AC arc stability and my new machine...

[bc30se]

Guys...

I suspect there is something wrong with my newly bought AC TIG.
It only occurs under AC welding, whatever settings applied.

Here you can see how it behaves... AC, 150HZ, the balance set to 70% penetration.., the work is clean...

http://www.youtube.com/watch?v=MhU9Bx_5xhI&feature=youtu.be

What happens is, to make the arc stable I must keep the electrode no higher than 1 mm above the pool, if I a move it away only by a fraction - 2/3mm, the arc starts to 'spatter' giving a jerky sound.... I used an AC welder last year borrowed from a friend of mine... did not notice such problems....

Now, is that correct or is there anything wrong really? It may look in the video that I lift the electrode too much, but it is not so, 3/4 mm max above the pool...

weird

 

[backpurge]

Set your balance to maximum cleaning and see if the same occurs

 

[bc30se]

The same occurs under 90% penetration... and the same occurs under 90% of cleaning.. it does not matter...

 

[matt1978]

There is a problem with the machine.

Changing the local settings (balance & frequency) won't solve that problem. If its a new machine take it back and tell them to repair it.

 

[bc30se]

Yes it's a new machine, and after only desribing the problem to the seller I was asked to send it back, but I didn't want to go into panic and just made a video sending it to the seller as well...

 

[matt1978]

Yeah it sounds like something wrong with the AC side of the inverter. If its brand new they will most probably just replace/exchange the machine.

 

[bc30se]

hopefully, they will make it work for me.... just had it for no longer than a week and used it twice

will let you know, but from the way the seller reacted wanting it back straight away, it sounded as if he had known the problem...

perhaps they have some service procedure for the machine that can be done on the bench? so why didn't they check it before dispatching.. I don't know...

 

[matt1978]

Unfortunately that's the way it is sometimes with electronics. Usually if they are going to fail they will fail in the first month or so.

What make is it? Is it the manufacturer who has asked for it back or the distributor?

 

[bc30se]

What make is it?


->
小林可夢偉（こばやし かむい




It was just the distributor wanting it.... I know they have a solid service for their machines and offer after-warranty repairs for reasonable money.

 

[matt1978]

Just ask them to replace the machine for you

 

[bc30se]

Here is a good example...

https://www.youtube.com/watch?v=G1VeeEAjdb8

They replaced the mobo and the inverter unit as an afterwarranty claim and the guy paid $120

 

[matt1978]

Fingers crossed it all gets sorted for you then. Let us know. That front panel looks familiar!

There is something called Half wave rectification, and its when the arc does not switch from + to -, so you get 3 or 4 + cycles before it switches onto the - and then the same again, it makes the arc very unstable.

It's usually more prone on 99.99% pure aluminium and you can see it if you create a weld pool (but add no filler) and just leave the arc there so it cleans all the oxide and eventually the same symptoms as you have will appear.

 

[Tigman]

Is the High Frequency at start working ? I had similar symptoms when HF didnt kick in on AC !

 

[bc30se]

As you see in the clip, HF works...

 

[wheresmejumper]

That front panel looks familiar!

very familiar

i must have got lucky

Everlasts version in the states have a history of arc stability issues aswell on AC

 

[bc30se]

It's not that bad... you don't pay for them as much as for a brand one, so issues are acceptable as long as they are sorted out...

Of course, it is not a machine to make money with on a daily basis, but for a hobbyist not a bad choice....

 

[wheresmejumper]

i couldnt complain about mine.its done everything asked so far
a couple of welders with 20+ years experience couldnt get over how it performs compared to price

 

[bc30se]

Guys, got a new machine sent last week and it runs as smooth as it only can...

glad with my purchase

 

[Shox Dr]

Good to hear you got it sorted. Looks like some of these machines suffer from AC problems. Although we (the forum) haven't seen any posts regarding faults with R-tech machines of the same design

 

[bc30se]

The matter is, last year I borrowed a very similar machine (3phase with bells and whistles Chinese..) and I ended up with welding inox only, it was my first time with TIG then, so a lot of guessing stuff...

Of course I did try to weld alu, AC pipes mainly but not only, however, I just could not get it. Later on, as I did some welding on inox, my friend asked me to help him to weld the alu railing on the recovery truck bed... ohh man noooo.... but let's face it again so I got round to it...

I failed, I just struggled to form a pool no matter how hard I tried (the same was with other alu stuff I tried). His machine did not have this jerky arc issue at all and for a rookie eye, it worked more or less OK.... but anyway..I told my friend that his welder might need servicing, but I was not an expert then (and am not now of course and he did not want to listen excusing the machine with our poor abilities...

So a year went by, and I bought mine... and straight out of the box as you see.... ok, as I said, I got a new one... and it works like a charm, alu welding has never been easier, just as with inox, and.... I even welded the ac pipes which I had not been able to with my friend's TIG.... the pool is right on the spot... ohh swee man

and... now, I call my friend and tell him about it, and I am now definetly sure his one is crapped, what he is going to do I don't know....

So.. there may be issues with AC current on these babies.... will of course report on my experience of this machine, I have 2 years warranty so I think I will live with it somehow...