questions on moving batt to firewall of eagle

Discussion in 'Christen Eagle' started by firefly9r68, Dec 2, 2014.

Help Support Biplane Forum by donating using the link above.
  1. Sep 13, 2018 #41

    Cameron

    Cameron

    Cameron

    Supporting Member Supporting Member

    Joined:
    Feb 1, 2007
    Messages:
    2,332
    Likes Received:
    683
    I read somewhere once that it wasn't recommended to mount a starter relay in the position shown above because g loading could overcome the spring in the solenoid and inadvertently engage the starter during aerobatic flight. I've never heard of this actually happening and I have my doubts as whether or not this is a valid concern, but it did cause me to mount my starter solenoid in a different orientation. Mark's been flying his airplane for a while and presumably hasn't had a problem...but food for thought....
     

    Attached Files:

  2. Sep 13, 2018 #42

    garyg

    garyg

    garyg

    Well-Known Member Lifetime Supporter

    Joined:
    Nov 3, 2011
    Messages:
    632
    Likes Received:
    99
    This is what I got from B and C:


    We do recommend that you mount the starter contactor horizontally in an aerobatic aircraft. Though rare, there have been instances of a vertically installed starter contactor making contact during high G maneuvers. As a result, the starter engaged with the ring gear and caused starter and ring gear damage.
     
  3. Sep 14, 2018 #43

    Tonto

    Tonto

    Tonto

    Member

    Joined:
    Apr 26, 2017
    Messages:
    15
    Likes Received:
    1
    Thanks for the replies fellas, I appreciate it. I'll find a way to mount it horizontally on the firewall; makes sense that it could trigger it with a bunch of positive G.
     
  4. Sep 14, 2018 #44

    Tonto

    Tonto

    Tonto

    Member

    Joined:
    Apr 26, 2017
    Messages:
    15
    Likes Received:
    1
    Great looking setup. What is the circuit breaker attached to the battery box used for?
     
  5. Sep 14, 2018 #45

    Cameron

    Cameron

    Cameron

    Supporting Member Supporting Member

    Joined:
    Feb 1, 2007
    Messages:
    2,332
    Likes Received:
    683
    That was originally going to be my main breaker. I ended up changing it to a firewall mounted ANL fuse.
     
  6. Sep 14, 2018 #46

    mbarker

    mbarker

    mbarker

    Registered Users Supporting Member

    Joined:
    Nov 10, 2011
    Messages:
    164
    Likes Received:
    14
    Interesting on the "G" thing for the starter relay ---- never heard of that. Good thoughts though. ------- Hey Cameron???----- how about a new Eagle event. Climb to 5,000 ft. AGL, shut the engine off, leave the mags on, and start pulling excessive Gs to try and engage the starter????? ---- I think Tommy and Randy might be in for that........ Great conversation. So far up to 5 positive and 3 negative no issues. Mark
     
    Cameron likes this.
  7. Sep 14, 2018 #47

    Neil

    Neil

    Neil

    Well-Known Member Lifetime Supporter

    Joined:
    Nov 10, 2006
    Messages:
    6,092
    Likes Received:
    877
    Gender:
    Male
    Location:
    Monroe, Louisiana
    We recently had to repair a Glasair that had a gear collapse due to a relay failure. I have a video of the relay failure test, but haven't figured out how to post the video. Short story is that the gear worked normally on the jacks but when we were running the engine the vibration caused the relay to engage causing the gear to unlock and collapse. The relay in question was mounted horizontally.
     
    Last edited: Sep 14, 2018
  8. Sep 14, 2018 #48

    cwilliamrose

    cwilliamrose

    cwilliamrose

    Well-Known Member Lifetime Supporter

    Joined:
    Nov 10, 2009
    Messages:
    7,732
    Likes Received:
    1,675
    Location:
    SW Florida (94FL)
    Here's Neil's video;

     
  9. Sep 14, 2018 #49

    Neil

    Neil

    Neil

    Well-Known Member Lifetime Supporter

    Joined:
    Nov 10, 2006
    Messages:
    6,092
    Likes Received:
    877
    Gender:
    Male
    Location:
    Monroe, Louisiana
    Thanks, Bill.
     
  10. Sep 14, 2018 #50

    Cameron

    Cameron

    Cameron

    Supporting Member Supporting Member

    Joined:
    Feb 1, 2007
    Messages:
    2,332
    Likes Received:
    683
    Neil, was the fact that the relay was mounted horizontally what led to the issue?
     
  11. Sep 14, 2018 #51

    marquartflyer

    marquartflyer

    marquartflyer

    Registered Users Lifetime Supporter

    Joined:
    Dec 20, 2010
    Messages:
    187
    Likes Received:
    111
    Looks like a suspect solenoid. - The internal spring may be broken?
    The return springs are usually prong to prevent arcing when turning 'off'.
    I have played with a number of solenoids, smacking / bouncing them to try to get hem to 'false engage'.
    It takes a pretty good whack just to get them to come off the rest position & couldn't get one to actually make contact.
     
  12. Sep 14, 2018 #52

    Neil

    Neil

    Neil

    Well-Known Member Lifetime Supporter

    Joined:
    Nov 10, 2006
    Messages:
    6,092
    Likes Received:
    877
    Gender:
    Male
    Location:
    Monroe, Louisiana
    The relay being mounted horizontally allowed the gear to function properly with a bad solenoid but it also allowed the solenoid, in this case the up solenoid, to engage unintentionally. It just rattled over sideways and made contact.
    The reason for the repair was that the nose gear collapsed due to the up solenoid engaging during the landing rollout and the nose gear folded resulting in destroying the prop and requiring a prop strike overhaul(540 Lyc) and repairs to the lower cowl and spinner and prop replacement.
    Had the solenoid been mounted with the cap up, some negative force may have unlocked the gear. Had it been mounted with the cap down the solenoid would not disengage and probably would have burned up the pump. Choose your failure mode.

    Fixed gear seems like a good idea.
     
  13. Sep 15, 2018 #53

    Cameron

    Cameron

    Cameron

    Supporting Member Supporting Member

    Joined:
    Feb 1, 2007
    Messages:
    2,332
    Likes Received:
    683
    Ouch!
     
  14. Sep 15, 2018 #54

    Tonto

    Tonto

    Tonto

    Member

    Joined:
    Apr 26, 2017
    Messages:
    15
    Likes Received:
    1
    Lamar states that the contactor can be mounted in any direction; hat up or down and horizontal. Maybe hat-down is the best setup? I think I’ll mount mine like Mark did if he's getting good results. I’m more worried about high G-load from my landings than my acro anyway!
     

Share This Page