This build takes advantage of the Ashigaru Mk2‘s 2.5mm main plate which is thicker than the standard 2mm of most 2.5″ frames. Namely, I’ve opted for beefier 1204 motors rather than the 1103’s typical of the size class and powered by a 3S 450mAh lipo. My goal is a nimble little basher capable of carrying an Insta360 Go v1 (approx 20g). Without the Go v1 and with the 3S 450mAh, the build is 139g AUW clocking just over 4 minutes of hard ripping. With the Go v1, it is a hefty 160g with just over 3 minutes of hard but heavy flying. I am anxiously waiting for the new Runcam Thumb 1080P 60FPS action camera which at less than 10g would be perfect for this build. The build is equipped with the HDZero digital FPV system and Runcam HDZero Nano.
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.
The Ashigaru Mk2 is built upon of a solid 2.5mm thick main plate. Note the proper orientation of the main plate.
Both in an effort to save weight as well as to accommodate the tight space, I oped to direct wire all the components rather than using connectors. (The single power harness connector off the lipo is in anticipation of the Runcam Thumb action camera.)
The Flywoo Goku GN745 F7 AIO flight controller with 40A BLHeli_32 ESCs rated for 2-6S is overkill for this build but they are my favorite FC and I stocked up on them as prices spiked from the chip shortage. So … #winning.
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.
As mentioned, I opted for bigger 1204 motors rather than the typical 1103’s used on 2.5″ builds. I went with RCInpower 1204 5000KV motors.
A 35V 330uf capacitor at the lipo is probably overkill for a 3S power system and will likely swap them out to 25V. I recommend low-ESR capacitors from Nichicon or Rubycon. I am using 18AWG silicone wires for the lipo harness measuring approximately 3 inches to reach around the back since there is little room on the sides.
It is also highly recommended to use a capacitor with the HDZero digital FPV system as it can be susceptible to voltage spikes.
The TBS Crossfire Nano RX is 3M-taped to the rear behind the main stack. Although there are no mounting holes for a rear stack to save weight, there is room to secure smaller components.
I am using an FPVCycle Minimortal T Antenna and minimalist TPU mounting to save weight. After some testing, I’ve found even 250mw will get me to the edges of my usual freestyle fly spot without LQ dipping dangerously low. I’m particularly confident at 500mw.
Click here to download STL files for 3D printed parts designed for the Ashigaru Mk2.
The HDZero TX5S.1 (whoop style) VTX has proven to be a very effective light-weight digital FPV solution.
I’m using the Runcam HDZero nano camera.
The Foxeer Lollipop Micro 5.8GHz RHCP antenna is a direct U.fl connection to the VTX minimizing signal loss as well as weight. A dab of hot glue helps to secure the U.fl connection. I would caution that the VTX is very capable of melting that hot glue if left on the bench at an active power level.
The following clean gyro_scaled traces for pitch and roll reflect the expected rigidity from a micro solid body frame.
After filters, the noise profile for the build is very clean.
As such, we can use filtering to achieve a pristine noise profile. Note that this filtering 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).
In my own experience, smaller micros tend to be tougher to PID tune than larger builds. In this case, I ran into an issue where despite what the blackbox traces suggested, using D Min and feed forward just felt off in the flight characteristics to me. So I decided to go by what I was feeling in flight rather than the maths and these are the PIDs I settled on.
Weight Analysis
The following highlights the top five components that make up the 139g AUW (with 4S 450mAh lipo but without the Insta360 Go v1). As is the case with most of these builds, the lipo and the motors make up nearly half the weight or 47% in this particular build. The frame makes up 16% of the AUW and is the third heaviest component. The take-away here is that the choice of battery and motor sizes significantly informs the AUW. (You can hover over the chart components for details.)
The following chart sorts all of the components by weight.
The Ashigaru Mk2 is designed to be a micro basher capable of carrying lighter HD action cameras. 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.
