mtd ap ( launch angle)

[hellsbells1]

Hi there i have a question regarding launch mode?. Im having a problem with launch angle with the mini talon! first off ive finally managed to get the plane flying straight and level  in manual mode but have had to put about 20 clicks of up in elevator to get her to fly straight which works well in manual flight. but when i try to use launch mode it seems to take off to steep so quickly have to move elevator to cancel launch mode! and then im ok in stb mode! what i want to know is if i set the launch angle to zero will it work? Reason im thinking this is because of say launch angle is 20 theres to much up added to elevator which i think is causeing too steep climb because of how i have the elevator set in manual mode if this makes sense?. So would setting launch angle to (0) work? other than that its flying ok . Also i have set (yaw-p) to 0 from what it was which was 4. look forward to feed back!!

                                               kind regards trevor 

                                                                                                 

[Coyote]

There is something way wrong with your setup Trevor, 20 clicks of trim is insane. It should be no clicks at all to 2 or 3 at the most mate. The Talon is the only plane I've ever flown that basically needs zero trimming.

This I think is why you are having all these problems, there is something fundamentally very wrong with your initial build of the plane.

It's either control surfaces, CG or thrust angle, but one of them is way way out.

[FPVSteve]

Have to say CG is critical on these planes - even moving the battery half an inch transforms the way it flies. I had a right game on trying to make mine fly level with trims etc until I got the CG 100% right.

[hellsbells1]

well ! to be honest regarding the build theres only one way to build it! i agree shouldnt need that much up trim and regarding c of g its at 55mm  and sits level but yes ! shouldnt need that much up trim . Dont understand because when i throttle down it glides fine in manual mode maybe thrust angle?

[Brucey]

Have to reset the stick centres in the mfd after adding the 20clicks of trim?
How does it fly in stab mode?

[hellsbells1]

hi brucy it flys well in stb mode i understand what ian is saying thats alot of up trim 20 clicks and havent changed thrust angle or anything ! not sure what you mean regarding resetting trims in ap?

[BigT]

Cal Joystick is a crucial step in setting up the MFD AP. After trimming for straight and level flight in man mode, land and without moving any trim go to the menu and find Cal Joystick and run it. If at any time the trims are moved on the tx even if the plane is not on, you must re trim in man mode and do cal joystick. This is how the AP knows where "centre" is for any of the auto modes.

Can you post a photo of the elevator position in level flight mode so we can see how much up there is?  Also worth mentioning that cg position is a starting point and may need customisation for individual planes. Here is a comprehensive chart that I have used for years to set up all my models. http://www.gbrcaa.org/acrobatfiles/Trim.pdf
I can guarantee that if you follow the chart and any model is still a pig to fly then it's the design of the model.

Sent from my iPad using Tapatalk

[hellsbells1]

many thanks for the reply T shall take a photo of elevator trim from neutral position of elevator its around 5mm of up which doesnt sound alot but i think what ian is saying is right! shouldnt need that much up for level flight this is why i think im having so much trouble with the other modes ! mainly auto launch , Shall try and post pictures T im thinking of resetting all and starting again which is a shame because ive calibrated voltage and current and there pretty spot on! So would have to do it all again!  But thats the nature of this hobby i suppose? tried to upload pictures but its not doing it for some reason. sorry
                                                       regards trevor

[hellsbells1]

T forgot to ask ya when doing common calibration it says in the manual to raise the nose slightly, but by how much? is the question ? 1" 1 1/2"  2" an idea would be helpfull? regards trevor

[BigT]

Raising the nose for CC is trial and error. I would want to be sure that I had the cg right first. Have a go at the manual trimming chart I linked. It's really very straight forward and works. My MFD Twin Dream launch angle was left as stock setting. However even on the TD if I don't get the battery in exactly the correct position every time I need to retrim. When flying LOS we don't see the small increases in lift and descend that we can see in FPV. Are you using a proper stand for setting the cg or just mark 1 eyeball and 2 fingers? I have used one of these for many years https://www.robotbirds.co.uk/default/test-equipment/blade-cg-balancer/multiplex-centre-of-gravity-gauge-693054.html

Takes the guess work out. There are plans to make similar on the net.  Even so that's only the starting point.

[hellsbells1]

Hi T i have a proper c of g stand, as we speak i have reset all in settings and set all surfaces to neutral gona try again! Ive moved c of g back about 5mm gona try that see if i can get it flying with little trim as possible. But many thanks for the link on trimming shall give it a go? shall report back let you know how its going . cheers trevor 

[hellsbells1]

ok just an update on mt testing!. set ap to reset and moved c of g back exactly half way between servo wire and spare and bingo! perfect just a couple of adjustments (alt-p) (cruize-p) (roll-p) each up by one!  and auto launch abit shaky but realized dont need to have it at full throttle! about 80% and away she goes as richard said in his tuning video perfect!. So really happy and gratefull for those who have helped along the way. Just need to find out how to upload a video for the next flight as coyote now and again keeps reminding me. But all in I think i have finally got it flying much better. If i remember coyote had something about how to upload vid?. cant find it!. But anyway big thanks to big T, coyote. cheers guys thanks for being patient with us.

                                                          kind regards trevor

[Coyote]

No worries glad you got it sorted out Trevor :)

[hellsbells1]

thanks ian