Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: portside II on April 17, 2010, 12:13:01 AM

Title: servo problem help
Post by: portside II on April 17, 2010, 12:13:01 AM
I am buliding another ship docking module tug , but this time with a pair of schottels .
So i ordered a pair of savox servos to handle the steering , they arived and were fitted and tested on the bench .
The first one was fine but when i plugged the second one in all it did was twitch realy bad , i switched them over , changed the radio gear / battery etc , i even plugged some more servos in but it still twitched .
I did notice one thing that when i plugged it into the 2.4ghz futaba reciever the green light went out and the red light blinked , but this did not happen with the other servo.
i have sent it back but they cannot find a problem , but they have sent me another one by return post .
So come on all you wizards what could be the problem , it has lost me .
daz
Title: Re: servo problem help
Post by: Martin [Admin] on April 17, 2010, 12:40:31 AM
Have you received the replacement servo yet?
Is it the same?
Title: Re: servo problem help
Post by: portside II on April 17, 2010, 04:59:30 PM
Thanks for all the replies  %) .
Yes martin i received the servo this morning and have it fitted in the hull , no twitching etc , so there must have been a problem with the old one .
I will let steve webb models know as soon as i can .
Next job to fit the motors , battery and radio gear , then i can learn how to operate it  :o .
daz
Title: Re: servo problem help
Post by: malcolmfrary on April 18, 2010, 12:20:01 PM
Seems to be standard practice with consumer electronics that when an item has a partial failure and it is returned, the problem never manifests itself in the retailer's testing laboratory, but the replacement they send does work.  Leaves me wondering whether they get tested or binned.
Title: Re: servo problem help
Post by: portside II on April 18, 2010, 05:53:34 PM
Maybe with standard servos it might be cost effective just to bin it , but these were 25.00 each and digital .
My local electrical store gave me a led disco light and a mini strobe that were returned faulty , the manufacturers said "bin them".
their loss my gain , but back to the servo , mine are working great so the returned one must have a fault and if i was the manufacturer i would like to know what it is.
daz
Title: Re: servo problem help
Post by: Martin [Admin] on April 18, 2010, 07:03:45 PM
Many years ago when home computers were young, someone I knew ran a computer game shop.
Faulty returns were sent out twice, if they returned twice, they were then deems faulty.  >:-o


Seems to be standard practice with consumer electronics that when an item has a partial failure and it is returned, the problem never manifests itself in the retailer's testing laboratory, but the replacement they send does work.  Leaves me wondering whether they get tested or binned.
Title: Re: servo problem help
Post by: Ticonderoga on April 26, 2010, 10:39:03 PM
If these pieces of kit are mass produced, and I guess they are likely to be, then it will be down to the manufacturer's QA process.

In a mass production run, only a small, but statistically significant, number of units will be tested. As this is a game of stats (Lies, Dam Lies and then Statistics) there is a probability that a bad unit will get through testing.

Sometimes, some of us will be unlucky.......
Title: Re: servo problem help
Post by: triumphjon on May 04, 2010, 05:51:30 PM
the joys of todays throw away society !  i think we are among a dieing breed who want to know how it works , or can we fix it again ! !