My throttle is reversed

[Pjbaker]

Good morning,

I have a pretty serious issue. I flew glow fuel for years but I am now switching to electrics and so this is all new to me.

I have a Spektrum DX7 radio and receiver. When I hooked everything up I had control of all my control surfaces but not of my throttle. After it sat for a little bit the the motor began to beep and when I moved the throttle stick up the ESC bound my throttle control in a reversed position - up is off and down on the stick is high throttle. The motor is running in the right direction and I know to simply change to motor connections to reverse that, so that is not the issue. I then went on my transmitter and reversed the throttle channel so that up is high and down is low as it should be. Yesterday I discovered a really bad problem with this. I accidentally shut off my transmitter before unplugging my battery as I was making final prep to go out to the field to fly which put the ESC into fail-safe mode, which normally would turn the throttle to off automatically but apparently because I have the transmitter reversed on the throttle it throw it into high. Luckily my plane only went zipping across the dining room table, hit a chair and nicked the wood, broke the prop before the battery (that I had hanging lose) disconnected. It could have been really bad but thankfully God was watching over me but boy is scared the dickens out of me.

How do I rebind the radio to the ESC or how do I get the fail safe to reverse on the ESC? I have no idea of how to even ask the question or look this up but I tried and couldn't find an answer, so really hoping someone here can help me out as this is a big problem.

Thanks in advance.
John Baker

 

[Robert S]

What flight controller do you have? Was it one that came with the transmitter as a package?

What pins do you have the ESC plugged into?

 

[Pjbaker]

I am using a Spectrum DX7 radio with an AR7000 receiver. The ESC is the Flite Test 35A ESC w/XT-60 Connector. I have the ESC plugged into the "throttle" channel/pins (#1) on the receiver. The motor is the Radial 2218/1180kV sold by FliteTest in their Power Pack C.

 

[Merv]

...I moved the throttle stick up...How do I rebind the radio to the ESC...

The first thing is to remove the prop, until you are sure this is fixed. Then reverse the throttle channel on the Tx.

By starting with the throttle high & moving it to low, you calibrated the ESC, something that needed to be done anyway. You are showing the ESC what full throttle & no throttle looks like on your Tx.

 

[Pjbaker]

The first thing is to remove the prop, until you are sure this is fixed. Then reverse the throttle channel on the Tx.

By starting with the throttle high & moving it to low, you calibrated the ESC, something that needed to be done anyway. You are showing the ESC what full throttle & no throttle looks like on your Tx.

Pardon my ignorance - this is all new to me. How do I do this? You say "by starting the throttle high & moving it to low, you calibrated the ESC," Is this the order of what I need to do...

• make sure the prop is off (did that and found out the hard way why that is important)
• turn on my tx and reverse the throttle back to its normal setting
• set my throttle to high/full position
• plug in the battery on my plane
• move the throttle from high to low

Should the motor beep in this process and if so, what beeps am I looking for?

 

[Merv]

... You say "by starting the throttle high & moving it to low, you calibrated the ESC," Is this the order of what I need to do...

Yes,

Here is the order to calibrate the ESC.
First remove the prop.
Turn on the Tx, move the throttle high.
Plug in the ESC, wait for the beep.
Move the throttle to low, wait for the beep.
Unplug the ESC, turn off the Tx, you are calibrated.

The exact beeps will depend on the brand of ESC, mine usually beep just once. With others, wait until the beeping stops.
You should only need to calibrate an ESC once, when it's new, or if you switch an ESC to a new Tx. You are 'teaching' the ESC what high & low throttle look like. Occasionally an ESC will loose calibration & you will need to repeat it.

BTW, the beeping comes from the motor, the ESC has no speaker or buzzer. It just vibrates the motor to produce a sound. If you unhook the motor, no beeps.

To reverse the throttle or not will depend on the ESC, some are normal some are reversed.

 

[Pjbaker]

One last question. If I plug in the ESC and the motor takes off in high, what do I do to force a recalibration or should it not do that? Is setting the throttle at high the signal to the ESC to calibrate it?

 

[Merv]

...Is setting the throttle at high the signal to the ESC to calibrate it?

Yes, starting the ESC with high throttle puts it in calibration mode.

 

[Pjbaker]

Yes, starting the ESC with high throttle puts it in calibration mode.

Sad to report the issue is still present. I made sure the transmitter throttle channel was set to normal. Turned the Tx on and off to double-check. Put throttle in high position. Plugged in the battery, the motor beeps several times in various pitches. The throttle worked as expected. I unplugged the battery to the ESC and plugged it back in again. All still functioned as expected, but if I turned the Tx off the motor would spin up to full throttle until I turned the Tx back on and reconnected with the receiver. That is working the opposite as I would expect it should. If the plane went out of range instead of killing the motor it would rev it to high.

