The second iteration of our micro long range frame, the Shinobi Mk2 shifts focus to durability while still managing to maintain flight times. As with the Mk1, the current design continues to be based around a 4S 1100mAh lightweight lipo spinning 4-inch bi-blades on low KV 1404 motors. For cinematic capabilities, many iterations were undertaken to ensure that propellers remain out of view for most FPV and HD camera form factors.
With that said, I opted to double down on the frame’s cinematic capabilities by designing a short range cinematic loadout making use of the HDZero Runcam Micro camera and the HDZero TX5S.1 VTX with a whoop form factor rather than a typical micro long range. Significant advances in HDZero’s system coupled with the larger sensor of the HDZero Runcam provide for reasonably impressive footage.
Click here to see a more traditional analog, micro long range build at the end of this article.
In addition to the build itself, we’ll be looking at the tuning and filtering strategy as well as a weight analysis so you can have a better idea of how to approach your own sub-250g build.
Although the Mk2 version of the Shinobi still comprises primarily of a unibody design, a brace plate was incorporated to significantly enhance rigidity and camera protection as well as provide a mechanism to secure a bottom-slung lipo. Note the proper orientation of the brace plate and main plate.
I’m always partial to adding LEDs to all of my builds as much for the practical purpose of assisting in crash retrieval as straight-up bling factor. These are Tiny’s LEDs Femto 8 and weigh 1.2g with harness. Very bright and very worth it.
And yet another build with a Flywoo Goku GN745 F7 AIO. At this point, you would think I was sponsored by Flywoo. Ahem.
Widely used by FPV hobbyists, MG Chemicals (422C) silicone conformal coating also comes in a UV sensitive version which will illuminate under UV-A light (black light) to easily identify areas which are not coated.
A 35V 330uf capacitor at the lipo has proven sufficient to mitigate noise for this 4S build. Be sure to use only good quality low-ESR capacitors from proven brands like Nichicon or Rubycon. I am using 16AWG silicone wires for the lipo harness measuring approximately 2-1/2 inches.
It is also highly recommended to use a capacitor with the HDZero digital FPV system as it can be susceptible to voltage spikes.
Rather than the low KV 1404s I typically use on micro long range frames, this one will be kitted with BetaFPV 1505 3600KV‘s. Since this is not meant for long range, I decided the extra power would allow for some cinematic acro and speed as needed.
A rear stack plate secures the TBS Crossfire Nano RX. A full-size TBS Immortal T antenna is tail mounted with a TPU mount. This is not the optimal antenna placement both in terms of the active and ground elements being so close to the carbon fiber as well as the flexibility of the long TPU mount contributing to gyro noise … but c’mon man, it’s meant to be a short range cruiser. Life’s too short.
Click here to download STL files for 3D printed parts designed for the Shinobi Mk2.
The HDZero TX5S.1 VTX with its whoop form factor really lends itself well to sub-250g builds.
In contrast to the Mk1’s 20mm camera cage clearance, the Mk2 tightens that tolerance to 19.3mm providing far more secure mounting without the needed for excessive spacers. The 0.3mm buffer is there since FPV cameras are rarely exactly 19mm wide.
The release of the HDZero Runcam Micro camera significantly upped the game in terms of the video quality the system is now capable of producing. So much so that it was the impetus for my building this as a short range cinematic.
The VTX antenna is a TrueRC OCP with a direct U.fl connection to minimize signal loss and secured with a dab of hot glue.
While bottom-slung lipos are traditionally used for long-range builds to provide antenna clearance, I’m opting for top mounting since I plan to use this build for short range. Unlike the Mk1 series, the Mk2 provides for a bottom-slung option.
AUW with a Pyrodrone 4S 75C 700mAh lipo with an XT30 connector is 249g.
While this is hardly a lightweight micro long range build, it was never meant to be one. It was meant to be a cinematic short range cruiser with the some acro ability.
It is recommended to use the following custom motor mix in light of the deadcat configuration of the Shinobi Mk2. For reference, the motor-to-motor measurements are as follows:
The build is very capable of what some might consider a fairly aggressive filtering strategy relying primarily on RPM and Dynamic Filtering. If you have a clean noise profile, your build should be able to handle this filtering without issue. In this build, I am experiencing some low frequency noise likely due to the Immortal T tail mount which had to be elongated to clear the rear, swept-back deadcat arms.
