Inverted Crashing

[amcutem]

I finally experience my first 3D flight today.

I flew a couple of packs today. I can tell i'm getting way better on my forward flights and figure 8s. On my second pack, i did it! I did flip. And i made it. On my third try though, i crashed.
I think something went wrong. It wouldn't flip back over. I totaly had no cyclic control and it was almost at the end battery pack when it happened. Could low voltage have caused it to happen?

My swash mix is at 65% for ail and elev; pitch is at 83%. Also, my flybrar weight is still on, it's on the middle. Where should swash mix be for HK450?

[jabo5778]

yes, if your esc's low voltage protection kicked in. It depends on how your esc is set up some will go to 50% and that means your a dieing duck. If you crashed in idle up mode you most likely did alot more damage then you know..... be careful on your next fligh especially with that lipo if you choose to use it again.

[Andrew Brinkhaus]

What determines a mix percentage and how is that setup? May be a dumb question but I'm still trying to figure all the terminology out.

[jabo5778]

MIX %? That refers to the swash plate i.e. swash mixing, which is the travel of your cyclic servos in ccpm. The higher the number the more cyclic reaction you will get(kind of like endpoints but it effects two servos that are tied together through the ccpm). If you are referring to the low voltage cutoff %, which is what I mentioned, then I have never personally programmed it myself. I just know that the way that it works is when your battery gets below a certain V/cell it 'cuts off' by going to 50% throttle. You can program the V/cell at which this will happen and you will have to read your esc manual to access programming mode and so forth.

Now a question for acutem, Now that I reread your post, you said you had no cyclic control. My question is did you notice if you had any pitch response? If the cyclics locked up and you still had pitch then your looking at a servo problem. If you had both, possible a brown out/rx/tx problem. If you in fact did have cyclic and not pitch then most likely the voltage cutoff. Another thing to keep in mind is that even though you probably dont run a BEC (battery eliminator circuit) the voltage cutoff would not shut out your cyclic controls. again make sure you do a good pre flight check, it would be best to let someone at you LHS look it over.

[Andrew Brinkhaus]

Thanks for the response.

[amcutem]

It all happend so fast????

It seems that the way the heli reacted just before it crashed was nothing like my first 2 flip attemps, which were successfull.


I can remember moving the cyclic on the Tx and watch as nothing happened on the heli. It just froze there upside down. I was like what the heck is going on here. That's when i knew for a brief second that something was wrong. Then i lost the tail and it fell.

I just wish i was experienced enough to hit throttle hold just before it hit the ground. It would make me feel a lot better about crashing.

I broke:

Main rotor housing
Blade Holder
Bent link rod
HK woody blades
mainshaft
feathering


I guess it's time to bring out those Dealextreme CF blades....

[jabo5778]

Well you will only be able to tell after you get it all back together. If you can do a range test with your tx then do that. It sounds more like a brown out which CAN happen with 2.4ghz. Possibly something wasnt strapped all the way down and the added g's of the flip knocked a wire out. Who knows, now you just have to try and make sure it doesnt happen again.

[amcutem]

So is that what could have happened, a brown out?

So the main rotor will keep on spinning on a brown out?

My esc cuts off at excatly 12minutes of newbie flying/hovering and figure 8s. When i started doing the flips, i was at around 10minutes. I guess i pushed my luck.

Im also ebrarassed to say, my idle up throttle is only at 70%. That's what gave me a headspeed of around 2500rpm. At 100%, it's spinning at 3200rpm.

[Kevo450]

Originally Posted by amcutem

So the main rotor will keep on spinning on a brown out?

.

Yes .. remember that One-Way bearing inside the main gear. That allows the blades to spin even with the motor stoped ( needed for that autorotation thinggy .. hehe )

[jstcriusen]

I was getting static on a all plastic EXI 450........
I thought my E'lcheapo tach was dieing setting it up. When ever I put the tach anywhere near it it would reset itself and start running through the blade settings. I blew it off and went to fly. I didnt realize it was static at the time........ Well the flight lasted like a minute before i lost total control with the heli..........

Platic tails seem to cause grief with static. I put a Copter X tail on it and thought i may have it fixed. I put my tach by it it still freaked out........ It was fine on my other 2 all cnc helis............ So I ran a wire from the boom to the AL. frame (to get Continuity to the frame), sanded the boom at the tail and scrathed up the inner cnc part of the tail . So in the end I got continuity thought the entire heli..........

I ripped out my tach and whalaaaaa........... it was working on the heli. I flew and never had a problem since........... This also happened why my belt was lubed!

From now on I make sure all my helies have continuity from head to tail. its not such a big problem unless you have a plastic tail...........then it takes some thinken........ but in the end its worth the hour or so it takes to do...... Lockouts really suck..........

[amcutem]

Originally Posted by jstcriusen

I was getting static on a all plastic EXI 450........
I thought my E'lcheapo tach was dieing setting it up. When ever I put the tach anywhere near it it would reset itself and start running through the blade settings. I blew it off and went to fly. I didnt realize it was static at the time........ Well the flight lasted like a minute before i lost total control with the heli..........

Platic tails seem to cause grief with static. I put a Copter X tail on it and thought i may have it fixed. I put my tach by it it still freaked out........ It was fine on my other 2 all cnc helis............ So I ran a wire from the boom to the AL. frame (to get Continuity to the frame), sanded the boom at the tail and scrathed up the inner cnc part of the tail . So in the end I got continuity thought the entire heli..........

I ripped out my tach and whalaaaaa........... it was working on the heli. I flew and never had a problem since........... This also happened why my belt was lubed!

From now on I make sure all my helies have continuity from head to tail. its not such a big problem unless you have a plastic tail...........then it takes some thinken........ but in the end its worth the hour or so it takes to do...... Lockouts really suck..........

Hey dude, i do have a plastic tail. So u mean plastic tail is bad and causes static. So what do i do....Ground the chassy into the negative terminal.. I can do that...

[Kevo450]

Originally Posted by amcutem

Hey dude, i do have a plastic tail. So u mean plastic tail is bad and causes static. So what do i do....Ground the chassy into the negative terminal.. I can do that...

The thing is that your tail belt can act as a Van_de_Graaff_generator. The goal is to make sure that no electrical potental differenece between two sections of the heli. This can cause a static discharge , think very very small bolt of lighting. Any metal should have a conductor to any other metal secton on the heli.

[ame]http://en.wikipedia.org/wiki/Van_de_Graaff_generator[/ame]

Its not grounding in the sense of the battery.( Even tho , acording to pure electrical theory you could use the chassie as a ground for the battery. But I have never heard of it being done.)

Its grounding to make sure that no static can build up.

[MavriC]

Originally Posted by jstcriusen

........... This also happened why my belt was lubed!...... Lockouts really suck..........

USE a good "Silicon" lube spray ONLY on the belt!

I've yet to see static buildup on any 450 to date (going on 4 years now) with NO brownouts. This goes for they guys at the club too.

DO NOT use WD40, V-Belt sticks (automotive) or anything other than a good Silicon Spray.

I used to run the "batman blades" and had no problems. I switched to carbon tail blades just for the authority it gives me. But still, no problems.

Rick.

[amcutem]

It's all good now. I've grounded the aluminum frame and boom to the neg. terminal of the esc....