this makes me want a laser machine - must stop reading these posts lol
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I originally started this thread some time ago because I was in the position to get one of these PUK 4 machines as a gift.
However I turned down the offer due to the cost involved, and because of the guilt factor, amongst other things!
Anyway since then I've constantly looked at these machines, viewed demonstration videos on the internet and so on. Andrew Berry did an short introduction video on the newest 4.1 version a short while ago too.
Whilst it was interesting to watch, theres still one thing puzzling me that I cant seem to work out. I grasp the technology and operation of the machine, thats the easy part, but its the welds themselves that confuse me.
For example if you were welding a bezel onto a backplate for instance, then are you left with an ugly weld / seam similar to those found on a bicycle frame, or are they minimally filleted as per a regular solder joint?
Its hard to gauge the relief of the welds from the videos I've seen, and I'm worried that there would be a hell of a lot of filing and cleaning up to do afterwards.
The other thing regarding the welds is that as the machine welds it appears to tarnish ( blacken ) the work area because of the localised electrical heat. As Argon gas is released at the time of the weld taking place, do the pieces still need pickling or does the Argon gas prevent oxidisation and therefore theres only really the usual polishing required on welded pieces?
Peter: I guess you 'may' well be able to answer these questions as the Laser system spot welds and appears to create joins of a similar appearance right?
Thanks,
Nick
Those are my concerns too Nick. Andrew Berry is supposed to be doing another video but I've been waiting patiently for such a long time
Purely from a laser perspective - the joints are more akin to TIG than anything else. The amount of fillet depends on how much filler you use; as with any other welding process, they're not all that tolerant of poor fit or manky metal.
I don't use argon all that much; only when the metal really requires it (eg Ti). There is some sooting - and with the laser on silver I scribble over the joint area with a black marker to kill reflection and improve heat absorption; I don't tend to need to do that for other metals. The soot brushes off (or more usually it goes when I blend the weld with a rubber polisher).
I can vary the beam diameter, which dictates the size of the weld (energy and duration are the other primary variables I can tweak, there's also pulse shaping which can be useful at times). The laser's refire rate means that although they're strictly spot welds, I can overlap them in a continuous seam, it's not a 1-shot job in the same way as I've seen done with the PUKs.
Everything's done at magnification, so what will seem like an ugly weld won't look anything like as bad when it's out from under the scope.
Biggest thing to remember is that solder will flow as a capillary joint, welds do not - if you haven't welded the root of the joint, welding the outside won't give it any strength.
Thanks Peter, forgot about the effect the high magnification has on the appearance of the weld!
Also 'sooting' is the term I was looking for and its useful to know that its not the same process to get rid of it as it is with copper oxide coming to the surface in silver and gold.
Keep meaning to book a demonstration in Birmingham with Suttons, and then that will finally answer any niggling questions I've got, as I've not yet seen a PUK in the flesh so to speak.
Thanks for the input Peter, appreciated as always.
Nick
hello nick martin, after many years what evolved with puk 04 ?
Ha ha, this forum is well known for its time travellers.
Unfortunately, Nick martin was captured by Daleks. Dennis.
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