FBL Gyro 3gx issue - Blade 300x

J

JonProphet

New Member
Hi, I found the sites video's on Youtube. The one I was following left out quite a bit and the videos filled in the gap.

Well unfortunately, before I finished the setup, I took it up and was able to hover with some difficulty and the second one I took it up and it pitched tail up and slammed into the ground. Only damage was it trashed the canopy, stripped the main gear and broke a blade grip. No worries I do have spares. It was the end of the night so I quit while I was ahead.

Couple of questions.

1. My pitch from positive to negative (during initian 90 degree setup) was 11.6 and 12.3, positive to negative. Is this an issue or should I have it equal? I'm not sure I can given the blade hardware is about 1 degree per full revolution.

2. I'm also using DS76 servo's on the cyclics and ds76t on the tail. Is there a better way to setup the tail blades to 0 pitch? I eye balled it but I'm afraid this may have caused my last crash.

I'll have more questions I'm sure.

Thanks again.

-JD-
 
B

bbj

Member
I am new to the hobby but everything I read said if I wanted a more docile heli to change my cyclic to 10 positive and negative and for pitch/ele to be 8 degrees. 12 in my understanding is for more advanced pilots. If you can try to get your positive/negative a little closer that might help, but it shouldn't be a major factor. You might want to check out freddy can fly youtube videos on setting up your heli, he does a great job of explaining. this is for a 450 heli with 3gx but it explains what is needed Align 3gx full setup video 3 (freddy can fly) - YouTube. He also explains now to set up other sizes. When I set up my tail blades I turned them towards each other so I could verify they were in alignment with each other. Then I set my limits for the servo etc.

BBJ
 
J

JonProphet

New Member
Freddy was the video series I was using when setting this up. I thought he was going to do a part 5 but I couldn't find it. That is when I found this site's vid's and they explained the tail and gov setup. I'm going to replace the gear and main blade grip and see how it flies.

Before I changed the pitch center on the tail and made some changes, the tail was twitching but I could hover.

Thanks for the response.
 
Tony

Tony

Staff member
Wait, you have different cyclic pitches? If so, then either you are checking it when NOT in DIR mode, or your swash is not level, or you have some funky servos on the helicopter. Or is this collective (throttle up and down)?
 
J

JonProphet

New Member
I'm using E-Flite DS76's on the cyclics and DS76T on the tail.

With the tail at me. I pitcch up (throttle full) swash moves up, pitch down (throttle 0) swash moves down. Ail right, swash right side goes down, left side goes up. Ail left, left swash goes down, right side goes up. Elevator down (stick down) swash tips back, front goes up. Elevator up, back swash raises and front goes down.

Yes, I was in DIR mode when checking ail pitch max.

Thanks.
 
J

JonProphet

New Member
Also, something new I noticed. The rudder is slowly going all the way to the limit to the left. I am centered and I had to use quite a bit of sub-trim to get the servo right at 90.

Any thoughts?

Thanks.
 
Tony

Tony

Staff member
As long as your servos are the same, then only reason you have different pitch on your blades is 1. you have different end points in your Tx or 2. you are using a digital pitch gauge and you are checking from both sides.

When you check your cyclic pitch, and collective for that matter, with a digital pitch gauge, you MUST calibrate the gauge across the front of the frame just in front of the main shaft/swash with the nose facing you. Then, after you calibrate it, you can ONLY check the pitch with the blades facing the front of your helicopter. When you figure out what your pitch settings need to be for the aileron (you can't check elevator this way), then just transfer your settings over to the elevator and it will be all done. A digital pitch gauge is a little harder to use, but easier. I will explain more when I get the video up. But hope this makes enough sense.
 
J

JonProphet

New Member
Ok, so..... I figured out that my tail servo was on its way out. I mentioned previously that it was slowly going completely left towards the boom if the heli just sat in normal ready to fly mode. Well, I went to adjust the servo wires and when I powered the unit back on, it had centering and that was it. It was chattering pretty bad before as well.

I had a HSG-5084MG for my 450x that I hadn't installed yet. I put it in and adjusted everything back to center. I had to mess with the gyro tail reverse and the reverse on my transmitter. I'm tired so I can't recall what the original settings for either were but, I got it. I spooled it up and it is controllable.

It does start to get light on the skids and tilt toward the right at or close to 50%. I'm not sure if this is due vibration. Its, cold, snowy, wet and worst of all, dark. So I just spooled it up, recorded it and shut it down for the night. I'm not going to put it in the ground right now.

I'd stay I still have some tuning to do, but it appeared to my eye, to be pretty stable. I'll know more when I'm in the air.

Thanks!
 
Lillyryan

Lillyryan

Member
HI. The 3gx can be pretty unstable when you are lifting off. It is better to lift off quick. once up in the air you should be fine.
To get your cyclic down to about 8 degrees just enter swash mix whilst in dir mode and adjust the values of the ailerons and elevator. They should be equal. What version are you running on the 3gx?
 
J

JonProphet

New Member
Can you explain adjusting the values a little more?

I thought, you adjusted the swash to ~10-12 degrees for one throw only. Is it a limitation setting inside the program?

I'm using 5.0 of 3gx.

Thanks.

- - - Updated - - -

I just went through the 3gx again. Correct me if I'm wrong but you are talking about ail/ele end point adjustment. The 8 + (.5 or .7) * 8 = say 12. This should give me an even 12 degrees of throw for each (ele or ail) positive or negative and should be equal? Correct?
 
Lillyryan

Lillyryan

Member
Yes that's right I think from what you are saying. It is adjusted in your swash mix though on your tx not in your endpoint adjustment. The 3gx doesn't like endpoints being adjusted in the tx.


Sent from my iPad using Tapatalk
 
J

JonProphet

New Member
I didn't make any adjustments last night. I did take it out for a hover or two.

Here is the video:

First flight of a Blade 300x and 3gx - YouTube

Let me know what you think on any adjustments. I didn't fly it any differently than any other heli I own. It seemed to want to sink on its own. The swash was REAL sluggish too. Any input seemed to not be enough.

Thanks.
 
Tony

Tony

Staff member
Did you have any kind of wind that day? Is the bobbing up and does the only sluggishness you felt?

if it feels like the collective is not enough, you can try adding more pitch in the swash menu.

Also, srt your pitch curve in normal to 46 48 50 75 100 if it's not there already. Head speed sounds fine, but you may want to go to a 0 45 70 70 70 throttle curve. This may help with the bobbing.
 
J

JonProphet

New Member
Tony said:
Did you have any kind of wind that day? Is the bobbing up and does the only sluggishness you felt?

if it feels like the collective is not enough, you can try adding more pitch in the swash menu.

Also, srt your pitch curve in normal to 46 48 50 75 100 if it's not there already. Head speed sounds fine, but you may want to go to a 0 45 70 70 70 throttle curve. This may help with the bobbing.
Click to expand...

It felt sluggish in every aspect. Collective up and down. Ail/Ele both were sluggish. So much so I'd give it input and it felt dead. It would finally over respond and I would have to correct. The corrections would be late and sooner or later the thing was all over and I had to bring it down.

My curves are standard linear curves for throttle and pitch. IU1 is 0 25 50 75 and 100. IU2 is like 75% or 80%. Wanted to keep head speeds down a little bit. Pitch curves are the same linear across 0 25 50 75 and 100.

Wind was minimal.
 
Tony

Tony

Staff member
Change it over to the curves that i posted, they help keep it a little more stable. And if you are running expo, cut it down by 10% and try it again. That will make it a little more responsive when barely moving the sticks.
 
Lillyryan

Lillyryan

Member
Have you got any expo in the tx?

- - - Updated - - -

Also have you got the parameters in the 3gx software set correctly for pitch dampening and expo?
 
J

JonProphet

New Member
I followed the video's by Tony. I took the usb cable back to who I borrowed it from. I'm waiting for mine to come in the mail. When I get it, I'll update it. I'm running 20% expo. I'll cut it down.
 
Lillyryan

Lillyryan

Member
Yes I would cut expo back to about 10 and try that or even cancel it all together


If it won't fly put a bigger engine on it!!!
 
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