K2-tokyo's blog View Details
Posted by K2-tokyo | Nov 11, 2017 @ 04:05 AM | 11,402 Views
I have been searching good 6-axis gyro flight controllers for multi-bladed micro scale helicopters of 150~250 classes. I tested some Walkera receivers for G400, V450, Master_CP, V120, and some other controllers, XK_K110, CC3D, Microbeast_plus, Trex_150GRS, Spirit, Naza-H_GPS.

I can conclude that G400 and XK_K110 are the best among all apart from Spirit and Naza-H; Naza-H is too large for my purpose and Spirit cannot handle a tail motor system because it has too sensitive tail gyro.

My criterion is not versatility, but that one can do an easy turning flight in a small room under such controllers. Such a criterion is due to recent difficulty of finding flight area caused by accidents of multicopter drones. XK_K110 and G400 receiver-gyros satisfy this criterion very well.

As for a successful application of a K110 board with a second S-FHSS receiver and a heading-lock gyro to a 1/43 Blackhawk (a reform of Nine Eagles's one), see:


As for a 4-blade 400-class Agusta with a G400 board, see:


The method above of applications of K110 boards requires a second receiver and another heading-lock tail gyro (a second receiver is good not only for getting a signal from the rudder channel, but also for getting signals from channels 7,8 for the 8-channel S-FHSS transmitter). However, recently an Australian RC Groups member "ptern" invented a new tail-brushless...Continue Reading
Posted by K2-tokyo | Jun 17, 2017 @ 01:43 AM | 7,225 Views
Hi guys,

I was testing flights of the SRB-4B micro helicopter by cheap gyros! This is because the original HIROBO 3-axis gyro system is too expensive, and only for 40, or 72 MHz transmitters.

The first experiment is by 3-axis gyros; a Tarot ZYX, a Walkera V-400 gyro-receiver:

SRB 4B (4 min 48 sec)

The second experiment is by 6-axis gyros; a Spirit flybarless gyro system and a Walkera Master CP gyro-receiver. The Walkera Master CP has shown a better performance than the Spirit (the rudder gyro of the Spirit is too sensitive for the tail motor systems!). So I introduce only the video of the Walkera MCP:

SRB4B 6axis gyro (2 min 17 sec)
...Continue Reading
Posted by K2-tokyo | Dec 21, 2014 @ 08:12 AM | 14,976 Views
I am testing my 1/22 comanche helicopter (see https://www.rcgroups.com/forums/show....php?t=2287333) equipped with an Openpilot CC3D flight controller. Such a controller came from Hobby King:

The result in the attitude mode (6-axis mode) is satisfactory, but not so excellent until now. I want to test the Apm 2.6 mini flight controller as in the pictures, too.
Posted by K2-tokyo | Nov 17, 2014 @ 08:41 PM | 12,220 Views
Hi guys,

I am making the version 2.0 of the 1/22 Comanche paper craft model, which is the successor of the former version:


The large improvement is the small slit in the front leg, which improves the side-view looking. Further I am testing some new motors for ducted fan because the old motor due to Aircraft is no more available..
Posted by K2-tokyo | Sep 24, 2013 @ 02:17 AM | 13,896 Views
Hi, guys

I am planning a conversion of my Agusta 109 400 coaxial helicopter in the former blog:


into a single rotor helicopter with 4 blades. I have already succeeded in a conversion concerning the main rotor system as in the picture.

I used the same plastic main frame with the coaxial mechanism and a 4-blade system due to Copter X:

with some modification. An old brushless motor of Aveox 27/26/2 with KV=2500 is used, and the current draw for the main rotor is 16~18A at 7.4V.

I installed a 21 g tail motor AEO ADH-300S with KV=2400 under APC 6X2 propeller, a sufficient tail power at 7.4V! The problem is that it's tail is very heavy! So a 70~80 g weight is necessary at the top.

For this weight problem, I changed our power system into one on 3 cell 11V; and so, the original Lipo 1600mAh is available.
The main motor : Hyperion HP-HS2221 with KV=1630,
The tail motor: AEO C20 PRO with KV=1550,

AEO C20 PRO burned probably because of a short circuit at the root of 3 wires (never overload). So I changed it into a brushless motor of KV=1600. And I installed a Flymentor auto-pilot system.
Posted by K2-tokyo | Aug 16, 2013 @ 06:12 PM | 14,231 Views
Here is a Youtube video of my friend Hino's experimental 8 bladed head micro-helicopter, whose rotor diameter is 440 mm. His aim is in making a 1/72 scale helicopter of Mil Mi-26 (for example, ZVEZDA plastic model; http://www.scale-rotors.com/galerie/...lo-zvezda.html). Only a rudder gyro, but a 3 g weight at the tip of each blade. So Hino succeeded in making variable pitch micro helicopters with heads of any number of blades;
(1/48 Academy CH-53, 7-blade head, in 2006),
(1/35 Heller Super Frelon, 6-blade head, in 2006),
(1/35 Trumpeter Mil Mi-8, 5-blade head, in 2006),
(1/48, 5-blade head, 3-blade head, which are in K2-tokyo's blog 2013),
(1/35 Academy Black Hawk, 4-blade head, in 2006):
‪Hino's 8-blade experimental micro-helicopter‬ (1 min 21 sec)

Hino 8blades 3. 2014 (1 min 6 sec)
...Continue Reading
Posted by K2-tokyo | Aug 05, 2013 @ 06:54 AM | 14,274 Views
Here are two variable-pitch micro-helicopters by my friend Hino. The first one has a 5-blade head with 246 mm rotor diameter; 175 g, 2 cell 300mAh, only rudder gyro, but 1.2 g weight at the tip of each wooden blade.
Hino's 5 blade experimental micro-helicopter (1 min 47 sec)

The second one has a 3-blade head with the same rotor diameter; 1 cell battery, walkera 3 axis gyro+0.6 g weight at the tip of each wooden blade.
Hino's 3 blade micro-helicopter (1 min 20 sec)
...Continue Reading
Posted by K2-tokyo | Jul 19, 2013 @ 09:20 PM | 13,631 Views
This bullet train completely retired in March 2012. This is the best one I like, and I often got on the front car of this train from Tokyo to Kyoto, or Kyoto to Tokyo. Some of this train had 16 cars including 4 double deck cars; in particular, I like a double deck restaurant car.
I was not interested in railway models until the retirement of Shinkansen type 100. See the N-gauge movie:
a kitchen bullet train (1 min 3 sec)

Posted by K2-tokyo | Jul 18, 2013 @ 10:28 PM | 14,381 Views
Hi Guys,

I bought that one from Italy:
Very cool and good for flying in a small room.
As you know, I am a mania of Agusta A 109 helicopters.
It is sorry that Art-Tech stopped the production of this heli(?).
The transmitter is of mode 2, but you can easily reform it to mode 1, or mode 3 (mine is of mode 3); some soldering and some mechanical adjustment are needed, but no additional parts are needed. (Be careful about the color of cables; white, red, black wires do not mean signal, plus, minus cables, respectively.)

After several flights, I lost the original blades at 3 small accidents. So I replaced the blades by new blades, which have larger widths 33mm; the original one has 27mm width. I was very surprised by so large difference, but the new ones are more scale-like.

I placed two small figurines of Disney Cinderella in the pilot room. So, the AUW increased to about 950 g; the current draw is about 8~9 A on 3 cell 1600mAh.