Futaba problem

[marktigere1]

Hi Chaps

Whilst setting up the mechanical settings for the Shuttle I've noticed a small problem.

When I move the elevator servo, the throttle and pitch servos move very slightly as well.

I don't as far as I know have any mix dialled in as I've not set any up yet.

What could be causing this problem? I've changed the servos over, removed the links so there is no strain and the problem still exists.

Is it the TX or the RX?

Its a FF7 with 138DF RX, 3001 and 148 servos. The engine has not been run yet and I have an NHP rear servo mount for the tail using a digital servo.

Any ideas greatfully received as I've not seen this behaviour before.

Cheers

Mark

[Stuart]

Mark,

Any other movement in servo's would normally be as a result of and mixing. If you have none dialled in and you've changed over the servo's then I'd either try another transmitter or a different reciever, the only other possible thing maybe the crystal at a longshot.

If you don't have another RX I have a spare one from a Cautro I've bought that I'm about to sell, but you can borrow it if you want to tryout the RX theory.

Do you know anyone with the same TX to tryout ?

[Ade_Law]

good way to test if you are getting strange stuff going on with the tx would be to switch to a different model memory and default it.

which FF7 is it? is it the old one (7U) or the new one (7C)

Ade

[marktigere1]

Hi Stuart and Ade

Thanks both for the replies.

Stuart, I would be very grateful of the loan of the receiver, only a bit nervous of it getting damaged in the post or worse, lost.

I think I will obtain some different crystals and try this. I need to change my channel number anyway, 72 appears to be very popular around my way.

Ade, thanks for the advice. I tried changing models last night and used the default settings. The TX is the new 7C and is not a year old yet, nor used in anger yet. Again the servos moved. The funny thing is they move in the direction you move the elevator ie. they don't move randomly but slightly in each direction.

It looks like some form of cross talk to me but I need to find out whether this is from the RX or TX.

I have a JR transmitter thanks to Stuart (again many thanks). Can I try this with the Futaba crystals or are they very different? Excuse my JR ignorance but I've not used anything other than Futaba before.

Thanks for the advice guys.

Cheers

Mark

[Ade_Law]

are you sure its in heli mode and not one of the funny plank modes?

Ade

[marktigere1]

Hi Ade

No, I checked this first of all. Collective works okay and I have the Heli symbol.

One thing that has crossed my mind is the Heli mode. I'm using 'H-1' which I believe is the standard non-CCPM mode but I'll check this when I get home.

Thanks again.

Mark

[Stuart]

PM me your home address and I'll send you the Futaba RX to try out.

[Ade_Law]

h1 is the correct mode.

every strange.

Ade

[Emcy]

Sounds silly, but do you use a fully charged battery?
I had the same what you described with a battery which I thought was fully charged but in real was only charging to half capacity.

[marktigere1]

Hi Emcy

Interesting what you say.

I upgraded to a 1400 mAh battery from the standard 600 and am still using the original charger. I charge overnight. Is this enough? Sounds as though I may need to charge for 48 hours.

Will give it a go. If this is the problem I'll be a very very happy man.

Cheers for all the replies.

Mark

[antsis]

Mark

The easiest way to determine charging time on your battery is to take the total capacity, add 20% and divide by the charger output. Eg for a 1400mA pack:- 1400 + 20% = 1680. If the original charger was for the 600mA pack, then the output will be 60mA. Therefore 1680/60 = 28 hours. Standard wall chargers supplied with most transmitters do not have a cutoff when the battery is full, so it's important to charge for the correct time period only.

[Emcy]

Mark,

Since you have changed the battery, is it a 4 or 5 cell battery?

According to the Futaba Manuel Page 10 using the 5 cell battery (6V) will last appr. only half the time of a 4 cell pack (4.8V) due to the higher current to the servos.

Since I'm using a 4 cell 2100mA battery pack no problems what so ever anymore (Only an empty wallet since I had to buy a fast charger for it)

[marktigere1]

Thanks Ant

Very useful.

Emcy I have the 4.8V 1400mAh 4 cell battery pack. Its the same type that I have used in the past with my old Heli's and had no trouble like this.

However, I don't think I have charged it for 28 hours yet. I also have a Futaba battery checker/discharger and I'm not sure I have read the full 4.8V through 2A load so it may be the battery has not conditioned/charged itself fully yet.

Its the old rechargeable battery black art again? I work for an electronics firm and I don't mind telling you what a minefield rechargeables are to sort out

Cheers all

Mark

[marktigere1]

Hi

Quick update.

Changed receiver battery : No change
Changed servos : No change
Changed crystals : No change
Switched to separate memory : No change
Switched to Acro mode : Throttle servo continued to move as before

I think I am definately looking at equipment failure. Got to decide whether its the TX or RX now.

Cheers for pointers.

Mark

[G-DAVE]

Send it off to Ripmax - I wouldn't second guess ??
Dave