10KW Homemade generator

[BobG_in_VA]

I was going to go the PTO generator route until this weekend. I ended up killing 3 birds with one check. I bought a Miller Trailblazer 250 AMP Welder/Generator. Welder does AC/DC Stick/Mig/Tig (Mig/Tig with attachments). Generator is 9000 watts start up with 8000 continuous with a 10 gallon tank. Has an Onan 20HP engine. Its actually a '99 model that (get this) only had 11 hours on the unit. It looks and is basically brand new. I also had the guy throw in his quick detach welding hoodups and his welding leads/ground clamp/rod clamp. I was considering a standalone welder and get a 15KW PTO gen set to run it. Now, don't need the PTO unit at this juncture. By the way, I also plowed my friends garden under today (about an acre) with my '57 Farmall 230. I love to plow! (in small doses as I have plowed for days at a time when I was kid and hated it past the 1 hour mark) PS was gonna use the PTO generator with the 47 year old Farmall.

 

[Soundguy]

</font><font color="blue" class="small">( Another consideration is whether you want to tie up your tractor during natural disasters. If you have a generator with its own motor, you do have one more engine to maintain, but you will be able to help people out with your tractor while your separate generator is powering the vital stuff in your house.
)</font>

See.. that's the best argument there is for having a second tractor. Have one for the genny.. and the other to work on!

Soundguy

 

[pras127]

I was reading about the motor speed equation, and what the 120 does in the eqation. My question is why do you have to pair the poles?

 

[slydog]

</font><font color="blue" class="small">( I was reading about the motor speed equation, and what the 120 does in the eqation. My question is why do you have to pair the poles? )</font>

I have read this thread from beginning to end, and I have to say it makes about as much sense to me as Chinese arithmetic! All I have to say is "MAN YOU GUYS ARE SMART!!!" Are most of you engineers or something? When I sit down to watch my tv, or drive across a big bridge, or watch a space flight, I think "its the good thing the world didn't depend on me to come up with this %^*&$ if it couldn't be built out of 2x4's and 16 penny nails! /forums/images/graemlins/frown.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/grin.gif

 

[Soundguy]

</font><font color="blue" class="small">( Are most of you engineers or something? )</font>

Compaired to many other sites I read.. I believe we have more engineers here than many other sites.

Soundguy

 

[BobB]

I have e-mail 3 companies (PTO genny manufacturers) per purchase of a gear box. (Speed increaser) Will keep everyone informed.

 

[Phred]

If you are willing to tinker a bit and have acess to a torch why not use a diff from a truck?

Think about it. A 4.10 rear end will reduce the output speed of the transmisison by a factor 4.10. So if you ran it backwards (hook your engine to the axel and your generator to the drive shaft input) you could step up the tractor pto from 540 rpm to ~2200 rpm.

Clearly 4.10 won't get the job done. But I understand that motorhomes and medium duty truck use larger ratios.

You need to find about a 7-8:1 rear end at a junk yard, torch off the axels close to the diff body, and then weld or otherwise connect up the generator and motor.

Fred

 

[Rollinns]

The 4.10 rear end can work when the tractor uses a 37 tooth gear and the axle uses a 23 tooth gear (or any combination of gears that gives a 1.6 gear ratio) 37 / 23 = 1.608


4.10 * 1.608 * 540 = 3560

That gets you 99% there.

Using a rear end and two gears you could probably put this all in a fairly compact package.


Lee

 

[MMM]

How do you keep oil in diff case?

 

[Phred]

As far as the oil in the dif case goes, I think it would depend on the configuration of the case and axel and would require some tinkering to make it work.
But if you can get a diff at a junk yard for almost nothing it might be worth a try.

Another option might be one of these:
http://www.gamweb.com/gear_line3.asp?line=Gearbox
But the cost is likely higher.

Fred

 

[Soundguy]

Well, the input yoke to the diff will already have a seal, and you could simply use the axle trumpet and oem axle seal, and keep the hub intact on the axle, and work from there couldn't you? That would solve the lube problem.

Soundguy

 

[tommu56]

try this link http://www.tbwoods.com/pdf/tim_sprk_blt.pdf
this would exceed the surface speed for chain
we use timeing pulleys all the time at work.
timeing pulleys or v belts would work but timing pulleys won't slip and you dont have to pull as tight (overhung load) to keep driving
3600/540 rpm you would need 6.666 to one ratio

dont forget the horsepower but some thing like these 1" to 2" wide belts should work.

for example
18h100 (18 tooth) generator
120h100 (120 tooth) drive line

and belt to go between them

some thing like 630h100

would be both sprockets and about 15" center to center

tom

 

[archangel]

Also, if you use an open differential and stop one axle from spinning, the other will go twice as fast, so a 4.11:1 would be spinning the tire like a 2.05:1 rear end, so would going the other way driving the electric motor off the drive shaft flange and the power going into the one free axle be the opposite, like an 8.22:1?

Just a late night thought. /forums/images/graemlins/confused.gif

 

[J_mack]

Hi Bob
Just a word of caution, if you build a generator, we put one together with a subaru and we belted it 2-1, it worked good until one day I started it by pumping the throttle a couple times and the throttle stuck above the 1800 rpm notch , it smoked the generator, we bought another one and it's got over 300 hours on it, it averages about 3 quarts a hour. we built a house with it. the only thing I can say is these generators don't have the power of a pto unit of the same rating. when our 5 hp started, it would work it, while my freinds pto unit would'nt even work,(8kw) but it weighs double and cost 3 times as much. I have a 85hp tractor did'nt want use it because when you really want a generator it's usally really cold. and the subaru starts excellent.
Just some ideas
Mack