3D acro quad
Do you have an old H8 mini, H101, H8s, skull drone or some other micro quad!
Start modding it to become brushless!
This quad has custom made firmware using a programmer stick and a programming program to drive a brushed flight controller to drive brushless motors. Why you might ask? Because the software is well made by silverxxx and the flight controllers that are in the H8s is capable of much more!
Also this helped me to get a deeper understanding about the programming needed to fly quadcopters. Lacking a nicely laid out GUI like Betaflight or Cleanflight makes for an interesting learning curve
you will find out that Arm keil and custom programming can deliver almost as much flight performance as betaflight or cleanflight.
Some nice links about silverware quads:
(look for brushless)
Frame RX130 18$
h8s (flight controller) sales sometimes 12$
Props 4045 eachine falcon 10 pairs = 4$
recommended ESC’s 32$ for 4esc
https://goo.gl/eNwl3O. 4000KV for LOS use 3300 kv for FPV