problems setting up Flightline Corsair rudder/tailwheel coordination

[davegee]

Hi All: I just got my new F4U Corsair from Flightline. It all went together pretty well, no problems there. However I have a big problem with the rudder and tailwheel and steering, (or lack of it). Wonder if anyone has any ideas what I might be overlooking or doing wrong. Haven't seen this issue before on other planes.
When the gear is up, the rudder functions normally, no problem. But when I put the gear down, that's when the "fun" begins. The gear cycles normally up and down and when the gear is down, the tailwheel doesn't respond to any control inputs to move left or right. Also, when the gear is down, the rudder now does not respond to any control inputs and actually is moved about 30 degrees off center and freezes there.
I have a Spektrum 18 and a Spektrum receiver which I think is working ok. Does anyone any ideas on a fix?

Thanks so much, Davegee

[xviper]

Did you do the rudder/tail wheel servo neutral set? While operating the sticks, did you make sure that both rods are not sticking through the servo arm cylinder too much as to ram into anything? Then, with the tail wheel down, did you set the neutral positions on both the rudder and tail wheel with the set screw on the servo arm loose? You may at this time, adjust the rod ends at the rudder and wheel so they actually reach the control arms in a comfortable manner. Then, holding the two rods fixed, lock down the set screw tightly? Where you have a tail dragger that utilizes a rod for the rudder and another rod for the tail wheel and where both rods go to the same servo, one or the other or both rods can slip through the rod locking device on the servo arm if the set screw is not secure.

[davegee]

Hi xviper. Thanks for the input. I've had several FMS, Freewing and Flightline fighters with tailwheels, so I feel pretty competent with them. However I will double check all the mechanical connections again as you suggested. I get the feeling that it is an electronic issue. as when the gear is extended, the rudder locks up immediately and moves 20 degrees to the right, as if by an electronic sequencer command or something. Very odd. With all the other planes I've flown extensively for years like the big FMS Corsair, P-47, and P-51, as well as Flightline P-47 razorback, never had an issue like this before. Very puzzling.

[xviper]

Since the rudder and tail wheel steering is physically linked and locked together, when the gear is down, both should move together. You say the rudder moves 20 degrees to the right. The tail wheel should also move to the right unless one of the rods is not moving at the same time as the other. If it’s an electronic thing, which it still could be, then both should move together when the gear is down. If one does something weird, the other should also do something weird. I would look closely up at the end of the rod where it actuates the wheel assembly. Perhaps something has come loose there. Also take note of what the rods are doing at the servo arm to see if one is not moving the same as the other.

[davegee]

Hi Xviper. This setup is similar I think to the FMS 1700 mm Corsair, where the rudder and tailwheel are not physically connected in any way, to my knowledge. The tailwheel operates from a direct drive servo to make it go left and right, and rudder is physically attached to the rudder servo via a conventional long metal rod that makes it move. A sequencer apparently melds the two movements together to operate as if they were physically attached. From other planes I have had in the past, this problem is totally new to me. This new Flightline Corsair has a new electronic box that coordinates all the inputs to the flight controls, throttle, gear, etc. That same box is supposed to deactivate movement of the tailwheel while the gear is up, but then allow it to move when the gear is down.

I have to think that there is something messed up with that box somehow. I have a query into the tech department at Motion and hopefully they'll respond back to

Apart from that, I am impressed what a good job they did on this latest model. I have already repainted it to the earlier tri color scheme and it will be painted up with markings from one of the planes flown by the top ace ever (25 kills) in the Corsair aircraft, Lt. Robert M. "Killer Bob" Hanson, USMCR.

[xviper]

You are correct. I just took a look at both of my Corsairs and they are similar in the way the rudder and steering is dealt with. My apologies. The 2 rods are for the elevator (doh!). Therefore, the two servos involved with steering and yaw are mixed in the control box and it's entirely possible that there is a poor connection or poor ground in that board, as has been noted previously regarding other connections. If you have a servo tester, pull out both plugs from the board (rudder and steering) and test them individually (hopefully, they go in the same direction without the need for a servo reverser). If they work, then it's likely there's a bad ground in the board. If that's the case, try using a "Y" for both rudder and steering and test again with servo tester. If that works, I'd plug both via the "Y" into the board or if you have enough channels on your RX, plug the steering into an empty port and do a mix. That will allow you to deactivate the steering when the gear is up.
PS. Those boards are a great invention but they aren't perfect yet. The quality control in their manufacture is still somewhat lacking.

[davegee]

Thanks, xviper. Those are excellent suggestions. I'll play with it a bit tonight. I hope to get in contact with the tech support guys at Motion tomorrow, and perhaps I'll have more info to add to this issue after doing some tests tonight.
Cheers

davegee

[Tim K]

I'm not 100% sure but I think the tail wheel steering is turned off when the gear is up. This is done at the blue box. You might try seeing where the rudder servo and tail wheel steer servo are plugged into the blue box and see if they are reversed. If they were not plugged in to the correct spot on the blue box the control horns my need to be recentered also. Or get a Y connection and try bypassing the blue box all together. If they work fine when plugged directly into the receiver then the problem in the blue box.

[davegee]

HOT OFF THE PRESSES!!! I put in a request to tech support over the weekend, and got a response from Wayne. Here is his response:

David,
If you are using any of the three receivers then you will experience this issue. Spektrum AR6000, AR7000 and AR8000 We have notified Freewing of this compatibility issue and they are looking into the matter. In the meantime you can use a Y-Harness for the Rudder and Tail Steering connected directly to the Rudder Channel on the receiver. If you are not using one of these receivers then please let us know which one it is.

I was using a AR7000 type receiver for all the problems I have been experiencing. I took Wayne's suggestion and connected a Y-harness from the tailwheel turning servo and the rudder servo to the rudder port of my Spektrum receiver, effectively bypassing that part of the blue multifunction box that came with the plane. So, it now works temporarily for now just fine, and I'll see if Flightline comes up with a permanent fix for all of us using Spektrum receivers and transmitters. So for the moment, my issues with this subject are complete. Hope this info helps any Spektrum users who are having similar issues to what I was having.

[Crazystick]

I had the same problem will my Corsair. Tried JR 921 , Spektrum 7000 and 8000 . Rudder and tail worked the same as yours , Installed a Spektrum 6210 and all was good . About 30 flight later the plane went on hold on take off , the RF board failed and the plane made an uncontrolled landing from about 15 feet . I was very lucky that the plane is repairable. I don't believe that the later RF problems had anything to do with the original problem .

[apmech1]

I set up a separate channel for tail wheel steering (tws). I have the tws servo centered when gear is retracted. Then I activate it 7 seconds after the gear is extended. This also allows me to have a separate trim trim for the tws. This bypasses the blue control box all together for the tws. I had to set up my fms warbirds like this due to the pin and hole setup missing the mark during gear extension. If you have a spare channel, it works out nicely.