HELP - Crash bent/broke motor mount at arm - FIX?

Hi everyone,

My saga continues in spectacular fashion with another crash of my 3dr Hexa. I have included some pictures and looking for any suggestions on a fix for the motor mount rather than replacing the arms again.

You can see from the pictures that the crash caused the motors to hit the ground and obviously torque the motor mount and cause the arm to crack.

Does anyone have a suggestion on how i could repair this rather than replace the arm? I have one replacement arm but it seems a shame to replace both of these if we can come up with fix. Other than the crack at the motor mount end of the arm all other areas are in good shape.

Any comments or suggestions would be much appreciated, looking for some creative solutions!



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  • flip the arms over and use washers if need be and make the holes bigger where they mount now so you can get the screwdriver though them  of course you could also straighten the damaged part and use washers on them too

  • For the newbies (me included) crashability is a worthy design requriement.  I have found that AL clamps on composite tubes does not work.  I have also found that securely attached motors to the firewalls is a mistake.  The nice looking stiff composite gear as in the HK Talon and others is a mistake too. 


    Use foam pool noodles for gear to absorbe landing and crash energy.  Keep the tube clamps just tigh enough for flight adn that twist on hard landings and crashes.  Remake the clamps from Delrin rather than AL.  The copter must be stiff enough to sustain flight but twist and break at points of attachment upon crashes. Use nylon screws that shear off in crashes.  Shed the battery on crashes using a single Velcro strap that fails. 

    The picture is of my copter after 6 crashes.  Cost per crash is a prop or some nylon screws.  Due to using nylon 3mm or 4-40 screws, the motors separate from the copter's firewalls  avoiding bent shafts and even broken props. 

    See the two pictures attached. 




  • MR60

    The long-term fix is to use round tubes.  Stronger and far easier to repair and maintain.

    Short-term fix.  Take the prop off.  Bend it back to shape (have a vice or strong hand and pliers).  Bond it with epoxy.  Good flyings.

  • Perhaps you could pick up a set of these and with longer screws and elastic lock nuts add them to the arms, bypassing the damaged section. Of course it would need to be done to all arms and you would need to drill the holes for mounting the brackets.

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