Dumpster Jedi
The One Who Speaks
Greetings and salutations good people of the internet! I am the Dumpster Jedi... self-proclaimed artist, philo-sophisor, engineer, cynic, member of the general public, friend to children and small animals, regular tax-paying ninja and all-around state-of-the-badass-art super-cool guy.
Yes, nine hyphens.
Anyhoo, I have sauntered into your little corner of the webbernets tonight to introduce myself, and being a new pilot and fan of Flite Test, I figured this would be the ideal place to show off my quad and discuss my build process and what I've learned along the way. I recommend grabbing a tasty beverage at this point, as I am liable to ramble on for a while.
After becoming infatuated with multicopters and all things RC over the past year I finally bit the bullet and after quite a bit of research, I dove in head first.
Two weeks ago:
The Goods:
X525 Frame
4x Aluminum Motor Mounts
4x Multistar 935kv motors
4x 20A Afro ESCs
KK 2.1 Flight Contoller w/ LED
XT60 -> 6x 3.5mm Battery Harness
5x 10cm Male-to-Male Servo Leads
1m Green LED strip
3s Balance plug -> 4x JST
Flight Gear:
Turnigy 6XS 2.4 Ghz Tx w/ XR7000s Rx
2x 3000mah 3s Zippy Flightmax
For my first build, it went quite well. Everything worked as it should, and aside from some instability due to tuning issues (PI gains set way too low), it flew decently.
It also crashed quite well, me being a new pilot and all.
The first casualty was a broken landing skid plate, no big deal. Next was a motor mount, bending the two fore booms in the process. Two more landing skids broke on that crash as well. I bolted the motor mount down through one of the holes, bent it back into shape best I could, patched the landing gear (zip ties are your friend), and finally managed to get it stuck in the top of a very tall tree.
I got it down with a bit of thrashing about with the throttle and aileron/elevator, ripping my admittedly shoddy LED wiring loose and breaking four props in the process.
It was at this point I officially declared my backyard aeronautics program grounded. I collected my observations about the weaknesses in my prototype design, and set about developing solutions. My observations on this hardware configuration are as thus:
1. The X525 is too large for my liking given my level of experience. The actual motor-to-motor distance on this frame is 600mm, and with 10x4.5 props, it is quite the lumbering beast.
2. The folding capability of this frame negatively affects how stiff the center assembly is and how well the booms stay in position. Constant adjustment is required to maintain alignment, no matter how tight the bolts are.
3. The fiberglass motor mounts included with the X525 have a fundamental design flaw in that the tip of each protrudes just beyond the end of the landing gear, and contacting the ground at even a slight deviation to the horizontal places these directly in harm's way. Leverage, man.
4. While the sprung landing gear is a neat concept, in practice it doesn't hold up terribly well, and with weight not being a concern at this point, the job can be done with less hardware.
5. With the LEDs mounted to the sides of the fore booms, they are not visible enough from below to effectively assist orientation. The do look damn cool, though.
So I set about implementing changes to the frame that will address these concerns. First, I removed 5cm from the end of each boom (doing away with the bent portions) and re-drilled the holes to mount them to the frame plates. I ordered the aluminum motor mounts from eBay and they are a perfect fit and lack the protrusion that so doomed their predecessors while being intrinsically stronger at the same relative mass. I rotated the top plate 90 degrees to offset the curved slots, effectively locking the booms in place. I repurposed parts from the landing gear to raise the secondary upper plate, offering a bit of protection to the FC board. LEDs have now been mounted to the bottom of the fore booms, where they should be able to better serve their purpose.
The end result, this being the fifth overall rebuild:
The quad now measures 500mm motor-to-motor, and with the plate rotation, the frame is very stiff with no play in the boom joints at all. Overall, I am very satisfied with the modifications I have made. Unfortunately, in my eagerness to perform a test flight, I neglected to tighten my prop nuts adequately, and lost one. It flew beautifully for a moment, but I will have to wait until tomorrow to procure a suitable replacement and fully test the aircraft.
