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About korreka

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  1. It may be a flip-flop or monostable multivibrator built with inverter gates to separate the PPM signal into two PWM signals:
  2. It´s a semi-proportional control car. The steering is proportional control and a single speed to go forward or backward. SN76604 i.c. was widely used the for steering control.
  3. Those 80´s toy grade cars have 6 functions control (7 functions including Stop). Here is a Nikko car with those functions: http://reparar-cochesrc.blogspot.com/2015/12/emisora-nikko-de-6-funciones-y.html Nikko used a square signal (50% duty cycle) for "forward - 350Hz" and "backward - 900Hz". On the "right" side it was 75% duty cycle and on the "left" it was 25% duty cycle. Taiyo used the same signal and frequencies but forward and backward were swapped. Other manufacturers used other I.C's decoders but the control signal was the same (the square signal frequencies could be different). Some of these i.c.´s are: TA7657 T8140
  4. The Kyosho Icarus is a 2WD entry-level RC car from the year 1985/1986. It has the same chassis as the Pegasus, Cosmo and Cox Bandido. The original motor is the 360ST, size 550, 22 turns - 22,000 rpm and it has independent suspension on four wheels with oil dampers. This buggy is the version that Graupner distributed in Germany. I bought it disassembled and there were parts that were not from this car: I have the original rims and the new front tires; I don't have the rear tires. There were other front rims and rear rims on the Tamiya Hornet. The chassis was strongly marked by scratches on the bottom but no broken parts. The shock absorbers were new as if they had changed. The most important thing was to have all the transmission parts because they are expensive, hard to find and there are no alternatives. I disassemble the gearbox because there is a strange noise. The gearbox is fine and had a loose bushing. It is cleaned and oiled. The motor pinion has 18 teeth and a 0.8M module. The gearbox has a ratio 18/52 * 18/52 ---> 8.35: 1 The wheel axle is worn in the rolling area. This also occurs in the Cosmo and the Pegasus. TThe previous owner did not do the maintenance and there was no grease in the bushings. It is better to use 10x6 mm flanged ball bearings A new wheel axle is quite expensive and difficult to obtain; I placed a needle roller bearing 10x6 mm and 10 mm wide. The transmission parts have strange measures and shapes and are not compatible with other spare parts: The LeMans 360ST motor has interchangeable brushes but cannot be opened. I put the very fine sandpaper in a screwdriver and put it in the hole of the brushes to polish the collector. I use a drill to turn the rotor. Video: https://youtu.be/sMPhT_h9Wl8 Complete transmission test and measure the motor speed (sound level meter): https://youtu.be/LEozlwM9lzs The chassis is clean and the transmission mounted. The battery is placed by opening a cover under the car The double wishbone front suspension is made up of flexible plastic arms: there is no axle. Suspension clearance is repaired with an o-ring. I made two polyethylene holders for the servo. I did not have the original holders. I have new chrome rims and a rear wheel adapter; I also have new front tires. I mount 4x8x3 bearings in the front wheels. The rear rims are 1.55" size and I can choose between the Tamiya Hornet or Marui tires that I have. I paint the white letters on the tires. I also mounted the ESC and the receiver in the car. The Icarus buggy looks like this: In action (video): https://youtu.be/PN9w7e1kkTs Translated from: https://reparar-cochesrc.blogspot.com/2020/03/restauracion-reparacion-de-kyosho-icarus.html (sorry for the translation errors)
  5. First, check the connections of the white, yellow and green wires of the servo. http://reparar-cochesrc.blogspot.com/2017/11/sustituir-un-servo-nikko-por-otro-servo.html Also, the received signal may be incorrect. To test if the steering signal is received, you must have an oscilloscope. Is the original transmitter the Nikko Bison car?
