GRRRRRRRRR I replaced the RX107 unit and also with a brand new RX and TX crystals and the problem remains: ------------------------------------------------------ I think me recieving unit RX107 is broke or something. When I turn on the transmitter (with throttle down and everything else as its should) and connect the battery to the helicopter then the recieving unit only flashes RED (and the Gyro flashes superfast) and nothing more happens.. No controls or servos react. The only thing that works is that servos goes on and off when transmitter is going on or off. ------------------------------------------------------
Then it must be the transmitter, there is simply nothing left that that can cause this problem. Crap I dont feel for replacing that part because its the most expensive one and tis costs 50% of completely new RTF package Any other tips? This made me wanting to quit this rc hobby
I solved the problem with the transimitter. I took it apart and I already knew that there is no problems with the potentiometers that the controls and trims are connected to. Beside that there are not so many components on the circuit board. I found 2 adjustable components that can't (or are not ment to be) adjusted by the end user. It was 2 small variable potentiometers that where marked as "FREQ" and "DEV". I didn't want to touch FREQ because it didnt believe that it was a frequency issue in the communication between tx<->rx. I mean the servos where reacting at switching on/off the TX. So I adjusted DEV a bit. I started to turn in counterclockwise but then I noticed that the servos didnt react anymore at all not even om on/off of the reciever. So I started to turn in clockwise and the servos started to live its own life! Like I was acting a mad man with the TX controls even if i didnt touch them. So i turned it a bit more clockwise and then I noticed that the servos stopped living its own life and they also reacted according to when I moved the controls. And even better was when I watched the RX107 stopped flasing the GAIN LED and the same for the gyro. The initialization seemed to work, the servos now reacted as they should and I could also start the motors! I didnt test flight it yet because it was to late but everything looks and works as it should now.
I hoped that this saved my from buying a TX. Ill keep you posted with my first test flight
Posts: 5
Joined: 4/18/2006 From: , ON, CANADA Status: offline
Dear Lostman, I have the Lynx-380XL and am having good luck and a lot of fun with it. I have just one question...and I direct it to you because you seem to be a dealer and in-the-know, or anyone else who can help me. 1. In the manual they mention up-grading the battery to a Lithium Polymer 11.1v 1400mAh for best aerobatic performance. I am using the stock battery that came with my unit; Lithium Polymer 7.4v. Can I upgrade to the 11.1v Li-Po and not change any-thing else??? or do I need to up-grade the speed-controller and motor as well? Thanks, Ken
Posts: 1
Joined: 11/29/2006 From: Chattanooga,
TN, USA Status: offline
I have a dark knight 2 with the same controller / rec. (the old)rx 107 i figured out how to get it started, but i believe there is some fine tuning to do to the servo "setup"
when it starts to take off it leans to the right and runs the rotors into the gurond, crashing before it ever gets airborn.
Posts: 4
Joined: 12/20/2006 From: Melbourne, AUSTRALIA Status: offline
Hi there lostman Icannot believe there is someone else with same problem as mine My lynx380 burnt out reciever controller exactly the same as yours unfortunately my lynx has not even managed to get of the ground I have a theory on why reciever burnt out 1 battery size 2 incorrect cable connection to controller (as in pink/white wires around the wrong way) Lyxn has not flown since new As I am new to Helis I think it has something to do with servo settings ie reversing
Posts: 4
Joined: 12/20/2006 From: Melbourne, AUSTRALIA Status: offline
Hi there buttheadgsxr1000 just a warning it may be incorrect but make sure higher voltage battery does not burnt out reciever/controller as i believe that is what has happened to mine
Posts: 4
Joined: 12/20/2006 From: Melbourne, AUSTRALIA Status: offline
Hi there buttheadgsxr1000 just a warning it may be incorrect but make sure higher voltage battery does not burnt out reciever/controller as i believe that is what has happened to mine
Posts: 5
Joined: 4/18/2006 From: , ON, CANADA Status: offline
Tooo late, I already burned mine out. I think the voltage was ok, but I used a 2200 mAh battery. I think you should not go any higher than around 1400mAh.
On the good side...I heard something rattling around in-side my receiver, so I took it apart only to find 2 ic's melted off the board. I managed to solder them back on...very carefully...and got it working again. I was lucky to have a spare receiver to see which way the ic's went on the board. They must have got so hot with the big battery that they melted the solder right off the tabs before they had a chance to burn out. Now i'm just keeping to the stock battery.
