# Running a mill or lathe on a generator



## cathead (Sep 28, 2020)

My new shop will be generator powered.  Is anyone else doing this?  I would like to add a lathe and or mill
to one corner and power it from a generator.  I have several generators, some gas and one diesel 220/120
unit.  A new lathe would be nice since I routinely run old machines that are pretty well worn.  Does anyone
have any recommendations regarding such a purchase?  I'm thinking a full sized mill and a 14 inch diameter
turn lathe, maybe Taiwan manufacture.  It would be 220v and single phase.


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## kb58 (Sep 28, 2020)

I think that the answer rests solely upon the generator manufacturer. For a purchase of that magnitude, I think I'd talk to them directly and not forums. That said, many generators aren't prepared to deal with the potentially large inrush current needed for such machinery, so you're going to have to oversize it, unless the mfg can say upfront that their units can handle it.


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## Chipper5783 (Sep 28, 2020)

Machine tools start pretty easily (across the line starting, but unloaded motors).  In your signature line you have some decent sized machines, are they all single phase too?  If you are buying new, you can often specify single phase in the smaller size industrial machines (lathe around 14" and mill ~9x48 are pretty small) - anything larger will be progressively more difficult to get in single phase (and pointless to get in single phase).


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## JimDawson (Sep 29, 2020)

As long as the generator will supply the starting current, then I don't see a problem.  I have run machine tools on a generator.


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## Bi11Hudson (Sep 29, 2020)

The generator should be powerful enough for any continuous load, plus the starting current (usually 3-5X) of the largest motor, plus a 10-25% "finagle" factor. The last is to oversize the engine enough that it is never run at or near full load. I used a generator for my splicing gear and trailer way back when. 6.5 KW (120/240) continuous (Honda gasoline) with only the AC as a heavy start-up load. It still resides out in the barn, exercised every few months to keep the battery charged. I don't have an hour meter, but the somewhat oversized engine has paid off. A true Honda plant is recommended, a Briggs and other "lawnmower" engines are not. Diesel is so much more preferable but hard on the wallet. For long term continuous use, avoid the price saving, go with quality.

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## Flyinfool (Sep 29, 2020)

Most generators have 2 numbers on them Max continuous load and Max surge. The surge rating is what can be a short peak like starting a motor.
If you plant to keep the generator for a long time and use it a lot, try to have the load at not much more than 50% of the generators ratings. Do not forget to include the loads for lighting cooling heating, other tools like a tool post grinder air compressor, and anything else that may be running in the shop. There is a reason that many generators give a bunch of info at 50% load.

Diesel is best, the fuel does not go bad like gasoline does but is expensive. If you get an inverter type generator, make sure it is sine wave and not modified sine wave. in case you will be running electronics like a computer or CNC conversion.


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## samstu (Sep 29, 2020)

Military generators are often both single and 3 phase with a variety of voltage outputs.  They are well under-rated as far as wattage output.  These can be often purchased cheaply as they are heavy, fuel thirsty and very loud.  

I know a guy who runs a pair of these to supply power to a large boring machine that exceeds to power available to his shop.


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## Flyinfool (Sep 29, 2020)

If you end up with a 3 phase lathe, you could always add a VFD to change the 1 PH into 3PH. Most VFDs also have the ability to soft start to help reduce the startup surges. 
A VFD will require a full sine wave generator output


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## cathead (Sep 30, 2020)