However, despite minimal filtering, we can still achieve fairly clean gyro traces.
This clean noise profile was achieved using minimal filtering. As mentioned, this strategy relies primarily on RPM and Dynamic Filtering. If your ESCs are BLHeli_S, you can use third party firmware to allow for RPM Filtering or compensate with additional notch filtering. Ultimately, you can enable sliders and incrementally reduce filtering to its optimal level (be sure to check motor operating temperatures often).
Based on the filtering, the following PIDs and Feed Forward settings were used.
Weight Analysis
The following highlights the top five components that make up the 249g AUW. It becomes fairly evident that the lipo, motors, and frame make up a significant proportion of the total. Note that the 3rd heaviest component (the frame) comprises 20% of the total while the 4th (the flight controller) comprises a mere 3%. This accentuates the fact that any major trade-offs typically involve a give and take between battery size and motor size. (You can hover over the chart components for details.)
The following chart sorts all of the components by weight.
Of note, wiring and solder can accounted for 6% (6.1g); PLA landing skids 2% (5.2g); and TPU antenna mounts 1% (2.4g). It in the details where one gram here and one gram there can really add up to remain sub-250g.
Micro Long Range Build
The following is a more traditional analog, micro long range build. It makes use of a bottom-slung lipo for optimal antenna clearance with a properly oriented Immortal T antenna.
A lightweight Caddx Baby Turtle HD split camera in whoop form factor provides both the FPV feed and 1080P 60FPS footage.
A tail mounted Matek M8Q-5883 GPS module provides fairly quick and reliable satellite lock. It’s a bit heavier than some other modules but the performance is really unparalleled.
Note that the Kuwagata lipo pad can also be trimmed and used to provide traction for a bottom-slung lipo.
The AUW for this analog, micro long range build with the GNB 1100mAh 4S lipo is 247g.
The aim of the second iteration of the Shinobi was to expand the durability and versatility of the micro long range platform. The purpose of this log is to provide ideas and inspiration for you to come up with your own perfect setup.
73
All products mentioned and used in this build log were purchased at retail. All links to product websites are non-affiliate / non-commission and no solicitations were made by companies to the author to promote these products.
Shinobi Mk2 Build Log
Updated on February 15, 2022
The second iteration of our micro long range frame, the Shinobi Mk2 shifts focus to durability while still managing to maintain flight times. As with the Mk1, the current design continues to be based around a 4S 1100mAh lightweight lipo spinning 4-inch bi-blades on low KV 1404 motors. For cinematic capabilities, many iterations were undertaken to ensure that propellers remain out of view for most FPV and HD camera form factors.
With that said, I opted to double down on the frame’s cinematic capabilities by designing a short range cinematic loadout making use of the HDZero Runcam Micro camera and the HDZero TX5S.1 VTX with a whoop form factor rather than a typical micro long range. Significant advances in HDZero’s system coupled with the larger sensor of the HDZero Runcam provide for reasonably impressive footage.
In addition to the build itself, we’ll be looking at the tuning and filtering strategy as well as a weight analysis so you can have a better idea of how to approach your own sub-250g build.
Build Log
Although the Mk2 version of the Shinobi still comprises primarily of a unibody design, a brace plate was incorporated to significantly enhance rigidity and camera protection as well as provide a mechanism to secure a bottom-slung lipo. Note the proper orientation of the brace plate and main plate.
I’m always partial to adding LEDs to all of my builds as much for the practical purpose of assisting in crash retrieval as straight-up bling factor. These are Tiny’s LEDs Femto 8 and weigh 1.2g with harness. Very bright and very worth it.
And yet another build with a Flywoo Goku GN745 F7 AIO. At this point, you would think I was sponsored by Flywoo. Ahem.
A 35V 330uf capacitor at the lipo has proven sufficient to mitigate noise for this 4S build. Be sure to use only good quality low-ESR capacitors from proven brands like Nichicon or Rubycon. I am using 16AWG silicone wires for the lipo harness measuring approximately 2-1/2 inches.
It is also highly recommended to use a capacitor with the HDZero digital FPV system as it can be susceptible to voltage spikes.
Rather than the low KV 1404s I typically use on micro long range frames, this one will be kitted with BetaFPV 1505 3600KV‘s. Since this is not meant for long range, I decided the extra power would allow for some cinematic acro and speed as needed.
