Hackaday Prize 2023: One-Handed Soldering With The Solder Sustainer

For a lot of us, soldering has become so ingrained that it’s muscle memory. We know exactly when the iron is hot enough, how long to leave the tip in contact with the joint to heat it up, and exactly where to dab in the solder to get it to flow. When you’re well-practiced it can be a beautiful thing, but for those who don’t do it frequently, soldering can be frustrating indeed.

The “Solder Sustainer” looks like it just might be aimed at solving that problem, as well as a few others. It comes to us from [RoboticWorx], and while it looks a little like the love child of a MIG welder and a tattoo machine, it’s got a lot going for it. The idea is to make soldering a one-handed task by combining the soldering iron and a solder wire feeder into one compact package. The solder feeder is very reminiscent of a filament extruder on a 3D printer, using a stepper to drive spring-loaded pinch wheels, which forces the solder down a curved 3D-printed tube that directs it toward the tip. The pancake stepper is driven by an ESP32, which also supports the touch sensor that lets you advance the solder. The whole thing can be powered off a USB-C power supply, or using the onboard USB charger that can be connected in line with the soldering iron supply.

The video below shows Solder Sustainer in use. Yes, we know — some of those joints look a little iffy. But that seems to have more to do with technique than with the automatic solder feed. And really, in situations where you’ve previously wished for a third hand while soldering, this would probably be just the thing.

The Solder Sustainer is an entry in the “Gearing Up” round of the 2023 Hackaday Prize. If you’ve got an idea for a tool, jig, fixture, or instrument that makes hacking easier, we want to know about it. But you’d better hurry — the round ends on August 8.

47 thoughts on “Hackaday Prize 2023: One-Handed Soldering With The Solder Sustainer

    1. I have one hand, NO! That doesn’t look like it’s designed with a one handed person in mind. It’s too bulky. It needs to be lighter. I see I’m going to have to post some of my setups. I have them on Instructables, but not hackaday.

  1. To me it just looks clumsy and unbalanced, especially with a full roll of solder loaded. I don’t quite know about how you have to grip the thing. Kinda hard to give the tip a good cleaning with that tube hovering right above it. Now do something similar (but a lot smaller) with a gun-type iron and you might have something.

      1. Considering the imprecision I’d suspect of these, what creates the apparently high demand for these based upon the number available on Amazon? The impracticality would seem to multiply with the ones that use large power drill battery packs.

      1. Ha, I thought you were exaggerating.

        For some reason, soldering on video is either by the extremely skilled, or by those who, for some reason, seem to be VERY scared to actually have the iron in contact with the pads?

        “Umm doot doot doot!”

    1. I was also triggered by the poor joints with the solder balled up *on top* of the pads and not fully bonded – like the soldering version of a tack weld.

      The commercial product with the Amazon link in the above comments seems less bulky but cheaply made. I wouldn’t trust the made-in-some-Chinese-factory-for-twenty-cents gimmick not to catch fire in my hand. I’ve seen some sketchy stuff at Harbor Freight, but that scared me. This may be the reason why the OP decided to make their own.

  2. TBF it looks like a solution in need of a problem. And on the video like 50% are cold joints.

    It’s like with welding, you don’t need $4000 Kemppi rig to learn basic TIG, but it also helps if you’re not using $50 “300 A” inverter made by Sum Ting Wong Industries in China.

      1. No offence to the Chinese people meant (I have only had the very best interactions with the people when travelling there), but Chinese companies will not think twice if they are sure that they can rip you off without consequences. It’s part of them doing business. They understood capitalism way better than we do.
        Search for RelayGate, for example. Solar inverters delivered to Germany lack a shut-down relay that is required by certification because it is not obvious that it’s missing and some money can be saved. So thousands of installations are no longer certified. Sue us, da bizi ren…
        I certainly feel entitled to mockery about Chinese business traditions and so does most everyone who ever did business with them.

          1. This kind of thing makes it perfectly reasonable to landlady 8 this business practices, but not racist language. If you think that’s too sensitive then maybe you’d best retire.

        1. I’ve dealt with mockery and racism towards Asians like myself for decades—since childhood. I can accept that your intent was not racist if you can understand that that sort of language is often used by racists who have far more malicious intent and is hurtful to hear. It also, whether you meant to or not, makes you look racist to other people who deal with this every day. So you may be projecting an image of yourself that is far more negative than you realize. Just sharing my point of view. Take it or leave it.

