A Homebrew Weller RT Soldering Station

Like a number of hackers before him, [MarcelMG] was impressed with Weller’s RT soldering iron tips, but considerably less enthused about the high purchase price on the station they’re designed to go into. Inspired by similar projects, he decided to try his hand at building his own soldering station which reaps the benefits of these active tips without the sticker shock.

The station’s user interface was kept intentionally simple, with little more than a four digit LED display to show the temperature and a rotary encoder to set it. The display alternates between the current temperature and the set temperature every few seconds while the knob is being turned, and if you push it in, the set temperature will be saved as the default for next time.

[MarcelMG] also included a feature that drops the iron’s temperature when it’s sitting in the holder, reducing tip wear and energy consumption. He originally planned on using a Hall effect sensor to detect when the iron was holstered without needing to physically interface with it, but in the end he realized the easiest approach was to simply connect one of the input pins on the microcontroller to the metal holder. Since the tip is grounded, he could easily detect if it was in place with a couple lines of code.

Speaking of which, the station is powered by an ATtiny24A with firmware written in C using the Atmel Studio IDE. [MarcelMG] mentions that the limited storage on the 24A was a bit of a challenge to work around, and suggests that anyone looking to follow in his footsteps uses something with a bit more flash under the hood. The LED display is a very common TM1637 type, the rotary encoder was salvaged from a radio, and the power supply was from an old laptop. All told, this looks like a very economical build.

Depending on your needs, a DIY soldering station can either have features to rival the commercial models or be exceedingly simplistic. In either case, the advent of low-voltage irons and active tips have made self-built soldering stations much more approachable. Attempts without the use of these modern niceties tended to be somewhat less glamorous.

14 thoughts on “A Homebrew Weller RT Soldering Station

  1. Great build. Wonder if it will fit inside the standard Weller workstation base unit , which reminded me I have my Weller workstation Soldering Iron waiting for me to copy the ceramic Pcb to a normal pcb after it cracked. Apparently this is a common issue, Weller are happy to fix it for me but the price is just short of buying a new unit. Thanks Weller thats what you get for over 30 years of using their products.

    Maybe i can use this instead.

        1. Oh, okay, I have actually seen some of these but have forgotten. Risks of getting old and trashing one’s brain in my youth. Yeah, obviously they support super high operating temperatures and have good thermal expansion properties. So you’d have to be careful about redesigning one on fiberglass and managing that.

          Neat. Thanks for the reminder. I have a rabbit hole to get into now.

      1. Here is a webpage that goes into the issues with my particular iron, which is an EC2100fe.

        https://www.eevblog.com/forum/repair/weller-station-repair-advice-weird-symptoms-for-non-heating-iron/

        From other reading it seems that the ceramic board was some kind of option/special, which figures since it was a work tool making milspec hardware back in the day. Work ditched them durring a retool which they did often, and they always bought the cookie stuff, that was not available on the high-street.

    1. I might still have a piece or two of weller kit collected up from toolbox full purchases, but I have specifically avoided paying retail for them for about 30 years, since it was that long ago I had my first nasty experience of their stuff being relatively delicate, then almost as expensive as new to repair.

  2. Nice job. Since the 1980´s I´d dropped to use Weller station anylonger. Reason, what happened to Marantz Model 10 ? Weller get so strong magnetic field that it saturated IF coils ! Nowadays, I use HAKKO station. Its a Chinese retro and Thermo – control station. With a 3.2mm Soldering tip (ELFA catalog 82-422-81) its a perfect !

  3. I think there may be a variety of different types of ceramic PCBs. Harman International was using them when I worked there 30 years ago. They look like composite paper PCBs but have properties closer to composite fiberglass PCBs (FR4, etc.). They are cheaper than fiberglass and have the advantage that holes can be punched — fiberglass requires that holes be drilled.

    There may also be ceramic PCBs closer to what we would normally think of as ceramic, a single glassy sheet. You’d see those used in applications where the deficiencies of epoxy would be a problem: precision oscilloscopes and hybrid integrated circuits.

    1. Cheaper, LOL, which is ironic considering you paid more for Weller stuff, because it was supposed to be better quality. The wand bit yes the rest I’m not so sure.
      That one iron cost more back in the day than my entire rework station did last year. My rework station is supposed to be Weller compatible, although as its wand has a nice feel to it, I have never bothered to find out.

Leave a Reply to Inhibit Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.