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Old Feb 22, 2012, 02:24 PM
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Should we be letting certain parts fly off in a crash? or do we lock'em down?

If you dont want to read all of this then answer me this: Would it be better to let the weight of the battery leave a crash or stay with it? Isnt the inertia already distributed before the seperation of the landing gear/battery takes place?

I find myself letting the landing gear/battery to go flying in a crash. I own a Walkera Mini-cp and I had heard its better to leave the landing gear loose so this can happen. I know people complained that the Walkera Genius did not have a sperate landing gear from the frame as do the Mini-cp. So that tells me that some people have broken the landing gear. And that maybe they wouldnt of if indeed the gear was removable.
I am at a crossroad here. The Mini-cp's canopy has cutouts to receive the landing gear as a hold down point. I have the problem that in a small crash, the canopy lifts off the landing gear and pops upward. So I have to stop my battery timer on the radio,, take the canopy off, re-install the canopy, turn the timer back on, and then I can fly some more.

Now say I start small, and I only lock the canopy down to the landing gear. I am unsure if a small crash that would normally only pop the canopy up would do any damage. But a large crash will let the landing gear which is heavier then the canopy (since it has the battery inside of it) go flying tearing at the canopy. The canopies rubber grommet mounts which have carbon rods attached to the frame would have no chance. They would break and so that leave me wanting to lock down the landing gear/battery tray.

Now what if I have them both locked down, then what. I am not a crash specialist, I do not know exactly what forces and stresses are put on all the parts. But isnt it better to have something enclosed in say, a bubble? A plastic canopy bubble? If the canopy stays put, then the electronic pcb board is safe. The mini linkages etc are safe. But is it truly the way to go?
Or is letting the weight of the 3.7 350mah battery go flying off in a crash take the insertia away from the other parts?
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Old Feb 22, 2012, 03:05 PM
The flightless bird
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I'd say stay. Why? Well there are a few problems with letting things detach during a crash... first of all.. you mentioned letting the battery go... this is a bad idea since Lipo batteries can explode or catch fire (although much less likely now) if impacted. Letting the battery stay in its compartment or under the canopy will protect it... and while the crash might damage the skids or other parts of the frame... you will save your expensive battery.

Then there's the problem of parts detaching when you don't want them to do so. There have been more than a few helis at my field, for example, that have been lost due to loose canopies or other parts going through the blades. And when that happens on a big 700 sized heli.. you can do a lot of damage.

Never happened to me on a heli but I've had a battery fall out of my at6 while inverted because the Velcro was old and weak. results weren't pretty. Point is : in my opinion, having parts that aren't completely secured on anything that flys is a big no-no. Regardless of how much money it can save you in a crash.
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Old Feb 22, 2012, 04:13 PM
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Quote:
Originally Posted by jameschen072 View Post
I'd say stay. Why? Well there are a few problems with letting things detach during a crash... first of all.. you mentioned letting the battery go... this is a bad idea since Lipo batteries can explode or catch fire (although much less likely now) if impacted. Letting the battery stay in its compartment or under the canopy will protect it... and while the crash might damage the skids or other parts of the frame... you will save your expensive battery.

Then there's the problem of parts detaching when you don't want them to do so. There have been more than a few helis at my field, for example, that have been lost due to loose canopies or other parts going through the blades. And when that happens on a big 700 sized heli.. you can do a lot of damage.

Never happened to me on a heli but I've had a battery fall out of my at6 while inverted because the Velcro was old and weak. results weren't pretty. Point is : in my opinion, having parts that aren't completely secured on anything that flys is a big no-no. Regardless of how much money it can save you in a crash.

Last year, about this time, I was flying my E-Flite Ultimate 20-300 with a power 15 and a 3s 2200mah battery. I'm flying alone on the beach, only a few spectators in the hotel window pretty far away.. But anyhow I'm flying along, practicing hovering, rolls, inverted etc. All of the sudden I see something falling from the sky WAAYY up there from my plane... And I'm like what the hell is this.... Turns out it was my lipo battery! I forgot to use the strap, it was just velcro'd in! ANYHOO.. NOT A SINGLE SCRATCH ON THE PLANE!!!! I mean this thing fell from WAY up there, and it just floated down since it is SO light without the battery. Obviously it was moving foward, but at a very slow pace. Mainly straight down!!!

But my first thought was O SH*T that battery is going to explode when it hits the ground! Thankfully it landed in the sand safely. Had to soak and dispose of it, was dented pretty good, didn't want to risk a fire.


So I'm 50/50 on this one, but for micro helis I'm thinking that probably not.
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Old Feb 23, 2012, 12:45 AM
The flightless bird
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Quote:
Originally Posted by perschek View Post
Last year, about this time, I was flying my E-Flite Ultimate 20-300 with a power 15 and a 3s 2200mah battery. I'm flying alone on the beach, only a few spectators in the hotel window pretty far away.. But anyhow I'm flying along, practicing hovering, rolls, inverted etc. All of the sudden I see something falling from the sky WAAYY up there from my plane... And I'm like what the hell is this.... Turns out it was my lipo battery! I forgot to use the strap, it was just velcro'd in! ANYHOO.. NOT A SINGLE SCRATCH ON THE PLANE!!!! I mean this thing fell from WAY up there, and it just floated down since it is SO light without the battery. Obviously it was moving foward, but at a very slow pace. Mainly straight down!!!

But my first thought was O SH*T that battery is going to explode when it hits the ground! Thankfully it landed in the sand safely. Had to soak and dispose of it, was dented pretty good, didn't want to risk a fire.


So I'm 50/50 on this one, but for micro helis I'm thinking that probably not.
Yeah, in micro helis the risk is low but still, I think people need to be very careful with lipos (people were very careful when they came out..but now seem to forget the dangers associated with these batteries.)

You did the right thing, but I've seen people crash hard...take their lipos out and fly them almost immediately after.. (have pictures somewhere of my friends' F16 on fire in the air :P... maiden with brand new battery and new electronics... all lost.)

anyways, back on topic, I advise everyone from beginners to seasoned pilots to have good safety practice throughout their fleets... be it small or large aircraft... because once you start doing things carelessly on your smaller craft, you'll start doing so on larger craft too (my painful experience )

These 'toys' are not toys guys! Safety is paramount.
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Old Feb 23, 2012, 07:17 AM
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The heli I am talking about letting the battery/gear fall out of is very light and small. I should have said "just these mini heli's" to stay on the topic. I would never fly my 450 with a loose battery. The heli I am talking about is the size of your hand.
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Old Feb 23, 2012, 12:33 PM
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I was just wondering the same the other day about the 9958s I have. I've lost the outside o rings on canopy and during some crashes canopy and sometimes landing gear comes loose. But I decided to do grommet mod on two of them to keep canopy on tighter. So far no broken frame posts or cracked canopy, and canopy is much tighter. It does get a little annoying when things come off, but I did consider that is part of absorbing the energy.

Will see what happens. I think it depends on circumstances, and if/when you get annoyed by re-attaching parts.
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Old Feb 23, 2012, 01:43 PM
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I would not like the battery to come loose, as it risks ripping the battery connection loose from the board.
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Old Feb 24, 2012, 07:20 PM
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I have the connection from the battery to the PCB glued. So,should we lock things down or let them fly?
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