Crow Brakes And Futaba T9C Tx

[Jerry Lunt]

Since taking up sloping I have experienced a problem using the standard set-up for crow brakes in that as I deploy the brakes, the model zooms up unless I compensate myself with the RH stick (mode 2). Happens with my FFish, Wizard and Typhoon. On the Fish I simply do not have enough down elevator to compensate.

A while back I met up with Zim at Burrough Hill and he mentioned that his JR9X II has a curve function for the elevator movement as the throttle stick is pulled down to deploy the brakes and that this is good because you usually need more down ele at the beginning and less once the plane has slowed down so he has a steep rise in the curve of ele movement which declines as the stick is pulled down. The T9C does not have this in its Crow (Butterfly/ARBK) function. On the T9C there is just a % value for the ele movement which is the maximum it will travel down related to stick position. There is even a delay function to delay the ele movement which to me seems the opposite to what is needed.

Then I realised that PMix 6 and 7 have curve functions and found it is possible to mix ELE to ARBK (master) and have a curve function to put in lots of ele movement early in the stick travel, then reducing as the stick comes down. It is even the case that the elevator down can be deployed before the flaps start to descend. This is controlled by how you set the PRESET value in the BUTTERFLY settings. I had mine at 86% which allows probably too much ele down movement prior to the flaps starting down. (I have not flown this setup yet so need to do some testing). The operation of this can be set to the same switch used to inhibit crow deployment (usually switch A). Of course I needed to set the ELEV % in the BUTTERFLY settings to 0% also. As well, I found that the curve for the ele movement has to be the opposite to that expected as the stick starts off at full up. So I set position 5 value to 0, 4 to 45-50%, 3 to 40%, 2 to 35% and 1 to 30%. These are provisional values I will have to try out sometime I can get the Wizard up again. If anyone knows more suitable values ........................

I hope this may be useful to others and not a lesson in egg sucking??

[Rooster-X]

I've found with my butterfly / crow setup that I used to have too much elevator compensation because of the initial blooming up as you describe. However once the model has slowed down on landing approach, too much elevator compensation means that it comes down moving forward too fast. I have now backed off the elevator so that it isn't travelling forward fast once I've got over the initial blooming. I deal with the blooming by pushing forward on the elevator stick when I pull crow, in fact in dodgy rotor conditions I find it easy diving with crow deployed through the rotor so that I have enough energy left in the model to keep it flying down to landing so that it doesn't drop out of the sky. Still playing with settings, I can have a curve as you describe (T8FG), but did not like it in the end so went back to linear response.

[isoaritfirst]

Just leave it linear,

Apply the brakes a little more slowly - you should not be banging out full brakes when you are travelling fast.

Have around 3 - 4 mm of down elevator at full crow. fine adjust after you have tried it a few times, aim to have the model diving very slightly when settled under full crow, as you get more comfortable also fly the crow settings to a landing, but initially best to just have it diving slightly under crow and pull up slightly as it nears the ground.

[Mr Ed]

Agreed Mike. Being too slow on a landing has always got me into more trouble than being too fast. Obviously within limits :-)

[Jerry Lunt]

_{Thanks for the responses, Guys. Valid points I think although we had a fine lesson in slow, nay stationary, landing approaches from AndyB, even with his Stingray at Rhosilli. But I guess in such a location you can be sure of smooth wind which does not suddenly drop to zero :eek:}

[Jerry Lunt]

Having been setting up the throws on my Wizard ('cos they was in a mess) I have reset the ele compensation to the linear method in the Butterfly settings. I could see that the method described in my OP would increase the down on the elevator as the flaps came up causing more of a dive into the deck :censored: