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Pumpkin drop event

UMX Radian won’t bind throttle

#1
First RC plane, ever. I got the UMX Radian <BNF> from Eflite, (because I knew I would crash so I went for a cheap starter)... also, as far a I know, the AS3X receiver helps a lot with corrective stabilization.

I plan to upgrade planes when I learn to pilot basic RC, so I got Spektrum 6e DSMX transmitter so I can control ailerons (etc) in future models.

Problem is, binding was partially successful - for elevator and rudder - but COULD NOT bind throttle!

workaround #1: throttle stick is bound, but has no effect. So I decided to use Trim slider as the throttle control. However, this method was unable to provide enough throttle to get airborne (I estimate it maxed 20% throttle?)

workaround #2; not sure what I did differently, but now I can get 100% throttle. But stick for throttle STILL don’t work, so I have to toggle a switch, which gives only 0% throttle or 100% throttle. Don’t really want that...

I really can’t figureout how to get the throttle stick to bind and respond as needed!

Can anyone offer guidance? It’s hard to find instructions (6e with UMX radian), since it’s probably trivial for most people with a 6+ channel transmitter to easily bind this basic sailplane.
 

FDS

Well-known member
#2
The TX is bound, it doesn’t bind individual channels. The bind process is a digital handshake that stops your receiver taking commands from other transmitters.
Did you have to assemble the plane or was it pre wired? If you wired it you might have a plug wrong.
Do the ailerons work?
You may have something going on in the settings. I suspect you have accidentally set a throttle cut or switch arm that is turning off the throttle. Your work around of having 100% throttle on a switch is not very safe, please don’t fly like that.
 
#3
It was pre-wired, BNF.

I have assigned a throttle cut switch for (1) right before crashing, and (2) my new situation where throttle is either 0 or 100.

The instruction manual with the BNF UMX Radian gave instruction for binding to a basic 3/4 channel receiver (whichever one is the cheapest Spektrum offers). Don’t work on Spektrum 6e....

My transmitter instructions differ, (Spektrum 6e DSMX - p.s. if you’re wondering my BNF AsX3 receiver is DSM2 and DSMX “ready”).

Elevator and rudder work perfectly, (even after repairing a rudder control horn which severed it from the rest of the rudder). From my best assessment, it appears that stabilization (“stab”) system is functional... automatic movements take place when I hold the plane and do unfavorable moves on elevator or rudder.

Throttle is the only real problem. When binding so that (A) the throttle TRIM adjusts throttle (not stick), I can’t pass ~25% throttle....it flies maybe ten feet from a 5 foot launch. Attempts to climb into wind with elevator up resulted in significant crashing (nose-down or looping into inverted crash land... usually).

So, I unbound the Radian, reset transmitter memory, this time set up for 3-mode prop sailplane models (1; launch ), (2; sail), (3; landing).
That’s when throttle trim was not necessary and NOW motor is either 0% or 100%. That’s the only change i’m aware of.

p.s. I know I have linear servos. I have NOT enabled any throttle curve variation or exponential curve on transmitter.

The one variation from instructions ( because instructions did not work ) was that I did not use BIND button on Spektrum 6e, but entered “System Setup”, temp disabling RF, thenn assigned Channels, set plane in bind mode, then Re-activated RF and chose BIND on the transmitter.... which successfully bound the plane... aside from throttle stick. (Now it’s 0 to 100; sure, cool for music, not cool for my plane)
 

Headbang

Well-known member
#4
You want the radian to be a standard acro model. Go to system and select acro, it will reset all settings to standard. Choose the wing and tail type. All should work. As FDS said, binding is binding. Everything else is in the settings. If throttle is in the throttle channel on the reciever and it still does not work, then calibrate the esc. Most esc's calibrate by unplugging the battery, move throttle stick to max, plug in battery and wait for a bunch of beeps, lower the throttle to 0. Not that the esc will arm, but just to be safe remove the prop for all bench testing and calibration.
 

rockyboy

Skill Collector
Mentor
#6
If the throttle trim button is adjusting the speed of the motor, then your problem isn't binding - it's something wrong with that stick in your transmitter. Both the throttle trim button and the throttle stick send control inputs inside the transmitter than tell it what final value to send to the receiver - and since a value is sent to the receiver with the trim, the channel binding is correct.

So I as I see it you've got two choices here - either call Horizon for warranty support on the transmitter, or pop the case open yourself (which could void the warranty if it is still active) and see if the throttle potentiometer is just unplugged or otherwise obviously damaged.

Also, this is an excellent first plane! I love my little UMX Radian for relaxing flights when the air is calm - especially sunrise & sunset flights :D
 

Headbang

Well-known member
#10
Quick question, I want to ask about whether an additional Servo can be added to the UMX Radian, and some advice about what I seek to achieve. What forum would be appropriate to ask this question?
Anything is possible. I personally do not have one, just helped others get theirs going at the field. Maybe @rockyboy can answer some more detailed questions.
 

The Hangar

Well-known member
#11
Quick question, I want to ask about whether an additional Servo can be added to the UMX Radian, and some advice about what I seek to achieve. What forum would be appropriate to ask this question?
For the micros I really don’t think you can add servos. But I only have the champ, so some other micro experts could give you better info on that. This forum is the right place to ask though!
 
#12
For the micros I really don’t think you can add servos. But I only have the champ, so some other micro experts could give you better info on that. This forum is the right place to ask though!
There are a couple of connectors on the brick that will accommodate servos so it should be possible. That said I never tried it and found the UMX Radian to be a very enjoyable plane to do most anything with as a 3 channel. My guess would be the tiny linier servos used on the Sport Cub S would work in that application.
 
#13
It was pre-wired, BNF.

I have assigned a throttle cut switch for (1) right before crashing, and (2) my new situation where throttle is either 0 or 100.

The instruction manual with the BNF UMX Radian gave instruction for binding to a basic 3/4 channel receiver (whichever one is the cheapest Spektrum offers). Don’t work on Spektrum 6e....

My transmitter instructions differ, (Spektrum 6e DSMX - p.s. if you’re wondering my BNF AsX3 receiver is DSM2 and DSMX “ready”).

Elevator and rudder work perfectly, (even after repairing a rudder control horn which severed it from the rest of the rudder). From my best assessment, it appears that stabilization (“stab”) system is functional... automatic movements take place when I hold the plane and do unfavorable moves on elevator or rudder.

Throttle is the only real problem. When binding so that (A) the throttle TRIM adjusts throttle (not stick), I can’t pass ~25% throttle....it flies maybe ten feet from a 5 foot launch. Attempts to climb into wind with elevator up resulted in significant crashing (nose-down or looping into inverted crash land... usually).

So, I unbound the Radian, reset transmitter memory, this time set up for 3-mode prop sailplane models (1; launch ), (2; sail), (3; landing).
That’s when throttle trim was not necessary and NOW motor is either 0% or 100%. That’s the only change i’m aware of.

p.s. I know I have linear servos. I have NOT enabled any throttle curve variation or exponential curve on transmitter.

The one variation from instructions ( because instructions did not work ) was that I did not use BIND button on Spektrum 6e, but entered “System Setup”, temp disabling RF, thenn assigned Channels, set plane in bind mode, then Re-activated RF and chose BIND on the transmitter.... which successfully bound the plane... aside from throttle stick. (Now it’s 0 to 100; sure, cool for music, not cool for my plane)
Try setting your Radian up as a three channel in acro mode on the 6e. I used throttle as is and set Rudder on the aileron channel. worked great for me using dual rates 70% 100%. To use it as a sail plane just kill the power and steer it.