[HN Gopher] The Beauty of Pulse Arc Welding
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The Beauty of Pulse Arc Welding
Author : mhb
Score : 110 points
Date : 2023-04-11 12:39 UTC (10 hours ago)
(HTM) web link (www.hermansilver.com)
(TXT) w3m dump (www.hermansilver.com)
| anfractuosity wrote:
| Intriguing, I wonder how this compares to laser welding for
| jewellery etc.
|
| Edit: Just noticed he mentions in the video laser welding is more
| suited to smaller items
| farkanoid wrote:
| I'm so infatuated with these machines that I've been working on
| designing my own version (using parts available at
| Mouser/Digikey) for close to a decade.
|
| Unfortunately I've been unable to maintain a decent work/life
| balance due to the high cost of living. As a result, I honestly
| die a little inside each time I see an article posted about them.
|
| The last update was in 2013, where I completed the EHT "popstart"
| circuit (to replace the expensive retractable electrode, and
| allow the use of a standard TIG head):
| https://www.youtube.com/watch?v=Y4c5Le2kT6w
|
| Some day I'll complete it!
| 1970-01-01 wrote:
| ChatGPT isn't going to destroy Jeff's job.
| Blackthorn wrote:
| Robotic welding processes have caused quite a bit of grief in
| the workforce before the advent of ChatGPT, unfortunately.
| buildsjets wrote:
| Any weld that can be economically automated should be.
| Several years ago I worked a project to help a supplier
| implement automated orbital tube welding for an aerospace
| product. There were two of these welds per part, and 8 parts
| per airplane, for an airplane that was being produced at
| around 50 per month. So they needed to make about 800 welds
| per month, about 37 per day. Including setup, each manual
| weld took around 15 minute, so over 9 hours of welding the
| exact same setup over and over, while being exposed to hot
| surfaces, UV light, and welding gasses. That's no job for a
| human.
| nimbius wrote:
| having worked in shops alongside automatic welders its a
| toss-up at best. See vendors like Fanuc and Motoman will say
| just about anything to get the bid for a process automation
| contract. 50k cycles per hour? sure. maintenance period every
| 25 years? why not. seamless switching between pulsemig,
| pulseGMAW and cupped tig? you know it. Vision system? it can
| see through time buddy, this robot does _eeeverything_.
|
| the problems start when your shop retools without a cycle
| time analysis, makes small tweaks to existing metal profiles
| without updating the bots, or finds out robots aren't magic
| money saving golems. for me its been the last one because
| every shop Ive been in will literally run an autowelder until
| the teeth in the gears sound like an empty bag of cheetos and
| the tool path leaves about an inch of over-weld and spatter.
| the overweld and quality issues get the grinder treatment
| from a line worker whos pulled out to do lots and lots of
| reworks so your cycle time is now bob's cycle time. now
| eventually the setup to pulsemig wont make sense anymore or
| nobody can remember how to switch it to GMAW or a customer
| needs a mig joint so more tweaks happen until your $250k bot
| is now just a pneumatic arm that shoots metal boogers at a
| joint and sends it to rework.
|
| no shop wants to spend money on a programmer or mechanical
| maintenance unless the machines literally swinging around in
| a fiery puddle of its own hydraulic.
| BizarroLand wrote:
| >the machines literally swinging around in a fiery puddle
| of its own hydraulic
|
| Just put the fire out and slap some jbweld on it. We don't
| have time for a repair call.
| jacquesm wrote:
| There is good money made by people fixing up after the
| robots.
| WheatMillington wrote:
| On a production line, sure. But not in the kind of work in
| the link, and not in almost any kind of repair work, bespoke
| work or built to order manufacturing.
| CoastalCoder wrote:
| How about ChatGPT producing a suitable CNC program?
|
| (I have no idea how feasible that is, I'm just curious.)
| Blackthorn wrote:
| And you thought chatgpt was bad with subtle bugs in generated
| Python code. Now just imagine it scrapping a thirteen hour
| part or crashing a $300,000 machine.
| CoastalCoder wrote:
| I've never worked with a CNC. Wouldn't they typically have
| safeguards against machine-damaging instructions?
| jaipilot747 wrote:
| Usually not. Especially not in machines where you
| manually set the bits and the machine has no idea of the
| bit and it's properties, nor of the piece you are
| machining.
