A simple generator frame

[HankB 16]

Hi folks,

Fellow boarder Jason M asked me quite some time ago for more information on my generator mount. I thought that if I posted the information here it might benefit others and provide the basis for some sharing of further ideas. My 'design' is hardly unique as I studied posts by others who have done this before me and got some ideas from them that made mine better.

Here's a picture of the generator in action during a one day outage this spring.

Detail in the vicinity of the quick-tach.

The washers that locate the attachment point are welded inboard of the frame rails.

Here's a side view of the frame.

Offset of the generator head from the respective frame member.

This is not a critical dimension as long as you leave sufficient allowance to align the generator pulley with the PTO pulley. In my case, I originally aligned the generator pulley with the smaller outboard groove in the PTO pulley. Unfortunately that resulted in frequency less than 60 Hz. I switched to the larger inboard groove on the PTO pulley and frequency was good at 60 Hz. I was lucky to have enough space on the generator shaft to move the pulley over without having to drill the mounting holes again.

Here is the width of the frame.

The dimension is not critical as long as it is wide enough to clear the mount point and narrow enough to clear the front tires at full turn.

Length of the frame from mount point.

to front edge of generator.

Bottom view.

Here is the belt I use.

Do note that the belt length will depend on the length of the frame and as the belt wears in, the generator will drop a bit.

Experience: I used it during one outage early this year when we lost power for about a day. I do not have a transfer switch so I just ran extensions to refrigerator and freezer and fish tanks. I did not run it continuously but ran a couple hours on and then left it off a couple hours. With the pulleys I have, I need to run the engine at full throttle to achieve line frequency. I wanted a pulley that would achieve that for me as that's where the engine makes maximum power and the only place where it has a chance to get anything close to full output from the generator. And in fact, I am only set up to run it at considerably less than full output. It uses a lot of gasoline (IIRC it was several hours on a full tank.) The one thing I do not know is how well the engine will regulate speed at less than full throttle. For the loads I ran, speed regulation was pretty good at full throttle.

I've probably left some details out so ask away if I've left any questions.

Edit: I see that the generator is on sale right now for $290: http://www.harborfreight.com/10000-watts-m...head-45416.html that's only a few $$$ more than I paid for it. (I used the 20% off coupon which is now disallowed for generators among other things. and when I bought mine, they were $299.)

thanks,

hank

[Michaelzz28 22]

:thumbs2: this is exactlly what I was looking to do thanks for sharing!

[squonk 41,018]

I did the same thing for a friend. We have a slotted plate for mounting the jenny to get the pulley lined up. He still hasn't finished hooking it up plus we still may have to play with the pulley diameter some. It's even got red wheeled casters! :thumbs2:

[EdG. 5]

Do you think the 12 HP would be too small for this gen.

Harbor Freight says it needs a 16HP.

[HankB 16]

Michael - only too happy to help.

Mike - Pictures or it's not happening!

Ed - The rule of thumb is 2 hp/kW output. It will work with a 12 hp engine but you might not get full output. I'm marginal with 14 hp and I think that HF recommends 16 hp. (I wouldn't let that stop me.) Or get a bigger tractor. :banghead:

[jmunzke 1]

:thumbs2: Thanks Hank!

[cheesegrader 433]

Hank,

You the man!

I was in Winfield helping my parents this spring after one of the storms.

While you were running the generator, I was probably making as much noise running my chipper!

I'm off to Harbor freight this weekend to get my generator head and start my next great project. It is hard to beat a 10k generator for $400 in parts and and a little labor. Should keep me busy for a few weeks this winter.

Thanks for giving me a flying start!

[bk-scouter 93]

Thanks Hank for the details on the generator setup.

Cheesegrader, we'd love to see pics of your 10K generator and see how it performs after your finished.

-BK

[HankB 16]

...

I'm off to Harbor freight this weekend to get my generator head and start my next great project. It is hard to beat a 10k generator for $400

...

Phone first. It is not a store stock item.

Also the price is $289.99 right now. I think they may be clearing them out. Search for 'generator' on their site and this unit does not come up. You have to search for 'belt drive generator.'

Don't dally! Get it while it's still available and on sale!

[HankB 16]

And another thing...

I forgot to identify the details on the pulley I used. It's This one from McMaster-Carr. In case they take that page down, here's an image scraped from the screen.

Another board member asked me about this and I'd prefer to keep the conversation on the forum for the benefit of others who may want to make one of these. He asked:

I have my generator head, and am starting on my mount.

