Constructive Criticism Please!

[Windy Miller]

Fetch it up to Rochester this weekend. I have some decent rods (Oerlikon 6013s) you can try with it. If it won't light them up, it won't light anything!

You can have a try with my old buzz box, and if you fancy a play, I'll drag out the Tig and we can try some arc welding with the handful of 7018s that I found in the airing cupboard the other day!

 

[Richard.]

It's as high as my fronius then. Low hys shouldn't be a problem.

 

[wheresmejumper]

It's as high as my fronius then. Low hys shouldn't be a problem.

I dont know the ins and outs of it,but the fronius 'acts' like it has 90ocv.this little thing will struggle hugely to light a 7018.it doesnt say on the dataplate if its ac or dc but normally when you see 48v its ac

 

[PTvor]

PTvor, I can't really think why that machine couldn't run 7018 - provided they're used on DC as they would be, I think they'll run off anything.

This isn't a DC machine, it's buzz box and with a no load voltage (OCV) of 48V, which is about what buzz boxes do. I think that apart from anything else there's an H&S limitation. The link to the sales schpiel was posted earlier. Most 7018s which will run on AC need an OCV of at least 60V. I think there are some sold in the US which will run on buzz boxes, but not in the UK.

Furthermore if it doesn't totally destroy a 2.5mm rod on its high (130A) setting, without any chance of welding, you have to wonder how honest the ratings are.

 

[wheresmejumper]

The fronius has a high working voltage id reckon,but lowish ocv.but a good dose of hotstart makes it more user friendly

 

[Richard.]

I dont know the ins and outs of it,but the fronius 'acts' like it has 90ocv.this little thing will struggle hugely to light a 7018.it doesnt say on the dataplate if its ac or dc but normally when you see 48v its ac

You know a lot more about the inns and outs of it than I do. Interesting stuff.

 

[wheresmejumper]

You know a lot more about the inns and outs of it than I do. Interesting stuff.

I have a buzzbox belonging to a friend in my shed at the minute,48ocv and no way will it light a 7018 or a 6011.its also the most inefficient thing ive seen,id say the internals are light on copper and high on ally.it trips a 20 amp c type mcb with a 3.2 6013 running on the hot side

 

[Richard.]

So the big Q I have is why is 48 ocv on one less capable than 48ocv on another. I had a play with mine this evening with a pack of 7016's 3.2 and it was burning them like they were made of chocolate. Mine is only 48ocv too.

 

[Bill Edwards]

This isn't a DC machine, it's buzz box and with a no load voltage (OCV) of 48V, which is about what buzz boxes do. I think that apart from anything else there's an H&S limitation. The link to the sales schpiel was posted earlier. Most 7018s which will run on AC need an OCV of at least 60V. I think there are some sold in the US which will run on buzz boxes, but not in the UK.

Oh! I (somehow) had it in my head that it's a little inverter, rather than a buzz box.

 

[Richard.]

Oh! I (somehow) had it in my head that it's a little inverter, rather than a buzz box.

I'll be honest when I first saw the picture I thought little inverter too.

 

[PTvor]

So the big Q I have is why is 48 ocv on one less capable than 48ocv on another. I had a play with mine this evening with a pack of 7016's 3.2 and it was burning them like they were made of chocolate. Mine is only 48ocv too.

I believe OCV only comes into it with AC. Inverters are different anyway because they are electronically controlled. They could have an OCV of a few volts just to detect that a contact had been made, then throw everything at it for a fraction of a second to establish the arc, then settle down to normal welding conditions.

Old style oil cooled welders had a high voltage range for lo-hys and cellulosics. Cellulosics are different again and need not only a high ocv but a drooping current characteristic.

I don't think you can run lo-hys on an Oxford on the low voltage range.

 

[Richard.]

Is it just me but don't alarm bells ring when you see a 200 amp inverter for that price. 70-80quid surely that's got to be something worth giving a wide birth. No????

 

[PTvor]

Is it just me but don't alarm bells ring when you see a 200 amp inverter for that price. 70-80quid surely that's got to be something worth giving a wide birth. No????

I must admit it wouldn't be on my shopping list were I looking for an inverter at a low price. Rtech do machines with a two year collect and return warranty for £150 and £200. Best value is probably an old buzz box from the time they were taken seriously, for £20 or £30, or an oil cooled, if you've got the room, which go for all sorts of prices. I know someone who bought a 110A Oxford for a ton and he reckons it's a cracker.

 

[GeorgeB]

I agree with mrfuzzy re. the great value of inverter welders available on eBay. I thought a £50 inverter I bought 5 or 6 years ago was brilliant value but it was only 75 amps. That' still going strong. Then, a few months ago I bought a 200 amp inverter on eBay for just £80 and I think it has HF start into the bargain. It works very well and the power can be turned down to 20 amps or lower, unlike the OP's transformer-based arc welder. I don't know why Richard sees 'alarm bells' - I see a great purchase opportunity. As for the OPs welds, I don't think they're too bad. I'd never grind them out - I'd just go over the top again, but that's me speaking as a rank amateur, rather than as a professional.

 

[Onoff]

Ref the grinding out.....I was grinding through "solid" metal. None of the "good" bits of welds I'd managed came away as in they seemed to have penetrated into the plates perfectly well. The issue areas were where I'd got the slag inclusion forming "hollows". I'm sure there are proper welding terms for it.

