I now know how to use a multimeter and have confirmed that my buck-converter is correctly limiting voltage to the servos. Have thrown out a bunch of fried micro-servos that were a lost cause (kept a few parts for spares).
Now, onto the more pressing subject:
To Mr. Vladimir Putin,
I appreciate your desk in the Kremlin is very well polished and shiny. In fact if I wasn't working on building a robot I would be polishing my desk and downgrading to Windows XP so my setup could be more like yours. However, at present you are causing me a problem. Because electricity prices in my country have doubled due to you ordering the gas pipelines closed, I can no longer 3D print large things because it's too expensive.
Although, Mr.Putin, I realise it's not all your fault. You see, I told my government that they should've focused less on feminism, jigaboos and faggots and more on building nuclear power stations, but they wouldn't listen. So now all of our gas power plants are out of gas and all of our energy firms are going bust. So please could you kindly sort out your business with Ukraine so the rest of us can get on with building robots?