Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Radio Equipment => Topic started by: Stavros on August 29, 2006, 11:39:57 pm

Title: Futaba going crackers
Post by: Stavros on August 29, 2006, 11:39:57 pm
Got a good one here It has driven me mad today,yesterday after around 5hrs of sailing my Yacht started turning around on it's own I put this down to run down batts,how wrong I was.Today after charging batts I had to redo some of my sheets so out with the radio gear and start to re sheet,I then noticed that the rudder servo was getting jittery,I initially ignored this but when the sail winch started doing the same panic set in,I changed the receiver thinking water had got in but still the same,connected 2 new servos still the same,took boat outside thinking I was getting interference still the same,the further I got away the worse it got with the rudder going mad .Now I then decided to change the whole system to my Acoms 4 channel, problem cured,no servo chatter smooth as a baby's bottom,why has my Futaba field force 6 gone bonkers overnight so to speak,any suggestions,Must admit I am thinking that I should send it in for service or whatever has anyone had this problem Whit futaba
Title: Re: Futaba going crackers
Post by: Eddy Matthews on August 29, 2006, 11:42:56 pm
Sounds like a common symptom of crystals that have gone faulty... Have you tried changing the crsytals, particularly the Rx crystal?

Regards
Eddy
Title: Re: Futaba going crackers
Post by: malcolmfrary on August 30, 2006, 01:09:18 pm
There isnt really much to go wrong with a crystal.  Try cleaning the pins.  If there is any surface contamination in the socket, inserting and withdrawing the crystal a few times should scrape any muck off.  If you have a set of crystals for an alternative channel, try these.
Title: Re: Futaba going crackers
Post by: Stavros on August 30, 2006, 10:47:28 pm
will try that lads anything is worth a try
Title: Re: Futaba going crackers
Post by: cbr900 on August 31, 2006, 07:46:07 pm
If that does not solve the problem it may be a dry joint, that is a problem I had with one of my radios, sent it to the radio repair guy he tracked it down soldered and no more problems..


Roy
Title: Re: Futaba going crackers
Post by: Tug on September 07, 2006, 06:09:38 pm
Twas said "There isn't really much to go wrong with a crystal. "

But crystals are very delicate insides, ( a postage stamp with a wire welded to each side allowing the wafer to vibrate and the lower the frequency the bigger the wafer, But miniscule postage stamps.)

  rattling spares around in a tobacco tin is not recommended [but often seen]
Tug
(yes I am back, new phone and new address but!)
Title: Re: Futaba going crackers
Post by: Barthez on September 09, 2006, 05:00:28 pm
My old Futba attack set gave me problems for a while then a fellow club member put a signal strength meter on it. My set did not even move the needle on the meter. I don't know why it lost it but it did. Changed the crystals same result.
Are you able to check the signal strength ?
Title: Re: Futaba going crackers
Post by: tigertiger on September 22, 2006, 03:22:32 am
I had a similar problem with my futaba. But with the sail winch.

However mine was nothing to do with the radio kit.

Symtoms
Servo appeared to be fully rotated in one direction and jammed. Boat only went around in circles.
 However after removing servo arm and servo the problem dissapeared. It reapeared again, and on dismanteling and reassembly it sovled itself agian.

Actual cause.
I had changed to a more powerful futaba sail servo, but being lazy used the same servo arm.
However the bit that fits over the splines on the servo was of a softer plastic than the one provided with the bigger servo.
What was happening was that under load the arm was slipping, until it reached the end of travel and then was jammed against the hull.
So every time I tried to rotate the servo it jitterd.

May not be the cause of your problem, but it is one to watch out for.