Thank you all for your input.  At present I am using mostly a Honda EU2000 inverter generator just for lights
or occasionally a table saw.  It will run a table saw but one has to be careful not to bog it down.  I also have
a Honda EM2500 which is not an inverter unit and it doesn't run the saw as well as the Honda EU2000.  
Also in the generator department is a Miller Generweld 130 amp stick welder with 120 volt output.  It runs a table saw
just fine but guzzles gasoline running at full 3600 rpm.  Another generator I have is a Deutz F1L812 diesel
which is 120/240, an interesting unit.  It is quite fuel efficient but very loud and also very heavy and vibrates a lot. 
This is getting long, sorry.  Also I picked up a HondaEM6500SX that is missing the fuel tank and starter rope.
It would be the best and most practical if I can get it into working condition and has electric start.  So that is
where I am at presently with generators.  The diesel has some fuel related issues as it is picking up air in
the intake line somewhere.  It has a small filter right under the fuel tank which is quite restrictive.  I'm thinking
that it is causing so much suction in the line that it is pulling air in through one of the fittings.  None of the
fittings leak however so a little perplexing.  Also in the fuel line is a larger "wool" type filter which has 
a little screw on top that has to bled of air after the engine runs a while and then stalls.  So, it's all good
fun working out the bugs.  I may add a spin on diesel filter in the line and improve on the existing lines
to clear up that problem.  It seems like if it is a diesel and it doesn't run, the problem is more than likely
fuel related.  Congratulations to all of you who have read this far on my generator story.


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## Flyinfool (Oct 1, 2020)

Wow, that is quite an assortment of generators you have.

You did not mention what size generator is on the  Deutz F1L812 engine. If it is big enough I would look further into that, it is old, parts may be an issue.
Whether the filter is too restrictive or not, air in the line is a leak, you need to find it.

I did find a thread on that engine that may help you.





						Deutz Diesel F1L 812 Generator
					

Hi All!  An F1L 812 Deutz Air cooled generator followed me home and after some degree of work, it runs.  I'm curious as to the vintage for one thing.  Also the engine drops off occasionally after warmed up and emits a lot of black smoke in catching up.  It was originally a Allmand Maxi-lite...



					www.smokstak.com
				




I do have a low time 3500 W commercial Baldor gen that I would like to sell and get a smaller one that is either diesel or propane powered.


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## Bi11Hudson (Oct 1, 2020)

Flyinfool said:


> Diesel is best, the fuel does not go bad like gasoline does but is expensive. If you get an inverter type generator, make sure it is sine wave and not modified sine wave. in case you will be running electronics like a computer or CNC conversion.



Diesel is lower cost than gasoline. It's the physical plant that costs more. There are many other reasons for running a diesel plant. Just be sure to find an engine of known brand to your parts people. 

There are ways to "adjust" the synthetic sine wave of an "inverter". *Some electronics are sensitive, some are not*. I have used an inverter short term with my splicing(fiber) machine with no ill effects because it used a "switching" supply. A motor load will not have any problem.  A VFD possibly would. I personally do not like a synthetic sine wave plant. More personal taste than any real problem.

The simplest way to "adjust" a synthetic sine wave is to have a magnetic device across the line full time. Such as a transformer. However, the cost of a transformer of sufficient size is such that if the cost were added to that of an inverter, you could just buy a true sine wave machine from the "git go". Keep in mind that I am "old school". I won't go into "magnetic amplifiers" and "sensodynes", but that is how far back my knowledge base goes.

Your last post implies that you are good at "scrounging". If that is indeed the case, a transformer would alleviate any concerns about "quasi-sine wave" generators at little cost. The bottom line is that you would have *no concerns about running a motor* on most any supply. They are usually rated for 50-60 cycles anyway. It's the electronics that are of concern. If there are none, just run whatever plant you have.

.


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## cathead (Oct 1, 2020)

Flyinfool said:


> Wow, that is quite an assortment of generators you have.
> 
> You did not mention what size generator is on the  Deutz F1L812 engine. If it is big enough I would look further into that, it is old, parts may be an issue.
> Whether the filter is too restrictive or not, air in the line is a leak, you need to find it.
> ...



I think the diesel is10 horsepower and the generator puts out 25 amperes at 220 volts running at 1800 rpm.
Parts were ordered for the Honda EM6500SX so will see where that goes....


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## Flyinfool (Oct 1, 2020)

That would be 5500 Watts.


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## cathead (Oct 1, 2020)

Bi11Hudson said:


> Diesel is lower cost than gasoline. It's the physical plant that costs more. There are many other reasons for running a diesel plant. Just be sure to find an engine of known brand to your parts people.
> 
> There are ways to "adjust" the synthetic sine wave of an "inverter". *Some electronics are sensitive, some are not*. I have used an inverter short term with my splicing(fiber) machine with no ill effects because it used a "switching" supply. A motor load will not have any problem.  A VFD possibly would. I personally do not like a synthetic sine wave plant. More personal taste than any real problem.
> 
> ...



