Migomat Magnum MIG 205L Welding Issues: Inconsistent Gas Flow?

Hi.
I have such a problem with the migomat, when welding for a few seconds it is good, then it starts firing, as if it lacked gas, shoots it for some time and it is good again for some time,
Is it gas fault or something damaged?
When you press the button, you can hear the air at first, but later as if it flew less.
I have freshly filled bottles, new reducer.

And how do you set the gas flow at the outlet of the regulator?

mateusz33 wrote:

When you press the button, you can hear the air at first, but later as if it flew less.

In this situation, the set outflow does not matter. This is how the most common reducers behave. This effect is not only found in two-stage reducers or after applying the so-called optimaga or optimizer. The names appear interchangeably.

mateusz33 wrote:

when welding for a few seconds it is good, then it starts firing

This symptom indicates the unstable operation of the welding arc. This can be caused by incorrect device adjustment (setting the wire feed speed to the set voltage).
It is also possible to block the wire in a spiral insert, or to cram the contact tip. In both cases, the above-mentioned symptom will occur. Check the spiral insert for clogging together with the contact tip. Also make sure that the terminal used matches the diameter of the wire you are using.
It is also possible to block the wire due to poor winding on the spool. It is then braided from time to time (one turn goes under the other, this applies to the cheapest wires).
Another thing to check is that sometimes the guide rollers are not too tight. Then the wire may flatten and it will not come out easily through the round end.

As for the quantity and in principle for setting the gas flow, it is calculated as follows.
The diameter of the wire is multiplied by 10. We get the required amount of gas in liters per minute, ensuring the right protection of the weld pool. If it is necessary to weld at a greater distance than is assumed (distance of the contact tip from the welded material), 2 liters of gas may be added.

30 bar,
I also set it to maximum and it was the same

My friend is normally set to 10 bar. The gas flow for wire diameters is to be:
0.8 mm- 8 to 10 l / min;
1 mm- 10 to 12 l / min .;
1.2 mm- 12 to 14 l / min.
So much and only so much gas, nothing more. Excessive outflow will cause air to be drawn into the area where the weld pool is and this will cause the weld to be porous (such as eaten by bark beetles).
In these values, you will protect the welding place and not go bankrupt.
Two clock reducer, right clock scaled in l / min:


Regulator with bar rotameter (most accurate settings) Together with the mentioned optimization element:

What type of device do you have (welding machine)?

In fact, because the last time I was welding, I got holes in the middle of the weld, just like bark beetles.
I have the most common reducer, the cheapest

Suitable for small jobs. Unfortunately, its quality is not the best (often it does not hold the pressure set). Clocks are also not very interesting . Set on it the expense that will come out of the calculations I gave earlier.
You can also stock up on such a rotameter:

All in all, it's the best solution when it comes to setting the amount of gas. You unfasten the rollers so that the wire does not escape. You put the rotameter on the tip of the burner (gas nozzle) and press the button on the handle. Then you adjust the regulator so that the ball in this rotameter indicates the appropriate gas value.

Migomat and without gas should have a stable arc. I had a problem with the Tatra migomat (such unbranded Chinese). The problem was that at a low welding current the arc was retreating towards the current nozzle. Problem not solved. The starting plate was 96% similar to that of magnum.

I bought this rotameter and we'll see what it shows.

In this 205L model there is also the possibility of MMA welding, and the electrode normally welds at any current, so I think with electronics everything is ok,

Tomorrow I will try to record a movie as it looks.
And if I can't help it, I'll give it to a service center or find a professional welder and let him assess because maybe the problem lies in the setting.

stasiekb100 wrote:

The problem was that at a low welding current the arc was retreating towards the current nozzle.

