Solderdoodle Is An Open Source, USB Rechargable Soldering Iron


Battery powered soldering irons are nothing new, but what about a soldering iron that can recharge via USB? [Solarcycle] realized that it might be handy to be able to recharge a portable soldering iron using such a ubiquitous connector and power source, so he developed the Solderdoodle.

The core component of the Solderdoodle is a Weller BP645 Soldering Iron. The heating element is removed from the Weller and placed into a custom case. The case is designed to be 3d printed. The STL files for the case are available if you want to make your own.

The Solderdoodle does away with large, disposable batteries and replaces them with a lithium ion battery pack. The battery contains no built-in protection circuitry in order to save space. Instead, this circuit is added later. [Solarcycle] appears to be using a circuit of his own design. The schematic and Gerber’s are available on his website.

The Instructable walks through all of the steps to build one of these yourself if you are so inclined. If you don’t have the spare time, you can fund the project’s Kickstarter and pre-order a production model. It’s always great to see a new commercial product with an open design.

[via Reddit]

44 thoughts on “Solderdoodle Is An Open Source, USB Rechargable Soldering Iron

  1. Open source design uses a propriety tip. The old Whal cordless iron had two screws for the tip, a secure connection. This looks like a trouble prone coaxial connection not up to the high amperage. I haven’t bought a tip for my Weller gun in decades, 10 gauge copper wire is open source.

    1. Copper tips are crap, like most ‘open source’.

      Sheesh, the ‘open source’ morons are getting dumber by the day. “If I can’t make easily obtained item myself, it’s BAD!!!!!”

      No doubt the poster made his own PC, house, internet, power station, clothes, smelter, chip fab, oil well, refinery…

        1. There’s plenty of ‘Open Source’ stupidity to go around.

          Complaining that a commonly available tip is bad because it’s not ‘open source’ (unlike a chunk of copper) is moronic.

          Bare copper? What is this, 1940?

    2. Ignoring the idiot below I’d say you are at least partially correct. However bare copper is a relatively bad solder tip – it’ll get “eaten” by the solder much faster than the standard copper core with steel surface. There are cheap 3rd party solder tips for most known iron makers however it can take a while to weed out tips that are simply crap (in all cases better than bare copper though, IME, YMMV).

    3. So fork it and make a derivative that uses your tip, then. Complaining about open source not doing what you want is like complaining about not liking the food you just cooked following a recipe. Needs more cinnamon? Add it!

      This is the real deal of Open Source. Everything’s available and you don’t have any BS like “we’ll release the files when we start shipping our Kickstarter”.

  2. Shouldn’t this be on Hack-a-Day Fail? Recharging via USB would be so slow as to be useless. I have a battery powered iron and I use NiMH AA cells. When the power gets low I can pop them out and put fresh ones in. *Instant* recharging! Then I charge the flat batteries in… a USB charger!!

    1. Not a fail it it ‘works’.

      It’s got a USB plug, that doesn’t stop you plugging it into a 10A source…

      Swapping batteries doesn’t make these things all that much more useful anyway, I’ll stick to gas. And then only if there’s no mains power.

        1. 10A no but there are commercial products using much higher than 500mA, case in point the Oppo Find 7/7a has a quick charge feature, claims 75% charge on a 3Ah battery in 30 minutes, by my maths that comes out to about 4.5A over a microUSB port at least.

        2. I’ve seen datasheets specify up to 6A (for Type-A). Dunno about the others, but Micro-USB is presumably in the 2.5A+ range.

          I have a USB power supply that’s rated (claims) 3A per port.

          The USB 3.0 specs can handle up to 100W (20v at 5A), at 5v that’s 25W.

  3. Unless battery powered portable soldering irons have changed in the last decade or so, this is probably another “fail”. Having tried almost every one since highschool in the 70’s, they all have one thing in common: they suck! Nothing will beat an electrically powered (“mains” for the UK folk) soldering iron. Butane powered ones are somewhat workable, but I don’t like the idea of having a canister of explosive fuel in front of me unless there are no other options. I’ve used an old Weller adjustable temp (with numeric readout) soldering iron for the past 10+ yrs.

  4. I’ve tried a couple of rechargeable irons and found them so damn frustrating!

    I much prefer my Weller butane powered unit, unless I find myself in the middle of an oil refinery with it again.
    The refinery worker went a funny shade of white when I went to light it, not sure why…


    1. Nope, but for USB 3.0 they did. The plan is to replace all chargers with USB ones.

      For example laptops typically have a ~19v @ 3.5A 65W charger, USB 3 allows 20v & 5A, so 100W. In future there will be only one charger type.

      Firewire does/did similar.

  5. And to build it, I have to butcher a fully functional Weller soldering iron or buy replacement parts at an exorbitant price? And then I get like 5 mins of soldiering tine before I have to plug it into a hipster macbook air? No, thanks, USB hipster nerds, I stay with my old school gas powered Weller, when I need to be mobile

  6. Great idea except for the barrel connector to charge. C’mon, why would you use a 5v, 1A standard and then use that stupid connector? I have a drawer full of mini and micro usb cell phone chargers.

    1. Butane soldering irons are bastards to get to the right idle temperature, and then they don’t regulate the power when you start soldering with them. They work in an emergency but for more regular use i would really want an electric regulated one with at least 15W

      1. Why not create a gas powered soldering iron with remote burning chamber, heat pipe to changeable soldering tip and electronic PID temperature controller. Best solutions from each technology.

        1. I think it’s hard to get a heatpipe to work well at those temperatures while retaining a good thermal transfer capacity over the entire span (150-450 Celsius)

          Any other thermal transfer method would drop too much over the length so the heater really needs to be as close to the tip as possible.

    1. I did an accelerated test for an 1 hour 17 minutes until the battery was drained. Under normal use, the power button automatically turns off when your finger isn’t touching the power button so it should last much longer.

  7. I have to agree with you guys here, there is limited use for a battery powered solder iron. The bad thing with this one is that is will be heavy.

    Still, i found 24v 48w solder irons are quite capable to solder stuff powered from a 9.6V accu… You know just in case something came lose with your model and you are out.

    1. Yeah but that one isn’t open source, is it?

      This one is so it’s better. It heats up to 11 as well.

      I mean, what if it breaks? Are you going to buy a new one for $20, or spend a lot of time & money making the new part yourself?

      I thought so.

      So yeah, open source is awesome because everyone says so.

  8. Having the tools and the time, no one needs to go and by there iron from Sears. What if you could say that about anything. So this iron isn’t space aged, its not made of gold, however, its one less thing that I need to wait for a paycheck to buy, and one less sale going to the man. I’m not going to fund the Kickstarter, but I will look this one up when my iron brakes. Please open source me a facial hair shaving device, I will not shave until its open sourced.

  9. I did specify that Solderdoodle is limited to up to 24 gauge wire with leaded solder. Perfect for small Arduino projects.
    It runs at 1.4 Amps at 5 Volts without any problems and weighs just 97g (3.4 oz). It is all controlled with a high-quality charge control circuit.
    With only one cell, 500ºF is the max temperature. Non-leaded solder does require much higher temperatures. Thicker wire would need much higher power too.
    Solderdoodle cools fast when cleaning the tip on a wet sponge, so it does need full-on power to recover and work consistently. A different version with 2-cells would probably be able to get above 500ºF and control to a higher temperature.
    The final production version should have the standard micro connector. Most likely the new PCB designs will incorporate all those standard features.

    1. I did do an hour long test, and the PLA held up. It did get soft, but it didn’t completely melt. When your finger isn’t on the tiny black button, the power shuts off automatically. I had to tape the button down to do the hour long accelerated test. Under normal use, holding down the power button a few minutes at a time, the PLA doesn’t get soft.

  10. Great news! After I first bypassed the 5V DC-DC converter and wired the heating element directly to the charge controller output, I was able to reach over 700ºF, but a backer wanted to know if the usage time changed so I did another accelerated test with the power button taped down. I fully charged Solderdoodle and took temperature measurements about every 30 minutes and it was able to reach 800ºF! The temperature declined over time so I made a graph of the results. The results show that Solderdoodle stays above 800ºF for 30 minutes, above 700ºF for an hour, and above 500ºF for two hours! I will now advertise it as a 700ºF soldering iron because that seems to be a good average temperature for about an hour. Next, I will have to test some non-leaded solder to see if Solderdoodle can melt higher temperature material. Stay tuned for more Solderdoodle results!

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