 

[FlyingMonkey]

Hey PJ!

First off, it sounds like the throttle setting in your controller may be reversed. This could happen if you used that receiver already in one of your glow planes, and set up the throttle reversed for that, and you didn't create a new model and rebind the receiver for the electric.

I ran into this exact problem when I was setting up an FM radio with my first electric plane. Futaba has it's throttle signal backwards from JR and the ESC's are set up for the JR/Spektrum systems apparently.

Not sure how long ago you used to fly, but if you remember the old FM radios, they used to have a channel reversing switch. That's all done internally with the radio now. Throttle is channel 1. Reversing the channel should solve that problem.


As to calibrating the end points in the ESC... This tells the ESC what the range of stick movement is. You'll need to do this now since the ESC was improperly calibrated when you first plugged it in and you had the run away plane.

With the airplane unplugged, and the radio off, you move the throttle stick to the full throttle position (high). When you plug in the airplane, this tells the ESC to go into programming mode. As soon as it beeps, you return the throttle to zero (down). This will let the ESC know where the high and low settings for the throttle range are.




All that being said, the best thing you should do is delete that model from the radio, and create a new one, and start over with a new bind to the receiver.

 

[FlyingMonkey]

https://www.manualslib.com/manual/719476/Spektrum-Dx7.html?page=21

 

[HVB79]

Two different issue here:
1. Throttle is reversed
2. Failsafe is set incorrectly. This is not an endpoint issue or radio programming issue, it is a receiver failsafe issue.

To fix:
1. Reverse the throttle channel and get it working correctly. Down is off, up is full.
2. With the throttle in the down position, rebind the receiver to the radio.

By default, Spektrum receivers set the failsafe to whatever position the sticks are at when you bind the receiver. Because you bound the receiver with the throttle channel flipped the receiver is using the wrong failsafe value.

 

[Pjbaker]

I figured it out!!! (yay) It had nothing to do with the reverse setting for the throttle on the Tx or the ESC. When I last set up the Tx and Rx for my gas planes I had the failsafe set opposite as I had the throttle channel reversed for the plane I was flying. I had to reset the Spektrum's fail-safe by rebinding the Tx and Rx. It was a simple process and now all is good to go. When the Tx is turned off, the throttle drops to 0 now as it should. Thanks, everyone for helping me track this down. I am learning a lot of new things with the electrics and this was just a dumb oversight that would have been a problem even with gas engines.

 

[Pjbaker]

Hey PJ!

First off, it sounds like the throttle setting in your controller may be reversed. This could happen if you used that receiver already in one of your glow planes, and set up the throttle reversed for that, and you didn't create a new model and rebind the receiver for the electric.

I ran into this exact problem when I was setting up an FM radio with my first electric plane. Futaba has it's throttle signal backwards from JR and the ESC's are set up for the JR/Spektrum systems apparently.

Not sure how long ago you used to fly, but if you remember the old FM radios, they used to have a channel reversing switch. That's all done internally with the radio now. Throttle is channel 1. Reversing the channel should solve that problem.


As to calibrating the end points in the ESC... This tells the ESC what the range of stick movement is. You'll need to do this now since the ESC was improperly calibrated when you first plugged it in and you had the run away plane.

With the airplane unplugged, and the radio off, you move the throttle stick to the full throttle position (high). When you plug in the airplane, this tells the ESC to go into programming mode. As soon as it beeps, you return the throttle to zero (down). This will let the ESC know where the high and low settings for the throttle range are.




All that being said, the best thing you should do is delete that model from the radio, and create a new one, and start over with a new bind to the receiver.

That was exactly the problem!! You responded as I was figuring it all out and hunting for my binding plug.

 

[Pjbaker]

Two different issue here:
1. Throttle is reversed
2. Failsafe is set incorrectly. This is not an endpoint issue or radio programming issue, it is a receiver failsafe issue.

To fix:
1. Reverse the throttle channel and get it working correctly. Down is off, up is full.
2. With the throttle in the down position, rebind the receiver to the radio.

By default, Spektrum receivers set the failsafe to whatever position the sticks are at when you bind the receiver. Because you bound the receiver with the throttle channel flipped the receiver is using the wrong failsafe value.

Thanks for your help today. That is exactly what the problem was. All is now working as expected and that is exactly what I did, I had the radio set up and bound when I had my gear in a different plane and the throttle was reversed.