WORKS Polar Bear


540class EP helicopter
Collective pitch controll

GYRO : FUTABA G-155 (mini type) (Now i use micro Piezo jyro Futaba GY401)
BATTERY : 8.4V(7cell) 1700mah (SANYO)KYOSHO's or 8.4V(7cell) 2000mah batterrypack
MOTOR : HPI(15t)with15Tgear or TAMIYA DYNATECH 02H with 13Tgear or YOKOMO13t with 14Tgear for akro or Hacker B40-9L blushless@or Lahner BASIC4200 with 14t gear
ROTORBLADES : JRC (Wash down type wood blade) Micloglass coated > KYOSHO FRP blade


Now I use ZEAL Z-12 head. It is good for hovering and turn and straight hish speed flight.

Right Image is 64pitch gear, It was made by my friend Mr Takeshita. It is so good, less power loss and more silent.
It use 125t spar gear(64pitch 1/10EP Car use) and 16t pinion gear (Kyosho's : EP consept's tail drive pinion)
I use 28t pinion gear at motor. It is near gear ration to normal 14t pinion.
Mr Takesita has good hands.

I get Futaba's GY240 piezo gyro. It is very very good! If you can get it, please use it. GOOD feering!
Now I use Futaba's GY401 piezo gyro. Variable sence, contorolled with TX's proglam mixing function.

Hacker B40-9L blushless motor ans schltue future 45be ESC tested. Remake motor mountingplate from 2mm aluminium plate.
This motor needs 16-18t pinion gear (at normal gear pitch), so I made 64pitch counter gear ( Mr Takeshita's way ).
At using 64pitch gears, spar gear 120t : pinion gear 30t is near ratio at normal pitch 16t pinion gear. And same way , use 32t pinion gear, it like 17t pinion gear at normal gear pitch. These spar and pinion gear, easy to get from 1/10 car's parts.


I test Lahner BASIC4200 motor. It has same pitch of motor holding , so can use normal motor mount plate. Kv is 4200 so I choice 14t pinion gear and 8cell batterry. 14T pinion gear can get from KYOSHO's genuie opitional parts.
Test flight is very good. Enougf power for high turn hovering, Use IDLE UP mode, very fast and high torque , no plpblem quick turn and vertical climb.
Full speed feel like 30 class GP heli.
After landing, motor can tanpareture is not so hot, can touch finger. If use 15T pinion gear, more hot I think.
Total flight time is 6minutes half over. Current has no ploblem.

BASIC4200 with 14t pinion gear and Suhulze Future 45 be and 2400mah 8cell, good matching.


Dracking hinge (2.6mmBolt at flapping plates) is fixed stainless solder. Move of drack is bad to tracking.
Ball links are adjusted so smooth.(Inportant!)

And now i use metal-type rotor head (It is so good), and i made metal washout links. These are good for tracking.

(original new type version before clash)
Stabiriser bar is 2mm musicwire. I add aluminium pipe (innner 2mm/outer 3mm) for anti vivration of bar.
The normal stabiriser holder is metal. It is heavy than aluminium (KYOSHO's option) It is good for training of first step, but it is too much stability for roop. So I use aluminium holder.
( Aluminium pipe was not good working. Now i stop using.)

The skid of huges500 is can put on EPconsept SR. To cut cabin (see picture). And make two holls for forward blace.(between 40mm) with 2mm drill,and tight with 2.6mm tapping screws.

Make a small hole at topcabin, for motor cooling.

Servo mounts are made from aluminium. Suitable for Futaba S-9601.
This picture use TAMIYA DYNATECH 02H. Pinion gear is 13T (R/C SHOP ASAMI tokyo 's orijinal)
In case of using HPI 15t motor, use pinion gear 15T (ASAMI)
Motor controll amp is KEYENCE A-01 Pro (High frecency type)
KYOSHO's optional parts Special PItch Slider.(good for pitch controll and fliction)
Picture of right is newest version.( so i clashed at chalange of loop)
Each side of lowerflame, i made reinforcer flom aluminium angle (10mm*10mm). It is good for gear train holding.
Skid is Huges500 type.

I made maintenance holl at lower flame for motor pinion gear.
Battery stopper(original bodymount) made from aluminium. keep stability of C/G, and hold battery tightly, no moving high lange flight. And add battery holder rear of lower flame, magic tape(belclo).
Body holders are 2 of lear of flame ( 2.6mm bolts) and 1of front lower is tighten with pin, like 1/10 R/C cars.
I made intake holes at top and bottom of body(nose), for cooling battery and motor and controll amp.

Roter blades

  1. orginal blade
  2. Kyosho's wood blade
  3. JRC wash down blade (miclo glass coated)
  4. ModelSport Carbon blade


HOVERING mode : +5.5 (at stick 50%) low -2.0 high +14.0
HOVERING throttre : 78% (realy 60%?)
IDLE UP mode : low -4.0 high +10.0
HOLD mode : low -4.0 high +14.0

( JRC blades , HPI 15t motor , 15T pinion gear.)
This setting can flight about 6minutes 30seconds, at no winds. If wids are blow flight time is extended.

Hand Made Parts for EP Concept

  1. Tail pitch slider
  2. Collective pitch linkage
  3. Tail boom brace
  4. Aluminium Wash-out links
  5. Aluminium Wash-out links Ball bearing type@Add GIF format Drawings.
  6. EP Concept SR BladeGlip (1998/01/25)
  7. Metal Elevator Linkage (1998/11/10) With DXF file (care for Japanese ranguage)
  8. Wash-out link holder
  9. Blushless Motor and cooling fin

do Concept SR expelimental works

  1. Stabiliser bar reinforcement
  2. Flame / Elevator linkage improvement
  3. Change metal ball
  4. Swash plate idea (1998/11/10)
  5. Rudder Servo Mount (1998/11/10)
  6. Stainless mast (1998/11/10)
  7. Antena holder for SR's skid (1998/11/10)
  8. Flame stiffner (1998/11/10)
  9. Tail pitch slider center hub (1999/02/02)

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Works Polar Bear