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lucky escape
Had really lucky escape with burnt servo today.
From the start: yesterday I crashed my 450 Pro. Lost orientation for a short moment in a piro, and before I straightened the heli it lost lift (as I learned later, due to slipped pinion) and hit ground, fast. The damage was little worse than average : broken main blades and skids, badly bent mainshaft, bent boom. Also broken horn on one cyclic servo and broken gear in another
. Luckily untouched tail and main head, only just a bit of slop in swashplate. Repaired all yesterday, including DS95 gear. Installed head today, checked everything for vibrations and performed new AR7200BX setup.
Later today on the field, first battery revealed tracking a little off, but otherwise cyclics and everything else seem good. Starting second battery and the motor slowed for a second. TH, walked to the heli and checked pinion and other gears (good), ESC (not signaling any errors - it's Kontronik Koby 40LV). Assumed it must have been vibrations caused by bad tracking affecting FBL, so up it goes. It's dropping RPM a bit in flight and, after a minute heli starts to roll pretty badly - "oops, something is wrong!". It is also losing RPMs so my reaction is try to straighten it and get closer to the ground, gently. Moment later, lots of smoke from one side! "That's really bad" so I hit TH, at the same time continuing to try to straighten the heli. It hits the grass from less than 1m. I run to it (blades good - feeling lucky!), heli is still smoking so I remove canopy as fast as I can - battery's good and smoke is somewhere else! Turns out, one of the wires from AR7200BX is burnt.
IMGP3594.jpgIMGP3596.jpg
And the good bit - nothing seem to have broken when I pressed TH! AR7200BX seem to work (I did not test servo outputs). Main shaft (new after yesterday crash!) is true, head seems good etc. Must have had enough positive pitch to stop blades when dropping, just in time when it touched ground. I feel very lucky today
As for the servo, I have one spare DS95, so will be easy to replace. Hope other wires are good.
Also, the lesson from yesterday's crash: hate that motor shaft on 450MX has no incision (what's the better word?). I made one yesterday with my Dremel but if it was there from the start, pinion would not have slipped yesterday
From the start: yesterday I crashed my 450 Pro. Lost orientation for a short moment in a piro, and before I straightened the heli it lost lift (as I learned later, due to slipped pinion) and hit ground, fast. The damage was little worse than average : broken main blades and skids, badly bent mainshaft, bent boom. Also broken horn on one cyclic servo and broken gear in another
. Luckily untouched tail and main head, only just a bit of slop in swashplate. Repaired all yesterday, including DS95 gear. Installed head today, checked everything for vibrations and performed new AR7200BX setup.Later today on the field, first battery revealed tracking a little off, but otherwise cyclics and everything else seem good. Starting second battery and the motor slowed for a second. TH, walked to the heli and checked pinion and other gears (good), ESC (not signaling any errors - it's Kontronik Koby 40LV). Assumed it must have been vibrations caused by bad tracking affecting FBL, so up it goes. It's dropping RPM a bit in flight and, after a minute heli starts to roll pretty badly - "oops, something is wrong!". It is also losing RPMs so my reaction is try to straighten it and get closer to the ground, gently. Moment later, lots of smoke from one side! "That's really bad" so I hit TH, at the same time continuing to try to straighten the heli. It hits the grass from less than 1m. I run to it (blades good - feeling lucky!), heli is still smoking so I remove canopy as fast as I can - battery's good and smoke is somewhere else! Turns out, one of the wires from AR7200BX is burnt.
IMGP3594.jpgIMGP3596.jpg
And the good bit - nothing seem to have broken when I pressed TH! AR7200BX seem to work (I did not test servo outputs). Main shaft (new after yesterday crash!) is true, head seems good etc. Must have had enough positive pitch to stop blades when dropping, just in time when it touched ground. I feel very lucky today
As for the servo, I have one spare DS95, so will be easy to replace. Hope other wires are good.
Also, the lesson from yesterday's crash: hate that motor shaft on 450MX has no incision (what's the better word?). I made one yesterday with my Dremel but if it was there from the start, pinion would not have slipped yesterday
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