The Liminal Build Guide THT – (Pt. 1 of 4)


Part 1.0 – THT

THT Diodes
(ft. Bendy Legs and Hot Rods)


1.1 | Tools and Stuff

A hobbyist should, and probably already does, have these basic tools in their fanny-pack of wonders. But These are the ones I recommend and use daily.

  1. A Good Temperature-Controlled Soldering Iron
    • The Hakko FX-888D is the hobbyist standard for many and has been the single best choice for some time now. Smart design, good construction, underrated colorway.
  2. Solder Wire
    • My Newest Favorite Being an Absolute Unit of Kester 60/40 .5mm ID Wire recommended by most of the 40% Discord. This roll is enough to last most people a lifetime.
  3. Flush Cutters
    • Klein makes a good pair but I’m pretty rough with my flush cutters and end up trying to cut a coat hanger on multiple occasions. I usually just recommend whatever the cheapest 4.5-5 Star option is.

1.2 | Preparing THT Diodes

There are a few ways the THT diodes can be prepared (or BENT) accordingly for the build.

Within my Original RoMac Github Repository there are files for a small diode bender tool you can use to get a uniform and clean bend on all the diodes individually. The tool is spec’d to the keeb.io diode footprints I use for my SMD/THT hybrid PCB footprints.

If using the tool, the process is simple. Just place the loose diodes individually into one of the wells and bend the legs straight down to a 90° set. Then set-aside and repeat!

If you are not using the diode bending tool…

not to worry. The diodes are simple to just hand bend each leg as close to the body as you can. This will be enough to allow the diodes to fit into the footprint holes in the PCB. You may just need to do a little more adjustment if you care about the look or “aesthetic” of the bottom.


1.3 | Polarity of THT Diodes

Let us party

THT Diodes (and all other switching diodes) do have a correct orientation (polarity). As such, they need to be soldering in the correct direction in order to function as intended.

Have a look at the images below. Take note of the sides of the diodes, and where they need to be positioned on the PCB.

Take a look at your prepared diodes and make sure you understand how they are seated correctly.

SOME DIODE LOCATIONS ON PCB ARE ORIENTED DIFFERENTLY
THAN THE REST.

DOUBLE CHECK ALL POTIONS TO MAKE SURE ALL
SQUARE HOLES ON PCB ARE LINED UP TO BARRED-LINES ON DIDOES.


1.4 | Seating/Soldering THT Diodes

Once again, there are a number of ways people prefer to set and soldering THT PCB components. In this guide I will be showing you my personal method.

A.) First we start by taking the prepared bent diodes and placing them into the diode positions along the PCB. I do this Row-by-Row just to lower the chances of stabbing myself on the surprisingly painful diode legs.


B.) Next I take a long strip of painters tape (masking works just as well), and lay the tape down to hold the diodes in place while we solder the other side (top of PCB).

(*the alternative way to do this is to forget the tape and just bend the legs outward at a sharp parallel angle to the PCB. Thus holding them in place. Albeit a fair bit looser than with the tape)


C.) Flip the PCB over after a row has been seated and tapped-down.


D.) Take your Soldering iron, set to a temp somewhere between 380-410°C, and touch the tip to an area of a diode hole while also touching a leg of the protruding diode leg.

Give it 2-4sec to get hot and then slowly lead-in some soldering wire till a small conical shape of solder holds itself around the diode leg.

Be confident in doing this. You have extra diodes if you mess up. Hold, lead, Cone, Let-Go.

Tap +2-4sec Hold
Lead-In Solder
Watch for Small Conical “Dome”

(*Repeat for Rest of Seated Row)


E.) Take your flush-cutters and clip the excess diode legs off as close to the PCB as you can.

Average-Tip: Hold ends of legs before snipping or you will shoot them around your desk and floor and proceed to stab the hell out of yourself with a hypodermic needle-like metal rod. (Its like a game but literally awful!)

(*I also tend to go back over my clipped leg ends and re-flow the solder once more to clean up the snip area and make it less “sharp”. Not needed at all for functionality)


F.) Now you can turn the PCB over, peel off that tape and admire your handwork for at least 23sec.

AND REPEAT!

Note: There are 52 Total Diode Positions*
*There is an 87% chance you will miss one or forget to solder one and not notice till you get your entire build done, all the while wondering why its not working.


1.5 | Snack Break

This is the part where you go wash your hands and say hello to your fellow friendly neighbor from a comfortable 4meter distance. After you engage in some extremely uncomfortable eye-contact, shut your door as slow as physically possible and wash your hands again. Then go grab hand-full of baby carrots and a case of some nice cold Capri-Sun.

Enjoy yourself. You are an extraordinary individual.