Are you saying I could clean up my AC by connecting up a 220 volt transformer in parallel with the line 
without connecting the secondary?  That sounds interesting to me.


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## Bi11Hudson (Oct 1, 2020)

Hooking a transformer across the line unloaded (open secondary) will *correct a square wave to some small extent*. To get better results, the transformer should be between the generator and the load. Based on your previous posts, a 5KVA 240/240 transformer would be large enough to carry the normal(<65%) load. I offer an article(small book) I wrote several years ago as reference;


			http://www.hudsontelcom.com/uploads/ShopElex.pdf
		

The part you would be referred to is deep(ppg 20+) into the text. It does not give specific formulas, rather an insight to the hysterysis of a magnetic circuit. There would be a major effect on power factor, down perhaps to 65% lagging. But you're talking field use so it really doesn't matter that much. The average power plant is little better, 85 to 90%. The only thing you would need to watch is when your output goes near the max.

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## cathead (Oct 6, 2020)

Bi11,

Would hooking an appropriately sized inductor across the line do the same thing?


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## Bi11Hudson (Oct 6, 2020)

An inductor connected "shunt" will give the same result as a transformer connected "open". Very little effective results. . .  An open transformer is essentially a shunt inductor. The bottom line here is that the more load current carried by the inductor, the transformer, the smoother the output will be. What is wanted is* the magnetic hysteresis effect of current *in the inductor. So the more current drawn by the inductor, the more magnetic "offset" is visible. This is limited, of course, by the maximum current of the inductor. 

The most direct result will be seen when the inductor is connected in *series* with the load. This, however, requires the inductor to carry the full load current. If such an inductor is available, by all means it can be used. 

A simpler solution is to use a transformer to carry as much of the load as possible. Again, limited by the transformer KVA rating. In the case of a portable generator, 5 KVA minimum. Most "non-technical" people will see the transformer as a straightforward transformer. Connect one side to the generator, the other side to the load. A _*series*_* inductor, while fully functional*, can be easily mis-interpreted as to its' connections. KVA is the normal rating for inductors or a transformer. It means thousands of "Volt-Amps". Simple arithmetic will give the actual numbers. Volts times Amps times 1000.

Many "industrial" transformers will be 240/480 volts on one side and 120/240 on the other. Connected 240 on both sides allows the "secondary" to be split for 120 volts to be pulled off. The effective neutral,  the center tap, should be referenced to ground, if possible. The connections will be labeled on the "high" side as H1, H2, H3, and H4 with the "low" side as X1, X2, X3, and X4. Connected with H1 and H3 as one line, and H2 and H4 as the other, allows 240 volt input. For the secondary, X1 is one side, X4 is the other. X2 and X3 are connected together as a "neutral" and grounded if possible. This allows for 240 volts from X1 and X4 with 120 volts from X1 to X2 *or* X3 to X4. The 120 volt lines should be balanced as much as practical.

There are many other possible connections for such a transformer. But there are two *hard and fast rules* that must be kept in mind. The voltage and current applied must never exceed the name plate rating. i.e. When H1 and H2 of the above transformer are connected to 24 volts, the output on X1 and X2 will be 12 volts. But the KVA is still rated at 240 volts and current must be kept at that level. The other is that all voltages given are AC at 60 CPS. DC can almost *never* be applied.

That last paragraph is digressing wildly, I am going into lecture mode. It really is not relevant to your case, just a comment.

.


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## cathead (Oct 7, 2020)

Maybe using a 1 to 1 transformer may be the best clean up action.


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## Bi11Hudson (Oct 7, 2020)

Essentially what I spoke of above. Just be sure to use proper voltage rating. Getting both 240 and 120 would require some sort of center tap.

