completion, rather than getting it working "good enough" and then never completing the finishing touches. It's like door trim. I'm super bad with door trim. Once the door's in, and it opens/closes, putting on the trim can always be done when I get a "roundtuit". Roundtuits are hard to find at our place.

 

[Industrial Toys]

It's why I don't enjoy building stuff. It's too hit and miss for the work and often expense involved. I figure my time and energy is better spend finding and buying already built, well engineered stuff, cheap! Also, easier to sell.

 

[DanMc77]

It's why I don't enjoy building stuff. It's too hit and miss for the work and often expense involved. I figure my time and energy is better spend finding and buying already built, well engineered stuff, cheap! Also, easier to sell.

Yup, unless what you're looking for is either too expensive, or just not available.

 

[Industrial Toys]

Yup. That is true. Those are the only two things I like!

 

[snowmansimon]

Great post. I have been looking to build one to run off the rear PTO but cant source a cheap generator head in Canada.

As for running these little diesels. I work in a mining environment and we have numerous light towers on trailers powered by these little kubotas, yanmars, etc. These things get left running for days and days unattended. Everytime I am in the field I check the hour meters if there is one near by just for fun. I see some with 18000 hrs and 25000 hrs on them and counting. Yes 25000 and not 2500!

 

[DanMc77]

The final details on this generator mount have been completed, using two coats of black POR-15 paint and adding the belt tensioner. The first pic shows the mount just before painting. Once the black paint is on, it's hard to see the detail of how it's built. Using a ratchet strap with springs for belt tension works perfectly and is super easy to adjust. Simple and sweet.

 

[texasranger556]

I just bought some por15 for a project and noted it is not recommended for UV exposure. I doubt it would be a problem in your application but just FYI.

Looks like that setup should work well for you.

 

[DanMc77]

UV exposure will cause POR-15 to lose its gloss. Otherwise its no issue.

 

[bmaverick]

DanMc77 great work! loved reading this thread. You got one impressive Yanmar.

I got a Yanmar too. Or in JE green it's a JD-850. The Yanmar version has a 4=speed PTO. 540, 6XX, 8XX and 1080. The tractor is 27~31Hp PTO, depending on who's source you look at. Whatever. LOL

My eye is on this little PTO driven alt/gen https://www.northerntool.com/shop/tools/product_200308467_200308467 Pricier than a full blown 9000W gas genset, BUT I can run the tractor about 1200rpms with the multi-speed PTO engaged for the easy stuff or to simple charge a battery bank. Thus, the fuel isn't eaten quickly and the noise is nearly a soft purr.

Is it possible to get a PTO gear head set from a brush mower or an auger? It's one way of getting the PTO output up to the 540rpms with a gear head set.

Does your machine have a built in PTO overrun clutch as a safety mean for the PTO? Or is the PTO overrun external?

 

[DanMc77]

Maverick,
The JD 332 is a garden tractor with a 16 hp Yanmar engine. The "PTO" is a 7" pulley on the front of the engine with a magnetic clutch. The generator head used with my project is from Harbor Freight and today costs $300. Amazingly, that's the same price I paid for mine about 6 years ago. It took me that long to find the time to do this. Total cost for the whole project was about $350. The bracket was built from junk laying around the house.

 

[DanMc77]

I figured I'd post a follow-up on this project now that I have been using it a little more than a year. I have put a good many hours on this thing now and am just thrilled with how well it works and how useful it is. It was critical for running the compressor while we framed up a new garage (remember this place is off-grid). One of my favorite features is the ability to increase the engine RPM a little with the middle-sized pulley. This gives me the ability to super charge tools as needed. In other words, if I need a little more power out of an electric power tool, I can tweak the voltage up a little higher by giving the engine a bit more throttle. I have pushed it up to 150 volts without any issues. Sure, it also increases the frequency, but that's no issue. I have a small portable Hitachi table saw that runs fantastic at 150 volts. I know, I'm taking some risk that I could burn out the motor, but I'm willing to experiment and live with that risk. What I know so far, is that the saw cuts like my larger 2hp table saw does running on grid power wired for 220 volts. The Hitachi running at 150 volts has shown no sign of motor overheating, or any other issue. The middle sized pulley will run anything I need, and if it struggles, then I give it some additional RPMs, but I never go over 150 just because that's the limit I have set, and the meters on the generator don't go much higher than that.

The only downside to the design is that it hangs off the front of the tractor and is quite low to the ground. One time I wasn't paying attention while I moved the tractor, and cracked one of the wood frame members. I fixed it and it's like new again.

This summer the generator failed and I found that the capacitor inside had died. Picked up two new caps (now I have a spare) on ebay and it's back to life now.

 

[LouNY]

Good to hear your setup is working for you :thumbsup: