Soldering pen – now with casing

It’s been a while since I got the soldering pen to work.

Now I’m back with more good news. I’ve printed the first casing for the electronics!

Yes it might not be much but it’s there! Looking more pen-ish than ever.


What do you think?

I haven’t added buttons yet – they will go in the two holes farthest from the tip.

The hole closes to the tip is for a small light-pipe so the LED can shine through the casing.

I was thinking some white PLA in 3mm would suffice.
I’m still working on buttons.

I’m not convinced that my initial idea will work so adding the buttons as small pieces of plastic might be the solution.


Here the pen is heating. The red LED is really bright!!

Next step is to convert all parts to 0603 so I maybe can have it produced locally.

Also I will be extending the PCB beyond the 50mm limit I was currently working on, making room for a barrel jack connector for the 12V.


I should make a gif.. the green is pulsing, indicating that working temperature has been reached.

The biggest problem is now that the mini-jack connector is only rated for 1A and the tip is requiring 2A..

The connector gets warm.. I don’t think I will have any luck finding a high-current low-profil mini-jack connector..

Any thoughts?


  1. Hi,

    I am following your project with interest and found this audio jack from Swithcraft (35RASMT4BHNTRX) which seems to be rated for 3A:

    Hope it maybe helps …



  2. To follow my previous post, this version (35RASMT2BHNTRX) of the Switchcraft jack would be probably more suitable as with no switches, so space saver and cheaper:



    • Hi JB,
      Thanks for the comment! That’s a good find and one I actually haven’t considered. The reason I haven’t found this was that I have only been looking for co-planar connector, which this seems not to be. It’s a small thing but having the tip in the center of the board plane (or at least really close to that) allows me to simplify the housing for the PCB which I can then model as a simple cylinder.
      It is a shame, really, because I think this connector is the right choice. It will allow me to use 12V instead of 24V, and maybe even lower (8V without breaking the rating for the plug). Alas, I have just ordered 250 PCBs with the co-planar connector. I will update this on the next batch if that ever happens (with 250 pieces this is not super likely yet)

  3. Yesterday I was browsing at the Conrad site (don’t ask… ๐Ÿ˜‰ ), I needed to order something there and came across a nice jack socket which is rated for 2000VDC and 5A:
    I ordered these 2 as well to evaluate ๐Ÿ™‚

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