  6. The Nikko Thunderbolt was sold with 380 and 540 motors. The 540 motor version was a 35T or 45T motor: 12600 rpm at 7.4V and 1.3A no load current y the car has full proportional control electronics. I have tried to put a 27T motor (Johnson "silvercan" motor of Tamiya) of 18,000 rpm and 1.6A no load current. The original electronics do not overheat. The original electronics have a "H-bridge" of bipolar transistors: 2SA1129 (pnp) and 2SC2654 (npn). These transistors have a maximum current Ic = 7A and drive a peak of 15A. The collector-emitter saturation voltage of these transistors is Vce-sat = 0.3V at Ic = 3A or Vce-sat = 0.6V at Ic = 5A, so the motor is powered between 0.6 or 1.2V less than the battery voltage. The motor speed is lower than the same car with ESC (electronic speed controller) of Mosfet transistors. In spanish lang. in http://reparar-cochesrc.blogspot.com/2020/01/cambio-de-motor-nikko-thunderbolt.html
  7. (In spanish lang. in http://reparar-cochesrc.blogspot.com/2020/01/cambio-de-motor-nikko-thunderbolt.html) There is also the option to change the wheel. The Nikko car wheel adapter copied from Tamiya. The Tamiya rear wheel (Hornet, Frog) can be attached to the Nikko adapter and also, the Nikko Thunderbolt wheel fits well to the Tamiya adapter. The Traxxas (The Cat) adapter is similar but I don't know how it fits well on Nikko or Tamiya wheels. If we want to use a wheel with a 12 mm hexagon, we have to use a long adapter that has a inner screw to fix the 5mm shaft of Nikko car. The picture shows the adaptor fixed to the shaft and a wheel with 0mm offset.
  8. Tires for Nikko Thunderbolt / Bison / Rhino: http://reparar-cochesrc.blogspot.com/2016/11/neumaticos-de-nikko-thunderbolt-bison.html The rim is 50mm in diameter (1.9 "); the original tire is hard to get. One option is to put a crawler tire with foam insert. The tire is bonded with contact adhesive. The tire diameter is 100mm. Another option is to put the Tamiya Hornet rear tire. This has an internal hole of 36mm (1.5 "). If you cut with a cutter the inner edge of the tire (very careful !!), the operation of mounting it on the rim is easier:
  9. Rims and complete wheels of Tamiya Hornet are compatible.
  10. I have put a car on sale on Ebay - only shipping on the EU https://www.ebay.co.uk/itm/184146976191
  11. The chassis is an aluminum-polyethylene panel and is very rigid. The buggy weighs about 1.5 kg with the battery. I do not think the chassis will break. Maybe, the holes threaded in the aluminum give me problems in the future but I can always put screws and nuts. The wheelbase is 260mm (same as the original Raider); the wheels are bigger and it seems that the wheelbase is smaller.
  12. I had many spare parts from Kyosho Raider and I thought I could build a new buggy: ... I needed many essential parts (shocks, bearings, shafts, suspension and steering arms,..) I started by checking and lubricating the transmission: "homemade" suspension arms in aluminium The shafts were obtained from a DVD-CD rom: the chassis diagram Building the chassis with a polyethylene-aluminum composite sheet: Building the front shock absorbers with aluminum tubes: Building the steering arms with two long screws I have put ball bearings and a 380 motor to test the transmission: I start to assemble the parts of the transmission and steering in the chassis: Servo and steering are assembled and adjusted: It starts to look like a car... The first test with a 540 motor, receiver, ESC and battery: Building a custom bumper. The curve is obtained with heat from a soldering iron Bumpers and body supports are already in place: Receiver and ESC has been mounted with Velcro: The lexan body is obtained from a toy-grade car: It's done !!!! the bumper is behind the body With its "brother", the original Kyosho Raider: (In Spanish here: http://reparar-cochesrc.blogspot.com/2019/01/fabricar-un-buggy-partir-de-piezas.html )
  13. With time, also the dogbones have been broken. Solution: Aluminum or bronze hollow spacers (the dogbones have been glued with epoxy-glue). Also the HPI 06006 dogbones (70mm) can be compatible.
  14. I have not thrown them away. !! I use these shock absorbers in a TL-01 chassis intended for a rally car.
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