aracopter

Should i wait for Futaba 7c 2.4fasst or buy the DX7 now?
i have a TREX 450se v.1

Patto

I'd wait for the Futaba if I were you, just because I like the programming of the Futaba radio better.

But, then again, if you have anything with dual elevator servos and one needs to be reversed, the 7C can't do it and make the trim work with it.

I've played around with the DX7 and I think it's a fantastic radio, competitively priced, (except for the receivers!) and it has a lot of features. The JR programming has always felt somewhat clumsy to me, though.

BillS

There have been a number of expensive airplane crashes with Spectrum due to low voltage spikes rebooting the receiver. It is too early to determine if Futaba has the same type of problem.

Bill

Radimani

So far there's no voltage issue reported for R606FS FASST. Does anybody know any problems for R606FS? Except its compatibility problem with forthcoming modules.

aeajr

My Feedback: (2)

All the 2.4 GHz receivers will have low voltage reboot issues as they are all little computers.

The problem is that our 72 MHz receivers are pretty dumb so they are less voltage sensitive. We may have been having problems all along but never felt it.

You have seen more about this on Spektrum because of the large installed base and because the receivers take longer to reboot, 3-4 seconds is what I have heard. The XPS reboot very quickly. There are so few Futabas out there that we may not be hearing about the problems.

If you properly size your receiver battery so you don't get voltage sag below 4 volts you should have no problems. If you have a BEC that is feeding your servos, make sure you are not overloading it.

Even with XPS or Futaba, assuming they can reboot faster, you still don't want to be in this situation. Many users are now going to 5 cell larger capacity receiver packs to insure this does not happen.

Just new stuff to watch based on new technology.

Iflyglow

My Feedback: (79)

If people would use common sence, there would be no problem with DX7. I actually witnissed a 80" Bipe with a 80cc twin crash last weekend with a DX7. The guy was flying it with the stock 1100 mah battery, and 8 thirsty servo's. The plane locked up on like the 3rd flight and spun in full throttle. He was smart enough to blame it on the battery and not the radio.[sm=idea.gif][sm=idea.gif][sm=idea.gif][sm=idea.gif]

DougV

My DX7 locked up on the first flight today for 3-4 seconds throttle went idle . It hasn't done it on my two helis though!

1800 5 cell batt.
-Doug

aeajr

My Feedback: (2)

Your Transmitter locked up? I have not heard of THAT problem. I have only heard of receiver locking up.

Ed

Amen brother. Since these Spektrum threads have started, I continue to be amazed at the number of people in this hobby, who for some reason, ( as you say, lack of common sense ? ) are just unable to provide the manufactures specified voltage to their receivers. All electronic devices have a low voltage at which they will fail. What is so difficult to understand ? ? ? I just don't get it.

Adios ................ I've got better things to do.

> Jim

kbless7

I will be getting the DX7 in a couple of days...so should I not use the provided Rx battery for my U-Can-Do w/ 6 servos or will I be charging it a lot more?

-Matt

Patto

I'd recommend going to 6V and 2000+ mAh's.

-Pat

kbless7

who makes a good cheap one?

bruce88123

It just doesn't seem like there are very many plane set-ups where the DX7 system, as sold from the factory, would work very well. Almost all nitro powered planes seem to need bigger batteries. Why do they even include a battery pack with the system if it's going to need to be replaced immediately?

rmh

If you look at the history of how basic radio systems have been sold -- you see the answer.
basic systems ALWAYS have included a basic set of servos and a battery pack suitable for a small sport model .
The DX7 took off like a rocket -sales wise -once users found how well they worked - --that started the so called problem.
The 3d craze and adding high throws and bigger servos -willy nilly- with little understanding about power consumption, left , (still leaves ) people with badly mismatched power/ power consumption arrangements.
In our current world of "turn key" desires - the first thing to be blamed is of course - the new system - NOT the user .
If you are flying any of the 2,4 systems - not just DX7 - you should look at the power/ consumption match
In spite of the PUFFING about better reset rates etc., on certian products - remember this : any of em will stop functioning correctly once the power supply drops into the 4 volt range .
I say this because 4.8 volt systems are the lowest battery pack voltages presently available and these are effectively depleted once they reach 4.8 volts . A 6 volt system is better in that the present products all work with it and the "overhead "of voltage is further from reset values (3.5 volts )

rcguy!

My Feedback: (69)

I ASSume you speak from experience?

Hmmmm...... I fly my Hangar 9 ShowTime 4D 90 with the 4 servos included with the DX7 radio package plus an 8411 on the rudder. I use a UBEC off the CC 85HV speed controller. I have NEVER had a problem. To add to this..I fly a turbine powered model on a single 4 cell 2300Mah pack running 6 digital servos on all flight surfaces...again NEVER a problem. The package is fine for sport type planes. Yeah...I'd upgrade the battery on more demanding service. For example:

http://www.rcuniverse.com/forum/m_6058973/tm.htm

Trust me when I tell you...I've seen long time R/C flyers truly abuse their battery packs and then claim "I got shot down"

"Yeah you're right...by your own stupidity!"

