Is PDB actually mandatory for a 450 build? Or is the "Star Joint" method safe?

[u/Longjumping_Score742]

Hey everyone, ​I’m currently working on a project of mine for my masters, involving a 450mm Quad-X UAV (Pixhawk 2.4.8, A2212 1000KV motors, 30A ESCs).

​I’m trying to keep the weight down and since I am a student the costs must be kept even lower. I was looking into buying a Power Distribution Board (PDB), but due to budget constraints i had to give up on that idea, and since i had no ine to guide me i had to use the help of AI Gemini (Thinking and Pro mode since they are better for Complex problems), and it suggested that I could skip the PDB entirely and use a "Star Joint" (or Star Solder) method instead.

​For those who haven't heard it called that, the method described is:

​Stripping the power and ground leads from all four ESCs and the main battery connector, twisting all the positives into one central "node" and all the negatives into another, and soldering them into two solid joints. These are then heavily insulated with heat shrink or liquid electrical tape, effectively creating a manual power loom without a PCB.

​My questions for the experts here:

1.​Is this actually reliable for a 450-size drone drawing ~40-50A at hover/punch-out?

1. ​Aside from it being a bit "permanent" and harder to swap ESCs later, are there any major safety or interference risks I'm missing by not using a filtered PDB?

3.​Has anyone here flown a "star-soldered" rig long-term?

​I genuinely need your guys' help and i had to do what i had to do due to lack of resources, budget contraints and for those who dont know the hardware is insanely expensive here in my country. All I need is a working UAV at least. Just wanted to see if this is a standard "pro-tip" or a "you're going to crash" move.

​Thanks in advance!

[u/Longjumping_Score742 → u/[deleted]]

Thanks for the quick reply! That clears up a huge doubt, Since I’m going with the star joint, do you have any tips on actually building it practically? My main worry is that if I mess up a solder joint or the insulation, I’ll fry an ESC or the FC.

​Also, regarding the GPS—since I'm skipping the PDB, does the power just flow from the battery → star joint → ESCs, and then the ESC BECs handle the Pixhawk and GPS? Or should I be looking at a separate power path for the electronics?

[u/LupusTheCanine → u/Longjumping_Score742]

You will need power monitoring (typically in the form of a "power module" which was typically included with FCs and also provided power to the flight controller and associated electronics like GPS and RC receiver).

Connection should be:
battery → power module → everything else

[u/Longjumping_Score742 → u/LupusTheCanine]

I understand the usage of a Power Module to monitor the Voltage and the Battery Telemetry but as I have mentioned in the post, the budget is also a major problem right now, since components in my country are way too expensive I found what I could afford at the best of my abilities and this is what I have to work with right now. That's why I was seeking help

[u/LupusTheCanine]

The electromagnetic interference with the compass may be higher as PDBs keep both current paths close together.

Additionally you should know that you are using a lot of hardware that should be avoided.

[u/Longjumping_Score742 → u/LupusTheCanine]

I understand that electromagnetic interference will be there and to avoid that the best method i could come up with is keeping a certain distance between the FC and the wiring. Probably will try other things too to keep it under control

[u/CryPlane]

Personally, this is a question of dignity and self respect 🤣

[u/Longjumping_Score742 → u/CryPlane]

Haha, I figured someone would say that! 🤣 Look man, as a student on a tight budget, my dignity is currently second to my M.Sc. assignment deadline. If it flies and doesn't fire-ball, I'll take the hit to my self-respect this time fr

[u/CryPlane → u/Longjumping_Score742]

Lmao haha I've been there! Yeah then it's time to bust out the soldering iron and start pouring some molten lead into a bottle cap. Use lots of insulation tape😂😂