A rear stack plate secures the TBS Crossfire Nano RX. A full-size TBS Immortal T antenna is tail mounted with a TPU mount. This is not the optimal antenna placement both in terms of the active and ground elements being so close to the carbon fiber as well as the flexibility of the long TPU mount contributing to gyro noise … but c’mon man, it’s meant to be a short range cruiser. Life’s too short.
The HDZero TX5S.1 VTX with its whoop form factor really lends itself well to sub-250g builds.
In contrast to the Mk1’s 20mm camera cage clearance, the Mk2 tightens that tolerance to 19.3mm providing far more secure mounting without the needed for excessive spacers. The 0.3mm buffer is there since FPV cameras are rarely exactly 19mm wide.
The release of the HDZero Runcam Micro camera significantly upped the game in terms of the video quality the system is now capable of producing. So much so that it was the impetus for my building this as a short range cinematic.
The VTX antenna is a TrueRC OCP with a direct U.fl connection to minimize signal loss and secured with a dab of hot glue.
While bottom-slung lipos are traditionally used for long-range builds to provide antenna clearance, I’m opting for top mounting since I plan to use this build for short range. Unlike the Mk1 series, the Mk2 provides for a bottom-slung option.
AUW with a Pyrodrone 4S 75C 700mAh lipo with an XT30 connector is 249g.
While this is hardly a lightweight micro long range build, it was never meant to be one. It was meant to be a cinematic short range cruiser with the some acro ability.
Tuning & Filter Strategy
It is recommended to use the following custom motor mix in light of the deadcat configuration of the Shinobi Mk2. For reference, the motor-to-motor measurements are as follows:
MTM: 176.64mm
2-1 / 4-3: 106.68mm
3-1: 136.60mm
4-2: 145.10mm
The following custom motor mix was calculated using the Multi-Rotor Motor Mixing Calculator. Apply the custom motor mix through the CLI command line.
The build is very capable of what some might consider a fairly aggressive filtering strategy relying primarily on RPM and Dynamic Filtering. If you have a clean noise profile, your build should be able to handle this filtering without issue. In this build, I am experiencing some low frequency noise likely due to the Immortal T tail mount which had to be elongated to clear the rear, swept-back deadcat arms.
However, despite minimal filtering, we can still achieve fairly clean gyro traces.
This clean noise profile was achieved using minimal filtering. As mentioned, this strategy relies primarily on RPM and Dynamic Filtering. If your ESCs are BLHeli_S, you can use third party firmware to allow for RPM Filtering or compensate with additional notch filtering. Ultimately, you can enable sliders and incrementally reduce filtering to its optimal level (be sure to check motor operating temperatures often).
Based on the filtering, the following PIDs and Feed Forward settings were used.
Weight Analysis
The following highlights the top five components that make up the 249g AUW. It becomes fairly evident that the lipo, motors, and frame make up a significant proportion of the total. Note that the 3rd heaviest component (the frame) comprises 20% of the total while the 4th (the flight controller) comprises a mere 3%. This accentuates the fact that any major trade-offs typically involve a give and take between battery size and motor size. (You can hover over the chart components for details.)
The following chart sorts all of the components by weight.
Of note, wiring and solder can accounted for 6% (6.1g); PLA landing skids 2% (5.2g); and TPU antenna mounts 1% (2.4g). It in the details where one gram here and one gram there can really add up to remain sub-250g.
Micro Long Range Build
The following is a more traditional analog, micro long range build. It makes use of a bottom-slung lipo for optimal antenna clearance with a properly oriented Immortal T antenna.
The build is based around a lightweight GNB 1100mAh 4S lipo powering T-Motor F1404 2900KV motors spinning Gemfan Hurricane 4024 bi-blades.
A lightweight Caddx Baby Turtle HD split camera in whoop form factor provides both the FPV feed and 1080P 60FPS footage.
A tail mounted Matek M8Q-5883 GPS module provides fairly quick and reliable satellite lock. It’s a bit heavier than some other modules but the performance is really unparalleled.
Note that the Kuwagata lipo pad can also be trimmed and used to provide traction for a bottom-slung lipo.
The AUW for this analog, micro long range build with the GNB 1100mAh 4S lipo is 247g.
The aim of the second iteration of the Shinobi was to expand the durability and versatility of the micro long range platform. The purpose of this log is to provide ideas and inspiration for you to come up with your own perfect setup.
73