Building portable welder

[shoquest2007]

So seeing how some of these alternator welders work, I have been asked by a few of the local guys who weld and are tired of lugging around big welders to weld thin metal 1/4" or thinner.
They had seen the Zena portable welder i put together, and of course i like to tinker around and came up with this idea ? I would like your input on it or any suggestions.

Here is the one I built, I can pick it up and load it easily in the back of my truck and move it around the jobs easily.




Now here is something i have put together on paper, and have thought about building it but I would like to see what you guys think about it and why it wouldnt work or what would make it better.

[shoquest2007]

the parts would consist of

***The 200 amp alternator

****The diode pack I found on ebay , would run the stator wires out to the diode block and the leads would hook up to the other side of the diode block

**** The relay would control the power on off from the push button on the stinger for the feild voltage to the alternator through the dimmer switch for the amount of volts that is fed to the feild.

[kolot]

not real good with the electronic but If I am correct you will have a decent DC amp out put could probably run 3/32 or maybe 1/8 rod, is that right?
How many HP motor do you think it will take to push the 200 amp alternator.
How does the unit you already built perform and how about a drawing on that one?

[shoquest2007]

I currently use 1/8" rod of 6011 , 6013 and 7018 with the above zena welder. The Zena unit I put together was from a kit that was about 500 for the alternator and leads and its control box, but after doing some tests its controlling the voltage to the feild from what i am able to determine. They added a second button to the stinger that feeds full voltage from the battery to the feild of the alternator. so you can easily start an arc, But I have had very little trouble starting an arc except when the stick is cold. If its hot it start right up and goes very little sticking.

i have access to multiple riding mower motors ranging from 15 to 18 hp. All have electric start and charging coils to charge the battery on the welder.

My whole reason for wanting to build another unit was a freind of mine builds gates and metal pipe fences and was really liking mine, I let him use it for the day and he came back and said what would it take to get something like that, and i told him about the zena kit, and he said that im sure you already know how its done so build me one. and the above drawing is what i came up with.

[MikeGyver]

As a quick estimate calculation, to burn 1/8 rod at around 130amps you'll need about 8hp min.

[jbmprods]

Originally Posted by MikeGyver

As a quick estimate calculation, to burn 1/8 rod at around 130amps you'll need about 8hp min.

the Scott welder i have is 125 amp dc and uses a 7.5hp Wisconsin Robin engine to power it. it handles 1/8" 7018 no problem.

it is the first engine drive welder i owned and still have it 25 years later. the cost of the machine was $0. i found it laying in the front yard one morning. must have fallen off somebody's truck when they made the turn. i posted it in the found section in the local newspaper but nobody came forward to claim it so i kept it. all it got when it hit the ground was a small dent in the gas tank. it still welds like a champ. i keep waiting for a new Miller TB to land in the yard.

[MikeGyver]

Originally Posted by jbmprods

the Scott welder i have is 125 amp dc and uses a 7.5hp Wisconsin Robin engine to power it. it handles 1/8" 7018 no problem.

Sounds about right. Technically you could get away with 6hp if you only had a 20 volt arc @ 130amps, I wouldn't aim for this though; it would be much better to have 30 volts at your disposal though. Typically alternator efficiency is .55-.6 by the way.

[rdop2001]

Originally Posted by jbmprods

the Scott welder i have is 125 amp dc and uses a 7.5hp Wisconsin Robin engine to power it. it handles 1/8" 7018 no problem.

it is the first engine drive welder i owned and still have it 25 years later. the cost of the machine was $0. i found it laying in the front yard one morning. must have fallen off somebody's truck when they made the turn. i posted it in the found section in the local newspaper but nobody came forward to claim it so i kept it. all it got when it hit the ground was a small dent in the gas tank. it still welds like a champ. i keep waiting for a new Miller TB to land in the yard.

I was wondering what happened to that thing. Thanks for keeping it safe for me. I'll be by to pick it up next time I'm in CA.

[shoquest2007]

got the alternator gutted, and ran a wire to the field, pulled the diodes out fo it, hooked up three heavy wires to the stator. where the diodes use to hook up. going to use the plasma cutter and cut the frame for the alternator to mount today, then hook up the wires to the diodes and the rest of the wiring to the motor, put the belt on and see what it does. Im still working out the wiring on the controls for the two buttons on the stinger. One will activate the Dimmer switch which will run at a controlled voltage , and the other button will feed the full 12v from the battery to the field to help start an arc if needed.

I plan to put the dimmer and the two buttons on the stinger. I like the way my Zena unit allows me to control the amps with out having to go over to the machine multiple times to adjust for different settings.

