Welding Tips and Tricks

Hi to all

I have had a Lincoln V160T for a dozen year now and am used to the HF start potentially creating an arc that will bridge up to 20mm if I accidentally touch the pedal before I am quite ready.

Just recently I have purchased a second hand Miller Dynasty DX200 (around 10 years old but apparently had little use in that time). This is to add to my fabrication options.
I find that it is requiring that I am almost touching the work surface before it will strike an arc. I estimate this to be within a 1-1.5mm.
Quite a contrast to the Lincoln where it will happily strike an arc will the electrode a 'safe' distance from the workpiece. ie where a slight hand movement the wrong way is not going to end up with me touching the electrode to the work.

This has been on clean aluminium with both 1.6 and 2.4mm electrodes, argon gas @ ~12cfh.

Of course my comparison for the Lincoln has been with steel but I did try the DX200 on steel this evening before running out of gas with the same sort of results.

When trying to start the arc with the DX200 I can hear the welder itself making noises that I am assuming are associated with trying to start the HF arc.

Is anyone else with a DX200 able to comment about the HF arc characteristics?

Once the arc is started it seems to be working OK as per my "learning to weld aluminium test piece shows". Its a start point






Thanks

Ralph

Ralph,
I'm not positive that your Dynasty even has points for the HF start or not. If it does they collect dust and crud when not used for any extended length of time. Sometimes they even need the gap set, my machine is an older Miller Dialarc HF (transformer) and their setting is .008".

Is your machine the DX or the SD?

I've heard others talk about the Blue Lightning start that can give you fits, but I don't recall in what context they where talking about though, sorry.

I know we have a few members who use the 280DX which is similar to your. Maybe one of them will chime in with some help for you. Be patient.

Len

Thanks Len
My DX200 serial number is LG260330L if that helps age the machine. My local welding shop (BOC) suggested that there may be points inside that may need adjustment but he wasn't sure so I thought that the power of the Forum could help.

Thanks

Ralph

Ralph,
Here's a link to your owner's manual if you don't already have one.

http://www.millerwelds.com/om/o2240m_mil.pdf

Just looking at the manual's parts list I would say that it uses a solid state HF start and not points.

Are you using a foot pedal? And if so do you have the "Output" set to RMT STD and the "Process" set to Tig HF ? Also is the Tig torch in the electrode connection and the ground clamp in the work connection? Do you have a pre-flow value set?

I know these questions may seem condescending, but I'm just trying to establish a baseline to work off of, so don't take offense I'm not questioning your knowledge, just trying to help.

Len

Hi Len

No offence taken whatsoever. One thing with things like this is that there are so many parameters/options to be listing. So mea culpa for missing them. And thanks for the link to the User Manual. Turns out that my model is the one mentioned on page 32 (Section 5-15)

• yes to a foot pedal (wireless)
• yes to RMT STD
• yes to leads in the correct locations
• yes to preflow set. Just gone to the shed again and it was set to the factory default of 0.2sec now adjusted to 2sec. Will have to wait til tomorrow at least for some more Argon.
• running on a 220V supply
• on power up the first meter items show 221 and 136 and then -3 before showing the last used parameters

Regards

Ralph

My 200dx will start an arc from way out. Your settings look right so it has to be internal. You have to have a good work return connection. Maybe it could be so be something simple like a faulty lead or connection.

Not sure if it's relevant with a solid state HF but when my machine was doing the same thing a few years ago it ended up being a capacitor that stored the juice for the HF. I noticed in the parts list that there is a capacitor listed, might be all it needs.

Everything has too much electronics in it for my liking. Might require a trip to a Miller service center unless your knowledge of electronics falls well above mine. Maybe someone here can add to your list of things to troubleshoot beyond what we've covered.

The good news is that your machine is equipped with a clean lift arc function that will let you use lift arc to weld Aluminum if need be, providing it works.

Len

I think its just a miller thing. I previously had a 200sd and I currently have a 350 and they both do what your explaining. What I found helps is if before you hit the pedal you actually touch or even a light scratch with the tungsten where you want your arc to start then pull it away and hit the pedal and the arc lights right up.

Hey you're right about that, I've had the same thing happen from time to time. I used to scratch it like you say, but then I found if I keep the pedal down (or torch switch pressed depending on what I am using) the arc will eventually start after what seems an eternity about in reality is probably only not much more than 5 seconds. It seems like its little brain is thinking about it a while before it decides to take off. Most of the time it behaves normally.

Hi to all
It will be interesting to see if it is "normal".
I have contacted the Miller agent who will be passing through town on Wednesday and he will stop by and give his thoughts on the matter. HF would be a bit of a waste of you still have to touch your tungsten to the weldment.

I will post what eventuates

Ralph

Hi to all
The Miller agent tried the machine and found that he got the same sort of behaviour as me where the electrode had to be very close to the weldment to get it to fire up an arc. Not so bad if the electrode was hot to get the arc to restart.
He had tried turning off the setting that lowers the OCV but that made no difference.

