[LAB80]

Hello there. My first post here, I am a beginner welder and am learning stick welding at the moment.

Anyway, I've watched a lot of youtube videos and always see americans using 6010 / 6011, and thought I was missing out. I finally found a 6010 supplier in New Zealand, and ordered 15kg of 2.5mm ( 3/32 ) welding rods. I have an inverter welder, with an OCV of approx 100 volts ( as measured by a voltmeter ). Yesterday I was finally able to test 6010 out, and although the inverter was able to start them up OK, the arc would randomly splutter and cut out, regardless of amperage or arc length. I have no dig / arc force or any such settings on my inverter, only amperage. Regardless, I was able to get a bit of a feel for how cellulose rods ran, which was exciting.

I half expected this to happen, as its mentioned a lot over the internet, and after watching this video here https://www.youtube.com/watch?v=ZGvPhJZCMvY decided to buy an old AC transformer arc welder, and put it in series with the earth lead of my inverter ( not connected to the mains, just like in the video ).

And I can now happily say that this worked! The 6010 electrodes start up and run without pauses, spluttering, or cutting out, even at around 25 amps, very smoothly. It even had an effect on 7016 (not tried 7018 yet), where basically 7016 seemed a lot more penetrating than previously; On 2mm sheet before adding the inductor (old arc welder transformer) I could run along at around 60 or 70 amps just fine, but with the inductor in series, it will blow through very quickly so I need to run it down at around 40 or 50 amps.

So anyone out there with an inverter, annoyed that they are having trouble running 6010/6011, I strongly suggest trying this out. I picked up the old transformer arc welder for $18, so its a cheap experiment.

An in closing, I can see why people like 6010; It is very easy to see the puddle! I am really enjoying learning the whip and pause method, and seeing the previous puddle solidify as I jump forward... and its a lot lot easier to fill in gaps too! Very very happy and excited.

I may post a photo of practice beads and ask for guidance at a later date.

Cheers

[tweake]

interesting.
certainly plenty of old transformer welders around to butcher.

tho i'm curious as to why it works.
i suspect that it stores power then when the arc dips the field collapses and boosts it up which relights it.

the other one i would like to try one day is to get an old HF unit. (modern version is the arc pig).

[Poland308]

I think it has to do with the effect of the transformers windings on the electron flow. I have used transformers to clean up power spikes by using a transformer that was straight across. Not a step down or step up.

[Jack Ryan]

i suspect that it stores power then when the arc dips the field collapses and boosts it up which relights it.

I think that is basically it. An inductance in series with the weld current acts to smooth it - in this case, it the arc tries to extinguish, the welding current drops and the stored energy in the inductance acts to maintain it and the arc.

The arc probably doesn't go out and relight - the inductance acts before the arc is extinguished to maintain it.

It would be interesting to capture the current on a storage CRO.

Jack

[Jack Ryan]

the other one i would like to try one day is to get an old HF unit. (modern version is the arc pig).

I'm not sure why HF start on ARC welders is not more common. Continuous HF would be a bit more convenient than having a massive transformer in your work lead and there would be a lot less "click-click-hummmmm" from some quarters.

Jack

[tweake]

i suspect that it stores power then when the arc dips the field collapses and boosts it up which relights it.

I think that is basically it. An inductance in series with the weld current acts to smooth it - in this case, it the arc tries to extinguish, the welding current drops and the stored energy in the inductance acts to maintain it and the arc.

The arc probably doesn't go out and relight - the inductance acts before the arc is extinguished to maintain it.

It would be interesting to capture the current on a storage CRO.

Jack

don't forget its not sine wave pulse, its square wave. very tiny bit of zero volts between each pulse.
that bit of smoothing may pump the voltage up enough. there is diagrams of filter arrangement that does that, but thats typically with sinewave.

[tweake]

the other one i would like to try one day is to get an old HF unit. (modern version is the arc pig).

I'm not sure why HF start on ARC welders is not more common. Continuous HF would be a bit more convenient than having a massive transformer in your work lead and there would be a lot less "click-click-hummmmm" from some quarters.

Jack

that would be handy in tight spots. put the rod in there and hit the button.

[LAB80]

interesting.
certainly plenty of old transformer welders around to butcher.

tho i'm curious as to why it works.
i suspect that it stores power then when the arc dips the field collapses and boosts it up which relights it.

the other one i would like to try one day is to get an old HF unit. (modern version is the arc pig).

Using the transformer welder like so is using it as an inductor, which is the electrical equivalent of a flywheel; Inductors resist changes in current. So say the inductor has 100 amps running through it and something happens to try and reduce that current, the inductor will react by increasing the voltage in order to maintain 100 amps. It does this by using energy stored in the magnetic field around the windings of the transformer. The same thing happens in reverse when there is 0A, or when the arc is struck, it initially wants to keep the current at 0A until a magnetic field is formed which means the rod is less likely to stick.

An inductor can react to a change in current faster than a micro controller can adjust its constant current circuit.

I wonder if winding a long earth lead around some lump of ferrous material would be enough to form a makeshift inductor ?

[Jack Ryan]

don't forget its not sine wave pulse, its square wave. very tiny bit of zero volts between each pulse.
that bit of smoothing may pump the voltage up enough. there is diagrams of filter arrangement that does that, but thats typically with sinewave.

Actually, it's DC. The smoothing I referred to was that of the current corresponding to the unstable arc.

Jack

[Jack Ryan]

An inductor can react to a change in current faster than a micro controller can adjust its constant current circuit.