THis is going on a 520h with a forward-swept front axle,

so I have to add a little length to clear the front tires. THe width and general layout of your design seems quite sound. I am looking at pulleys, and wonder if you know what size you used.

I plan to match the small PTO diameter, and if I can't get enough speed, I can run the belt off the bigger PTO pulley to compensate.

I am also thinking of using the hydro and the lift bar for my

snowblower to control the front end. Hanging by the belt worries me, without some additional support. I worry about violent bouncing+belt damage when driving it out to my barn.

Any ideas?

Thanks,

[...]

The pulley is described on the McMaster Carr web page. Since you have a higher HP engine you might consider going with a smaller pulley so you can run at a somewhat lower RPM. Mine works well with the engine (M-14) at full throttle and on the larger PTO pulley groove.

If you need a longer frame, that will affect belt tension. If you want to know the belt tension, it will be approximately the weight of the generator / the tan(angle from horizontal for the belt). As the angle gets closer to horizontal (what happens as you move the generator further forward) then the tension on the belt goes up. I calculated the tension for my setup and decided that it was OK based on tension requirements I looked up on the 'net. (see http://www.gizmology.net/pulleysbelts.htm) For your setup you might need to add a spring to reduce belt tension to acceptable levels.

The snowblower lift tube and flag should work well enough to support the generator. I didn't have that so I fashioned a 'T' shaped piece that mounts to the tach-a-matic with a threaded end the goes through the cross brace on the generator frame. I can use that to support the generator for transport over rough ground.

[tmix 34]

That is so cool T MIX

[cheesegrader 433]

bump

[Hydro 131]

I remember the front castors and the fact the weight of the unit was the tensioner. I am wanting to build a similar unit but my expectations are for a smaller gen head. Thanks for bringing this forward. I know others will be coming in on this.

Happy New Year

[WildHorses 382]

Has anyone else built one of these? I'm getting ready to start and I'm curious about the pulley size in relationship to engine horsepower. I've got a 416, a 520 and a 310... I would like to be able to hook it up on all 3 but I'm thinking different size/power may need a different drive pulley. If anyone could weigh in on pulleys diameter and problems they've had I would appreciate it.

[dodgemike 52]

Can you imagine what we all

could build if we came to a central

shop with all the tools parts etc.

The knowledge on this forum just

astounds me! If we wanted for a

WheelHorse we could fab it.

Sent from my SCH-S720C using Tapatalk 2

[smoreau 658]

Has anyone else built one of these? I'm getting ready to start and I'm curious about the pulley size in relationship to engine horsepower. I've got a 416, a 520 and a 310... I would like to be able to hook it up on all 3 but I'm thinking different size/power may need a different drive pulley. If anyone could weigh in on pulleys diameter and problems they've had I would appreciate it.

you need a variable sized pulley, They thread in and out to change the size and have a lock to keep it in the spot you want. mostly seen made out of aluminum and may not hold up too ling though.

[bmsgaffer 2,043]

These generators change the output frequency based on speed in which they are spinning.

 

All our engines should be run at 3/4 to full speed for cooling and max torque, and the belt driven generators are also designed to be run at a certain speed (usually 3600 rpm, same speed as the engine at full tilt).

 

So for all of them you will need approximately a 1:1 pulley setup, but you will have to size your generator head to the smallest tractor you want to run it on. 10hp should be no greater than 5kw, but if you stick with the other two tractors only, you could handily run a 7.5-10kw.

[Tankman 3,518]

this is exactlly what I was looking to do thanks for sharing!

I'm with Michael on this one! Great job, work! I see this as a spring project! Thanks for posting!

[shorts 182]

When I was doing standby power the majic numbers are;

1.54 hp per kw.

and it takes 3 kw to start a 1hp motor,

but only 1kw to keep it running,

 

you can put a 10 kw generator head on any size engine but it will only produce the amount of power that the engine can make,  engine hp divided by 1.54kw so a 10 k gen on a 8hp engine will make 5 kw of power and a 12hp will make 7.5 kw

 

most of these small generators need to run at 3600rpm at the generator to produce 60 cycle or 60hz power,

 

size your generator by your power needs, look at the amperage size of the absolute necessities and can they be cycled on/off to keep your system needs workable

 

In my mind the priorities would be

sump pump must be able to run to keep all of the mechanical systems dry so they can function on a rotating basis

heat plant, blowers and or pumps,

well pump for potable water, for drinking and flushing the toilet

power the refrigerator and freezer to maintain food supply

[erwine13b 27]

i was searching and thinking, then bam you guys had it all figured out. im so glad i found this forum