Posts: 12
Joined: 11/23/2006 From: EU, FINLAND Status: offline
Fixing new Lynx transmitter faults and straightening blade axle
quote:
ORIGINAL: buttheadgsxr1000 On the good side...I heard something rattling around in-side my receiver, so I took it apart only to find 2 ic's melted off the board. I managed to solder them back on...very carefully...and got it working again. I was lucky to have a spare receiver to see which way the ic's went on the board. They must have got so hot with the big battery that they melted the solder right off the tabs before they had a chance to burn out. Now i'm just keeping to the stock battery.
21.12.2006
Thanks for the warnings! Yes, with a heavier battery a heli will get heavier, too, resulting to more amperage, which heats the ESC fets. Yours were apparently heated melting hot!
Lynx transmitter errors
My Lynx 380 had some soldering faults in its transmitter already as new. I wonder if any of you did get a tx with similar errors? The directions of 3D and gyro switches were reversed (see photos). So was the pitch trim on the left upper corner of the tx. I resoldered them to work correct. Also, the pitch trim pushed the blade slider against its end. I rescaled the trimmer with an added 5 k resistor.
The aileron and elevator controls produced sudden pitch jump at their ends as they seemed to drive the servos against their stops. Their ranges had to be limited by soldering 2 k resistors to each ends of the potentiometers - a kind of fixed D/R modification. Also, the elevator stick fad a troublesome affect on pitch. Pushing the stick would drop the heli down, and pulling it would add lift. I did away with this effect out by moving the links in the two rear servo horns one hole closer to servo axle. Now the pitch seems to remain rather unaffected from elevator movement.
The pitch scaling trimmer on the right upper corner (see pic) of the tx produced a different problem. If it was set to low (ccw) in 3D mode, it produced sudden jump from positive to negative pitch. This is evidently a transmitter mixer programming error. In flight, it would probably have smashed the heli against ground. In its clockwise position the trim did not twitch the rotor pitch, so I readjusted it by scaling out the defect section by soldering a 12 k resistor on the ccw end of the trimmer pot.
Twisted blade axle
The Lynx blades looked a little weird as they seemed to hang. The heli shook violently when blades rotated. The reason for it appeared to be a curved axle between blade holders. I straightened it, which did away with the shaking problem.
For straightening the axle, the blade holder bearings were extracted from the axle with two pliers. Axle was fastened in a rotating three jaw chuck of a drill, and knocked gently with a plastic hammer until it was straight. Its straightness was visually checked by rotating the drill.
At the same time I checked the crossbolt on the main axle that felt loose. It proved to be broken in its hole. This heli seemed to have experienced some hard test flying in the factory. As a replacement to the 1,2 mm dia crossbolt, I bent a cotter from piano wire of similar thickness.
ARF, not RTF
Otherways, it seems mechanically a quite nice heli, and surely worth its price, after these initial faults are spotted and corrected. Also spare parts are moderately priced. The head lock gyro GY400 seems quite good and appears to work, at least on tabletop.
Correctly, the text on its box states that it is 95 % ready built and so almost ready to fly (ARF), not ready to fly (RTF)!
I have not yet dared to actually fly the heli. Will try it after Christmas. Here are some images of it.
- Juha -
Edit 28.12.2006:
First flights
Now the Lynx has been flown for a few days on our front yard! It behaves rather well for so low cost heli. It is quite stable, and with some skill it can be flown in gusty wind, too. No 3-D trials yet. In normal mode the gyro works well, but in heading hold mode it wags tail. The heli is also rather impact proof. Only a couple of blade fixes and axle straightenings this far..!
< Message edited by J. Hartikka -- 12/28/2006 3:15:48 PM >
Posts: 12
Joined: 11/23/2006 From: EU, FINLAND Status: offline
Now the Lynx electronics have been rather heavily modified and it has new home made lightweight balsa blades that help make the steering response quicker.
Its 10 year old owner likes it and tells that it is easier to fly than Dragonfly 4, his previous trainingheli.
We also tried it with a TV camera attached under its belly with a clothespin. Photos below.
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All Forums >> RC Helicopters >> Electric RC Helis >> Walkera Helis - Dragonfly, etc.. >> RE: 2006 Colco LYNX 380XL 6CH RC Helicopter 
RE: 2006 Colco LYNX 380XL 6CH RC Helicopter - 
