Narrowly missed disaster today!

[medtech]

Well, I knew things were going to smoothly with my new hurri. I had flown thru about 10 packs with no issues.

So today I go outside with my heli and newly installed Eagletree LCD display. I spool up and hover no problem at all. After a few minutes I realize I didn't start my timer. No big deal, I have the lcd.

After what I guess is 5 minutes I land, only used 1600 out of 3200mah batteries. Fly around some more, land after a few minutes, only up to 2000, I figure one more minute of hover. As soon as I get about 10 feet up the heli drops, recovers, and drops again. I land as quick as possible. LCD only says 2200mah.

I get inside and download the eagletree data. To my surprise almost 2700mah was taken from the packs. The voltage low was 18.5v. This is alot lower than I would have liked. It's just a bit over max so I'm not super worried about damage to the batteries.

Now, I have to figure out what happened. I quickly realize that after 3 minutes the eagletree started a whole new session right in the middle of flight so the mah counter restarted. I had no idea why the eagletree would have done this and made 2 sessions.

After a bit more inspection I realize that right when the eagletree reset and started a new session the brushless rpm went to 0. I take a look at the brushless sensor and see that the extra wire I had tucked into the front of the frame made it all the way under the motor mount and into the pinion. This shorted the wires and caused the eagletree to reset.

Now I realize this could have really sucked. The motor could have siezed and the heli crashed, the eagletree could have completely self destructed when the sensor shorted, the batteries could have drained a ton more and died. All told I'm out the $15 brushless sensor, no big deal! Lesson learned, zip tie every last wire, no matter how out of the way it looks!! :wow2:

[mjdee14]

Wow......You were lucky !!!

Good lesson for me as I leave my motor wires hanging out with the sensor also..

Glad you didn't have any damage...and better that you actually could trace the problem...nothing worse than loosing power and not knowing why...

[medtech]

well, I didn't avoid disaster today! :arggg: :(

Up until today I have been flying in my front yard. It's a small yard so I've been practicing hovering and real slow flight. That's it. Today I went across the street to my neighbors house. He has about a 3 acre field. I finally got to see what the hurri could do. I have never done anything besides hovering. I figured I can do rolls and flips on the sim so I tightened up my sack and went for it. I did a roll. No problem. Piece of cake. Next I tried a loop. Again, nothing to it! Both times I used negative pitch so the heli basically stayed in one place. I wanted to do a big loop so I just went around, came zooming down to about 10 feet. A bit lower than I'd like but I still made it.

I continued to do loops and rolls, one after another. Multiple loops and rolls no problem. First set of packs run out. I land and change the batteries. I take off, play around a bit more. Now I get the bright idea, lets try hovering upside down. I roll left, stop half way and hold it. No problem, hover for about 30 seconds inverted! :happyd

Suddenly the sun comes from behind a cloud, directly in line with my heli. I can't see crap. Next thing I know the heli is zooming full speed toward the ground. Of course, not being very familiar with inverted flight I was at a complete loss as far as reaction. I watched it crash nose first into a snow pile from 50+ feet up.

Damage ended up being, canopy (totalled), main blades, flybar rod, and front main gear. So $30 isn't nearly as bad as it looked.

The batteries did take pretty much a direct hit. How do I know if they are damaged? Eagletree says all is fine and voltage still checks out good. The packs never got hot. They do look a bit smooshed on the front but this is where the wires are so the cells themselves look fine.

All in all, a great day, tons of firsts! First flip, first roll, first total crash. I now know that I can't get too cocky and need to take it slow! Lesson learned!!


P.S. Sorry for my long posts, lol!!

[modelholic]

Well done - look at it this way a lot of fun had for $40.
The Hurricane is one resilient heli - you'll be a rollin' and a loopin' again before you know it!
Makes me want to try a few!!

Simon

[mysticmead]

:Pics

take pics of your packs.. you may have just earned your membership to Team Taco (talk to fireup or finless) now, to tell if the packs are toast... did they puff? if they puffed up, they're no good. if not, when you charge them, do it outside and keep an eye on them.

[medtech]

I have everything to get it flying again except the gear so I'll be waiting a few days for that. I can't complain, I learned more today than I have in the past year.

