Spektrum Dx5e and battery power (a tale of woe).
 

Hello,

Have (had) an Eflite Apprentice with the Spektrum Dx5e transmitter. Had the original Alkaline double A batteries in it. Had been to the flying field about 9 times with it and was still showing 3 out of 4 LED lights on the charge indicator (75% power?). Was flying with a fully charged lipo battery in the plane when I noticed the plane was not responding well to my inputs, so I tried to bring it down. All the sudden I lost all control and the plane went to full throttle. Result was a full speed nose dive into the ground. Major bummer. After the crash I looked at the charge indicator and I was down to 2 out of 4 lights.

So my questions are. What did I do wrong and how can I prevent this from happening again? Another question would be could something else have caused the signal loss? Should I take it that the charge indicator lights are not that accurate? I am pretty new to the hobby so your advice is appreciated.

Hi And Welcome to Wattflyers, only fly your plane if you have all 4 lights on, if not, charge or replace your batteries, I am not sure if that radio has a charge plug or not, but always go out to the field with your transmitter fully charged, if not, a crash will happen, as you found out, and spectrum radios dont like low Voltage, Hope that helps, Chellie

Get some rechargeable enloops and keep them charged. I'd consider the lights to be a pretty crude indicator of voltage.

Rechargeable will keep their power up longer but when they run out they go pretty fast so don't push the envelope. They don't start out as high but hang in better. Almost all better TX are powered by NiXX rechargeable packs.

williamk
I've not been a fan of any radio that uses alkaline cells. Why? How many times have you had to "shake" your flashlite to make it come on? :(

I'd much rather have soldered or welded connections to your batteries than pressure contacts to the single use cells. :D

William,

Be wary of that E-Flite ESC in your bird. I saw one burn out today in my friends Apprentice. I have also seen a few Apprentices fall from the sky for unexplained reasons and we are thinking that ESC is not a good one. Spend 20 bucks of insurance and get a Castle UBEC so you can at least glide it in when that ESC lets go.

My pal has a PZ Corsair with that ESC and was having loss of control issues intermittantly. He replaced the stock E-Flite ESC with a 40 amp Turnigy Plush and it has not glitched since.

Well, this has been a lesson learned the hard way. I did some reading of my Spektrum manual and the spektrum website. The website gives the below warning. The manual says NOTHING about the charge indicator lights. The only thing the manual says is that an alarm will sound and the LEDs flash if the battery voltage drops below 4.7. I never heard an alarm.

So anyway, the way I read the below warning is that a bad ESC, loose battery contacts, etc, could also have been the cause of my crash. Would rather believe that then the fault was mine for being stupid enough to fly with a not fully charged battery :).

So do I have any other battery options with the DX5 or do I need to upgrade to the DX6 to get the battery pack?

WEBSITE INFO
Do ensure your system has adequate voltage

The #1 problem encountered by DSM fliers: inadequate power supply. Unlike PCM, where servos get "crunchy" at voltages as low as 2.5 volts, the digital system used in DSM shuts down at 3.2 volts. 99% of fliers have no problem, but when you do, it's a toughie. New QuickConnect software allows restoration of your radio link the instant voltage is restored.

CAUSES

• Regulators heat up, losing voltage
• Use of new generation high performance servos without increasing power available
• Ni-Cd/Ni-MH batteries with poor capacity/high impedance that cannot deliver the wattage the system needs
• Add-on power supply systems are sometimes not robust enough to handle high current for extended periods of time

Larry,

The Eflite ESC is supposed to have a built in UBEC. Not sure if I could bypass that to use an external one or not. So if the UBEC works properly would it have kept me from going full throttle? Even with no control if the motor had no power I may have had a more graceful crash, if there is such a thing.

Most ESC have a LVC Low, Voltage, Cuttout, that can be programed, if your plane went to full throttle, thats was more than likely a brown out, the receiver quit working for a few seconds, that problem may have been caused by the transmitter signal being weak, or by the BEC in the ESC getting hot, and not delivering voltage to the receiver or low voltage, a UBEC is a external bec to provide power to the receiver and servos and ESC, and is seperate of the ESC, the Eflite ESC has a linear bec in it, the newer ones have a switching bec, much better, if you have the older linear bec in the ESC, that very well may be the problem, and a UBEC will correct that, here is a great ubec from Castle Creations, its cheap insurance, Take care, Chellie

PS, the original red wire in the ESC, that goes to the receiver is removed to use the UBEC, if your receiver has only 4 channels, then you will need to use a y connector in the throttle port of the receiver to power the receiver and servos.

http://www.castlecreations.com/products/cc_bec.html

http://www.wattflyer.com/forums/show...&highlight=bec

http://www.wattflyer.com/forums/showthread.php?t=39138

William,
The DX6i uses 4 AA batteries as well, but comes with rechargeable AA cells. You can do the same thing, get a set of rechargables with a a charger so you can top them up before going out to fly. I have been using the AAs for a year now with hundreds of flights and it has been rock solid. The DX5 is a decent radio, I bought one for my daughter so we could buddy box.


I really think your problem is the ESC, read the links Chellie posted, a seperate UBEC can be used with the E-Flite ESC.

Thanks for your input guys. The replacement motor I have in mind requires a different ESC anyway. Looking to replace the motor with a 3548-09 from Heads UP RC and the ESC with a Power Up Pro 40A ESC. This ESC has a switching BEC. This combo will only cost me a few dollars more than just a replacement motor from E-Flite.

