I Setup My New Yak 54 67" With A Dx7 I Flew Maybe 10 Flights With No Problems At All, It Seemed To Work Fine Untill Yesterday, I Took Off In Kind Of Heavy Winds Maybe 10 Mph,i Took It Up To About 300 Feet
Nose Into The Wind My Sato 125 Was Running Perfectly,no Problems,
Then All Of A Sudden It Went Nutts, I Had No Controll It Rolled To The Right And Started To Dive Back With The Wind, I Was Moving My Sticks Around Like A Mad Man With No Responce At All, Then I Tryed Running Tward The Plane With My Tx Held Up As High As I Could Get It
She Was 35 Feet From Disaster When I Regained Controll, I Landed With No Damage, Only By The Grace Of God,pure Luck, I Shut It Down ,and Noticed That The Orange Led On The External Rx Was Out,i Packed It Up And Brought It Home,and Checked It Again,the Led Was Back On
Im Like Thats It,i Am Not A Beta Tester,not With My Nearly 1000$ Woth Of Model, I Spent Most Of The Night Re Setting Up My Futaba 7 Chp With A Pcm Rx And New Lipo System..now I Cant Figure Out How To Setup Dual Elevator Servos On The 7 Chp I Have Them Setup
On 2 And 6 In P-mix 1 With 2 As Master And 6 As Slave It Works Fine But The Dial Acts Like A Trim For The Left Eleavator Is There Any Way To Avoid That?????

I liked it better when you didn't use your shift key at all.

http://www.rcgroups.com/forums/showt...91#post7486191
http://www.rcgroups.com/forums/showt...83#post7486183

what the hell does that mean ?

Yakman,

What are you using for an RX power source?

Originally Posted by Yakman13

what the hell does that mean ?

I believe he was commenting on the odd capitalization of the first letter of each word in your post.

But to respond to the problem, like Critical Mach, I wonder if you pulled the voltage down too low on your RX pack and reset the Spektrum RX.

Originally Posted by bjpaul

But to respond to the problem, like Critical Mach, I wonder if you pulled the voltage down too low on your RX pack and reset the Spektrum RX.

That's what I was thinking. Were you using a separate battery source for the RX or sharing power with the servos, from a main battery pack.

Originally Posted by Yakman13

what the hell does that mean ?

It means unusual application of the Caps...........

Anyways, 10 flights of how many minutes each? Lets say at least 8, and the Spektrum supplied digital servo load (how many servos?) on top of that?
Were you using just the one supplied 4 cell Spektrum 1100NiCad?
My guess is that the load on your battery after 80 minutes of prior flight drew the voltage down to below the Rx tolerance (see a couple of other threads on that issue).

As for me, I go with a 5 cell NiMh and on big models I go dual battery 1500mah each.

Cheers,
-Mike

i think that was {bc} in the original text i left the caps on,and when i uploaded the post it did that with the caps for some reason,i wasent about to re typ all that cuz of caps...lol
anyway i was using pac that the spectrum came with and the voltage meeter was bright green in all stick positions...

i dont think it was the pac at all,cuz it happened it the first min. of flight but i did go ahead and replace that as well "just in case" now i cant figure out how to program the futaba 7chp for dual eleavators can anyone help with that ?

thanks
jim

There was another thread where the same thing happened and after calling Horizon they recommended switching to a 5 cell pack.

Yakman:

Could you just clarify the state of the battery. Was this the first or the 11th flight of the day? (I assume the first, but others read it differently). Had you given the 1100 mAh pack a full charge with a suitable rate charger?

Yakman: On the Rx battery low volts aspect perhaps you consider investing in an audible or audio/visual alarm for the LiPo pack - have a look at http://www.tjtrc.com/LiPoV2.html.

"Thanh" runs it and has several kits from just a low volt 93db beeper alarm up to strobing LED's. Tell him how many battery cells are involved and he'll set the safe "under load" volts on the PCB so that the various alarms go off before you suffer power loss and/or battery damage. The costs are reasonable - either make-up kit or fully assembled and with a power takeoff from your battery to the PCB plus a signal connection to a spare Rx channel. There are several other makes available but Thanh can talk to you about your exact needs. Cheap insurance.

Good luck.

Hi Yakman,


There are probably a lot of us who are interested in the power system details.

I just want to confim...

What servos were you using and how many were there?

This has been reported in other posts and I've seen in my own tests that the small 4.8 volt and even AA 6 volt packs do not handle digitals well. 1 stalled digital can pull around 1 amp.

Can you put the stock pack on a discharge cycle of 3 - 5 amps and see what the resulting voltage is? It would be worth it to find out it it is dropping below 3.5 volts. The rx is rumoured to reset at about 3.1 volts.

If you had a beefy pack that was charged up well that's another matter.

Thanks in advance for the info.

By the way, what Yak are you flying. 67" sounds good. I might want one.

The RX resets at 3.*7* volts. That's rather high for a typical RX.

Short answer: use 5 cell or a proper regulated setup, especially on something expensive. A 2-cell lipo and a big switchmode BEC is lighter than a nickel pack anyway, and a trivial fraction of the cost of the plane.

Originally Posted by Yakman13

now i cant figure out how to program the futaba 7chp for dual eleavators can anyone help with that ?

The 7C doesn't support dual elevators.

Although it's billed as a 7-channel version of the 9C, the 7C is actually missing quite a bit of its big brother's functionality and dual elevators (with linked trim) is just one of the nice 9C features that was dropped.

Originally Posted by Andrew McGregor

The RX resets at 3.*7* volts. That's rather high for a typical RX.

Short answer: use 5 cell or a proper regulated setup, especially on something expensive. A 2-cell lipo and a big switchmode BEC is lighter than a nickel pack anyway, and a trivial fraction of the cost of the plane.

Someone on another post both recently and extensively tested the 7000 RX with a variable DC power source on an oscilloscope and consistently got a reset voltage of 3.1 volts. See my next post.

How did you arrive at 3.7 volts?

Have you tested this and with what type of equipment?

Thx,

r