Dave

Panzlflyer

My Feedback: (15)

amen to that

RaceCity

Amen to a bunch of what has just been said. A little common sense goes a long way. Just because one can plug in a bunch of servos (with a current draw greater than the starter motor on an old Peterbilt) doesn't mean it's necessarily a good idea with the stock battery, and illustrates that some have checking account balances that far exceeds their IQ.

Incidentally while we're criticizing the puny little battery.....the "stock"1100ma/h battery supplied with the DX-7 (and other JR models) is considerably larger than the 600-700ma/h batteries supplied by other manufacturers. So.....Spektrum/JR are at least TRYING to give you a chance. Obviously, if this isn't enough....USE A BIGGER BATTERY. Just like we always did.

Patto

Here are some batteries from Battery Island on ebay. I've bought from them many times, and one of the guys in my club did some tests on their batteries and was very impressed with the results. They are, as an added bonus, very affordable!

http://cgi.ebay.com/2-RC-6V-2500mAh-...QQcmdZViewItem

If that one has ended, here's another one:

http://cgi.ebay.com/2-RC-6V-2500mAh-...QQcmdZViewItem

These folks ship quickly and provide great service if you have any problems.

I hope this helps. I, for one, have no use at all for stock batteries, although I would agree that Spektrum and JR are at least giving you some mAh's to play with compared to my radio brand, (Futaba) who only gives you a few hundred mAh's with their systems...

-Pat

fadi

Never had a problem with my DX-7 provided receiver and battery.
I installed them on a funstar 3D, and it works perfectly, never had a glitch or a lock up.

I shall admit that sometimes it doesn't bind, and I have to turn off the transmitter and then turn it back on. But that's of course when I am still on the ground and never when flying
I've never tried to figure out why, but can it be bcs of voltage levels?

I highly recommend the DX-7 if that's what you are budgeting for, and the programming features are enough for you.

rmh

These may be really good cells -
It pays tho to check out the prescribed application of the cells
If for example -they are like a particular Sanyo 2700cell which is a terrific long life design - may also have extremely high internal resistance .
this type cell is great for cameras etc..
If you go to cheap batts or No BS -in some cases they list the impedance of the cells
For our uses - really good cells have impedance ratings no higher than 10 - the Sanyo I mentioned is --25--
The problem with the high impedance cells is that the cells ability to hold voltage levels -under load- is poor -so even if you check cells before and after a flight the IN USE voltage can be faaaar lower .
FWIW I check my cells by watching a tiny LCD Voltmeter which is plugged into the rx .
this shows voltage that the system sees IN USE
As an example the V meter may fluctuate down one or two bars on really hard mixing of all the controls .
In any case , I never let it get to the RED bars ( Green-Orange -Red). If I am adjusting one servo at a time - I have on occasion, seen the meter drop instantly as I apply -say - for example full left rudder - This indicates that the servo has for whatever reason hit a load point which is drawing huge current . I then reset that point till load no longer causes a drop.
It is a simple way of setting up the system and in reading some bitter complaints about "the radio" -it is obvious from the complaint that the user has no idea as the loads in the system .
Some well known flyers are also guilty of poor servo/ power setups- relying on bullsh-t fro the power unit mfgrs
If you want to get best possible setup - check out your system yourself -it is extremely simple
remember - NO before or after readings mean squat - it is the IN USE readings which count.

kbless7

Would these batteries work with the AR7000. It says its for futaba, JR, and Hitec. I just want to make sure the connections are standard all around.

kbless7

Also,

Should I get a NiCd battery or a NiMH? Does the wall charger have to be specific to the battery?

-Matt

JCINTEXAS

"I check my cells by watching a tiny LCD Voltmeter which is plugged into the rx . this shows voltage that the system sees IN USE"

Dick,
Great idea.
I want to do this too. Please advise as to what "tiny LCD Voltmeter" you
are using, where these may be purchased, and any instructions needed
as to how to install this little Voltmeter in my airborne system.
Regards
JC

BTerry

My Feedback: (8)

JC, here are a few options for you. Buy it at any LHS (or online), plug it in just like a servo.

http://www2.towerhobbies.com/cgi-bin...?&I=LXHDJ2&P=7

http://www.horizonhobby.com/Products...ProdID=EXRA501

http://www.horizonhobby.com/Products...ProdID=EXRA500

http://www.maxxprod.com/mpi/mpi-6.html

Patto

KBless:

your standard wall charger will work for the NiMh batteries, which I definitely recommend over NiCd's. And yes, if it says it will work for JR, it will work for Spektrum, as far as the connectors go.

JC:

If you look at the ebay store Battery Island, where I linked earlier, it just so happens that they sell similar LED volt monitoring meters for cheap. I think you get three for like $25, compared to about $15 for one through most other places.

-Pat