Thread: Cheap Auto helmets and low amps

Gidday Grahame

As always good food for thought and discussion. I think at the end of the day most auto darkening helmets have their limitations regardless of cost and reported features.

I use a more expensive MAsk made by Miller its a great piece of kit and delivers the 'goods' in regards to comfort and making welding that little more easier and enjoyable!

Generally speaking I have been extremely happy with it n to date its delivered trouble free use since I got it some 3 years or so ago now. I use it for Mig Stick and Tig Welding............

However there are certain circumstances and positions that work against it and appear to cause issues with the auto darkening feature................And indeed it appears that in some circumstances a standard lens is better suited to the Job.

For instance the mask i use isn't recommended for Overhead Use. Additionally Ive found in pipe work when shooting the gap to lay root runs or in circumstances were the masks sensors are obscured by objects before or in front of your line of sight of the weld pool it can interfere with the autodarkening and cause it to flicker.................

The problem is generally intermittent and usually resolves itself but In the past I have received a decent arc flash from time to time due to the autodarkening feature playing up!

Indeed ive noticed this on occasions when using the Tig process at Low Amps however usually an adjustment of the sensitivity feature on my mask resolves the issue. In a nutshell Ive noticed in certain circumstances Autodarkening has its limitations.

My solution to 'the issue' has been to take a horses for courses approach So I got my hands on a MAsk with a big Viewing Area that uses a standard non autodarkening lens n if required shes put into use ..................... which to date has been very rare!

By my reckoning it stands to reason that these issues would be amplified by cheaper masks with fewer sensors (Mine has 4). In summary when considering what type of helmet to buy its probably worth while considering a higher end mask if you planning to do anything other than general Welding with Stick or Mig!!!!

Regards Lou

Grahame, by frequency, are you referring to AC welding aluminium? I was having trouble with a cheap auto helmet but it was relatively low current (50-70 amps) DC.

I've only ever owned 2 auto helmets, at each end of the price scale, so don't have much experience with them but think you're both right, it you're going to weld with TIG, the cheap auto helmets just don't cut it.

Hi Pete,
Inverters ,as suggested by their name invert current frequency by means of solid state electronics.
To get a handle on it ,think of a normal transformer based tig where the frequency is 50 Hertz.

With an inverter machine frequencies star out as input at 50 hertz but are boosted by the electronics to the multi thousand hertz per second ranges.

As far as I can understand it, when the (Inverter) amps are set very low,the frequency ( triggering your electonic lense ) does not work well with settings used on the cheaper electronic helmets.
I believe the settings cause inconsistant triggering in the helmet sensors.

We are talking below 20 and 30 amps - and this probably varies between helmet to helmet and diffrent machines.

I am keen to find out if any one is using a cheaper electronic helmet on very low amps with a transformer type tig and NOT having problems.

That would help prove my theory.

When I last used transformer based tig electronic helmets had not yet been made so I have no personal experince to fall on.

Aluminium on AC and steel on DC- would not make much diffrence. At the moment its just that, a theory.

Grahame

Hmmm, ok, I didn't know they worked that way. I don't know much at all about welders but my background was electronics so I can possibly also look into it and let you know what I find out if you like. If all else fails I will put an oscilloscope probe on the tungsten and see what the waveform looks like. I'd always just assumed the DC was just straight DC and wasn't pulsed in any way (except of course for the HF start). If so, it shouldn't matter "how it gets there" if you like, it's the end result that matters. My welder is pretty basic and has just a DC and 2 different AC frequency settings. But as I understand it you're saying it's actually a pulsed DC waveform?

Pete

Sounds like you have an old Miller.CY 350?
They were big mother transformer units which the AC side was tapped off and the DC was from a rectifier.

The inverters vary from straight DC outputs to AC and DC which are the bigger bucks model.

I did see a schematic on the web somewhere and will have a look for it for you soon.I have some big medical stuff in the next few days which will keep me occuppied.

Grahame

Originally Posted by Grahame Collins

Sounds like you have an old Miller.CY 350?
They were big mother transformer units which the AC side was tapped off and the DC was from a rectifier.

The inverters vary from straight DC outputs to AC and DC which are the bigger bucks model.

I did see a schematic on the web somewhere and will have a look for it for you soon.I have some big medical stuff in the next few days which will keep me occuppied.