I hope you enjoyed my process, and perhaps what I've learned here can be of use to other aspiring pilots. I look forward to discussing my build, so please offer advice and comments at will.
Yes, nine hyphens.
Anyhoo, I have sauntered into your little corner of the webbernets tonight to introduce myself, and being a new pilot and fan of Flite Test, I figured this would be the ideal place to show off my quad and discuss my build process and what I've learned along the way. I recommend grabbing a tasty beverage at this point, as I am liable to ramble on for a while.
After becoming infatuated with multicopters and all things RC over the past year I finally bit the bullet and after quite a bit of research, I dove in head first.
Two weeks ago:
The Goods:
X525 Frame
4x Aluminum Motor Mounts
4x Multistar 935kv motors
4x 20A Afro ESCs
KK 2.1 Flight Contoller w/ LED
XT60 -> 6x 3.5mm Battery Harness
5x 10cm Male-to-Male Servo Leads
1m Green LED strip
3s Balance plug -> 4x JST
Flight Gear:
Turnigy 6XS 2.4 Ghz Tx w/ XR7000s Rx
2x 3000mah 3s Zippy Flightmax
For my first build, it went quite well. Everything worked as it should, and aside from some instability due to tuning issues (PI gains set way too low), it flew decently.
It also crashed quite well, me being a new pilot and all.
The first casualty was a broken landing skid plate, no big deal. Next was a motor mount, bending the two fore booms in the process. Two more landing skids broke on that crash as well. I bolted the motor mount down through one of the holes, bent it back into shape best I could, patched the landing gear (zip ties are your friend), and finally managed to get it stuck in the top of a very tall tree.
I got it down with a bit of thrashing about with the throttle and aileron/elevator, ripping my admittedly shoddy LED wiring loose and breaking four props in the process.
It was at this point I officially declared my backyard aeronautics program grounded. I collected my observations about the weaknesses in my prototype design, and set about developing solutions. My observations on this hardware configuration are as thus:
1. The X525 is too large for my liking given my level of experience. The actual motor-to-motor distance on this frame is 600mm, and with 10x4.5 props, it is quite the lumbering beast.
2. The folding capability of this frame negatively affects how stiff the center assembly is and how well the booms stay in position. Constant adjustment is required to maintain alignment, no matter how tight the bolts are.
3. The fiberglass motor mounts included with the X525 have a fundamental design flaw in that the tip of each protrudes just beyond the end of the landing gear, and contacting the ground at even a slight deviation to the horizontal places these directly in harm's way. Leverage, man.
4. While the sprung landing gear is a neat concept, in practice it doesn't hold up terribly well, and with weight not being a concern at this point, the job can be done with less hardware.
5. With the LEDs mounted to the sides of the fore booms, they are not visible enough from below to effectively assist orientation. The do look damn cool, though.
So I set about implementing changes to the frame that will address these concerns. First, I removed 5cm from the end of each boom (doing away with the bent portions) and re-drilled the holes to mount them to the frame plates. I ordered the aluminum motor mounts from eBay and they are a perfect fit and lack the protrusion that so doomed their predecessors while being intrinsically stronger at the same relative mass. I rotated the top plate 90 degrees to offset the curved slots, effectively locking the booms in place. I repurposed parts from the landing gear to raise the secondary upper plate, offering a bit of protection to the FC board. LEDs have now been mounted to the bottom of the fore booms, where they should be able to better serve their purpose.
The end result, this being the fifth overall rebuild:
The quad now measures 500mm motor-to-motor, and with the plate rotation, the frame is very stiff with no play in the boom joints at all. Overall, I am very satisfied with the modifications I have made. Unfortunately, in my eagerness to perform a test flight, I neglected to tighten my prop nuts adequately, and lost one. It flew beautifully for a moment, but I will have to wait until tomorrow to procure a suitable replacement and fully test the aircraft.
I hope you enjoyed my process, and perhaps what I've learned here can be of use to other aspiring pilots. I look forward to discussing my build, so please offer advice and comments at will.
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