450 HK450-GT MAIDEN AND CRASH

[fireman7234]

Here is a video of the maiden flight and crash. Before the video i was checking tail and watching skids and adjusting trims. Then in flight gave to much throtle got nervous and chopped it (controls are prety sensitive need to lower rates and more expo) and thats all she wrote, but that is all part of the experience I will rebuild it and hope next time it goes better plus here are some pics of the aftermath.

 

[D.O.G.]

Ouch, that hurts fireman7234 . That stinks but we all have done that once or twice ... before . Like you said, it's all part of the experience. Good luck on the rebuild and will be watching for take 2

 

[Chris Hadley]

I know it's hard but the best thing to do is not to panic... instead of chopping the throttle you need to lower the throttle. It's easy to say I know but valiant effort fireman. Like D.O.G said, we've all done it

 

[Tony]

Bummer dude. What was your collective set to? And just a pointer, only set about -2º of negative pitch in normal mode. That way it won't plow itself into the ground. It will still come down quickly, but not quite that quickly. Also, training gear is fantastic if you are just starting out. Looks like crap, but trust me, it can save the helicopter. Fly, Crash, Rebuild & Fly AGAIN!

 

[Chris Hadley]

Takes me back 3 years... my first 450, and first build was an HK450GT...
Also became my second build.... third build... forth build... lmao. You get the picture

 

[Derek]

Whats your throttle and pitch curve?

 

[Admiral]

Bugger, as everybody says we have all done it on more than one occasion, good effort though until the panic shut the throttle off.

Full marks though for putting the video up, I probably would have pretended that it did not happen.

You will do better next time, every time you crash teaches you something, my ratio of take offs to landing is not that great but I keep going back up.

 

[Smoggie]

Sorry to see that, but he did seem to be flying well before the crash. Like the others have said, maybe look at your throttle and pitch curves.... So how have you got those set?

 

[fireman7234]

Bummer dude. What was your collective set to? And just a pointer, only set about -2º of negative pitch in normal mode. That way it won't plow itself into the ground. It will still come down quickly, but not quite that quickly. Also, training gear is fantastic if you are just starting out. Looks like crap, but trust me, it can save the helicopter. Fly, Crash, Rebuild & Fly AGAIN!

in normal mode pitch curve is set to low 45% 1. 47% 2.50% 3. 75% high 100%

 

[fireman7234]

Sorry to see that, but he did seem to be flying well before the crash. Like the others have said, maybe look at your throttle and pitch curves.... So how have you got those set?

in normal mode pitch curve is set to low 45% 1. 47% 2.50% 3. 75% high 100%
in normal mode throttle curve is linear low at 0% and high is 100%

 

[Tony]

What is your full collective pitch?

 

[Smoggie]

I thought that might be the case... your problem is your throttle curve. The way a collective pitch heli is meant to work is that the RPM stays about constant and you control the 'up and down' with collective pitch only. So what you should have is a pretty much 'flat' throttle curve so as to maintain a constant RPM all the time.
If you feel better to run normal mode then it should ramp up very quickly then be almost flat.. something like : low 0% 1. 70% 2.70% 3. 75% high 80% (the slight increase in throttle % is to stop bogging under load)

The problem with the curve as you have it is that the RPM will be changing rapidly as you adjust collective pitch. Because RPM lags slightly behind stick movement, the heli will end up zooming up and down with you 'chasing it' on the collective pitch. Collective control will be very unpredictable and non-linear resulting in exactly what we saw in the video.

Once you get it fixed you will find that changing the throttle curve makes a huge difference. A bit of a hard way to learn the lesson but that's heli flying for you, they aren't very forgiving.

 

[fireman7234]

What is your full collective pitch?

11.5 postive and 11 negative

 

[Tony]

Your swash is just a touch too low. I would extend all 3 servo to swash links one turn, which will give you more positive pitch, and then I would go in and lower that collective to 9.5 to 10 to help soften it up even more.

 

[fireman7234]

thanks tony ill do that once i get it rebuilt

 

[fireman7234]

Like to get everyone's opinions on the rebuild.
Here is what broke when it crashed bent the flybar,blades(of course),tail boom,bent the tail pushrod,1 of the tail blades,landing skids, bottom frame plate and stripped two of the cyclic servos. Had to cut slots in screws to take frame apart (cheap clone kits) to get servos out.
My question is should I rebuild it or buy an newer align 450 flybarless kit?

 

[Tony]

That is going to be a call that only you can make. The newer kits with flybarless gyros can be setup to be more stable, but they also come with more powerful motors. Meaning you will need to set your throttle curve lower, something like 0 65 65 65 65 in normal mode. IMO, I would go for it and get away from the clones. I can't even bring myself to rebuild the SE V2 which is a clone frame with full Align parts.

 

[Eggy 71]

It comes down to 2 things. How much can you spend and availability of parts. First helis are as much an exercise in building them as learning to fly them. I started out on a Blade 130x and then 180cfx. They have both been totally rebuilt many many times. Other than the 180 motor and both ESCs everything's been replaced at least once if not 4 times.
If parts are still available I'd stick with what you have purely on a cost perspective. If parts are getting scarce then it's time to step up. The newer machines are really nice to fly and handle great but you will be rebuilding them as well.

 

[fireman7234]

That is going to be a call that only you can make. The newer kits with flybarless gyros can be setup to be more stable, but they also come with more powerful motors. Meaning you will need to set your throttle curve lower, something like 0 65 65 65 65 in normal mode. IMO, I would go for it and get away from the clones. I can't even bring myself to rebuild the SE V2 which is a clone frame with full Align parts.

Question on the newer kits could I use the same motor I have on the flybarless kits or would it not be enough power?

 

[Tony]

What motor are you running?