### T-motor specs

Hi

I have been looking at specs posted by t-motors on the 300KV motors:

Lets assume a model mass of 3kg(1.2kg of batteries the rest dedicated to the chassis, motors and controllers) on a quad, this is 0.75kg per a motor or 750grams of thrust to sustain hover. A logical approach would be to find the highest efficiency(Thrust/power) for the given hover mass. Doing a visual interpolation of the table(:)---->always wanted to say that) the DJI 15X5.5 would be the most efficient to sustain this mass at hover. In theory does this mean at roughly 60 watts(yes great visual interpolation), using V=P/I, I Will be able to use a 22.2v LIPO with capacity of 12000mah for 1hr? Surely this logic is flawed?

In my personal capacity I have run many motors on a rig that I have developed and this logic baffles me unless t-motors have hit gold.

#### Replies

• You are correct the mass of the batteries were under estimated. I wonder what the break even point is currently.....i.e. (when adding more batteries(mass) to achieve a better flight time become negated by the payload(batteries))

• Using MotoCalc ,  the thrust & power consumption values do seem to come very close the specs. in the table using an APC 14 x 4.7 propeller ( There is no DJI prop in the MotoCalc database)

However, a 6-cell battery (or batteries)  totalling 12000mAh in capacity would weigh about 2 Kg.

So now the total all-up-weight is more like 4 Kg, and each of the four motors needs to provide 1Kg of thrust, and the amperage increases from 3 to 5 Amps each (about 110 watts),  reducing the flight time to about 35 minutes (+/- 3 minutes)

The motors weigh 205 grams, the T-40 ESC's are 35g each, totalling 960 grams not including propellers or prop adapters.

My number crunching was not scientifically rigorous, but its good to first approximation or(10%).

Chris

This reply was deleted.

### Activity

DIY Robocars via Twitter
RT @chr1sa: Donkeycar 4.4 released with tons of new features, including path learning (useful with GPS outdoors), better Web and Lidar supp…
Nov 27, 2022
DIY Robocars via Twitter
RT @NXP: We are already biting our nails in anticipation of the #NXPCupEMEA challenge! 😉 Did you know there are great cash prizes to be won…
Nov 24, 2022
DIY Robocars via Twitter
RT @gclue_akira: レースまであと3日。今回のコースは激ムズかも。あと一歩 #jetracer https://t.co/GKcEjImQ3t
Nov 24, 2022
DIY Robocars via Twitter
UC Berkeley's DIY robocar program https://roar.berkeley.edu/
Nov 24, 2022
DIY Robocars via Twitter
RT @chr1sa: The next @DIYRobocars autonomous car race at @circuitlaunch will be on Sat, Dec 10. Thrills, spills and a Brazilian BBQ. Fun…
Nov 24, 2022
DIY Robocars via Twitter
RT @arthiak_tc: Donkey car platform ... Still training uses behavioral cloning #TCXpo #diyrobocar @OttawaAVGroup https://t.co/PHBYwlFlnE
Nov 20, 2022
DIY Robocars via Twitter
RT @emurmur77: Points for style. @donkeycar racing in @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video. https://t.co/Y2hMyj1…
Nov 20, 2022
DIY Robocars via Twitter
RT @SmallpixelCar: Going to @diyrobocars race at @UCSDJacobs https://t.co/Rrf9vDJ8TJ
Nov 8, 2022
DIY Robocars via Twitter
RT @SmallpixelCar: Race @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video. https://t.co/kK686Hb9Ej
Nov 8, 2022
DIY Robocars via Twitter
RT @PiWarsRobotics: Presenting: the Hacky Racers Robotic Racing Series in collaboration with #PiWars. Find out more and register your inter…
Oct 23, 2022
DIY Robocars via Twitter
RT @Hacky_Racers: There will be three classes at this event: A4, A2, and Hacky Racer! A4 and A2 are based around UK paper sizing and existi…
Oct 23, 2022
DIY Robocars via Twitter
Oct 19, 2022
DIY Robocars via Twitter
RT @NeaveEng: Calling all UK based folks interested in @diyrobocars, @f1tenth, @donkey_car, and similar robot racing competitions! @hacky_r…
Oct 13, 2022
DIY Robocars via Twitter
RT @araffin2: 🏎️ After hours of video editing, I'm happy to share a best of my Twitch videos on learning to race with RL. 🏎️ Each part is…
Oct 13, 2022