Grahame

Actually mine is a cheap-#### Asian unit, in fact I think it's even called "New Asia" from memory, but that means nothing, hence why I don't even remember. Bought from Token a few years back. I'm actually quite happy with it but have found its limitations and wouldn't mind replacing it with a more complete unit but it's difficult to justify at this stage.

Pete

Edit: Oh, sorry, didn't know you can't say #### on this BB :P

Gday Grahame,

I use a cheap as helmet (Tekmen) that I have been borrowing off my cousin whilst I save up to buy my own. I have been planning on spending a little bit more on a helmet as when I use this one to Arc weld the switching time is unacceptable. I find that I get flash when scratch starting a cold rod. Its also a bit ordinary when bright sunlight is hitting the mask from certain angles. Once running the bead though its fine.

With TIG welding however, the unit performs well. A week ago I was repairing an ultra thin piece of steel that had cracked through a bolt hole. It was a part for my chainsaw (a plate that holds the blade locking mechanism in place). I dont know how thin it was, but it was real thin....especially by the time I had sanded it around the crack. 15 amps went straight through it. 5 amps was not enough, and 10 amps was what I used for the job.

The helmet was switching perfectly at these amperages. I alwasy thought it was the pulse of light that triggered the auto darken helmets? Not frequency? You learn something new every day.

Helmet issues aside, I was quite chuffed with myself for being able to weld this part. The TIG process never ceases to amaze me.

Isn't it a great feeling when you can use your skills to bring an item back to usable condition?

I get more pleasure from repairing an item,than I do from making a new one.

With regards to the comments about the frequency, dont take as rock solid fact just yet. This is, what I suspect is happening.

It just seems to me that there is a correlation between inverter frequentcy, low amps and the lower cost
electronic helmets.

My Techman has problems at low amps when used in conjunction with my Fronius 1700 magic wave inverter welder.Funny though I can weld in stick mode and go down to 30 amps with out losing helmet trigger action.

Inverter welders are controlled through changing frequentcy on the output side. This enables some fancy manipulation of the arc charecteristics just not possible with the old transformer rectifier units.

Thats not to say those older units still don't have a place these days.The better made ones will do what is required of them for years to come.

Grahame

Yeah repairing things is where its at. I could easily have written this chainsaw off as too hard, and just bought a new one. But where is the fun in that. Its a good saw which runs well, and now its got a few more hours of work left in it.

I've been using 3ph TIG inverters, including 3ph TIG recifiers with my modestly priced CIG auto helmet which has a 2.5 magnifier fitted and it's been working perfectly, but I've just purchased a pricey 240V Kemppi TIG inverter and for some reason the arc on this machine seems incredibly bright, in fact so bright I can barely see what I'm doing. What's going on?? I also increased darkness from 11 to 13 but that didn't help.

I've had a Speedglas 9000V helmet for over 10 years, and it has been fine with TIG (transformer TIG AC & DC from 10 to >200A, and more recently inverter >25A). The sensitivity dial was useful to get the trigger point right at first, but I haven't needed to adjust it since. I'll experiment at lower amps with the inverter to see if I get any issues similar to those you describe.

I went to a mates place and took the welder and helmet to compare set-ups and settings etc....He spotted that the sensitivity knob was in the low position....D'oh!... Being shoved in and pulled out of bags it had been moved from high to low and THAT was my problem. Always look for the simple solutions first. Mind you, after using his helmet I've decided I want something similar and one with 4 sensors not 2.

Personally I don't use the things. I guess I'm old school. Give me a glass # 11 shade & let me go. I've tried the auto's beaucoup times. They have their limitations. I've found out if your working in a well lighted shop, by yourself, they are ok. But, when your out in the field, I don't like them. I've found out that they have a habit of unshading when you work in a dark area, or if you are working high & above the lights. I've been flashed by the bloody things more times then I can remember. That's why I hardly ever use them.
But, now I very rarely get to weld. I'm a now retired pipefitter & I get to work in my woodshop now, when I get a chance that is.

i have a token tool inverter dc tig welder ,wich are now sold by boc for a lot more ,and a budget helmet , Get the odd flash ,but working up a ladder the leads weigh more than the welder, and the safety of being able to see when your not welding is a big plus .Also great for tacking things up .There is always a place for the fixed filter helmet in the shop , but use it less and less .