The L-shaped part.
Self milled from 2mm thick carbon fiber sheet.
Motors, ESCs, PDB, power connector total137gr – 35gr = 102gr
First flights without FPV, weight with battery 264gr:
Final setup with FPV capability, 230gr without battery and 302gr with 950mAh 3S battery. The FPV setup (camera + TX) added 32gr weight):
Really hard. Either the carbon fiber resonates or some motors are unbalanced. However with these PID values I got somehow decent full throttle:
I used betaflight with these new filters:
set gyro_cut_hz = 40
set pterm_cut_hz = 30
set dterm_cut_hz = 12
.. But returned back to defaults.
This is my version of a carbon 250 quad. It’s based on Hammer v 3.0 plans (big thanks!) but I have made some modifications that suit my taste.
The carbon pieces are self milled on 1.1mm carbide tool. 16.200rpm, 0.5mm layer, 210mm/min.
Each arm weights 10.1gr. Thickness 2.91mm. Modified from Hammer arms; removed that suddenly narrowing shape (weak point) and made it “evenly breakable”. They are still 100% compatible with the original Hammer design.
The two identical base body plates weighted 23,8gr each. They are 2mm thick carbon fiber.
Motivational assembly! 100gr total at this point.
PDB is a good plus but one can solder the leads together
Props: 5″ 2-blade, for example: http://www.banggood.com/2-Pairs-Gemfan-5030-Fiberglass-Nylon-Propeller-For-250mm-Quadcopter-CWCCW-p-976118.html?rmmds=search
Battery: 850-1000mAh 2S
Quick FPV-addon (cam+video tx) : http://www.banggood.com/FX-FX798T-5_8G-600TVL-25mW-40CH-Mini-Transmitter-Camera-Combo-For-FPV-Multicopter-p-1053038.html?rmmds=search REMEMBER TO PROTECT THE ANTENNA!
Goggles for FPV: https://hobbyking.com/en_us/quanum-cyclops-v2-fpv-goggle.html
All body parts: 16.1gr
6.5mm birch plywood. Flying weight 245gr. Without battery 163gr.
H: 223mm x W: 186
From front motor to back motor: 202mm
Tail servo-bay assembly: