Introduction: Hakko T12 Soldering Iron Kit Assembly

About: I love tinkering with Arduinos and other electronics. I am the owner of A2D Electronics, an online store based in Ottawa, ON that is committed to providing Arduinos, Raspberry Pis, accessories, and other elect…

I recently bought a new soldering iron kit because the tips on my old one were all worn out, and I couldn’t find replacements anywhere. I decided to go with a T12 kit from China, for only $20 it was a great deal.

Once I received it though, I realized I had a problem: I could not find connection diagrams or instructions anywhere.

I finally found one set of pictures that showed the connections. There were a few sellers on eBay that provided them. You can find a link here.

Once I assembled it all, I was very happy with it, especially for only $20. The only other soldering iron I have used is a no name, 60W, wattage controlled iron. In comparison to that, it is so much better. It heats up extremely quickly, there are replacement tips for it, and it is temperature controlled.

To save everyone else that has or will buy these poorly documented kits, I have put together some instructions here.

My apologies for the bad pictures - they were taken with an iPhone 4S

Step 1: Soldering LED, Vibration Switch, and 5pin Connector

Yes, you do need a soldering iron to assemble this soldering iron.

The first thing to do is to solder the red LED on to the main control board. It should be fairly obvious where this goes - no trickery here.

The 5 pin connector gets soldered in to the left hand of the board. The numbers do not really matter, just the positions of the pins, but it is nice to have the numbers lined up too.

For the vibration switch, solder it to the green PCB where the rectangle is, the gold pin to the hole labeled 1, silver pin to hole labeled 2.

Step 2: Connecting Everything Together

A huge thanks to the eBay sellers for providing the connection diagram. You can see the listing here.

Connect the 5 pin connector and the green PCB together with the 5 core wire according to the above diagram.

Make sure to slide the silver clamp and the soldering iron handle over the wire before soldering! You don't want to have to redo the soldering later.

Attach it all with a zip tie as shown so that there is less stress on the solder joints.

Step 3: Powering the Soldering Iron

The power input rating is 12-24V. Connect the power to the white connector on the top of the control board.

I am using a 12V power supply, and stepping it up to 20V with a 150W boost converter.

I also added a switch and DC input jack for easy connection.

Step 4: Creating an Enclosure

For the time being, I just used 2 rectangular pieces of wood, attached them with angle brackets, and used zip ties and M3 screws and bolts to secure everything in place.

It is certainly functional, but not the best. I plan to create a 3D printed / Laser Cut / CNC milled enclosure in the future. Let me know if you want to see one made.

Thanks for reading!

If you love Arduinos and are in Canada I have started an online store (A2D Electronics) for Arduinos and other hobby electronics parts - no need to wait for 8-10 week shipping from overseas.

Also, check out my other instructables for a very simple pin header soldering tool to solder straight PCB pin headers all the time, without a breadboard.