I think you have learned a lot here in a very short time Williamk :D thats what we are all here for, We Dont have a life, Wattflyers is our life :Q Take care and have fun, Chellie

Thanks Chellie, you too.

A word of caution if you plan to replace the dry cells with rechargeables. The battery box on the E5 is undersized and will not accept any cells that are at the high end of the allowable sizes for AA cells. There is a standard for cell size and the battery box on the E5 will not accept those cells at the wide end of the allowable physical dimensions. In my case, the Duracells would not fit but some other brands will.

Thanks for the advice
 

Even though your post is over a year old, it has good advice. I had the same problem and then took your advice and went with UBEC's. It cured all my hot and failing ESC problems.
Thanks,
Frank

Actually only May of this year.
I still feel the OP's problem was the Tx batteries. The loss of control and full throttle was the "smoking gun". Failure to correctly set throttle failsafe and then confirm that it is set properly is a big problem with 2.4Ghz radios. I know I'm making an assumption:o, but is a safe one;).
We just had a nasty incident with a large gasser at our field, the plane was on the runway, when the loose fitting Spektrum conversion module lost contact, the model carreened out of control, fortunatly only the model was damaged.
Pete

Battery fit is THE problem
 

I just went through this problem with a new guy at our field. I test flew an Eflite L4 for him and lost link about 100 feet away.
This past Saturday he brought the repaired plane back to the field. I insisted on another, more rigorous, range test this time. While I was walking away I lost link a couple times. I finally tracked the problem to the battery box. The batteries weren't seating firmly and the Tx kept rebooting. I removed the lower metal battery tab and put some small bends in it to help make better contact. That helped for now but this is a mechanical problem that is causing crashes. A minor redesign of the battery tabs would fix this.

I've never been much of a fan of those battery boxes for the alkaline, Nicad, or Nickel Hydride "AA" batteries. Just think of the times you've used a flashlite where you had to shake it around to get it to light up. :(

IMHO, only use a Nicad or Nickel Hydride battery pack with their welded and soldered wiring in the transmitters and receivers for something as expensive as a radio controlled model airplane. :tc:

Just a Thought for you... before you change out the busted motor, contact horizon, A buddy of mine had a similar incident, and they replaced the motor and esc free of charge.. they didn't even make him send the old one back...

One thing I would double check... make sure you bind it with throttle off... that way if it does brownout, it will kill the throttle instead of going to full throttle...

SK

Ministeve, that was another indicator that the link was dropping. When the 'student' (in his early 70's) bound the Rx he must of had the throttle trim up because the little Eflite Park 250 would just start ticking over every time link was lost.

DX5e - I too have had problems with the tx batteries losing contact whilst operating the unit - then application of failsafe and (after joggling the batteries) a lengthy re-boot/re-connect before control is re-asserted. I'm using it for a model boat and zero throttle equates to full speed astern - not very nice either! No matter what position I put the throttle stick in during the bind procedure (ideally I'd like it at mid position 1.5mSec - for my boat), the throttle channel always sets itself to (a measured) 0.91mSec ie low throttle (or full throttle if you've set up your ESC/motor incorrectly!) Can anyone else confirm this is 'normal' - the DX5e manual seems to *suggest* the throttle will failsafe to the position it was set during binding, though they instruct you to put it fully down (zero throttle for aircraft) in the procedure.

By the way, I'm into electric flight as well - but indoor free-flight and am developing a timer/flight profiler that may be of interest to you guys

YouTube - Revised Electronic Free Flight Timer [Bench Trial]

This is off topic of this thread. But ???

Those PicChips can be a lot of fun. I've put together a number of these units that show total number of flights, total flight time, total ampere hours, then changes over to either ampere hours for the current flight when the motor is off, or amperes when the motor is running.

Its range is 0-51 Amperes, and some of my models have had over 250 Ampere Hours cycles through my 6S2P A123 battery packs.

If you've not made circuit boards before, check out www.expresspcb.com. They have their "Miniboard" service where they will deliver three 3.8 by 2.5 inch double sided, plated through hole circuit boards for $59, delivered to your house. Their web page has all the schematic layout, PCB layout software for this type of project. If your project is small, you can put several projects on one 3.8 by 2.5 inch board, and saw them up into individual boards for your project. I can put six of these meter displays on one circuit board.

Before retiring, I had them make several circuit boards that were 12 by 8 inches in size.

@kyleservicetech - I'm totally out-classed with my offering! Very smart bit of kit you've nailed together there! I'm very familiar with expresspcb, use it to plan veroboard (stripboard) layouts prior to building them - but never called on them to supply a PCB. The unit you saw in my video was a conventional component version (for development) prior to going surface mount for small indoor models using 6mm pager motors. A pal in industry (like you I'm retired now) has offered to do a load of my half postage stamp size boards on the edge of one of his production board runs, and just cut them off for me!

You should have seen my first projects with these microcontrollers. Those were the days when getting an LED to flash was a major accomplishment. That was 20 years ago.

I'm using the Picchip Pickit 3 with assembly code on various projects. Microchip allows you to program your project, set up break points, and so on, to single stepping through your program. You can program these chips in circuit, and try, erase, try, erase. You get the idea.

Send me a personal email if you are interested.

Will a Picchip Pickit 3 keep my DX5e from losing power? Where can I get one?

Lets see. :D :D :D

Picchip Pickit 3 =$60
Project boards =$60
PicChips =$2 each
Practice lots of practice with these :censor: chips =100 hours or more
Interface between PicChip and DX5e $100

H'mmm
Might be cheaper to buy another DX5e :D :D :D