Register and gain access to Discussions, Reviews, Tech Tips, How to Articles, and much more - on the largest Large Scale RC community for RC enthusiasts that covers all aspects of the Large Scale RC!

Register Today It's free! This box will disappear once registered!

Symptoms of an overheating servo?

Discussion in 'Large Scale RC Electronics' started by Ducky, Jan 17, 2009.

Tags:
  1. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    I wondered if anyone had ideas of what symptoms an overheating servo would show; would it start to slow down or become erratic etc?
     
  2. dc2 man

    dc2 man Reading the Rules!

    Joined:
    Feb 20, 2008
    Messages:
    869
    Likes Received:
    0
    Location:
    limerick/munster
    well ducky hows the going.

    this is my experience.

    the only thing i can say is when i got my fg beetle i never ever had servo trouble just maybe small nitro type servos with my nitro cars, i did make a mistake one day though,what i done was pluged the battery conector the opposite way on,and it is the very same thing a servo just does when the motor decides to die in it,it is real quick and fast and you wont even notice it just slows down rapidly and just eventually stops solid after say a minute and they just heat up then and smoke(burn)

    heavy load would even cause this.
    all parts are fully repairable anyhow on servos,/motor/gears etc. but for the price i rekon you would be better off buying new.
     
  3. Clubin

    Clubin Well-Known Member

    Joined:
    Dec 26, 2007
    Messages:
    1,124
    Likes Received:
    0
    Location:
    Manitoba
    I have never had a issue with a servo overheating, I had one that got wet, but deffinetly not a overheat thing, so long as your endpoints are set properly overheating should never be a issue. If they do, I would immagine they would just fry out. Like any electronics that "overheat".
     
  4. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    Cheers for the info peeps, I'm just doing some testing with micro servos and trying to narrow down the possible causes for the problems I'm seeing. Really need something to test the Kg-loading I'm putting on them to see what forces they're experiencing.
     
  5. Bigger the Better

    Bigger the Better LSF Plus Member
    PLUS member

    Joined:
    Feb 19, 2007
    Messages:
    7,738
    Likes Received:
    2
    Location:
    Minnesota
    Is that for the throttle only or are you using it for something else?
     
  6. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    Is it for the throttle as I've recently switched from the Futaba S3154 (1.7kg/pull) to a Hitec HS65MG (2.2kg/pull), after experiencing problems with the Futaba at 6v (a known issue it seems).

    However when I add a small (v.weak) spring to shut the throttle off the hitec gets hot after a while, slows down and becomes erratic, so I've removed the spring for now and will try rewiring the car so all the servos take a direct feed from the battery, rather than take power via the receiver. This is all tested without the engine running.
     
  7. Bigger the Better

    Bigger the Better LSF Plus Member
    PLUS member

    Joined:
    Feb 19, 2007
    Messages:
    7,738
    Likes Received:
    2
    Location:
    Minnesota
    I see ya, the spring may be putting too much load on it? With such a small servo you think you could go with a small spring? I take it its for a failsafe?
     
  8. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    Yeah I got a selecting of small springs and they hardly feel that strong, yet it seems to cause the servo issues....will try direct 6v feed to see if that makes a difference. It is for a fail safe yes (already have an electronic one on the throttle) as I want a mechanical fail safe also.
     
  9. Bigger the Better

    Bigger the Better LSF Plus Member
    PLUS member

    Joined:
    Feb 19, 2007
    Messages:
    7,738
    Likes Received:
    2
    Location:
    Minnesota
    Do you have an extra open channel to install a failsafe? That way you could eliminate the spring.
     
  10. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    No unfortunately I only have 3 channels on my 3GR and they're all used up (throttle/brakes/steering) otherwise I would have got something like P2b kill switch. Currently have a basic fail safe in-line with the throttle, but it's not a kill switch, just a position reset sadly.
     
  11. Trip

    Trip Well-Known Member

    Joined:
    Apr 25, 2007
    Messages:
    2,682
    Likes Received:
    0
    Location:
    Ypsilanti Michigan U.S.
    ...Just a thought, instead of closing the throttle, could you set it up to hit the kill switch on the motor instead?

    Trip..
     
  12. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    Nah the kill switch I have just plugs in the servo line and just lets you preset the servo position in the event it loses signal from your transmitter. The P2b version that is able to kill the engine requires a 3rd channel to function sadly.
     
  13. Trip

    Trip Well-Known Member

    Joined:
    Apr 25, 2007
    Messages:
    2,682
    Likes Received:
    0
    Location:
    Ypsilanti Michigan U.S.
    I have 1 inline "Fail safe", 1 built into my receiver and my Hitec throttle servo is programed for full brake, but I wasn't happy with "Just" that. So I ran a Y harness from the inline fail safe to another servo I mounted on the roll bar, in the event of a signal loss the failsafe sends the throttle and the "Rollbar" servos to full brake. The rollbar servo in turn pushes the kill switch on the motor. I didn't know if you knew what I was talking about in my last post, so I thought I would clarify myself.

    If nothing else maybe someone else could use the info. ;)

    I wish I had pictures of it, but I tore down my truck after I smoked the motor.

    Oh well,
    Trip..
     
  14. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    Now that's an interesting way to do it, pictures would have been good although I have vision of it looking a little messy? I know the fail safes work if the transmitter loses signal, but if you cut the power to the car they won't respond...one reason I wanted a mechanical method on the throttle.
     
  15. Trip

    Trip Well-Known Member

    Joined:
    Apr 25, 2007
    Messages:
    2,682
    Likes Received:
    0
    Location:
    Ypsilanti Michigan U.S.
    True pics would have been nice, but I should have my motor tomorrow and I'll set it back up. It is actually a pretty clean setup. and as far as a power loss, I thought of that too... I have my main 5 cell sub c pack, but I also have a small hump pack made for an 1/8 scale buggy wired (parallel of course) in a y harness. That way I could double my chances for success.

    Originally I had that small battery just sitting there so if the main pack dumped, I could swap out the plugs and get back to my 1/1 car (These things are heavy as hell and I don't like to carry it!) Swap the plugs and fire it back up and charge the main back up..

    Tell me what you think..

    Trip..
     
    #15 Trip, Jan 21, 2009
    Last edited: Jan 21, 2009
  16. Ducky

    Ducky Well-Known Member

    Joined:
    Aug 9, 2008
    Messages:
    644
    Likes Received:
    0
    Location:
    Kent, UK
    Interesting, would love to see how you have it all configured once you get it back together. Have you managed to get all the wires into the small electrics box on the FG?
     
  17. Trip

    Trip Well-Known Member

    Joined:
    Apr 25, 2007
    Messages:
    2,682
    Likes Received:
    0
    Location:
    Ypsilanti Michigan U.S.
    Everything except for the 2 packs. It's a little snug, but my Futaba receiver (being really small) sure helps.