These are the fully 3D printed T4 (quadcopter), Mini T4 (quadcopter), and T6 (coaxial hexacopter) designs I've posted on Thingiverse.com (aside: "T" is for Tubular). The comments section on Thingiverse doesn't provide a great place for discussing designs so I've created this topic here instead.
These designs are based on a tubular arm with a vertical "I" beam running down the centre. This design seems to be very strong and rigid and all of these designs are very stable in flight.
Other common features include:
- motor wiring is routed through the arms and down into an enclosed (ventilated) power and ESC tray.
- batteries are located in the centre of rotation (T6 is designed for dual batteries).
- bevelled cable "tunnels" provide a way to route cables between the power tray and top plate.
- Top plate is designed for Pixhawk or APM flight controllers with elevated GPS.
- Bottom tray has mounting points for a Tarot Gimbal.
- Optional long and short legs include "springy" feet. The legs are designed so the 3D printed threads "wrap around" the arms which makes them quite strong for their length.
- Sketchup files are included so folks can modify both designs to suit their needs.
I figure I've put hundreds of hours into these designs with prototypes and drawing time. I'd love to get feedback from anyone who makes one. Together we can improve these designs for everyone's benefit.
Replies
well i did get it to work, but now the problem is the motors will not spin till the stick is at 50% power. then they spin... is their any setup in the qbrain i have to change?
Hi Glenn. Sorry for not replying to your earlier post - busy at work today (and on a public holiday too!). To be honest I don't remember how I calibrated the QBrain but I think it was via the Pixhawk. The APM is slightly easier as you don't need to worry about pressing the safety button.
I assume you followed the all-at-once calibration instructions on the Wiki? Do you have a PWM RC receiver? If so you could try plugging the throttle channel straight into the # 1 ESC on the QBrain and see if you get the same 50% behaviour. If so, perhaps just try calibrating the #1 ESC by itself first?
ya i did follow the all at once. but i will try with it plug into channel 1. i know my 3dr frame with APM 1.0 is different but i cam spin the motors at slow speed. Oh i just did a re-calibration and after calibration i can move the stick up and the motors spin...but if i arm the APM then it will not spin till 50%
So only a problem through APM? How does the radio calibration look in Mission Planner? Is APM seeing the bottom half of the throttle channel movement? What firmware version are you running?
no what i was saying was if i do a all at once calibration, it works. and then move the stick up and the motor spin. bet then after i power down the quad. power back up, that is when i have to be above 50%. Hmm but i am looking. Oh firmware is 3.15
Well i did a complete reset of my APM 2.5... and that did fix it. i will get some pictures up on here. thanks for all your help Brendan, and a great Quad...
Yep, so when you do the full throttle / toggle power then the APM starts passing throttle directly through to the ESCs so you can calibrate them. Everything stays that way until you toggle power again at which point the APM takes control of the ESC signal again ...which sounds like when your problems start. Hence the comment about checking the radio calibration screen in Mission Planner.
ya in the radio calibration screen the throttle does not kick in till i get to 1544. the stick reading is 1124 and stick all up is 1912. and this is on a APM 2.5 with the qbrain.
ya i am going to try this APM in my 3dr X frame and see what happens.... But thanks for all your help. you did help a lot.
I'm not sure I completely understand. Are the Min/Max values in the radio calibration screen set properly?
Also what flight mode are you in? Stabilise? Just a random thought but obviously the Alt-hold kind of modes not kick in until you get above half throttle.