[medtech]

here's some pics. I already rebuilt the heli so all I have are the leftover pieces, lol. You can't really see much on the batteries but the wrinkles in the shrinkwrap is about the only visible damage.

[mysticmead]

ouch.. I think those packs should be good... barely even touched them.. now if you had bent them up like a banana or taco.. you'd be a member of team taco real quick... I'm dreading the day that I earn my membership.. glad you got your heli ready to fly so fast

[medtech]

actually, I think the packs did get hit prettty good but the way they were held allowed them to move back into the frame instead of being crushed! I will charge them in my fire proof safe and see if they come out ok!

[mysticmead]

good idea... better safe (pun intended) than sorry

[bearwood]

I figured I can do rolls and flips on the sim so I tightened up my sack and went for it.

Man, I like your style, live by the Nike moto.... Just do it.:thumbup:

[mjdee14]

I was surprised the first time I did a loop...I was nervous as heck, but it pulled through with no problems...I do use 0 pitch on the way up and over the top so it doesn't fall at the top...

This heli is so responsive that if you have enough altitude, and orientation, it is easy to get out of a bad situation.....(if the sun isn't in your eyes blinding you).

I guess as soon as I get "Too" comfortable i'll bury it in the dirt.

[medtech]

I've spend quite a bit of time going over the whole thing in my mind. The fact is I couldn't see it to know where the problem began. Had it been right side up my natural instinct might've kicked in and saved it at the last second when I finally could see it again. Being inverted for the first time I had no chance in that last second before impact.

I still learned to watch out for the sun and also that crashes will and do happen so keep lots of spare parts!:YeaBaby:

[mysticmead]

as long as you learned something... then its all good.. I learn more and more every day that I read these forums.. so I guess it's a good way to spend my time when I should be working :D

[mjdee14]

I know sometimes we have no option on where the sun is...but it is very important to kind of plan your flights so as not to fly thru or in the sun....Planks are not too bad...they at least maintain a heading..but helis do weird things at the worst times....

[bearwood]

I was surprised the first time I did a loop...I was nervous as heck, but it pulled through with no problems...I do use 0 pitch on the way up and over the top so it doesn't fall at the top...

mjdee14,

I don't get the 0 pitch thing. A Roll or a Loop are both positive G maneuvers, so FF and pull or roll and hold the stick (cyclic pitch) until level again?? Where does the 0 pitch fit in?
I have probably misinterpreted your post but I am intrigued. By pitch I am thinking collective pitch which i thought would remain constant throughout the maneuver. Falling off the top is a result of insufficient speed into the loop or roll.

I haven't worked up the nerve (or tightened my sack) to try a roll or loop with the Heli yet but the above works in a fixed wing so It should be the same in a heli? Correct me if I am wrong.


Edit: Found a writeup on "Raptor Technique" which discribes the technique for a forward flip (loop?). Appears that the heli is quite a different machine doing acrobatics.

[medtech]

basically by using negative pitch you can flip and roll without the heli moving. Use less pitch to make loops and rolls as big as you want.

[mjdee14]

I use the 0 pitch to just keep the heli from trying to pull in the direction of the blades....try a stall turn...if you keep high pitch at the top of the stall...the heli will try and pull in that direction....

On the loop you still need plenty of speed...and I just just reduce cyclic at the top, then start feeding it in again on the down side....but if you use too much the loop gets all out of shape.

At the top with hih pitch, what will the heli want to do..."head toward the ground" with 0 pitch it goes over the top and you feed pos pitch in on the way down.

Hope that make sense...

[oppie]

I know sometimes we have no option on where the sun is...but it is very important to kind of plan your flights so as not to fly thru or in the sun....Planks are not too bad...they at least maintain a heading..but helis do weird things at the worst times....

Man this is something that is not talked about much ....The location of the pilot and the sun. Several of my crashes were made worse by not only did I get disorented then ended up the Heli was between me and the sun. Yes plan where you have the sun behind you as much as you can.

[vicrc]

Sorry about your crash. Those batteries are nice, I would help protect them with a fiberglass canopy by all means. The plastic one is horrid and it basically selfs destructs on impact. Well at least now its time for that upgrade.