My first quad: HMB-235 Buildlog – Building part 1

Buildlog, Multirotor, RC

The first for the HMB-235 parts have arrived, so it’s time to start building! Not all parts have arrived yet, but I should be able to get the most important parts working.

The first order of business was to dry-fit the motor’s, ESC’s and PDB to figure out the best placement for all of them. Since there is only limited space between the baseplate and topplate, I decided I wanted the ESC’s on the arms, this will mean a bigger risk of damaging them in crash, but I needed the space inside the frame and it will also provide some extra airflow for cooling them. Most of the existing wires on the ESC’s were long enough, but I needed to lengthen 2 wires on the rear ones to be able to make it to the PDB. I did consider putting all new wires on all ESC’s so I could route them better and more neatly, but I didn’t want to destroy my ESC’s with my poor soldering skills 😉

Next up in line was the FC, I opted for 90 degree pin headers inwards over the board to install the ESC signal wires to keep the build somewhat tidy and still be able to swap out ESC’s relatively easy.

One nice thing about the SPRacing F3 board is that most connections are done with JST-SH connectors, so that means a lot less soldering and eass of swapping out components. The cables look a bit unwieldy, but you can pop out the unused wires and make for a relatively clean build.


Offcourse, no build is without problems, and unfortunatelythis one was no exception. As you might know, electric equipment works on magic smoke, and once you let it escape from a component, it’s dead.
As you might have spotted from the pictires, 1 ESC is missing. I let out the magic smoke out of it, and the story turns out to be true. No more smoke, component dead. Rest In Peace ESC, you served me well for the 10 seconds you worked. The exact cause of the failure is unknown to me, but I suspect I accidentally overheated the ESC or bridged some contacts while soldering. Of course I made the mistake to not order a spare ESC, so the build had to continue with only 3 of them for now.

A little cable management later it was time to see if the top would still fit, and it did! It’s already starting to look like a real quad now!


Time to order some extra ESC’s so I can continue!