This is only possible if there is a problem with free wire feed or with poorly selected parameters. In mag type devices, the welding voltage and wire feed speed are set. Current is the resultant of these two values. The easiest way to set up is to weld on a piece of waste and then correct the wire speed.
@ stasiekb100 check the roller pressure and patency of the spiral insert. I assume that the handle is guided at a constant speed (without unnecessary acceleration, so-called arc breaking).

mateusz33 wrote:

In this 205L model there is also the possibility of MMA welding, and the electrode normally welds at any current,

Buddy, yes and no. This is related to the characteristics of the welding arc and more specifically the voltage characteristics of the power source.
In coated electrode welding, the source has a soft characteristic, while in the MAG method this characteristic is stiff (voltage does not drop so much under the influence of flowing current.
I just saw one more thing in this welder. There you have the option of regulating the welding circuit inductance. Also choose this value (experimentally). Through this change you can get so-called hard or soft arc.
You use a hard arc when welding in forced positions (vertical, wall, ceiling and eaves). Unfortunately, there are a lot of splinters.
You use a soft arc at high welding currents. You have a wide weld face and less spatter.

mariusz999 wrote:

stasiekb100 wrote:
The problem was that at a low welding current the arc was retreating towards the current nozzle.

This is only possible if there is a problem with free wire feed or with poorly selected parameters. In mag type devices, the welding voltage and wire feed speed are set. Current is the resultant of these two values. The easiest way to set up is to weld on a piece of waste and then correct the wire speed.
@ stasiekb100 check the pressure of the rollers and the patency of the spiral insert. I assume that the handle is guided at a constant speed (without unnecessary acceleration, so-called arc breaking).

Yes, buddy, you're right. Only that I connected this migomat to the twin engine feeder esaba with a tachometric generator and it was still the same. Feeder supply was independent. I was just too weak for him.

stasiekb100 wrote:

Feeder supply was independent.

This confirms my statement as to the cause of the reversing arc effect. Just by giving an independent power supply I check quickly whether the built-in control works or is damaged. It is because of laziness I do it, I can connect the power faster and check how the machine welds. Otherwise the matter looks like it is not possible to set the right speed for the set voltage (there are such cases and it is not uncommon).
Most often in synergistic devices.

Forehead.
Today I recorded how it all looks
At the beginning a rotameter to the tip and here's what it showed
https://www.youtube.com/watch?v=gRgdSV_waFg

Then I started welding, I will definitely get all welding done, but I did it quickly, at the end you can see how it happens, I adjusted the speed and it was still the same.
https://www.youtube.com/watch?v=8oroQ-1uliM

And I recorded the wire feeder, it shoots something but it feeds on mine smoothly
https://www.youtube.com/watch?v=6NnFPD0UpHk

And finally, I noticed that the curved tip that turns out of the handle rotates, can it have anything to do with it?

mateusz33 wrote:

And I recorded the wire feeder, it shoots something but it feeds on mine smoothly

We have the culprit. It is in this video that you can see how the wire is unevenly wound. This makes welding very difficult. Especially for two-roller feeders. Four roller still can handle such a winding. He cannot grow freely, but every now and then he can be seen trapped under another scroll. Buy a wire spool, paying attention to the packaging with the information "Precision coil".

As for the welding itself, change the direction. Do not pull the handle but push it. The head on the left points towards the handle and the handle tilts to the right. The opposite situation will occur for left-handed people.

The weld will be flat first and secondly you will be able to see the place where you weld well.
The effect of boosting gas in the initial phase is typical for simple reducers. It is because of this effect that gas consumption is high. Then you will have the same gas flow and savings.
These 15 l / min is what you get for a diameter of 1.2 mm. For a 1 mm wire, reduce to about 10-12 l / min. As you noticed, the rotameter indication is different than on the reducer clock. These are all leaks in the system and for this reason the gas flow should be set on the handle and not on the reducer.
Such a small thing a matter.
As I mentioned, you can use an additional device called the optimizer or optimag.
For example, like this:

Someone will say that this is an unnecessary expense, after all, you can weld without it. Of course you can and a very large group of people are welding like this. The only question is whether it is worth considering and calculating what savings will be obtained by using this solution. You pay for gas, so maybe an expense worth considering.
This can be seen very quickly when welding in TIG. Where gas costs are not small.

@ mariusz999 thanks for the answers and tips.
I will replace the wire and see what happens, the same will apply your instructions on how to guide the tip.
Now I have to choose a wire, which company do you recommend?
I don't weld much, the wire that is now inserted is new, 3 years old, and 1/3 of it has not been welded,
I found from ESAB "ESAB OK Autrod 12.51 0.8 mm 5 kg" will it work?