Apparently the early DX200 had HF issues that the Miller company was not particularly keen to admit to. There is the chance to help deal with this with a firmware upgrade (See this http://www.millerwelds.com/resources/co ... re-upgrade on the Miller forum from 9 years ago.)

The rep. said that the technical service person could potential improve it by rewinding a coil and adjusting the points in the machine. So the DX200 has gone to the 'doctor' for some attention likely to cost around US$100. Should be back in a weeks time.

I will let you know the results

Regards

Ralph

Metal_pig2001 wrote:Hi Len

No offence taken whatsoever. One thing with things like this is that there are so many parameters/options to be listing. So mea culpa for missing them. And thanks for the link to the User Manual. Turns out that my model is the one mentioned on page 32 (Section 5-15)

• yes to a foot pedal (wireless)
• yes to RMT STD
• yes to leads in the correct locations
• yes to preflow set. Just gone to the shed again and it was set to the factory default of 0.2sec now adjusted to 2sec. Will have to wait til tomorrow at least for some more Argon.
• running on a 220V supply
• on power up the first meter items show 221 and 136 and then -3 before showing the last used parameters

Regards

Ralph

"preflow set. Just gone to the shed again and it was set to the factory default of 0.2sec now adjusted to 2sec"

2 seconds preflow before the HF starts is an eternity, in AL welding,
leaving you wondering why it ain't lightin' uP.
Suggest leaving it at the 0.2 second flow time.

Hi Dave,
I guess that I was getting desperate to see some sort of improvement. The first thing the Miler rep did was a factory reset and change the OCV setting, So hopefully my mistake has been eliminated

Thanks for your suggestion
Regards
Ralph

Ralph,
Your HF start has no idea if your Argon has been flowing for .2 seconds or 2 seconds or 2 days.

Len

Hi to all

Here are the comments from the invoice for the repair:

No travel. To check Miller Dynasty 200 with low HF. Test weld with stock setup. Tig won't start easly. Test with workshop
'short' tig torch. Weld starts easy. Wind 1 more turn onto HF coil and increase spark gap. Test with original torch. Weld
starting better.

I will not get the machine back until Wednesday so I await with interest for what improvement has been achieved.
For your info the 'short' TIG torch has a 4 metre cable.

Regards
Ralph

Hi to all
the final result is that my Miller agent managed to get his hands on a 4m Superflex (NOS) that I got for a very good price.
That combined with the previously detailed work by the repair agent has given me a much less frustrating experience.
The arc will start when the tungsten is around 8mm away from the work. Still doesn't have the capability of my Lincoln V160 but still way better than it was.

Yesterday I cobbled together some brackets for suspending a LED tubed light fitting in the garage'.




Not Zank-Grade but I was in a rush to get the light up and out of the way to avoid it getting damaged. Much more practice required.
Plenty of faults including cratering at the end of a weld, could have cleaned more, could have been gentler on the edge of the material etc.

The photos above are of a bracket that has yet to be used. 4.5 x 30mm if anyone was wondering. The light has been screwed to a piece of 100x20mm timber, the bracket attaches to the back of the timber and then the bracket slides onto a horizontally driven nail. I wanted to be able to shift the light to another position as required so didn't want a permanent installation.

Regards and thanks for everyone's thought on the issue that I was having

Ralph

Ralph,
Glad to see you've got it working better.

If I might make a suggestion, when you're welding smallish Aluminum parts that build heat up quickly, start your weld in from the corner and work out, then go back over it and start adding filler again when you get back to your starting point. When you get close to the other end start tailing of on the pedal while adding enough filler to cool the puddle. I hope that made sense. You probably welded those faster than it took me to type this out.

Try using your pulse function to limit heat input also. Lots of folks here can explain that better than I though.

Len

Thanks Len
Yes, it was a bit awkward with the heat build up. Working in from each side would have worked better.

Regards
Ralph

I have a Miller Dynasty 280 DX. It sometimes arcs from over 1/2" out. This is without pushing on the pedal much.

Is yours one of the Blue Lightening models
Ralph

No sir it's not

Sorry. I was reading more on it and it has the "blue lightening" technology

Glad that it makes the difference needed
Regards
Ralph

kblenker#22 wrote:I think its just a miller thing. I previously had a 200sd and I currently have a 350 and they both do what your explaining. What I found helps is if before you hit the pedal you actually touch or even a light scratch with the tungsten where you want your arc to start then pull it away and hit the pedal and the arc lights right up.

I have this as a hibit now when using my dynasty 300DX. The blue lightnings are supposed to be better for arc starting, however I have heard them doing the same thing. Only time mine will light off far away is when I just freshly ground it on my diamond wheel. Even Miller has a vid on this and Andy Weinburg(sp) shows to touch the work before pressing the pedal.

I've noticed this peculiar phenomenon with our Syncrowaves at work. They will HF start more reliable if I ground the tungsten to the desired start point (as if to discharge static electricity, though I doubt that's what's going on), lift off, then hit the pedal.

Not "lift arc" or "scratch start". Just a "neutralization" of the circuit before asking the HF start to work seems to help with easy starts.

Anyone else notice this?

Steve S