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## cathead (Oct 11, 2020)

I'm pretty sure of my chances of getting the Honda EM6500SX running  as it has great compression.
 I decided to make a frame for it and mount it on wheels as just the generator and
motor weigh about 200 pounds.  It was a bit difficult lifting the unit and configuring a wheeled base but
in the end it is on the base now and I can proceed with building the top part of the rack that holds the
fuel tank and electrical stuff.  I used a skid steer to lift it using some ropes to hold on to it so I didn't
break off any aluminum brackets.  I am making the top part of the rack removable as it would be no
easy task to set the generator unit into a one piece frame.  It will have handles, possibly foldable,
to wheel it around.  



 The wheels are solid rubber about six inches in diameter, good enough to move on a relatively flat surface.  
	

		
			
		

		
	



The vertical tabs will allow me to build the top part of the rack with the generator unit sitting on the wheeled base.  

The generator was a basket case found at the local scrap yard so just a fun challenge to get it together and hopefully
operating.


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## FOMOGO (Oct 11, 2020)

I bought a 12k  backup generator for the house this year and plumbed it to my 500 gal propane tank. Did the same with the grill while I was at it. At $1.40 a gal, it seemed like a no brainer. Propane is about 10% less efficient, but runs much cleaner, fewer oil changes, your engine life will be extended significantly, and the fuel is delivered to you. Also kinder to the environment, if that's important to you. Mike


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## cathead (Oct 11, 2020)

Well, today has been a great day for antisocial distancing with some free time in the shop.  The frame part is
pretty much under control and I even added oil to the crank case in preparation for starting the engine. 
The wind is just howling up here today so happy to have respite in the shop.  Some of the welding was
gas welding and a bit with SMAW and the foreman is presently looking over my work.  At any rate, it is
starting to look like a real generator so happy with that.  Dang, he has the photogenic look that I wish I had!!


So far, I am happy with the progress.   It does have electric start so will have to make a place for
the battery.

Dogs and cats can transfer Covid-19 but pigeons do not carry the 19 Strain I read.  I have had several cats
in the past but lately only pigeons.  Blue jays who are welcome to  feed here as well.  I see crows too on occasion and they are fun to watch as they are acutely interesting.  Ravens are even better!


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## hman (Oct 11, 2020)

OK ... as long as the foreman doesn't decide to express his approval by "anointing" your newly refurbished generator!


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## Flyinfool (Oct 12, 2020)

I sure hope it will start and make electricity after all the work you put in to it.


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## hanermo2 (Oct 12, 2020)

Glad Your stuff is advancing. !
Well done.

You can produce the power You want in terms of volts/amps any way You want..
Your motors or motive elements wont care ..
unless it is high load or multiple excess load and no cooling.

It is easy to electrically load a motor that is only appropriate for say 1/4 of that.
Basically all of the stuff regarding old motors and VFDs is bookum.

My old Bp motor, 3-phase, excellent, extremely expensive at the time, 18 kg, 1/2 hp, is an example.

My 2.5 kW cont. servo motor for my lathe is about 15x better in terms of power, heat, accuracy and position.
Vs a 5 kg ac induction motor.


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## cathead (Oct 12, 2020)

Today I hooked up a battery and put a little fuel in the intake.  It started right up.  The innards of the generator look
good so am pretty optimistic that it will be a working unit eventually.  An optimist looks at the possibilities and a pessimist
would just walk by it at the scrap yard and give it a kick.


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## cathead (Oct 13, 2020)

Wow! This is pretty exciting.  This morning I poured some gas into the carb and used the electric starter to start up the generator.  I had connected a big motor with a wire wheel that would run if there was indeed power.  
The generator ran for maybe 30 seconds and it did power the wire wheel with a 1 horse+ electric motor! 
The next step will be to fix up some loose ends, do some painting and come up with a fuel tank.  It occurs
to me that a 6 gallon outboard motor fuel tank would fit right in the top of the machine with no modification other than
making a place for it to sit.  I had originally planned to make an aluminum TIG welded tank but maybe the
Johnson or Mercury outboard tank would be a simpler solution.  The original replacement fuel tank is over
$500 so that is out of the question.  If not, I will have to hone my TIG welding skills and make up something
that looks at somewhat similar to what it came with.


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## Flyinfool (Oct 13, 2020)

WAY COOL!!!

I have rescued many useful things from the trash heap.

Check the output frequency and or the engine rpm to verify that the govoner is holding the correct speed. Should show 60 Hz or 3600 RPM. Govs get old and sticky.

You can even use the gov as a sort of motor speed control. I would not go to much up on the high side so that you do not put a rod thru the side of the engine. When going slower you will have to keep an eye on temperatures of the engine, then generator itself and the motor it is running since the slower fan speed will not cool as well.
This will only work on an induction motor, it will not work on a universal motor (A motor with brushes). Or any type of motor that already uses a speed controller. You do not want to go


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## hman (Oct 13, 2020)

Congrats on your successful test run!  Sounds like the outboard motor tank will work for you.  Just be careful to test run the generator long enough to make sure it doesn't get too hot for the plastic tank!


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## cathead (Oct 13, 2020)

hman said:


> Congrats on your successful test run!  Sounds like the outboard motor tank will work for you.  Just be careful to test run the generator long enough to make sure it doesn't get too hot for the plastic tank!



Outboard tanks I have are made of steel.  They feed from the top but I would think they would siphon.


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## hman (Oct 13, 2020)

Yeeeee-Haaaaa!  Haven't seen a steel outboard motor tank in quite a while.  Glad you have one.


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## cathead (Oct 19, 2020)

Well, the plot thickens...  I turned on the flywheel  end of the crankshaft and felt and heard a grindy sound associated
with rotating the crankshaft.  It had a "dry sound" not a sound one would hear from a bad rod or piston as much as I could
ascertain.  Anyhow, after further checking, I found the far end bearing on the generator was worn out and in need of
replacement.  The bearing is a common #6204RS but this bearing had a groove in it for some reason.  I ordered a new
6204RS so hopefully will be reassembling the unit shortly.  I could see no reason for the groove so hope that will fit and
be functional.  I struggled with the grinding noise and disassembled half the machine till I found the problem.  The part
is on order so hopefully in a few days that will be resolved and I can weld up a fuel tank and haul this thing to where
it will be used.  I'm thinking I will weld up a steel tank at this point as my aluminum skills still need some work.  I had thought of using some .050 5052 aluminum and trying some TIG but am still a little bit leery.  I would appreciate
any input from you guys.  It would be a 6 to 8 gallon aluminum tank I would fabricate.


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## Bi11Hudson (Oct 20, 2020)

As it happens, I also am in the market for a couple of steel outboard tanks. Gasoline is not to be messed with. A plastic tank is an explosion looking for a place to happen. A steel tank is the optimum solution. Aluminium can be welded up but there is a liquid compound that is swirled around inside before use. Find a supplier for home built airplanes, they will stock it.  According to some home built pilots of my acquaintance, it is renewed on a regular basis.

For what it's worth, even a manufactured tank for diesel fuel cannot(?) be rated for gasoline. Some years back, "we" had a large tank built for a  bucket truck. An older truck, the mileage wasn't that good. It was cheaper to use a larger tank than turbo-charge the diesel. The fairly small stock tank was to be used for a gasoline "pony" engine to run the boom so the engine and PTO wouldn't run un-necessarily. The gasoline leaked out. It would hold diesel, but wouldn't hold gasoline. Had to use a boat tank.

Modern "gasoline" is not true gasoline, it is called "motor fuel" for a reason. There are so many chemicals in it that it can only be called such. In the deep south, we are forced to use a mixture that is 15%(?) alcohol. It eats fuel hoses and does other undocumented damage to an engines. My personal experience has been very unsatisfactory with jury rigged and plastic tanks. Including Wife's favorite pick-up, which caught fire on the road. It only had 42K miles, but was 10 years old. Ten years of that funky "gasoline" literally dissolved the fuel system and it went up. She knows well how to handle an emergency and got out in time. But the truck was burned to the ground.

.


