Resistance Spot Welding

admin

hi guys, i'm new here so im not sure if my query should be posted here.I have a spot welding machine which i got recently, it's a Dalex PMS 11-4 and aorund 25 years old. The difficulty i have with this machine is how to set the current (Amps). I have the manual for this machine and it says that the current can be set by "phase shift from 27degrees to 153degrees by potentiometer". I know where the knob for the potentiometer is but i do not know how to use it.For example if i want the current to be set to 6kA at what point should i set the knob?Not knowing how to set the current is a big problem for me as i cannot stay wasting time using the trial and error method. Any help would be kindly appreciated.
Reply:If you know the kA capability, then hopefully the middle of the range is in the middle of the pot setting.  A couple of test welds, one above and one below mid-range, will tell you which direction is + or -.  Shouldn't take too much to dial it in if you have a spirit of adventure.[Note to self:  A guy who can't be bothered to waste his time is messing with a 25 year old machine?  Hmm...]"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:its still going to be trial and error due to pressure and tip diameter factors. and although you can use an ultrasonic tester to tell you how the welds are,you can only do that after long term destructive testing for correlation .miller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:Originally Posted by OldendumIf you know the kA capability, then hopefully the middle of the range is in the middle of the pot setting.  A couple of test welds, one above and one below mid-range, will tell you which direction is + or -.  Shouldn't take too much to dial it in if you have a spirit of adventure.[Note to self:  A guy who can't be bothered to waste his time is messing with a 25 year old machine?  Hmm...]
Reply:I would start by making sure the tips are in cherry condition,and redress and maybe put some mig spray lightly on them while testing so metal doesn't stick to electrodes, the mfg's reccomend setting the distance between the tongs gripped together at half the distance between the combined thickness of two metals being fused, do not force the two together use a pair of vise grips nearby if you have to but this can cause the circuit to go through the vise grips if your metal is not clean.I have used the Miller spot welder and bought my own without a self initiating timer and like it the way the miller is set to fuse, when you clamp the handles, because the units are heavy and should not be angled more than 10 degrees.You want to check to see that a nugget is formed inside the two surfaces, I checked mine in the bodyshop by clamping one end to a dozer and the other chained to the floor.Personally I would crank the power wide open and vary the time from .5 sec on depending on tip diameter.If you have a pot on the machine it may have been designed for very thin sheet metal.
Reply:Can anybody help me?I'm looking for a standard (mainly EN, or ISO) for welding foil (strip) for roller seam foil resistance welding (225 process according to ISO 857).I'm talking about this process:Butt welding between copper rollers, and the plate edges are covered with 0.2 mm thick and 4 mm wide strip on both sides.I need the standard of this welding strip (or foil), what specify the requirements of material, dimensions and tolerances etc.Thanks for response.
Reply:I haven't seen resistance welding in a similar setup, normally foil gets welded in overlap position.
Reply:It doesn't need to use foil with lap joint.It can be easily welded without any foil.This is the advantage of foil resistance welding.You can weld butt joint. Foil welded joint can be water tight, and more aesthetic than lap joint.
Reply:Originally Posted by jcksn82chrvlIt doesn't need to use foil with lap joint.It can be easily welded without any foil
Reply:Sorry.Normally you don't need welding foil (welding consumable) to weld lap joint with roller resistance welder.Like this:If you want to weld butt joint with a roller resistance welder, the only way is foil welding (see figure in my first post).I have never seen lap joint welded with foil.This foil is actually a "filler material".Here is a foil welded joint (stainless steel):And I need the standard of this filler material for non alloyed structural steel
Reply:so the "7" in your first figure, is actually filler material (= foil) ?never seen this before, but sure sounds interesting.I have worked with R-welding in the past, both spot and roller welding, and I have used process tape with spot welding (for anti-wear properties on the elektrodes), but never used filler material.Last edited by kingnero; 01-21-2014 at 06:27 AM.
Reply:Yes. You're right.It is filler material.So it is not a copper foil, what keeps the roller electrode.Well, it's really not an often used welding process.Unfortunately I cannot find a better photo.
Reply:One of our partners, who are especially dealing with resistance welding have found something.There is a specification in "DVS 2906-04 Merkblatt".It is a German standard.So I think this problem is solved.So, if somebody will have the same problem, it could be a helpful information.But I think there are not a lot of company who use this technology.