Makerfire 200A Upgraded Watt Meter with Longer Wire, High Precision Power Analyzer Battery Testers Voltage Amp Consumption Performance Monitor with LCD Backlight Screen for RC,Solar,Wind Power,Ebike

You mention "scale" but didn't the Mustang swing a 4-blade prop? Edit: An inexpensive watt meter like the one below will save you time and money in keeping your motors and ESCs from burning up. Definitely recommended if you're experimenting with prop/motor combinations. https://a.co/d/0ewDA7Lb