As for quality of this welder........seems to be nicely finished, no sharp edges. the top cover is a heavy enough gauge, not tinny, has a reasonably deep hum to it and when I manage a decent arc it sounds "smooth" and doesn't struggle. I'll take the cover off some time so people can see the internals and comment.

Let me play with my technique and post back up. I've a dye penetrating kit so could cut through some scrap and see what that looks like.

I'm learning is the big thing for me and figure IF I can get to weld with this I can weld with anything! My other option was to rewind a couple of microwave transformers!

 

[Richard.]

I agree with mrfuzzy re. the great value of inverter welders available on eBay. I thought a £50 inverter I bought 5 or 6 years ago was brilliant value but it was only 75 amps. That' still going strong. Then, a few months ago I bought a 200 amp inverter on eBay for just £80 and I think it has HF start into the bargain. It works very well and the power can be turned down to 20 amps or lower, unlike the OP's transformer-based arc welder. I don't know why Richard sees 'alarm bells' - I see a great purchase opportunity. As for the OPs welds, I don't think they're too bad. I'd never grind them out - I'd just go over the top again, but that's me speaking as a rank amateur, rather than as a professional.

Those welds are littered with slag traps!!!! Professional or not welding on top of slag does not make it go away it creates more slag which will increase the problem further. Bad advise and the welds will fail. ALL slag traps must be removed and re welded.

 

[Kent]

If you melt metal from a rod it forms as metal hence you grind metal away. What you don't see unless its real bad is the small inclusions in that metal! On a machine like this you actually need proper quality welds due the stresses it gets bombarded with constantly in use. The welds produced so far wouldn't rate as high as a lot of us could produce with a £300 inverter and running the rod with our eyes tight shut and honestly I am not kidding on that. If you can weld even a bit you should get way better than that if the set and the rods are up to it.
If you want to build this you need a reasonable set that will burn a 3.2 mm 7018 as a minimum IMO. so something around 160-200 amp (best keep your eyes pen though) The rest is down to the guy using it.
You could perhaps move a 5 birth caravan with a fiat 500 you see it just wouldn't be a good idea

 

[HughF]

/begin[Constructive criticism warning]

Take that POS transformer back, find someone to do the welds for you

 

[Onoff]

Didn't realise POS was a make! Chinese is it? (Took me a while to figure that )

Anyway.......tonight's attempts for anyone who's not sick of me! I noted people's comments here. I also watched the vidoes on here and tried to be concious of keeping the rod at 30 - 45 degrees - presumably that's from the horizontal as that's what I did. Was trying to pay attention to this arc too short / long thing in the videos as well but need to work on that I think:

All cleaned out first and properly so. Tried first with the new 2.5mm rods. Not sure here, IMO it started off OK but then the top side went south. Not centred into the V enough?

I'd read somewhere that it's easier for a beginner to use 3.2mm rods. The only rods I had were the damp, manky ones from my first post but I'd left a handful atop the oil boiler for 24hrs. So I tried one. I think at least that it looks a bit better with less slag inclusion compared to my first attempts. Again the first bit (to me at least) looks "good". Guess this is due to the improved rod angle? It then of course goes awry:

I then unfortunately got a bit cocky and tried to go over the good edge of the run above paying little attention to keeping straight.........or anything else. BUT, something I'd not heard until now which I was pleased about was that when I finished and stepped back I heard a "crack" and an actual piece of slag lifted off on it's own which I was quite pleased about........was going to photograph it but dropped it? This is the bit it came off of:

Thanks for looking!

 

[Onoff]

Arc length is too long or its running cold, you want the rod end about the thickness of the electrode off the workpiece (3.2mm for a 3.2 etc)
Problem is with your set,the 2 amp options aren't good...5 amps either way of an ideal setting can be unusuable..thats why old school buzz boxes or inverters are far better...much more scope for amp adjustment and a lot better duty cycle on inverters...

I know they say a bad workman blames his tools...but your on a hiding to nothing and can't make proper progress as that "welder" just isn't up to it...wouldn't likely even make a decent doorstop...perhaps Ronco could stick their name on it...seller should get taken for misleading advertising for making it look like an inverter when its a 15 quid buzzbox in a fancy case at an inflated price...I REALLY advise you to cut your losses and send it back as not fit for purpose....I could weld better with a pair of kanackered car batteries wired in series....do yourself a favour...swallow your pride and return it and get even a chinese inverter off ebay...they are a LOT better to use...

ESAB are a good brand of rods...I got 5KG of 3.2 E6013 for < £18 inc VAT and they are far better than cheapies or even Lincoln Arcweld rods 6013 (which are frankly dire and disgrace to Lincolns brand)...gave a mate at college some ESABs to use as the college lincoln rods were driving him nuts...came back a while later...lot happier and reckoned they were a lot easier to get consistent welds with

Cheers for that. Just to be clear here I did know it wasn't an inverter. Just bought it as a small, lightweight arc welder. TBH until I came on here I thought inverters started at around £500 so wasn't even considering one.

They have a 30-day return policy:

2. If, for any reason, you aren’t happy with your purchase please let us know within 30 days. We will refund unused item(s) that are received in re-saleable condition however, you will need to pay for the return carriage.

It's clearly used so I don't think I'll be able to return for a refund and their advert isn't to my mind misleading.