| jdboyd wrote:
| They might try, but it is hard to know which instructions
| will damage something. The machine might not not what the
| shape of the work piece inside of it is supposed to be,
| and if it doesn't know that, it might not know when one
| operation fails in a way that would now cause a later
| operation to incorrectly collide part of the machine with
| the work piece.
|
| On stupider machines that are only 10s of thousands of
| dollars/euros/etc, you also have to be certain that what
| the machine expects for tool geometry matches reality
| (meaning that the correct tool was in the correct tool
| location, that the tool is mounted in the holder at just
| the right length, that the tool itself hasn't deformed,
| etc.
|
| That said, I wouldn't bet against AI stuff potentially
| being good at generating tool paths in the future.
|
| Sometimes I think that existing CNC stuff might be too
| dumb. Where is the lathe equivalent of auto-probing a 3d
| printer bed or using machine vision to monitor the print?
| Where is the mill equivalent of visual examining each
| part like a pick and place machine does? Why can't I put
| a piece of metal in a vise and just tell the mill to
| square of the ends? It could be that what I'm picturing
| is only stuff that casual users would be interested in,
| and thus there isn't sufficient money to develop it.
| bglazer wrote:
| I'm surprised there's not closed loop control for feeds
| and speeds. Like, it seems relatively easy to tell when
| the tool is chattering, even a simple microphone and
| audio processing would probably give a decent signal that
| could then instruct the machine to slow the feed or take
| smaller bites.
| jacquesm wrote:
| There is, actually. Just not on all machines. Typically
| there is a current sensor and you can set some pretty
| tight tolerances on what is acceptable under cutting
| load. This also helps to detect worn out tooling (though
| normally you'd pre-program this in advance, but there are
| workpieces that are so large they'll wear out the tool in
| less than one pass).
| di4na wrote:
| Re auto probing: it exists but usually not at your level
| because you rarely need that precision for the work you
| do. On top of this, it gets far more expensive because
| the levelling mechanism end up having a precision cost
| too.
|
| Also let say that the use case are a bit different. a 3d
| printer is a far far far more controlled environment
| Kirby64 wrote:
| The difference is simple, a 3d printer starts with
| nothing on the 'table' or platform and adds. It has 100%
| of the information of what is added, so in theory it's
| possible to know where any potential collisions are (this
| is not done in practice, and also doesn't account for
| adhesion print failures, etc, but it's possible).
|
| A CNC starts with an unknown block on the table, held by
| an unknown workholding fixture, made of an unknown
| material. There just is not enough information to not
| crash into something unless programmed around it. Or just
| run way too fast and destroy tools.
|
| In theory you could design sets of rules, but now you're
| having to add so much specificity to a design it's a big
| time waste. There's not really any meaningful entry level
| CNC machines, so if you can pay for the big machine...
| you kind of can pay for the expertise to not destroy the
| machine.
| kube-system wrote:
| There are FDM processes that go back down in Z direction
| - like printing multiple units on the same build plate
| one at a time. And in those situations you do have to be
| careful not to crash the print head into an already
| printed part.
| Kirby64 wrote:
| Almost noone does this, though. But, even then, you have
| all the information you need in theory because you're
| putting down the plastic.
| dale_glass wrote:
| Most will print every copy at once, switching between
| them.
|
| It also often works better because doing small parts can
| overheat the plastic. Moving between copies lets things
| cool down.
| Blackthorn wrote:
| What the machine knows:
|
| (1) Where the head is. (2) If you program it right, where
| the end of the tool is. (3) If you program it right, what
| the width of the cutting edge of the tool is.
|
| That's it. You could maybe prevent it from diving the
| tool into the table. But you won't prevent it from trying
| to take a 2" cut into D2 steel. Or going down into a
| pocket and crashing the tool _holder_ into a section of
| the workpiece. Or going down into a pocket and rapid
| moving left, slamming the tool into the workpiece (which
| if you 're lucky will just break the tool).
| mauvehaus wrote:
| ... And depending on whether it uses steppers or servos,
| it may only know where the head is relative to where it
| was last told its origin was.
|
| ... _And_ , if it's using steppers, it only knows that
| much if it hasn't slipped/missed/lost a step.
| at_a_remove wrote:
| Terrifying amounts of no, not even a little.
