Draupnir 200pcs 3D Printing Brass Nuts, M3 Threaded Insert, Female Thread Knurled Heat Embedment Nut,Knurled Brass Nuts for 3D Printing Parts Automotive Plastic Shell(M3x4x5mm)

Hello. I have and have used both of those. RRC+ is more reliable and has reverse polarity protection. If the battery is backwards it won’t fry. I have fried a quark like they. Coincidentally. On the missile works downloads page it has the RRC3 manual. On the last page it gives the equation for determining altitude. ABS is fine. I use PETG for mine. Make sure to get the brass nuts for the nylon screws to press into the filament for a good https://a.co/d/3SjmQrb like these. I add some super glue as well. By all means still use the quark. But eggtimer now also has quantums that are pre soldered 90% that makes things super easy. And it records the flight data as well. Good luck!