Trex 600 CF Flybarless

After my experimental Flybarless Trex450 , I decide to convert my Trex600 as well. I forsee the fast cyclic response is good enough for 3D.




Using 15mm linkage ball. 8cm linkage rod.
Extend the upper swashplate ball distance.
Phase angle washout hold in position with hex nut, at 0 deg.
I use one arm only , but will put another arm soon . As during 3D, a cyclic punch will rotate the arm a bit and result in undesirable/ abnormal cyclic response. In addition, the old design Trex600 swashplate has the upper balls off center ( A design flaw).





Leading edge. But the grip screw nut become the top.
Tx swashplate Ail -44%, elevator 55%, collective 40%
Cyclic 13 deg, collective 12deg.
D/R exp Ail/ elev -30%




Result :
I am very happy with the fast cyclic even at very low headspeed ~1900. The forward flip is 2x faster than my 600N @2100 rpm with light paddle.
In head on wind, pitch up is significant.
Hovering/ Control is much stable than Trex450.
Will try to add a pitch gyro to see if the pitch up/ballooning will disappear.

Short video, cannot record the 3D part because memory card is full.

Coast Guard Build Thread

Hurricane EP550 body and .30 Funkey fuselage with wheel retraction driven by 2 servos.

Steps:

1) Retraction system , waiting PIC burning for slow retraction and LED lighting.

2) Trex 600L motor too tall. Have to put back my 1000kv BL. Then have to gear up with 16T / 50T front gear to achieve HS ~1900.

3) The tail hub have to trim at the link ball lever.

4) Swashplate may hit the fuselage on highest range. Need to trim 3 slots.

5) Battery weight better bear on the frame rather than on the fuselage, as the fuselage is not yet mounted secure enough to the main frame.

6) Hurricane EP550 seems a good fit for the .30 fuselage

7) Thinking of putting some seat and pilot inside.

Trex 450 flybarless (2)

Trex 450 Flybarless

Version 1 with direct drive. Poor collective resolution as the gain is et to 35% only.








Version 2 with mixer at hub to half the collective pitch travel, to improve resolution. However, the cyclic pitch travel is also halfed.

The cyclic travel can only be isolated from the collective pitch travel at the swashplate level. That is the swashplate upper/ lower diameter ratio.

TH2 CCPM mixer board from tech product

The rotor phase angle adjuster . 10 minsutes job from a shaft collar and fiberglass. Will make a better one.




****1st version

Direct Swashplate drive the blade grip.

Mechanical Setup:
1) taken away all flybar, seesaw and mixer arm. Direct swashplate drive to gip hub.
2) GY401 as elevator dampenig. Align 500X as rudder gyro
3) towerpro CCPM servo, Hitec 56HB rudder servo
4) TH2 CCPM mixing
5) Main grip leading edge control. Mechanical Phase angle adjusted 11 o'clock.
6) Servo horn distance shorter ??mm

CCPM mixer and Tx setup:
1) TH2 gain : Aileron 60%, elevator 65%, pitch 35% (way too small resolution)
2) Aileron D/R 80, Exp -50; Elevator D/R 70, Exp -50;
3) Cyclic 12 deg; pitch 10 deg

Result :
Hovering
1) Unexpected oscillation at pitch axis. Likely too high pitch gyro gain, sloppy servo , soft head dampening. Touchdown of expensive carbon blade with minimal damage.

****2nd flight
1) Hardening head dampener rubber
2) reduce sloppy servo, use Align 500X as pitch gyro with gain 20%
3) Add mixer arm to increase blade pitch resolution. 2x travel now
4) Servo horn distance same as flybar trex 450
5) Th2 setting: Aileron gain 65%, Elevator gain 70%, pitch gain 45%.
6) Achieved Max. pitch +/- 10deg, cyclic only 8-10 degree ( needs more)
6) Tx Ail. D/R 90, Exp -40; Ele D/R 90, Exp -30.

Result:
Stable hovering. Perfect figure of 8. No oscillaltion. Needs constant attention to roll (cause lack of aileron stabalization). Cyclic response at HS 2000 is almost as fast at HS2800.

N.B. TH2 has a behaviour that trimming on the Tx will greatly reduce the SW travel to the opposite direction. Therefore, all trimming best done mechanically or on the TH2 itself.

Next test schedule:
1) To test backward flight.
2) To test inverted flight.
3) To test 3D performance

Plan:
1) Need to increase inner swashplate diameter and decrease outer SW diameter. This will increase cyclic travel mechanically.
2) resolve some mechanical binding at mixer arm and central hub.
3) Change a more powerful BEC as the clamped BEC current is over 2.6A with 4 servos/2 gyros/ TH2 and receiver.

****3rd flight
Forward flight, stabel, no pitch up problem.
Backward figure of 8, pretty stable.
Pitch gyro gain at 30%. No osciallation as the head dampener is pretty hard.
With a plastic blade the cyclic is very fast and predictable. D/R 100%, Exp -25%
On pumping up/ down collective pitch, the heli may drift a bit ? realted to plastic blade being too flexible?
Plan for hard 3D in windy condition this weekend.




Phase angle set to zero











All linkages are straight now. No slop at all (except at the swashplate itself). Collective control is precise.

High speed control surface servo torque

I have no idea (no intention to know) the existence of control surface servo calculation , until I crash my F16 and blue angle. The 2 crashes resulted from inability to pull back the plane from a very high speed dive >150kph. It seems the plane cannot escape from the vertical dive.

