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Setup of Jumper T16 w/ Apprentice S 15e

Hello All,

I am new to the forum, new to flite test, and new to RC. Please speak slowly and use small words. My plans are to build foam planes with my son and learns how to fly; in the preparation we have purchased an apprentice 15e BNF and a Jumper T15 for a primary transmitter for what is to come in the future. I was able to setup ch 5 (beginner, intermediate, advance) modes, ch 6 panic mode, throttle input block, and dual rate/expos. The problem is this: the control surfaces move even when it is on the floor of my living room. it seem to start after I give input from the radio and hold a stick in a position for about 30 to 40 sec. a control surface does quick moves to neutral and back to the stick position typically the one under stick control, moves when throttle is running (alerions), and moves when absolutely nothing is giving input (after running throttle - alerions). The movement repeats and not on a predictable cycle. The rudder, elevator, and alerions move independently; does not seem that multiple surfaces move at the same time. If anyone have had a similar experience or know of a solution please share.


mach1 rc

Elite member
Does it cycle only twice because that's supposed to happen. And after the 2 cycles the control surfaces should move when the aircraft is moved (for stabilization).
Yes, totally agree. It goes through its initialization and I have it on the living room floor with the prop off. I was testing my setup when I notice it. I though it was input from the radio; however the control surfaces move even when its sitting still. I though signal loss; as the servo moves to neutral and then back to the position of the stick. I am holding stick in position for about a min.; but it occurs even when all sticks are in zero output position and sitting on a flat floor. Occurs on all surfaces (R, E, A) and throttle. Outside of this, it seem to respond well to dual rate, hard to see a difference between beginner, intermediate, and advance on the ground. I should check panic by moving it around and maintain the ch6 output. It would be really scary for the rudder and elevator to move unexpectedly during landing. Need to learn how to fly fast! and then get rid of SAFE and Panic, still need it for now. They (Rudder, Elevator) seem to only move when I hold the stick in position. The alerions move when I keep stick in position, when running throttle alone, or when throttle is at zero output/sticks are at neutral after running up the throttle. I though SAFE activates after throttle is moved up above 25% and active after that until ESC is disabled. This happens before I activate the throttle primarily when I hold stick in position (A, E, R). I need to understand the SAFE control algorithms better, the override of the stick output if I keep it in position is a little disconcerting, maybe that is how it controls roll, pitch ect.? Why activate on a level living room floor (same where it initialized and in all three flight modes (ch 5))?

mach1 rc

Elite member
Sorry don't know how to help then. I did run into some problems with other eflite airplanes so I just fixed them by doing what the manual said over and over again. Good luck
@WrongWay_Anderson - maybe buy a standard RX (FS-iA6 would be good) and run the plan without any fancy gear - I can attest that the iA6 RX works with the Jumper (select FS 2A protocol).
Yes, I can. I would need to collect some new hardware and do without SAFE and Panic. I also set up with a DXe from a previous plane and it seem to work flawlessly. My doubleganger really want to use his Jumper T16, so there is the adventure. I just looked at the P40 build and perhaps that will be our first foam. At that point we can pick hardware that has telemetry battery voltage, gps, ect. The iA6 may very well be item one on the bill of material. Thanks for the pairing info, I will have to look it up. the jumper t16 holds really nicely, getting it in use early may be worthwhile. I want the P38 my son want the F4U, looking forward to glue and foam this holiday break. I really enjoyed learning about openTX and using it in these basic forms for the apprentice 15e setup; would be nice if I can iron things out.
@WrongWay_Anderson - do you have an option to set up the plane in a basic way without any panic modes (SAFE), and if so, is there any servo jitter?
I did not notice servo jitter. I assume this is like an industrial servo hunting for position. I will check again more closely. The is a loud noise (radio, did not sound like an oscillating servo) coming from the craft, could be jitter showing up as noise?


Legendary member
I have just swapped all my planes to the Jumper T16 and so far I am liking what I see - I use three different Rx's and they are all binding well - I doubt it is a Jumper issue for you, more the setup is probably the key - I do have a stabiliser that I set up on my FSi6s Tx and they are a bit weird when turned on if the unit is not flat to the wing and tail, and also parallel to the ground at startup - is the safe unit sitting at the CG of the wing (I was told that is important)?!
Thanks for the info. Setup is the factory setup; I have not moved any components around and it initializes level on the tripod landing gear. I will keep pushing on this, perhaps a light bulb will go off. Thanks for the Rx recommendation, I am really looking forward to building foam planes and using the T16 for that. Do you have any recommendations on telemetry Rx and sensors and T16? Thanks again for all your help.