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## cathead (Oct 20, 2020)

Thanks Bi11 Hudson for your post.  I'm glad someone reads the details of my life in the shop.  The clear and easy solution is an old Evinrude or Johnson 6 gallon boat tank.  I think the Johnson tanks said"cruise a day" on them if I remember correctly.
I'm pretty sure I can find something at my local scrap yard.  It's snowing heavily here right now and we are expecting about
ten inches this week.  Winter is getting an early start up here I guess.  Ten inches of snow in the lake will lead to early ice
so it will be a looooong winter in northern Minnesota.  Here there are three grades of auto fuel, regular, somewhat better
still with 10% alcohol, and off road gasoline for boats, atv and lawn mowers with no alcohol added and 92 octane rating.
I get a kick out out of the labeling on the local gas pump.  It says something like "enhanced with 10% alcohol" when in reality it should say "degraded with 10% alcohol".


Edit:  Thanks to hman of Chandler, Arizona for following along and liking my posts as well as anyone else who participates.

         Another thing:  In Minneapolis they have the "I can't breathe" syndrome but up here it is the "I can't drive" condition.  
                                 With the new snow on the roads, some folks insist on driving like it is summertime.  They tailgate
                                 in long no passing zones and pass on the right and do not slow down when one is slowing down on the
                                 highway for a turn.  Defensive driving is quite helpful up here as anywhere I am sure.   They
                                 need a fender bender to make them wise up maybe.


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## cathead (Oct 23, 2020)

Today I was able to get my hands on a crusty 6 gallon Johnson or maybe Evinrude 6 gallon boat tank.  I did spend
several hours on cleaning it up as it was somewhat rusty inside.  I had to make a gasket for the top feed assembly 
too but that was sort of expected since this type of tank is likely 50 years old or better.  I intend to use it on a fairly
large Honda generator  and wondering if it will work siphoning fuel from the top fixture or if I would better off drilling
a hole in the bottom and using gravity only.  My common sense tells me that gravity will cause less problems for me
since air leaks would shut down the generator if siphoning.  I'm looking for some common sense ideas here so let me know 
what you  guys are thinking.  



Yes, it has a couple dents but way easier than trying to make a 6 gallon fuel container out of flat stock.  

As always thanks everyone for your comments.


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## hman (Oct 23, 2020)

That stylized "E" leads me to think it's an Evinrude.  But then, I've also heard that "Johnson and Evinrude are made in the same factory, just on alternate days."  Great find!


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## cathead (Oct 23, 2020)

I have to agree on that point.


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## cathead (Oct 26, 2020)

I have 10 dollars invested in the Evinrude tank so went ahead and made a 1/4 inch female outlet for
fuel on the bottom of the tank.  The fitting was made of steel on the lathe and tapped for 1/4 NPT.
Then I silver soldered it on to the tank bottom.  After a leak test, I drilled a small hole in the bottom of the
tank thru the silver soldered fitting.  There is no screen on this set up so will add an in line screen
on the way to the carburetor.  Now all that is left to get this outfit operating is to mount the tank securely
welding up a cradle to hold the tank and do the required plumbing.  
	

		
			
		

		
	



The fitting is tucked up higher than the lower part of the tank rim so if I ever want to use it as a boat tank again,
I can unscrew the valve and install a flush plug.


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## hman (Oct 26, 2020)

Great design!


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## cathead (Oct 27, 2020)

hman said:


> Great design!



Thanks!  It was a matter of necessity as the choice was to fabricate a tank or simply use an existing tank
of the same size needed.  I have a TIG machine that I have not used much so later on I might experiment
with making one in aluminum.  For the moment, it was the best way to finish up my generator project quickly and
shuffle it out the door and be able to make use of it.  Tomorrow I will get some square tubing and finish  up the
mounting of the tank and plumb the fuel line.


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## cathead (Oct 27, 2020)

Well, it is up and running with the boat tank and happy it all works and generates as it is supposed to.  The idle function works too since I figured out the wiring mess. The next step is to see what it will power.  I have a lot of 220 volt single phase
equipment that would hopefully work with a generator, 220V band saws and such plus a 220V compressor hopefully.


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