[shoquest2007]

I chose the 300 amp diodes cause i thought for an extra 10 dollars in cost for those it wouldnt be pushing them as hard as if I had chose 200 amp ones, plus it would also allow for growth if an alternator of a higher amperage was put on it

[kolot]

how much weight saving do you think. Not to go negative on you but a small Lincoln welder, older of course say the Weldnpower AC130 or AC/DC 150 are comparble welders if not better , go about 425 lbs. and usually sell running under 500 used. With buying the Zena and realated parts and the build labor wondering if it is worth it. Now the cool factor on the other hand , Priceless! If you build your new designe, let us know how it works out.

[shoquest2007]

I currently have a boat ancor miller roughneck, way too heavy to load by myself and move around the job. I havent weighed the zena unit yet, but i bet its under 200 lbs. I live out in the country and there are tons of riding mowers i can pick up for 50 bucks or less, alternators are 150 to 250 new, diodes are 65 bucks on ebay, garden tractor battery 30 bucks. Leads I have plenty of. I will buy a new stinger with a different handle the one i found i like that would give me room for the button is 30 bucks

So in all I have would be 250+65+30+30=375

If i didnt already have the leads id say another 100 bucks for that stuff. While your right the miller might be a much better welder but for what we weld is mostly dcen. I have three other welders in the shop for indoor stuff, but i like the portability of the zena unit i put together.

I already have a 140 amp alternator and a 15hp motor running , I might get the diodes and see how that works. I have an alternator shop who said they would sell me a 200 amp unit with no regulator and diodes for 175. ready to do what i want with it. Might even put the stator wires on an insulated screw terminal sticking out the back of the alternator, I would just feel pitty for the fool who touched one while running.

also costs of repairing it would be next to nothing as parts are all over for the motors, usually in stock, alternator shops are plentiful in DFW area, the diodes might be the only hard thing for me to get quickly as the rest of it can be bought at a place called tanner electronics locally. So I would say the diodes would be the only part that would hold it up from being able to be repaired quickly

[kolot]

Originally Posted by shoquest2007

I currently have a boat ancor miller roughneck, way too heavy to load by myself and move around the job. I havent weighed the zena unit yet, but i bet its under 200 lbs. I live out in the country and there are tons of riding mowers i can pick up for 50 bucks or less, alternators are 150 to 250 new, diodes are 65 bucks on ebay, garden tractor battery 30 bucks. Leads I have plenty of. I will buy a new stinger with a different handle the one i found i like that would give me room for the button is 30 bucks

So in all I have would be 250+65+30+30=375

If i didnt already have the leads id say another 100 bucks for that stuff. While your right the miller might be a much better welder but for what we weld is mostly dcen. I have three other welders in the shop for indoor stuff, but i like the portability of the zena unit i put together.

I already have a 140 amp alternator and a 15hp motor running , I might get the diodes and see how that works. I have an alternator shop who said they would sell me a 200 amp unit with no regulator and diodes for 175. ready to do what i want with it. Might even put the stator wires on an insulated screw terminal sticking out the back of the alternator, I would just feel pitty for the fool who touched one while running.

also costs of repairing it would be next to nothing as parts are all over for the motors, usually in stock, alternator shops are plentiful in DFW area, the diodes might be the only hard thing for me to get quickly as the rest of it can be bought at a place called tanner electronics locally. So I would say the diodes would be the only part that would hold it up from being able to be repaired quickly

Didn't realize it was under or around 200Lb. I would have thought more with the engine unit, frame and all. That is something to think about. 200 is not something you just pick up and throw in the truck, maybe when I was younger, but sliding or walking it up a plank is very do able alone. Might not be bad to have on hand. Would be very popular with the guys who use the ZENA, off road and 4x4, maybe some stock car guys.

[AndyA]

jbmprods, when Big blue airpaks start falling from the sky, let me know!

shoquest2007, I wonder if you'll need/want an inductor after your rectifier. The idea being it will smooth out the current, and provide a voltage kick whenever the arc wants to quit.

[shoquest2007]

When i build the unit i will play with the idea of a inductor, but the zena unit doesnt have one

[shoquest2007]

since i have that 140 amp alternator and I have this 10hp motor which i know is running I figured I would start building the frame and getting everything in order to test out this setup. I have a 15hp motor but im waiting on a new carb from ebay for it. The 15hp motor will replace the 10hp motor when i get the carb for it. But all the wiring and so on wont change.




I started on collecting a couple of relays to make the control box part of it. Im thinking about getting an amp gauge and putting it on there to see what the amps are set to with a volt meter showing the output voltage to the field.