Ashigaru Mk2 Build Log
Updated on February 21, 2022
This build takes advantage of the Ashigaru Mk2‘s 2.5mm main plate which is thicker than the standard 2mm of most 2.5″ frames. Namely, I’ve opted for beefier 1204 motors rather than the 1103’s typical of the size class and powered by a 3S 450mAh lipo. My goal is a nimble little basher capable of carrying an Insta360 Go v1 (approx 20g). Without the Go v1 and with the 3S 450mAh, the build is 139g AUW clocking just over 4 minutes of hard ripping. With the Go v1, it is a hefty 160g with just over 3 minutes of hard but heavy flying. I am anxiously waiting for the new Runcam Thumb 1080P 60FPS action camera which at less than 10g would be perfect for this build. The build is equipped with the HDZero digital FPV system and Runcam HDZero Nano.
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
The Ashigaru Mk2 is built upon of a solid 2.5mm thick main plate. Note the proper orientation of the main plate.
Both in an effort to save weight as well as to accommodate the tight space, I oped to direct wire all the components rather than using connectors. (The single power harness connector off the lipo is in anticipation of the Runcam Thumb action camera.)
The Flywoo Goku GN745 F7 AIO flight controller with 40A BLHeli_32 ESCs rated for 2-6S is overkill for this build but they are my favorite FC and I stocked up on them as prices spiked from the chip shortage. So … #winning.
As mentioned, I opted for bigger 1204 motors rather than the typical 1103’s used on 2.5″ builds. I went with RCInpower 1204 5000KV motors.
A 35V 330uf capacitor at the lipo is probably overkill for a 3S power system and will likely swap them out to 25V. I recommend low-ESR capacitors from Nichicon or Rubycon. I am using 18AWG silicone wires for the lipo harness measuring approximately 3 inches to reach around the back since there is little room on the sides.
It is also highly recommended to use a capacitor with the HDZero digital FPV system as it can be susceptible to voltage spikes.
The TBS Crossfire Nano RX is 3M-taped to the rear behind the main stack. Although there are no mounting holes for a rear stack to save weight, there is room to secure smaller components.
I am using an FPVCycle Minimortal T Antenna and minimalist TPU mounting to save weight. After some testing, I’ve found even 250mw will get me to the edges of my usual freestyle fly spot without LQ dipping dangerously low. I’m particularly confident at 500mw.
The HDZero TX5S.1 (whoop style) VTX has proven to be a very effective light-weight digital FPV solution.
I’m using the Runcam HDZero nano camera.
The Foxeer Lollipop Micro 5.8GHz RHCP antenna is a direct U.fl connection to the VTX minimizing signal loss as well as weight. A dab of hot glue helps to secure the U.fl connection. I would caution that the VTX is very capable of melting that hot glue if left on the bench at an active power level.
The Kuwagata lipo pad is custom cut for the Mk2 line.
The HQ Prop 2.5×3.5×3 props pair well with the 1204 5000KVs.
AUW with a Tattu 3S 75C 450mAh lipo an XT30 connector is 139g.
AUW with an Insta360 Go v1 and a Tattu 3S 75C 450mAh lipo an XT30 connector is 160g.
Tuning & Filter Strategy
The following clean gyro_scaled traces for pitch and roll reflect the expected rigidity from a micro solid body frame.
After filters, the noise profile for the build is very clean.
As such, we can use filtering to achieve a pristine noise profile. Note that this filtering 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).
In my own experience, smaller micros tend to be tougher to PID tune than larger builds. In this case, I ran into an issue where despite what the blackbox traces suggested, using D Min and feed forward just felt off in the flight characteristics to me. So I decided to go by what I was feeling in flight rather than the maths and these are the PIDs I settled on.
Weight Analysis
The following highlights the top five components that make up the 139g AUW (with 4S 450mAh lipo but without the Insta360 Go v1). As is the case with most of these builds, the lipo and the motors make up nearly half the weight or 47% in this particular build. The frame makes up 16% of the AUW and is the third heaviest component. The take-away here is that the choice of battery and motor sizes significantly informs the AUW. (You can hover over the chart components for details.)
The following chart sorts all of the components by weight.
The Ashigaru Mk2 is designed to be a micro basher capable of carrying lighter HD action cameras. The purpose of this log is to provide ideas and inspiration for you to come up with your own perfect setup.
73