Quark UBEC for my Neu 1515 1.5y/s brushless system ; 5A or 6A? which way should I go?

[BrianG]

Welcome to the forums!

First of all, you probably mean 5v or 6v (not amps), right?

Assuming so, 5v or 6v usually makes no difference, 6v just allows the servos to work at the max potential. Most of todays servos work fine at 6v (and some even higher). So, that's probably not as issue.

If the insulation actually melted, it usually means that the wires heated up a LOT, which tells me you are pulling more current than the wires are rated for the servo(s) you are using. More likely, the insulation simply wore down from rubbing on something until the wire touched the metal.

For up to 6s lipo, the Castle Creations UBEC would be a good choice. It will allow you to dial in whatever voltage you want and supplies a good amount of current. If you think you may go higher voltage in the future, the KoolFlight UBEC is a good choice. That one is good for up to 35v IIRC (8s lipo) and 3.5A. I've tested it and it provides a clean, noise-free output voltage (important for senstive receiver circuits) and stays cool even under heavy loads.

So, in short, your current battery voltage and BEC output voltage (5/6) probably was not a contributing factor in what happened to your Quark UBEC.