| davemp wrote:
| From my at a glance knowledge of the space, complex CNC
| setups can have NP path routing problems to go from a
| model to the actual job. So I wouldn't be surprised if
| the tools are underdeveloped. You're only selling a
| couple of these machines to very sophisticated operators
| after all. There isn't the scale/market to justify much
| polish.
| jacquesm wrote:
| To some degree. But if you purposefully program in a
| toolstrike and ignore the warnings you'll get a
| toolstrike and depending on how beefy the tool/machine is
| the damage may well be considerable. Hold down clamps are
| a particularly good source of toolstrikes.
| [deleted]
| auxym wrote:
| Nope, not in my experience. They will happily ram
| themselves at full speed into your solid-block-of-steel
| workpiece if you tell them you (thereby probably causing
| tens of thousands of dollars in damage).
| edrxty wrote:
| I'm sure you could train it on a bunch of g code and get g
| code out but it wouldn't have any context for the
| specifically targeted CNC machine and would probably just
| gouge random holes in the bed with random tools
| abakker wrote:
| SO BAD. It is NOT aware of G and M codes on a per machine
| basis and will create amazing crashes will full conviction
| that it will work.
|
| Edit to add: E.g. it fully recommended that I use a G38
| instead of g31 in a macro, which would on my machine would
| probably destroy my probe.
| knodi123 wrote:
| > crashes will full conviction that it will work
|
| That 'full conviction' part is the kicker. I don't mind if
| an AI says "gee, this might work", or "maybe this?" But the
| confident idiocy is going to kill someone. I asked one what
| the best breed of dog was for a family with a child who had
| allergy problems and was sensitive to dander. It said a
| golden retriever was best, since they are hypoallergenic
| and don't ever shed, plus they're friendly and eager to
| please.
| m463 wrote:
| maybe wait for gcodeGPT?
| MisterTea wrote:
| That custom micro TIG setup is really nice. That articulated arm
| is really neat, but that scope head must be very light. I'd like
| to know the brand as it looks plenty solid.
|
| Pulsed welding is super useful for filling and repair operations
| on thin sheet where you can "shoot" a tiny blob of filler wire
| into the joint/hole/gap and fill it in. Or perform small butt-
| seam welds without filler. I've worked with fiber and yag lasers
| and the welds are really clean and solid. You can even weld
| larger parts together with decent strength or tack fo larger
| welding operations. Even some of the electron beam welders there
| had a pulse welding mode.
|
| "Won't fit in a laser cabinet" - You just need a better laser
| setup instead of a fixed optics machine. Buy a fiber laser, like
| an IPG QCW 450/4500 get a small D30 head, 125mm lens, coax nozzle
| with a camera tube (don't buy the camera from them as they just
| resell a Sentech for double the $) and build another station like
| your TIG setup but mount the laser head instead. You'll have one
| hell of a fiber welder. You might even be able to move work over
| from your TIG setup. They might offer a binocular setup for the
| head or have one fabricated if you don't want the camera/monitor
| setup.
| gertrunde wrote:
| The article refers to it as a "Lampert PUK04" - a search turned
| up this link: https://www.lampertusa.com/products/puk04-with-
| microscope-sm...
|
| I suspect that it has since been superseded by the current PUK6
| model (and previously the PUK 5, judging by search results)
| geocrasher wrote:
| This reminds me of TIG welding, but on an even more refined
| level. What an art!
| eimrine wrote:
| Deleting "DJD" from a knife is kind of adblock but for metal
| things, as far as I have understood.
| Blackthorn wrote:
| Only somewhat related: has anyone tried pulse stick? I don't have
| a machine capable of it, but it seems like it would allow some
| pretty easy stick welds. Especially on thinner pieces.
| dsfyu404ed wrote:
| The venn diagram of people who get really exited over pulse
| welding and people who spend enough time using a stick welder
| to notice yet alone realize any benefit from those settings" is
| just two circles.
|
| I can see the theoretical benefit in how quickly you can put
| down material but all of the people who actually need that in
| practice are probably already using something that feeds off a
| spool.
| shirleyquirk wrote:
| Correct. In a stick welder I care about: working all day, in
| the rain, up a ladder, at 130A. For ease/quality of the weld,
| I pay for quality welding rods, not more settings.
| causi wrote:
| _Sometimes the joined area is not visibly accessible, and I don
| 't know if lead has been used._
|
| You could use a lead test swab. They come as small as precision
| q-tips.