        2. Yeah, it’s just the same as people feeling entitled to mockery about American business traditions, like Boeing’s failures and subsequent cover-up on their autopilot software, which resulted in the death of 346 people, or about German business traditions, like using special “defeat devices” to fool tests evaluating their car’s emissions, leading to years of toxic particulate emissions damaging people’s health.

          No offence to American or German people meant, but their companies will not think twice if they are sure they can rip you off without consequences (to them) and will obfuscate, lie and cover things up in order to avoid accountability when they’re finally caught. It’s part of them doing business.

    1. It could be useful to fix a component, like a connector, in place. I commonly do that with a little solder on the iron, as my other hand is holding the connector, then solder all the other pins, and finally fix the initial bad solder joint.

    2. I don’t see how the automatic feeding leads to cold solder joints. If he held the iron on the joint for two seconds before feeding the solder, then kept the iron on the joint for another second the joints would be great. But an amateur using a soldering iron thinks melting the solder is all that’s required, and doesn’t realize they need to heat up the pin and pad before applying the solder.

  3. It’s got great potential, he just needs to up the temperature, use lead solder, and/or wait about a half second longer before he feeds the solder.

    A smaller roll of solder would probably help balance the thing too. I wonder if a solder-paste extruder would work better..

  4. It needs to be able to feed the solder into the point of contact between the soldering iron tip and the component leg/pad. Feeding onto the top of the iron tip and pushing the tip against the bottom is very bad technique. Most of the flux will have been smoked off by the time the solder gets to the proposed join.

    Pre heating pad and leg then getting the fluxing in the right point is the key to good soldering, not just the application of hot solder. As tell my students “It is not glue, we actually want creat a chemical reaction at that point, ie to get the solder to make a very thin amalgam joint to the components.

    So maybe a side feed, toward the very bottom, point of contact of the iron tip would be better??

    1. “As tell my students “It is not glue, we actually want creat a chemical reaction at that point, ie to get the solder to make a very thin amalgam joint to the components.”

      The answer to an exam question for IPC certification was that solder joints have an unlimited number of times they can be resoldered.
      But the Kester website points out that the metals erode slightly with each soldering.

  5. I feel like I’m on Kickstarter page when the product is something you can order already on Amazen or ally Xpress. Prices look to go from $12-$30.

    Possible improvement: use some copper or aluminum tube instead of a plastic pointer.

  6. Definately needs a v2. For instance, a 3d printing pen does basically the same thing, stealing the extruder from one (maybe the electronics as well) and modifying them to feed the soldering wire shouldn’t be too difficult. 3d printer PTFE tube as a wire guide and power wires for the power feeding bits back to the soldering station / solder holder. You could get the cable braid wrap stuff to put around everything to keep it tidy. Also really needs a bent pipe (metal straw?) Going to the hot bits for feeding the solder.

  7. I get cramp in my hand and see all the havoc I’d create burning stuff and getting solder everywhere just looking at the picture.
    And the video does not make it go away.

  8. I can see this being helpful for those with disabilities…but it will need some revision. As others have pointed out…it feeds the solder to the wrong location on the joint (I usually feed the solder to the opposite side of the joint to where I am heating, use the joint to melt the solder…not the iron).

    For my use case. I prefer as light and nimble of an iron as I can possibly get…I even removed the smoke extractor which came on my built in iron on my hotair station since it gets in the way when I am working.

    Too easy to have stuff like that cause you to bump into something and get caught up. Plus, not sure if you have every accidentally dropped an iron…but it will complicate things with a spool of solder there.

    That being said…it has it’s uses. Don’t let us professional solderers dissuade you from making :)

  9. 2 great laughs. STW Industries and this handheld high tech Rube Goldberg way of feeding solder through a thick plastic tube over a hot iron in the wrong place. A toothed wheel and a finger trigger feed ratchet or even just finger turned feed wheel, and an aluminum tube hardware store sourced. Simple. Only with a foot pedal does anything require such complexity and then a little geared DC motor will feed with control.

    I was given one of those STW sourced facsimiles mentioned above. It does heat up fast for a plugin and go iron. I haven’t put solder in it, but it’s “power cord” is thin stuff of such a scary dimension. That’s what’s really to laugh at. Something is wrong with such non-certified stuff on the marketplace.

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