Need project ideas for the winter

Gas engines' horsepower doesn't translate well to watts. If you want to replace a 7.5hp electric motor, you need an 18 hp gas engine (this data from Quincy, the air compressor folks).

Translating, that means from a 5hp motor you can get *maybe* 1500 watts. At 15V,

100 amps tops.

Don't think you have enough oomph there for welders.

Suggest you clean them up, change their oil, and sell them on your local craigslist and then take the money and go buy an old gas-powered welder and fix it up. It's a beautiful thing to be able to buy parts ..

GWE

ShadowHawk wrote:

Let's see, for welding at 20 volts across the arc and 90 amps (very minimal welding), you would need 1800 watts. That is way over 2 HP and does not account for various energy losses.

It says:

? 16 Hp input recommended

5 HP is not going to be enough to develop full nameplate power.

I am not sure just how great these motors are, but most such motors were designed to run only very few hundred hours. It may be OK for a lawnmower, for example I use my lawnmower maybe 10 hours a year at most, and 200 hours could last me 20 years.

Somehow I feel that it would a waste of time to use such low lifetime motors on other things like generators.

It is cheaper to just buy a used real welding machine, than to mess with this stuff. Just MHO.

i

Says the guy who's building his own AC chopper for a DC welder?

Hmm.

Why not get creative?

Actually, your irony is 100% justified. Considering the value of my time, I would have been financially much better off buying a new Miller AC/DC TIG welder at MSRP, and making money by taking a side computer programming job.

That's not even considering the cost of parts.

I am not practicing what I am preaching.

In my defense, I must say that I did not anticipate the amount of time it would take, and also that I like to spend time this way, and do not need to earn more money.

i

That's quite amazing indeed. Just curious, as a side question, are motorcycle engines easy to start in cold weather?

i

Thanks Grant... I'm starting to see a trend to the replies.. I may just do that....

Rex S.

Grant Erwin wrote in news: snipped-for-privacy@corp.supernews.com:

The motor is not much more difficult to start, the problem is batteries are less efficient in the cold.

I think one needs to make a distinction between doing something because it's educational and fun vs. doing it because it'll save you money. There are very few manufactured articles that a well-educated US citizen can make for less time/effort/money than they can buy.

But it's less educational and less fun to buy stuff sometimes.

So I try to remember, when I'm thinking about making stuff, to ask if I'm doing it because I can't get the thing, because I know I can do better than I can buy (there are some areas where I'm a good craftsman), because I will enjoy the process of making it, or because I have my head up my assumptions. In the first three cases I make, in the last I buy...

Hmm.. I hadn't seen the listing online... and the printed catalog neglects to mention the input HP required... I suppose I can find some other smaller use for them or sell 'em for $$ towards a "real" gas-powered welder.

I've currently got a little Italian-built (If I remember correctly) HandyMig that is great for real thin gauge work.. but I wouldn't trust my life with the welds... and thicker (like regular 'ole 2x2 angle iron) needs some more oomph than my little crackerbox has...

I've got a set of Glen'L plans for a pop-up camper I want to build... so am needing a higher output welder for the trailer's frame. Was wanting to get away from the plug-in AC powered, just because I'd rather fire up the welder and have more than enough power for teh job, then too little with not enough penetration...

Thanks again, Rex S. Richardson, Tx

Ignoramus12137 wrote in news:5iknf.65383$ snipped-for-privacy@fe28.usenetserver.com:

wrote in news:gCknf.9741$Ea6.9347@trnddc08:

Now THAT's a good looking project! ha! I'm thinking I'd be better off finding a less power-hungry project for these little motors...

Thanks, Rex S. Richardson, Tx

Ignoramus12137 wrote in news:PFknf.35297$% snipped-for-privacy@fe29.usenetserver.com:

My battery needed a little "boost" last week when I fired it up during our little freeze here in Dallas.... If you;ve got the proper viscosity of oil in the crankcase for the temp, you should be good with a motorcycle engine..

Hmm... I've got a *spare* '82 XJ750 engine in my back yard... Rated at about 70Hp, IIRC...

Rex S.

The only such item that is an exception has been a phase converter.

Yes. And besides, if one accepts the philosophy that tools should not be made and should be bought, there is only a small step from that to realizing that

1) since tools are not needed to make other tools, 2) they are only needed for house projects and 3) one does not need tools at all and could hire handymen, professional weldors etc.

