Get ready for the Mitsuko 150 Frame! Unlike most of current mini quads that have X configuration, the Mitsuko is a plus + frame. It’s as tiny as a 150mm frame but capable of running 4 inch propellers.
The creator of Mitsuko 150 frame, Andy Shen, is one of the very few mini quad frame designers that can constantly come up with unique designs. Many of us are probably familiar with his other famous products including the Krieger and Tweaker (which we will be reviewing soon too shortly after). He also writes a very interesting blog with quality images, explaining in detail about his designs and concepts.
Get your Mitsuko 150 from ShenDrones and don’t forget to check out Andy’s blog too.
Mitsuko 150 Frame Review
Mitsuko is a 150mm frame that has a plus (+) configuration. Frame kit contains:
- 3mm bottom plate
- square 1.5mm top plate
- FPV camera plate
- 2 x 1.5mm side plates
- 5 standoffs (4 for the main frame body and 1 for FPV camera cage support)
- M2 bolts
- Mitsuko sticker
Frame design is simple, minimalistic I would say. Single 3mm bottom plate with a circle cut-out in the middle and two slots for the battery strap.
Assembled frame weights 57g.
All electronics must be fitted in the little cube space between top and bottom plates which is only about 46x46mm. On top of the frame you will see an very interesting construction, which is designed to hold FPV cam in place. Camera plate design allows the tilt angle to be adjusted freely.
It is capable of running 4″ props on a frame that has a motor-to-motor distance of 150mm, which is very impressive given the small form factor. Andy Shen explained the process of design in this article.
Mitsuko Mini Quad Build
Parts used for building Mitsuko:
- Cobra 2204 2300kv motors
- LittleBee 20A ESC
- Demon Core PDB
- Dodo Flight Controller
- D4R-II RX
- Aomway 200mw VTX
- HS1177 FPV Cam
- Camera and VTX cage
The build began from the top of the craft – the FPV setup :)
According to information on ShenDrones’ blog, the frame is designed for a specific VTX (e.g. the FX799T and similar) that has a 90 degree SMA antenna connector, so it can be fitted to the top plate via dedicated cut-out. This VTX isn’t available to me when building the Mitsuko, so I had to improvise and used the Aomway in there instead.
I tried different configurations, using the current hole for mounting VTX and the only option was to drill the hole in the side plate to get the VTX through.
Also used the cheap VTX antenna because its flexibility vs. FatShark spironet that I normally use on other quads.
FPV cam is held securely by double sided tape on the VTX, which pushes it against the camera plate. This doesn’t seem to be a proper way of mounting the FPV camera nor have any assembly instructions, so this is complete improvisation. Not very beginner friendly at all.
In the end my mod appeared to be working pretty well, it also saves space underneath the top plate – all video components are located above it. Pre-drilled SMA hole in the top plate was used to put the buzzer through it.
Motors, ESC and PDB
When mounting motors on the frame it turned out that I couldn’t screw in all four bolts, due to design of the motor mount holes. The only option was to use only two bolts, to avoid doing any extra drilling.
After motors were mounted on, I put the ESCs on and cut the cables as short as possible. I trimmed off all servo plugs to save weight, because I wanted to solder motor signals and grounds directly to the flight controller.
PDB is mounted upside down so the regulators and LC filters are clear from the top, leaving me more space to work with cables going into FC later.
Dodo and D4R-II RX
I prepared the Dodo flight controller and stripped D4R-II receiver to the bone for space saving. All pins were removed from it and I did a direct soldering to the Dodo. Wrapped the RX with electrical tape so it stays safe when it’s sandwiched between PDB and Dodo
Dodo FC and D4R-II RX were installed on above the PDB and signal/ground cables from ESC were soldered directly to FC.
Before connecting the top frame section with the rest, I soldered the cables for VTX and CAM on PDB
Installing RunCam on the top for recording HD video using only zip ties.
Voila! It wasn’t super difficult to build the Mitsuko, just required careful planning on cable lengths and doings few preparations.
Few weight measurements:
Mitsuko without lipo 275g
Mitsuko + Nano-Tech 850mah 4S 380g
Mitsuko + DroneLabs 1500mah 4S 420g
Mitsuko + Nano-Tech 1800 4S 505g
Tuning and flying
I tried 850mah 4S, 1500mah 4S and even 1800mah 4S (for science and fun), and I found it fly much better with the lightest 850 lipo battery, probably due to the small size.
This is a PLUS configuration so yaw adjustment needs to be change to compensate for it. I used betaflight on this build, default PID was causing terrible vibrations. Even just hovering the motors were getting terribly warm. Also tried cleanflight 1.11 and motors were still getting hot easily and oscillations were visible.
I dropped all P, I and D values down. Started with P at 2.0 on Pitch and Roll and 3.0 on YAW slowly going up. Motors stopped being hot with P @ Pitch and roll on value 3.0 and Yaw at 4.0. After few initial tuning sessions I found that P need to be raised only few points up to get quad behaving even smoother. Another hover test in the house and all looked smooth (finally).
First flight outside was quite promising with straight lines, but the quad behaved strangely on ROLL and YAW which was very unstable. I found it very strange because I had never encountered such behaviour on any previous builds, regardless how many times I tried to tune it.
Video showing this problem: https://www.youtube.com/watch?v=AHNH-Yf-ZGw
This is the best result I could get from the Mitsuko build for now. Still not sure whether all that uncontrollable movements come from the plus configuration design or not, and if that can be fixed.
Little stroll over the usual FPV spot.
Great things about Mitsuko
- Unique Plus design
- Very good quality of carbon fibre
- 150mm quad that accepts 4″ props – very compact
- Designers attention to detail
- Tool free adjustable camera angle
Things to improve on Mitsuko
- Motor mounting holes not allowing for all four screws to be done
- Original design only for specific VTX
- Lack of assembly instruction
- Very hard to tune, and not much info on tuning available
This is a very special build for me, I like unique design and plus configuration. I hope that the more time I spend with Mitsuko the better I know it and hopefully will tune it properly.
At this stage it is just for fun flying. Every other pilots in my local flying group find my little Mitsuko amusing.
This is how ridiculous it looks mounting a 4S 1800mah LiPo on a 150 mini quad :)