Then I realise the importance of calculating the control surface servo torque requirement. To my surprise, the torque requirement is not linear.

For example , the elevator flap of my F16 measured as a triangular surfaces with chord 7cm and length 12cm, deflection 30deg, servo travel 45degree .
At speed of 100kph, the 2 flaps exert a torque of 8Ncm. (http://www.csd.net/~cgadd/eflight/calcs_servo.htm) My Towerpro 9G servo of 11Ncm is enough.
But at a speed of 150kph, the requirement is 18Ncm, which exceed the servo spec.

That result in crash....from a high dive at full speed.

OS50 suddenly lost power - fixed

Suddenly lost power after 50 flights. The OS50 shows signs of overheat after 2-3 tic toc and the Carbsmart tends to richen the needle. Head temperature reads ~130 degC. Normally it reads <110deg C as adjusted in the carbsmart.

Turn out to be the damaged ring and sleeve (previous scotched) .
After replacing them, it works pretty well again.

F18 Blue Angle reach 120km/h airspeed!

My Align Team.







Align F16 400, modified with twin vertical fin.
Wt . of plane 350g + 210g (3s lipo)
450T/1800kv/2200mAh 18c/35A ESC
It reaches top speed of 107km/h at 280W with 3s.




Then, 4s 18c lipo of wt. : 280g
At 4s it pulls 380W, reaches my record breaking of 124 km/h.
With 6x5.8, motor is slight warm. Unlimited vertical.
With 7x7 propeller, the speed is not impressive and the motor is hot.

Another test flight with 3s/3000kv 450TH/5x5 APC, pulls >38A and speed ~ 110km/h. Acceleration is not impressive. Cannot performed vertical> 4s.

3s/3000kv/4.75x 4.75, pulls 32A, though calculated pitch speed>150km/h, but the thrust cannot overcome the drag to produce enough acceleration to reach the desired pitch speed. Unfortunately, I found my propeller mount slipping against the shaft and may result in the poor performance.

Align Muffler Pressure Hose

The engine sudden lost power on tic-toc and was richen with lots of smoke. The CSM carbsmart is working and richen the fuel to prevent engine overheating. On landing and found the pressure hose copper adapter has stripped the thread in the muffler.




I replaced the original 4mm copper adapter to a 5mm one (cost only HKD 10).

New Z50 780kv motor

Left - new Z50 stator core with thinner stator plate. It runs cooler than my old Z50 which is broken due to crash with fractured motor end cap.

CSM Carb Smart temperature sensor

Installation pretty easy.
I take away the power source "signal wire" as early user complain the feedback "signal wire" may jam the (JR) receiver.
Remove the needle valve retch.
I use longer 3mm screw for the needle clamp. The stock is bit too short to secure the nut.





DIY a servo mount.
I use the ball link rod from my Trex450. You can use spare Trex600 servo link (the one connect the T-connector) , which is a perfect match/ length.
I change the ball inwards later, finding that the outer servo horn ball may touch the canopy.






Full lean position setup. Use the CarbSmart potentiometer to adjust. Actually, you can have servo travel by 80 degree only. I set :
Most Lean - 1 turn
"neutral/ failsafe" - 1 turn 4 click
Most Rich - 1 1/4 turn




Mount the sensor on os head. Use DIY aluminium sawdust mixed with A/B glue.


Since the sensor is easy to be destroyed on dismounting from the engine block , you can DIY your sensor by using a 100K thermistor, cost $2 only.

Must remember to adjust the gain after the initial setup as it is easy to leave the potentiometer at extreme anti-clockwise( during rich needle setup). This leaves the gain at zero. Now I adjust the gain to around 80%.

Installing carbsmart for almost 2 galloon, I finally can see my needle goes to richess position on landing. Actually Carbsmart save me today. My engine suddenly lost power after 4 mins. violent tic toc, piro-flip for 1 min, and funnel. The smokes get thicker and I land it immediately. I read the needle is at most counter-clockwise for almost 15 seconds!! I was surprised to find that the muffler back pressure hose was completely detached from the muffler !
What the hell! This cheap little gadget did save my engine! Last time my leaking hose blown my piston before I had this carbsmart!





More fine tune. The needle neutral position was turned more lean by few degree (see the circle). This make a huge difference and I can see the Carbsmart is now richen the needle at end of 3D. 3D flight is more powerful. Now the gain is set ~60%.

New Zealand Trip - Milford Sound, Te Anau

Lakeside of Queenstown.







Mirror Lake









Milford Sound






Waterfall in Milford Sound













Dinner at Te Anau

NZ Queenstown

My first Nitro Heli- Trex600N Pro

So happy to buy myself a Trex600N as a career promotion gift.

Much easier to set up an engine than I imagine.

Much powerful than amy A123 14s Trex600.

But I hate the oil!!

3S A123 Trex 450

Target at 3D

@15T, 3000kv 450TH, HS 2300-2400 only.

3s A123 is 230g. However, the performance is far poorer than a 3s 2200mAH 18c lipo. Cos the voltage is low <9v>70 oC. For gentle flying, 3S A123 is perfect. Or you need a higher kv~3800 motor for 3S.

Another picture is a 3s lipo curve, @14T/ HS 2700-2800

Max power ~250W. Current <20a.

無刷 Servo Futaba BLS451

剛出了便第一時間買3隻

Torque 10.5kg/cm

Speed 0.1 s

正,即裝上Trex 600 激玩3D

以後唔會死Brush 啦