Lorch help please

[GrahamGKD]

Hi,
In the operators manual for my Lorch HT220 AC/DC the table in section 11 for the 'main parameters' has percentage values for the ranges of upslope, downslope and gas post flow. Does anyone know what these are percentages of please, or is this just a typo? I would have expected these parameters to be expressed in units of time (e.g. seconds). At the moment I'm muddling along with the factory settings which seem to work OK but, being of an inquisitive nature, I'd like to understand what these settings are?

(One thought I had was that they are supposed to be a percentage of the pre flow which is expressed in seconds but that would give a maximum post flow duration of 50 seconds which seems a bit on the long side?)

Apologies if I am being dim!

Cheers,
Graham.

 

[Archie]

I believe they are a percentage of the factory default for whatever power setting etc you're using. I.e the machine decides what settings it thinks are best given info such as power, electrode diameter etc and sets the rest accordingly. If you want to change them you can give a percentage of the existing value. The advantage being that if you change something like the power setting and the machine then changes the postflow, for example, your change remains because it's set as a percentage of the value the machine has decided on. I hope that makes sense? It did to me! I have the T Series and it has an extra screen. One shows the percentage and the other the real valu in seconds or whatever. I guess that's one differentiator between the two models.

 

[GrahamGKD]

Cheers Archie. I think I'm part way to understanding it. Yes, I agree that the percentage values are good in that they will automatically correct if the main current is altered, if that is indeed how they work. My user guide doesn't have any units given in the default settings either but (from memory, since I don't have the book with me at the moment) I think the post gas is something like 100 and the variation of this is (something like) 1 (might be 10) to 500 percent. What would be a reasonable maximum setting for post gas?

Cheers,

Graham.

 

[Archie]

For the post gas, unless you have specific need to change it, I'd just put it on 100% and leave the machine to work it out itself.

 

[GrahamGKD]

Thanks Archie. Yes, I fiddled around with the settings a bit but soon realised the best thing would be to re-set the factory settings so I did that - as you suggest.

Thanks for your help.

Graham.

 

[matt1978]

Hi Graham,

Sorry I missed this question, I will dig a manual out and give you a more detailed answer when I get back in the office.

Cheers,

Matt

 

[matt1978]

Hi Graham,

I havn't been back to the office since and didnt want to appear as if I am ignoring you so I will answer off the top of my head......

The Upslope and Downslopes are expressed as a percentage, the higher the percentage the longer (shallower) the slopes, the lower the number, the shorter (steeper) they will be. They are in relation to your I1 setting (main welding current) so if you change you main welding current up or down, the machine will change the length of the downslope and post gas for example to suit (from memory I think the slope is about 10 amps per second). As a hotter weldpool, will need a longer slope and more post gas afterwards.

Start and End currents are also as a percentage, for the same reason that if you go from welding 100 amps, to 200 amps, you would need very different Start and End currents than when you was welding at 100 amps, so it makes sense to have as a percentage of the main welding current, so it changes as you change the I1.

Ta,

Matt

 

[GrahamGKD]

Cheers Matt - I think that's all making sense - I'd appreciate confirmation of the actual values when you get a chance please (like the 10A per second that you mentioned from memory). I think I need to work up some additional notes for my instruction book (this and the stuff you wrote about four stroke mode in another thread the other day). Unless there are already some such notes available somewhere??

I haven’t spent so much time playing with the machine yet but I seem to be OK with mild steel and a bit ‘random’ on aluminium. I’ve had reasonable results on odd bits of ali but sometimes I just can’t get it to go right. Last night I tried a fillet on some 2mm plate and I couldn’t get the bead to form between the two pieces – either the filler would glob onto one piece or onto the other. I’ve got the stainless wire brushes now and I thought I had the material clean. I tried breaking a lump off the tungsten in case it was contaminated. I did realise after that I had the door open – how sensitive is this process to draft?

If I continue to struggle I think I’ll negotiate for some coaching with an expert welder at a workshop up the road from me.

Thanks,

Graham.

 

[asmeix6g]

graham.dore that sounds like a sensible thing, getting a few lessons/tips off a local welder. no amount of advice or reading can compare to 1st hand experience