Відео

By two servos it allows full directional control

Do you mean turning left and right ?

Like many ornithopters a high performance kite fabric is used. This one is a polyurethane coated polyester called Icarex. It is difficult to source but I have been able to find it on ebay.

@@OrnithopterZone1 Thank you!

@@OrnithopterZone1 I have purchased kite fabric, it is really strong. I see that the material is sewn, but you also use some kind of glue to hold the thin carbon rods in place. What kind of glue or glue tape do you use for this? Thanks!

Speed and torque for each of the three servos tested are shown in the video. The best servo for this ornithopter (of the three that were tested) was Hitec HSB-9360TH. It has a torque of 17 kg-cm and speed of 0.06 sec@60deg at 7.4 volts. As mentioned in the video, using a slower servo with more torque, HSB-9370TH, was not helpful. Additional information on the servos can be obtained from Hitec: hitecrcd.com/products/servos/digital ...or Servo City, which is also a good place to buy them from: www.servocity.com/servos

Yes. Although I did try even lower frequency and it was not as good. There is an optimal value.

It's actually PicBasic. The code works within the limitations of the PIC 12F683, simple but effective. I do use Arduino for most projects, and then I use a sine function instead of the lookup tables. '**************************************************************** '* Name : UNTITLED.BAS * '* Author : Nathan Chronister * '* Notice : Copyright (c) 2013 Nathan Chronister * '* : All Rights Reserved * '* Date : 12/16/2013 * '* Version : 1.0 * '* Notes : * '* : * '**************************************************************** ' The CONFIG section allows GP3 to be used as an input. #CONFIG ifdef PM_USED device pic12F683, intrc_osc_noclkout, wdt_on, mclr_off, protect_off else __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF endif #ENDCONFIG Define ADC_BITS 8 ' Set number of bits in result Define ADC_CLOCK 3 ' Set clock source (3=rc) Define ADC_SAMPLEUS 50 ' Set sampling time in uS flapcycle var byte flapcyclemax var byte pwout var byte angleL var byte angleR var byte ch5 var byte ch4 var byte ch3 var byte ch2 var byte ch1 var byte volt var byte ' The servos interfere with programming, and also ' you will need to unsolder the power connection to the receiver. servoR Con 4 ' Alias GPIO.4 servoL Con 2 ' Alias GPIO.2 rx1 con 5 CMCON0 = 7 ' Analog comparators off GPIO = %00000000 ' All outputs = 0 on boot TRISIO = %00100000 ' Set input pins ANSEL = %00000000 ' %00000100 Set analog input pins volt = 150 flapcycle = 0 flapcyclemax = 10 start: ' pause 4000 do gpio.4 = 0 gpio.2 = 0 gosub radio ' voltage check -- allows only low power flapping ' adcin 2, volt ' if volt < 110 and ch3 > 30 then ' ch3 = 30 ' endif ' look up wing positions if flapcyclemax = 10 then ' 4.5 cycles per second lookup flapcycle,[48,24,0,24,48,72,96,120,96,72],angleR lookup flapcycle,[48,24,0,24,48,72,96,120,96,72],angleL ' was [50,30,10,30,50,70,90,110,90,70] elseif flapcyclemax = 8 then ' 5.7 cycles per second lookup flapcycle,[60,30,0,30,60,90,120,90],angleR lookup flapcycle,[60,30,0,30,60,90,120,90],angleL ' was [60,35,10,35,60,85,110,85] else ' 7.6 cycles per second lookup flapcycle,[40,0,40,80,120,80],angleR lookup flapcycle,[40,0,40,80,120,80],angleL endif ' throttle scaling angleR = 55 + ((angleR * ch3) / 100) - ((50 * ch3) / 100) angleL = 55 + ((angleL * ch3) / 100) - ((50 * ch3) / 100) ' pitch down compensation (dihedral varies with throttle) ' this will not work with reverse rotation servos ' angleR = angleR - (ch3/16) ' angleL = angleL - (ch3/16) ' yaw steering adjustment (will not work with high tail angle) ' this may not work with reverse rotation servos angleR = angleR + ch1/2 - 75 angleL = angleL - ch1/2 + 75 ' reset flapcycle counter flapcycle = flapcycle + 1 if flapcycle = flapcyclemax then flapcycle = 0 gosub servo loop end servo: pwout = ch2/3 + angleR - 180 pulsout servoR,pwout pwout = 255 - ch2/3 - angleL pulsout servoL,pwout return radio: pulsin rx1,1,ch1 'aileron pulsin rx1,1,ch2 'elevator pulsin rx1,1,ch3 'throttle pulsin rx1,1,ch4 'rudder pulsin rx1,1,ch5 'aux 1 'pulsin rx1,1,ch6 'aux 2 if ch3 < 80 then ch3 = 80 endif ch3 = ch3 - 80 ' causes throttle to range about 0 to 100 if ch5 > 150 then flapcyclemax = 10 elseif ch5 > 100 then flapcyclemax = 8 else flapcyclemax = 6 endif return

@@OrnithopterZone1 Thank you. Much appreciated

this is a much simpler approach -- probably because Schmidt knew that the wings broke in the wind tunnel or probably he wanted to simplify it to the max so that he could improve it later

I never had any problem with the servos even after many flights. It is amazing, because they are very cheap servos. I rarely had servos quit working in other ornithopters. It is always cheap servos and I never had any problems with the Hitec brushless servos that I use in my larger ornithopters.

why would the servos break after a few minutes? get nice servos with enough torque

It can carry a payload at least 100 grams. With all ornithopters there is not a particular weight limit but rather the flight characteristics will degrade gradually as more weight is added.

Nathan it's me Obaid. Thank you so much for all your responses. For your lovely work and your support throughout.

It can use a flight controller, and would be set up similar to a fixed wing airplane. There are 3 kits left, available from BirdKit.com, and then it will be out of production.

Gyros, flight recorders, etc. are readily available from RC aircraft suppliers, and can be used with any RC aircraft. Researchers have also used cameras on the ground to track the motion of ornithopters or other aircraft. That method might be best for your purposes as it can be used with a tiny ornithopter without adding weight. I cannot provide a scaled down version of the Crossbow 2, but ornithopters can be made very small. You can start with a toy like GoGoBird if you are not into building your own.

Someday I hope to make a video like that.

Kindly guide because I need to do it a school project