@/matthew/ it all depends on the material you weld. Based on the type of material, you choose a binder (wire).
Generally used and to the so-called of ordinary sheet metal, wire: G4Si1 (formerly SG3) is sufficient. All you have to do is enter this seller identification.
The ESAB wire you change is also a good binder. Generally, different names are given in commerce. Binder markings in accordance with standards are used for selection.
In the case of ESAB binders, there is no such problem, welders know their products quite well and you could say that they know them by heart.
I personally use the binders of Metalweld and Oerlikon.
For the technologies developed in my company I used binders from these companies, why these are a lot of translation. In short, it is about the results of tests of joints made for the recognition of technology.
This translates into later contracts. A company with approved qualifications and technologies has greater orders and confidence in the market. Of course, this does not apply to tenders where the price decides, but is another topic.

This catalog of Bohler binders may be useful:

I don't weld a lot, but once it is ordinary sheets, closed profiles, angles, ordinary black steel.
Could you recommend a particular wire?

One of the better weld joints is Carbifil 1a Oerlikon company. It's a wire with really good parameters.
Unfortunately, I don't remember the prices. Rather easily available in most welding consumables stores. I advise against only all kinds of "Chinese". If somewhere you will find a non-copper wire, i.e. not covered with copper but enamel, then it is welded much better. It is true that the price is also a little higher.
Copper improves conduction a bit and nothing else. You can hear about its impact on corrosion protection which is bullshit. After looking at the large enlargement of the copper wire in cross section, you can see a beautiful layer of corrosion between the wire and copper. This is often found in wires imported from China.
As for ESAB, well manufacturer = price. Many reputable companies do the same.
Are you able to put on 15 kg spools? ?
One more thing. Under the term "ordinary black steel" you can plant many species. I understand that we are talking about the most popular steel S235 (formerly St3s).
Remember that as Black steel can be a high grade material. Then there may be problems in the form of e.g. cracking joints.

I found Carbofil 1a only 16 kg, unfortunately I can't find smaller ones
I have no idea if it is possible, but on the other hand it is not worth to put such a big one because sooner the machine will fall than I will use 1/3 of it.
As for steel ... I'm going to buy, buy profiles or angles, and I don't say what quality it is supposed to be,
I do not weld for profit but only for myself, I also do not pay attention to quality, you probably guess what I mean
I will buy this esaba and it should be ok, 5 kg cost about PLN 100, so it's not a lot, and the company is one of the best, unless something better at this price and in small spools

I only use large spools. If you want to lay a wire on your welder for a long time, you really don't have to bother with them. If you have a longer break in welding, remove the wire and put it in a plastic bag. Together with the wire, put in several sachets to absorb moisture (such as in packaging with shoes). There will be no moisture, the wire will no longer corrode.
Just make sure it is wound up precisely and it will be oki
One more thing because you can't see it exactly. What is the distance between the gas nozzle (so called scales) and the material? It should be no more than 15 mm. The weld (these ala bark beetles) will grow differently.

Hello
After this time, has the arc instability during welding been resolved?
What was the reason for this?
The problem also occurs in my welder, which is extremely troublesome, also magnum mig 205l.
Replacing the rollers, welding torch, rotameter and wire did not help.
For some time he welds without any problems, and for some time he can't just weld.

Could someone take pictures of the inside of this welder? I would be very grateful.

Hello everyone, I have the same problem and I think so, since dear colleagues have already checked everything and it's OK! the problem is in the power supply or rather its low efficiency. I live near the trafo (237v), the workshop power supply is 4 * 4mm2 so it should be fine, but it is not. There is one more clue that nobody took into account, namely the power cord. It looks solid but it is not known if it has the right cross-section (Chinese jumper cables) -bunch of laughter). I weld occasionally, but this welder is already throwing me off balance. I will try to replace the cable with the appropriate one (4 mm2) and we will see.

For me, she still works as she wants, I gave it up because I hardly ever use it, although I am thinking of changing it

or maybe someone will tell you - the Einhell migomat welds beautifully on the highest current, and on the low current setting and thin elements of grease and scabs. I will add that when I bought it, it welded nicely regardless of what I welded.

tomasz24121 wrote:

or maybe someone will tell you - the einhell migomat welds beautifully on the highest current, and on the low current setting and thin elements of grease and scabs I will add that when I bought it, it welded nicely regardless of what I welded.

What kind of welder is it?
Did you open the casing?