WTB: Thermal arc GS1

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As the title states, in good working condition, I know its a long shot but I had to try.
Reply:Anyone know of anyone with plasma welders looking to get rid of a GS1 (gas slope controller)?
Reply:Like you say, a gas slope control will be hard to come by.  You must be planning to do some keyhole plasma?  You don't here of many people doing keyhole plasma, probably because sloping the plasma gas to start and close the keyhole has got to be very finicky.Have tried contacting Weldplus, it looks like they have a bunch of Thermal Dynamics sequencers, and I don't see a gas control, but maybe they can point you to one.  http://www.weldplus.com/products_show.aspFor someone who knows plc control (not me), it would be fairly easy to program a small plc to work a mass flow controller.  I see these kind of automation components on ebay all the time.I just noticed this machine at Weldplus, http://www.weldplus.com/product_details.asp?id=1040 , this unit was one of my machines at the airbag inflator factory, used for components of the dual actuated driver side bag, hence "dual driver"Last edited by pulser; 01-06-2010 at 10:19 AM.
Reply:Originally Posted by pulserLike you say, a gas slope control will be hard to come by.  You must be planning to do some keyhole plasma?  You don't here of many people doing keyhole plasma, probably because sloping the plasma gas to start and close the keyhole has got to be very finicky.Have tried contacting Weldplus, it looks like they have a bunch of Thermal Dynamics sequencers, and I don't see a gas control, but maybe they can point you to one.  http://www.weldplus.com/products_show.aspFor someone who knows plc control (not me), it would be fairly easy to program a small plc to work a mass flow controller.  I see these kind of automation components on ebay all the time.I just noticed this machine at Weldplus, http://www.weldplus.com/product_details.asp?id=1040 , this unit was one of my machines at the airbag inflator factory, used for components of the dual actuated driver side bag, hence "dual driver"
Reply:The plasma station was fully automated, with a conveyor bringing three stacked components in on a pallet, the assembly was lifted and clamped between two shafts, the torch came into position on a pnematic slide, the assembly rotated and was autogeneously welded, joining a thin Inconel disc between steel parts.  We didn't do anything keyhole, all conduction mode.  Plasma was used instead of TIG to eliminate TIG arc starting issues.Good luck with the gas sloper.  Are you sure it's worth the trouble, it seems like the tie-in/overlap sloping could be very tricky?
Reply:Originally Posted by pulserGood luck with the gas sloper.  Are you sure it's worth the trouble, it seems like the tie-in/overlap sloping could be very tricky?
Reply:This is probably the wrong thread to go on about keyhole plasma, but wtf.  If you're like me, if someone says it can't be done, you'll be more determined to prove them wrong.  I've never tried keyhole plasma, just read it about it over the years, so I'd like to hear about your results.  To me it seems that gas control is more difficult than current, speed, arc gap, etc. because gas is compressible, and it does not seem that it would react instantly like the other variables.  Good luck, how about some pics of the keyhole welds you have had some luck with?
Reply:No such thing as a bad place to go on about keyhole welding on a welding forum!I'll see if I still have any of the weld samples from playing around with keyhole. I was actually getting it down pretty good, if I could just slope the plasma gas back on the final current slope when I finish the weld I think I'll be pretty happy. Basically I am trying to achieve welds that are as narrow as possible, while maintaining full penetration and minimal heat input.
Reply:Have you ever experienced unusually wide and shallow welds on a new batch of stainless steel, when you previously had a narrow and deep weld on a different batch of parts using the same parameters?  Do you know about the Marangoni fluid flow phenonema, also refered to as Thermocapillary Convection?  This is one of my favorite welding subjects.http://weldingweb.com/vbb/showthread.php...ight=marangoni
Reply:Originally Posted by pulserHave you ever experienced unusually wide and shallow welds on a new batch of stainless steel, when you previously had a narrow and deep weld on a different batch of parts using the same parameters?  Do you know about the Marangoni fluid flow phenonema, also refered to as Thermocapillary Convection?  This is one of my favorite welding subjects.http://weldingweb.com/vbb/showthread.php...ight=marangoni
Reply:Still lookin fellas...
Reply:Bump of hopelessness
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Reply:Apparently keyhole plasma is not at all common these days.  The last application I recall hearing about was a sophisticated automated variable polarity system for vertical up welding of aluminum rocket fuel tanks (for the Shuttle?), and that had to be at least 15 years ago.There has got to be some old gas slope units sitting around collecting dust in various aerospace company weld development labs, and they should be available real cheap, but as you know, the problem is finding the obscure auction buyer that happened to come across one in a lot of all kinds of other welding stuff.  It may happen some day on Ebay.Have you tried calling Thermal Arc directly?  If you can dig down into the system, you may find a old technician/engineer who is ready to retire, and who may have a lead on where to find one of these units.Edit:  I see you said you did contact TA directly, maybe more digging there and finding the right contact could give you a lead.Last edited by pulser; 06-04-2010 at 12:04 AM.