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Old 07-18-2021, 02:50 PM   #1 (permalink)
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Default Safe mode crash

I recently configured my blade 300x with the FC6250HX to turn on safe mode when in normal flight mode. I spent quite a bit of time leveling and trimming flight in Normal/safe mode, so it was working fine, I thought perhaps it would save me sometime that I could quickly get out of idle up and stabilize. Well today I took off in normal/safe, then went to idle up and did my flight, all good. Then I lined it up for landing and thought I would switch to normal to see how it would react. I was hovering maybe 20 feet off the ground, switched back to normal/safe and the Heli immediately flip over and planted itself in the ground.

Has anyone experienced any similar behavior? Needless to say, I will not use safe mode any more, very disappointing how that ended. I also have bailout configured on switch A so I can get to it real fast. It appears to be working fine.
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Old 07-20-2021, 05:58 AM   #2 (permalink)
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In most cases an uncommanded movement while in SAFE mode is due to vibration reaching the FC, and it seeing it as movement (i.e it rolled over in one direction because it thought it was rolling over in the other).
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Old 07-20-2021, 01:33 PM   #3 (permalink)
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A Blade 300x is like a $10 Blender from Walmart. It is full of vibes, even when flying perfectly. They don't handle high headspeed well and those vibes go up exponentially. As others have mentioned, its worthwhile for you to chase the vibes down. Don't construe this as hate for the 300x, I have quite a few of them, but they are a lot of work to get self level working reliably, at least for me with Ikon. The nice thing about the Ikon is it has a graph and logging that shows you how bad the issue is.

A bit of my struggles here:

https://www.rcgroups.com/forums/show...&postcount=298
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Old 07-20-2021, 03:09 PM   #4 (permalink)
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It probably is vibration related, similar to issues with the BeastX, although I never experienced it with the 6250. That being said, it really didn't feel like it had vibration issues, its back flying again and all seems to be well, but no more SAFE mode for me...

Thanks for the reply's
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Old 07-20-2021, 03:37 PM   #5 (permalink)
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When they are in the air, they don't feel like they have vibes and you don't get the blurry tail or skids as much as with other helis (probably due to the plastic frame). But spool them up on the bench without blades and compare to something like a Goblin 380 and they feel really rough. That's where the logging on the FBL really comes it, its black and white. I've mentioned this before, I really wish FBLs had a warning light or a pre-flight pitch sequence that alerted you of excess vibes, because it is easy to tell.

I wouldn't give up on the self level, and especially bail out. I have mine on a quick momentary switch, I get the heli up each session and tap the button. A fraction of a second is all I need to know its trying to flip over.
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Old 08-15-2021, 01:39 PM   #6 (permalink)
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I am very surprised that SAFE mode (or "stability", "level" or "angle" -modes) works so poorly in 6250. The AR636 in my Blade 230V3 performs as expected in SAFE mode. I also took an open stock AR636 and flashed it with the Blade230V2 firmware and used it in my old Gaui 550 Hurricane. Worked great, even in SAFE mode.


All the three scale machines I have with 6250 has flipped and crashed in SAFE mode during take off or landing at some point. Also noticed some hard drifting in flight some times. Last time I managed to land, with cyclic stick hard left and back.



The sales pitch is the SAFE mode should be a help for novice pilots, but it seems not so with the 6250. You could even call it UNSAFE.


Will 6250 SAFE mode ever be corrected? As of now, it is flawed.

/A
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Old 08-16-2021, 11:01 AM   #7 (permalink)
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I had a brand new 230s crash as soon as I turned on stability mode. There isn't a unit that is fully immune to vibes. Even the amazingly vibe tolerant 6g unit that is on the K110 has a tipping point.
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Old 08-16-2021, 03:39 PM   #8 (permalink)
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This has been mentioned in many other gyro threads and maybe needs mentioning here. SAFE is a form of self-levelling and when the sticks are at rest, the helicopter will try and maintain that attitude. Self-levelling, when put on during the take-off and landing of a helicopter that has high vibration levels, tends to get adverse reactions from the gyro and was recommended by a number of those gyro manufacturers to not engage in takeoff and landing. Since there is no capabiliity of logging vibrations with the 6250, you may need to go up 3 mistakes high before engaging this feature. You could also make a vibration log unit up out of an unused gyro that has this feature. I did so with an old Skookum 720 and successfully logged a number of flights to check what vibrations were present. As good luck had it, nothing above 1 on it's scale. Take care.

Don
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