Mostly yes but it depends on the time constant of the circuit. Also, it is not the speed that is possible that is important - it is the speed that is necessary. Arc stabilising software usually does a pretty good job of keeping an arc going.

Jack

[LAB80]

LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?

[tweake]

don't forget its not sine wave pulse, its square wave. very tiny bit of zero volts between each pulse.
that bit of smoothing may pump the voltage up enough. there is diagrams of filter arrangement that does that, but thats typically with sinewave.

Actually, it's DC. The smoothing I referred to was that of the current corresponding to the unstable arc.

Jack

its not 100% dc. its rectified square wave. it needs smoothing to make it 100% dc.

[Jack Ryan]

LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?

No, both the current and the voltage are governed by the circuit time constant.

Jack

[LAB80]

LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?

No, both the current and the voltage are governed by the circuit time constant.

Jack

Are you talking about inductor or an inverters constant current circuit ?

[Jack Ryan]

its not 100% dc. its rectified square wave. it needs smoothing to make it 100% dc.

Yes, it is primarily DC with an AC component but there are no reversals and no zero crossings so the arc cannot be lost due to a zero crossing.

One might argue that a rectified square wave does go to zero twice per cycle but with the reactive components in the circuit, I would think that the voltage doesn't actually get to zero and it would be near zero for such a short period that the arc would not extinguish. That is why AC (square) TIG does not need continuous HF start.

It would be interesting to see some of these waveforms - the manufacturers only seem to give (if at all), idialised waveforms.

Jack

[Jack Ryan]

LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?

No, both the current and the voltage are governed by the circuit time constant.

Jack

Are you talking about inductor or an inverters constant current circuit ?

Not sure what you're asking but I responded to this:

"LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?"

The time constant of the inductor and everything else in the loop.

You might have a constant current source but if that is fed via an inductor to the load, the load current ramps up and down to match the steady state source current.

Jack

[LAB80]

Not sure what you're asking but I responded to this:

"LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?"

The time constant of the inductor and everything else in the loop.

You might have a constant current source but if that is fed via an inductor to the load, the load current ramps up and down to match the steady state source current.

Jack

Right yes, inductors are slow to change current. But what I am getting at is that inductors will instantly produce large voltage spikes across them, ie say you suddenly open circuit an inductor with a current going through it, the voltage across the inductor will spike, instantly. Like if you are moving the rod around, which is a change of the load resistance and hence an attempt to change the current through the inductor, the voltage change across the inductor to try and maintain the same current is instant.

[Jack Ryan]

Not sure what you're asking but I responded to this:

"LR time constant is for the change in current, not voltage... The voltage reaction to maintain a constant current is instant?"

The time constant of the inductor and everything else in the loop.

You might have a constant current source but if that is fed via an inductor to the load, the load current ramps up and down to match the steady state source current.

Jack

Right yes, inductors are slow to change current. But what I am getting at is that inductors will instantly produce large voltage spikes across them, ie say you suddenly open circuit an inductor with a current going through it, the voltage across the inductor will spike, instantly. Like if you are moving the rod around, which is a change of the load resistance and hence an attempt to change the current through the inductor, the voltage change across the inductor to try and maintain the same current is instant.

I'm with you, yes that's right. Both the voltage and current are controlled by the time constant but the voltage across the inductor steps and then decays and current does the reverse.

Inductor V-I.png (6.26 KiB) Viewed 1261071 times

Jack

[LAB80]

I'm with you, yes that's right. Both the voltage and current are controlled by the time constant but the voltage across the inductor steps and then decays and current does the reverse.


Inductor V-I.png

Jack

Right assuming a constant R. Changes in R are compensated by the back EMF, instantly, and while there is decay afterwards it gives the inverter constant current circuit breathing room to catch up and react to the change in load resistance. That's why I think it works, anyhows.

[Poland308]

You have to throw in the fact that the transformer isn’t just a conductor, it is a coil with an iron core. So stored energy in the form of inductance.

[LAB80]

Hellos again.

And so I tripped over a box of bourbons and stumbled into my welder again, and accidentally started playing with 6010 again.

So here is my second attempt at welding 6010 stuff.

The top most collection of stuff is using a 2.5mm / 3/32 rod, at around 35-45 amps or so (analogue dial).

The bottom few beads is using a 3.2mm / 1/8th rod, at about 60 amps.

This is all on 2mm or 5/64 metal. The 1/8th rod started really heating up the bottom edge.

Is this sort of kind of how it should look? Any suggestions, obvious things I am doing wrong, etc ?

Thanks

6010_A.jpg (4.46 MiB) Viewed 1261015 times

[Louie1961]

So anyone out there with an inverter, annoyed that they are having trouble running 6010/6011, I strongly suggest trying this out. I picked up the old transformer arc welder for $18, so its a cheap experiment.

Why not just buy 6011 rod instead of 6010? 6011 runs on virtually any inverter. I get that you are experimenting for fun, but this is almost as useful as Oscar's water cooled electrode holder for stick welding.

[Gdarc21]

What, there is water cooled handle for stick welding, That would be gold though

[LAB80]

So anyone out there with an inverter, annoyed that they are having trouble running 6010/6011, I strongly suggest trying this out. I picked up the old transformer arc welder for $18, so its a cheap experiment.

Why not just buy 6011 rod instead of 6010? 6011 runs on virtually any inverter. I get that you are experimenting for fun, but this is almost as useful as Oscar's water cooled electrode holder for stick welding.

Yeah I hear ya, except cellulose rods are hard to find here in NZ, and the few places I found them were all 6010. A water cooled electrode holder is hillarious though

[Louie1961]

Cellulose rods are over rated. You would be just fine without them.