| Tepix wrote:
| Neat, i didn't know this was possible (removing engravings).
| convolvatron wrote:
| I have done a little silver work with a tig, down around 15A. I
| really felt this was the bottom of the range and struggled to
| maintain a puddle. is there anything fundamentally different
| about this process?
| shirleyquirk wrote:
| Not fundamentally different, technically, just optimized for
| that low end. I think this model maxes out at 13A. And you're
| looking at your weld *through a microscope*.
| 1970-01-01 wrote:
| This is pulsed MIG.
|
| Edit: It's TIG in the video. I assumed jewelry used MIG because
| that's normally how thin copper is welded:
| https://www.youtube.com/watch?v=IyAaX0RZMVc&t=70s
| shirleyquirk wrote:
| No it's not, there's no spool. It's tungsten electrode, inert
| gas. Feed wire and electrode diameters are, like, 0.3mm
| 1970-01-01 wrote:
| You're right, I see in the video he has a filler rod and
| tungsten electrode.
| galangalalgol wrote:
| Why is it ok to touch the tungsten to the silver, when it
| isn't ok to touch it to steel?
| tylerag wrote:
| And therefor you don't need to maintain a puddle in the
| workpiece. I'm assuming silver tig welds like copper, the
| heat flows away from the puddle so fast that the entire thing
| turns into a blob.
| 1970-01-01 wrote:
| Yes, silver has the fastest heat conduction of any metal.
| It's faster than copper.
| convolvatron wrote:
| thanks, that's pretty key. I've done plenty of copper, but
| for some reason (maybe just the cost), I didn't think of it
| like Al or Cu where you really need to take into account
| thermal mass and preheat. I suspect that's where the pulse
| settings really shine - getting really local hot spots in a
| very short period of time.
|
| if silver starts becoming more decorative and less of a
| specie I'll probably try in earnest
| LorenDB wrote:
| What an annoying website - when you right-click the page, it pops
| up a copyright notice dialog.
| h4ch1 wrote:
| https://0x0.st/HXU8.png
|
| anyone know what these POSTs to play.google.com/log are for
| haunter wrote:
| Don't see this in Chrome + uBlock
| smegsicle wrote:
| excellent use of a Free Scroll to Top Button from
| ScrollToTop.com however!
| calvinmorrison wrote:
| What a throw back you mean! Haven't seen one of those in years
| mhb wrote:
| In Firefox, if you click a few times, it offers the option of
| suppressing that notice in the future.
| danhau wrote:
| I think Shift+Rightclick should work too. At least it used
| to.
| analog31 wrote:
| The first thing I saw was no protective gear. Does this process
| really produce no UV?
| Gh0stRAT wrote:
| >Does this process really produce no UV?
|
| I have no idea, but the microscope he's looking through could
| certainly have UV protection built-in. Or perhaps the pulses
| are so short and small that the cumulative risk is negligible?
|
| Either way, it seems to me like there could be ways for it to
| be safe enough to require minimal PPE while still producing
| some non-zero amount of UV.
| analog31 wrote:
| I'm also thinking about skin exposure. Fortunately glass
| optics are at least opaque to the most dangerous bands of UV,
| but not to retinal blue, which has its own special place in
| the regulations.
| gaze wrote:
| the microscope blanks when the arc is fired
| MaxikCZ wrote:
| What happens if one time it fails? Does it instant blind?
| monknomo wrote:
| Looking straight into a welding arc doesn't blind you
| instantly. Eventually, sure.
|
| More rapidly it gives you a lingering after image and
| feeling like your eyeball is full of sand
| convolvatron wrote:
| the 'eyeball full of sand' can last for several days, and
| really interfere with your normal functioning. that and
| the greatly increased acceleration of cataract
| development means really dont look at the blue light.
| michaelt wrote:
| Auto-darkening welding masks block UV and IR all the time
| [1] so you're protected against things like arc-eye even if
| it fails to darken. Also, masks generally fail-safe (to
| darkened, e.g. for flat batteries) and presumably this
| welding microscope is designed to the same standard.
|
| [1] https://youtu.be/qMyeVXuElkQ?t=333
| binarymax wrote:
| Really beautiful work. Though not as detailed, This Old Tony has
| an amazing pulse TIG welding video, for those who want to see it
| in action https://youtu.be/a6fUCApr03g
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