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The project involves lighting a simple LED from a Raspberry Pi, and I am planning on ditching the breadboard and soldering parts directly onto to each other. For instance: 3.3v pin - LED positive leg resistor - LED negative leg - ground header pin
I am considering the health of the wires if I directly solder them together without a breadboard. Will they be damaged easily and shall I invest in heat shrink to cover the soldered parts?
Soldering resistors and LEDs using wires (aka flying leads) is very commonplace. Heatshrink is best for insulating them and providing a strain relief, the latter is especially important where vibration is an issue. Otherwise the joints will flex and work-harden, become brittle and eventually break.
Breadboards are a tool to allow for rapid prototyping without semi-permanent applications like crimping or soldering. They are not required.
Jumper wire, which is typically 20-24 AWG wire, is ideal for small current applications like a single led.
Depending on how you mount that led, you should consider heat shrink or any other type of non-conductive covering. Tape works. Hot Glue works fine. If you mount the led in a panel or hole of some type, so it doesn't flop around, then you really don't need to insulate the leads, but it still helps.
Heat shrink or other insulators do help improve the mechanical strength of bare wire. Solid wire is stronger, but more brittle than stranded wire. Even with heat shrink on, solid wire will break at the bend point if you bend it too much (metal fatigue), while stranded wire will last longer (but will break eventually too). Heat Shrink makes both last longer.
If the wire is stranded, provide some kind of strain relief or ensure both ends are mounted rigidly. Soldered stranded wire will be likely to break at the end of the soldered region if it is flexed repeatedly.
Heat shrink is a fine way to insulate the soldered joints, and can help with the strain relief.
Also, make sure your soldering tools and technique are efficient, so that you do not apply heat so long that the wire insulation melts away from the hot wire. (This is not harmful in itself; it just means the wire is less insulated than you intended.) Use flux, and tin the wires before attempting to make the joint.
Soldering wires can be trickier than soldering through-hole PCB mounted parts because there is nothing firmly holding the two wires in the position you want. (At least, I find it so; some make it look easy.)
The answer is yes. Circuits can be soldered together with only components or on copper breadboards (solid plane with cuts or the kind with through holes). One is only limited by ones creativity. In fact this is one of the best prototyping methods because by making a direct connection you are reducing parasitic effects. (jumper breadboards have lots of stray capacitance and connection resistance) By soldering directly these can be eliminated
Jim Williams who was the lead engineer of one of the leading manufacturers of IC's uses this method to prototype circuits extensively. Shown here and here So put that soldering iron to good use, make good clean prototypes and use copper plated breadboards instead of lossy breadboards with jumpers.
Yes. Breadboards are for prototyping and testing, so you don't have to solder and resolder Everytime you want to change the circuitry.
As for the health of the wires, I wouldn't worry. As long as you use decent quality materials and solder correctly you'll be fine.
But of course you'll still want to insulate them if you can. Bare wires are an accident waiting to happen
