Alright my friends! Here is the &^(*#&($(&^&^$%#&^!(@%&*^#%(&@% Culprit..
OK .. So .. Right after the crash , as you would on any Torque Tube heli .. is check if it was the gears that caused it or .. if they survived the crash .
So I turn the head and check all the gears.. and tail moved with the head just like it was supposed to.. No Issues there. All gears survived. So, my misconception of a power faliure basically took ground as I didnt see anything failed in the transmission of the heli ..
Well.. I listened to the video again and again and what baffled me was that I lost my tail and that kept knawing at me.. cause I have lost power on a heli before in a worst condition, and I never lost my tail hold. So either Ikon had given in and just lost all electronics, or something esle was wrong. Well.. The Ikon was on when I came back from crash and the JR satellite light wasnt blinking. all that meant was I never lost a bind. So I had power. I get my headphones and turn up the volume and I never hear a power cut out, and actually hear tail making that whiny noise and skip a couple times before I hear it just crap out and then I hear loss of power. Well the only logical thing was that I hit Throttle hold as a knee jerk reaxction To the faliure I saw. I do that.. cause keeping heli powered isnt gonna help at all once I loose control. That is why the tail also stopped spinning for a second cause there wasnt any torque left to the tail anymore It was all the head and tail's own momentum.
Ok .. So I get the bird and just for funsies hold the tail and turn the head. Guess what the head turned with friction but almost freely with tail under pressure, and as i let go, the tail caught up again. Looked in and the lower bevel gear you see in the picture below in the front TT assembly was stopped and the rest was spinning with the head.
So notice that the bevel gear has a grub screw in it. That is what is holding it on the shaft ... as that shaft, the bevel gear and the top straight cut gear are all seperate parts that come together as one with the help of these dog point grub screws..
So .. Now I wanted to see exactly what had happened. Had there been a shearing of the grub screw due to torque, cause there was still resistance.. which made sure to give me the illusion of a holding tail .. , but no actual hold against torque applied to it. So I decided to take the grub screws out of the top gear (the straight cut) and tap the whole shaft out expecting it to just drop out like there wasnt anything holding it. with some force for sure, but the shaft did start slipping out.
As I pull it out, I notice this.. SCORING on the shaft all around it .. black marks. from a slipping grub screw on the shaft..
Well there .. I had found a point of faliure but why .. ?
So I go the gears next : Here is what that bevel looked like :
I take the dog point grub screw out. and this is what I find.. The "dog point" part of it wasnt in that retaining hole at all.. It
Notice the dog point part of the screw now has an indented curvature of the jack shaft it ran on.
So this wasnt a failed screw / gear. This was a builders fault.. Ohh no! thats not good!! But how ?
Well .. I replaced the dog point grub screw. put loctite on it .. and screwed it in .. Compared it to the photographs and found that the stupid thing actually stopped hard at a point similar to the pics, but not aware of that thtats not enough and frsutrated cause it was taunting at me I gave it a good amount of torque and I hear the gear starting to align with the shaft and actually feel metal going into metal and it seating itself into that cavity . So just because I thought while building it first, I dont wanna strip a small grub screw or the more expensive gear to cause issues , I didnt apply a ton of force on it and hoped loctite would do its job.. That was my fault then .. in this case. .Now I finally made sure all such screws in the frame were in the way they were supposed to.. and guess what .. I found another one on the tail ouput gear. It hadnt slipped cause It didnt have a chance to the front one gave in first.
So there was a faliure. That little stupid grub screw cost me my maiden and the Hobby allowance for this month
STUPID STUPID STUPID... but regardless lesson learned!
So take note everyone...
Now that I am at it.. I want to show something that I thought was cool. In the crash the canopy mount took a good brunt and got bent.. bending the Carbon fibre with it. I thought i would have to repair the frame. but NO!
Those are sitting on breakaway carbon fibre canopy mounts which can rip out before the frame is affected..
And are available as a very cheap replacement part that I did and the frame was untouched. and now with the all the parts in, I am waiting for the logs collection tonight. So once I have those, I will post them here too . .So we can look and analyze what kind of power consumption and other stuff I was running at that point.
