Also I like to ask if there are recommendations for connectors that can be mounted to a 3D printed case from 2 - 8 pins. Above I like SUB-D but perhaps there are some good alternatives also.
You are buying cheap stuff from Ali so cable quality may not be great .
Soldering direct to a PCB is not great, use header pins and connect to those , then use heat shrink to cover them and give more strength .
Practice your soldering and look at you tube vid.
Using connectors is your choice, choose something that gas the correct power rating ( same for cable !)
Silicone cables are easy enough to find. They are really meant for situations of high temperatures and high voltages. There's no real advantage when soldering other than not tending for the insulation to "roll back" when soldering.
You can solder directly to PCBs, but it can be problematic if movement is involved, leading to loose connections.
Headers are better and crimp types Molex KK, JST are secure for board to board. FFC connectors and cable as well.
Your case connector depends on usage. As @hammy says, power is a factor, protection level, indoor or outdoor use, how many "ways".
Circular connectors are always easier to cut. D-sub connectors for good retention, but there are plenty of locking connectors available. The audio DIN types cater for about 6 pins.
Cannon circular connectors up to 30, 40 ways.
That are good thoughts. I am soldering cables directly to PCB mostly if it is a simple setup like 4 I2C cables to avoid crimping the perfect connector cable. But it is only because I am being lazy to be honest…will change that.
But anyway, which isolation would be the best to avoid the “roll back”?
The common setup is an external sensor (e.g. 1-wire) connected to an ESP32, so nothing with high current. In most cases I use JST connectors soldered onto a board (https://github.com/NilsRo/HotWaterRecirculatingPump/raw/main/img/Case%20with%20components.JPG) but I like to have something that I can mount to the case without a PCB. Audio DIN type I have available but there are very large. The “cannon circular” looks great but seems little oversized for connecting sensors…as also D-sub as there are more pins available with shielding…
You can also avoid crimping by purchasing sets of JST headers/sockets and precrimped wires on amazon. They are pretty cheap and worth it in time savings.
When looking at connectors, be sure to note the ratings for the number of times they can be mated and disconnected. When I looked into the DB series of connectors, I think they gave a number of 50 times.
The last project for which I used silicone insulated wire inside a 3D printed case I used something like this {LINK}.
For connectors there are many possibilities. I like mini DIN or standard DIN connectors. You can get panel mount or PCB mount. One can also get assembled cables.
clamp the socket firmly in a small vice so it will be steady while doing the soldering.
I like mating the M/F connectors together then go thru the same process that you do.
This makes sure the pins stay properly oriented while soldering the pins.
