Other hobbies and money-pit obsessions...

[Lazerjock]

Adam,
Be careful! That thing may not kill you but it could easily send you to the emergency room for a few stiches.

When ever I fire up a new 450 class heli I hold them by the tail boom close to the frame with my index finger on one side of the frame and thumb on the other. This keeps the heli from twisting into your arm and away from your body.

Make sure you look over everything before trying to fly it again, a few teeth missing from a gear or belt can be a really bad day. Make sure the blades are put on correctly and that they spin the right way. On a Trex 450 the main rotor spins clockwise when looking at it from the top. The tail rotor should spin counter clockwise when looking at the left side of the heli another way to look at it is that the tail blade closest to the main rotor should be moving up. This allows the down wash from the main rotor to give the tail rotor more authority. I've seen this backwards many times. If it is wrong you will need to reverse your tail servo and gyro sensing too.

Wish I was closer I could help.
Glad your ok.
Chris

[Stuka]

You folks that fly helicopters are nuts!!

Damn, wait a minute -
I resemble that statement!!

Glad you're OK Adam!!

I had a nitro 20-size bird - my first RC helicopter - beat me up pretty good when I failed to notice I was at almost 1/2 throttle when I started it!
Ouch!!!

I hear you about the terrifying part ~
Just looking at the blades of my next big bird scares the crap out of me!!!!

[buffo]

Thanks for the advice Chris!

The main and tail rotors are turning in the correct direction. And all the gear teeth look fine. But the servos on the swash plate are screwed up. Well, two out of the three for sure are... Not positive about the third one. But the one on the right front and the one in the rear just sit there and "chatter" when I power the bird up.

Control is all screwed up too - when the rotor spins up, the servos don't move until you give lots of input, and then the swash plate "snaps" into the new position, which is usually a violent change. No way I'll put it in the air like this - it would be uncontrollable. Truthfully the thing really scares me now, because with the rotor up to speed, seeing it "snap" like that is downright frightening. (And this is only at ~ 50 % speed.) I did some troubleshooting earlier today in the yard, and I didn't want to spin it up after I saw that the first time. (The fact that my chest still hurts is a grim reminder!)

The tail rotor servo is fine, and the one on the front left of the swash plate seems OK, but I can't tell for certain because the other two are shaking so bad I can't tell if the third one is also shaking or if it's just following the movements of the swash plate. Damn!

Either way - something is hosed for sure. I need to contact Bang Good tonight. Sure hope I can get it resolved before SELEM...

As for Stuka's new beast, it's quite a bit larger. 600-series, if I'm not mistaken. Big bird! (And lethal energy in the rotor head when it's up to speed.)

Adam

[Pockels]

Adam,
Be careful! That thing may not kill you but it could easily send you to the emergency room for a few stiches.

When ever I fire up a new 450 class heli I hold them by the tail boom close to the frame with my index finger on one side of the frame and thumb on the other. This keeps the heli from twisting into your arm and away from your body.

Make sure you look over everything before trying to fly it again, a few teeth missing from a gear or belt can be a really bad day. Make sure the blades are put on correctly and that they spin the right way. On a Trex 450 the main rotor spins clockwise when looking at it from the top. The tail rotor should spin counter clockwise when looking at the left side of the heli another way to look at it is that the tail blade closest to the main rotor should be moving up. This allows the down wash from the main rotor to give the tail rotor more authority. I've seen this backwards many times. If it is wrong you will need to reverse your tail servo and gyro sensing too.

Wish I was closer I could help.
Glad your ok.
Chris

Wise words there Chris! I speak from personal and painful experience with a 30 class

[buffo]

Well, I have an update on the 450 bird. All three servos that control the swash plate are stripped! Evidently they used the cheapest Chinese servos they could find in this thing. All plastic gears, etc. So I just need to replace them and I should be golden. Will probably go with metal gears this time.

Good news is that the mast and rotor head are all fine.

Adam

[JasonB]

Hi Buffo,

When I got my first 400 Trex clone I ended up needing to visit a friends house from my R/C club to finalize the setup. The mechanical setup is pretty tricky to figure out, everything has to be perfect; somebody with experience can really teach you a ton in a short time. So I suppose what I'm sayin' is I think its normal to seek help up setting up your first one. I sent a few e-mails with some photos and he said 'Just come over, I have everything you need to get it set up'. My friend explained how to set up the swash plate servos and set my throttle curves for a beginner to intermediate pilot. He re-explained the flight modes (normal, idle up, throttle hold), which are VERY important as you learned, some modes spin the rotor up to near 100% and the heli is controlled by the pitch of the blades (for advanced to expert heli pilots). He did a safety inspection for me too. I consider myself an expert in fixed wing because I compete in aerobatic competitions with a giant scale gasoline planes, but the heli was a whole other animal.

So the purpose of this note is make sure you don't feel bad on this adventure. We, in the R/C community want you to be successful and to stay safe. Yeah, those lipo batteries can source an extreme amount of current for short bursts.... Keep an eye on those bad boys when charging!

Have fun and stay safe!

-Jason

[buffo]

Hi Jason;

Thanks for the tips! I really should try to meet some more experienced Heli pilots here in town. There are several at work, but right now I'm ahead of all of them on the learning curve. (They are still flying Blade micros or coax birds. One guy has a 200 series fixed-pitch bird and just bought a 150 series collective pitch, but he can't fly it worth a damned yet.)

I used fly planes 3 decades ago, but that was back in Wisconsin and all those people in that club are long gone. Still, I'm sure there are people here in town though who are flying some really big stuff. I just need to get together with them.

Randy (Stuka) mentioned blade-balancing, which is something I haven't done yet. I'll also need to set up the swash plate servos after I install new ones. There is a chapter in the manual about it, but I can see where having some assistance there would be helpful.

I do have the throttle and pitch curves set up already though. (Well, except for the fact that the switches are backwards, but I can fix that in software.) Truthfully, most of it was set up at the factory, and I didn't make too many changes.

My bird in normal mode runs a combination of variable rotor speed (to a max of around 70 %) and variable pitch in the positive direction only. But when you switch to idle-up, then you're in 3D mode with the rotors spinning close to 100% speed all the time and you can pull 10 degrees positive or 10 degrees negative pitch. (There is still a small speed curve on the rotor head even in this mode, as you want a bit more torque when you're pulling max pitch in either direction, but even so, at zero pitch you're still turning 85 to 90 % speed.)

Hope to get some video of the bird flying in hover soon so I can post it here. And of course it will be at SELEM, although it will NOT be flying indoors. (Too dangerous!)

Adam

[luxilid]

I dabble in pyrotechnics as a hobby where all your money invested literally goes up in smoke!
Also modular synthesizers where Gear Acquisition Syndrome (GAS) runs rampant!!

[Stuka]

I dabble in pyrotechnics as a hobby where all your money invested literally goes up in smoke!
Also modular synthesizers where Gear Acquisition Syndrome (GAS) runs rampant!!

Yep, I feel your pain there!!

[steve-o]

Gear Acquisition Syndrome (GAS)

Nice I gotta remember that one .