That would be a very boring world.

Telling the last case from others is not always easy...

i

If you're going to put the time and effort into a project, the engine may be the least valuable part. For example - new surplus 5hp, delivered price $80 here

Not from any of those plans, but I did build a backup generator for a home power setup from a new surplus engine and a $5 alternator from the wrecker. 75A continuous at 24V nominal. Counting the enclosure blower, about 2200W output. Of course I still needed sheaves, starting battery, rectifier upgrade, electronic field control, breakers, fuses, switches, etc. And now that I've worked out the bugs I'm going to replace the junker alternator with a heavier version with custom-wound components, perhaps some meters.... the list goes on. For a specialized application, it's great. But as a substitute for a useful welder, probably not a good idea unless you want to do it mostly for the educational value.

Nope.

Nope.

You could use the 5hp and a car alternator as a portable charger for a couple of batteries, and use those to power a Ready Welder

a second alternator or inverter for AC power. Perhaps as little as $600 total cost. A setup like that would in some ways be better than a store bought engine-driven welder/generator. The batteries and Ready Welder could be one package, suitable on their own for light or brief work. The power supply could be a separate package. Each under a hundred pounds.

Wayne

Roger P Williams Feb 24 1998, 12:00 am show options Newsgroups: misc.survivalism From: Roger P Williams - Find messages by this author Date: 1998/02/24 Subject: Welder from Alternator, was: Re: good inexpensive welders ? Reply to Author | Forward | Print | Individual Message | Show original | Report Abuse

This is a synopsis of an article found in Mother Earth News #66, November/December 1980, "Build a $20 Portable DC Arc Welder."

Materials:

--------- Lawnmower Automobile alternator (remember, this was 1980 when most of them didn't have voltage regulators built in) pulleys and V-belt deep-cycle battery Two 1 1/2 ohm, 8 amp resistors (found at auto parts store) diode and thermal overload switch (usually part of alternator) ground clamp & welding rod holder

Construction:

------------ The alternator is mounted on the side of the lawnmower so it can be powered with a V-belt from the lawnmower shaft. The battery sits atop the mower in front of the 3HP engine. I can't reproduce the wiring diagram but it is simple enough to describe:

Alternator Ground to diode Anode (positive end) and ground clamp

diode Cathode (negative) end to battery negative and Alternator Armature

Alternator Field series-connected *through* thermal overload, the two resistors in series, and on/off switch to battery positive and welding rod holder

Remember, you have to use *thick* wire capable of handling heavy current, and make good electrical connections.

Comments from the text:

---------------------- Power is adjusted by varying lawnmower engine speed. Without the resistors to cut the field voltage, striking an arc would just about kill the engine. With a 50 amp alternator maximum penetration is about

1/4" and because of the low voltage, the welding rod must be held very close to the work to maintain an arc; but because it's DC this is easier because there is little tendency for it to stick. The unit should also only be used about 20 min. at a time to avoid overheating the alternator. "The thermal cutout will let you know when enough is enough."

Needless to say, the $20 estimate assumes that you scrounge the mower, battery, and alternator.

Disclaimer:

---------- I have not tried this myself, but it sounds like it would work.

--Roger

Somewhere in my Stuff..is a Scott Welder..gotten from I think Jerry Martes some years ago...I guess I should find a motor myself and make one up....

Ya know..I wonder..if a guy could make a few bucks making up a new version of the old Scott welder and pushing it through the 4x4 magazines and so forth?

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

That would be a lot of fun to do with a lil diesel from an Isuzu Pup or Mercedes....

Too bad I have to drive a hundred miles to find snow...shrug

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

ROFLMAO!!!!!!!!!! Now thats exellent thinking outside the box! And yes..they start as well as anything else in the cold.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

A two horse can be used to charge a battery. I have done that much. As for welding, I can't say but suspect it would load up too much and loose RPMs. The 5 horse should do nicely but makes for problems with mounting eveything. The charger I made used a 36-42A Delco alternator with the shaft direct coupled to the motor. I started out with a belt drive and then tried a coupling and it was good enough to charge the batteries on our camping trailer when we were out hunting far from a power source.

I wld def make a log splitter out of one of them.

If it works, maybe make two more and sell them.

BR