450 Align t-rex 450 pro dfc build and 3gx setup

[stokke]

You're welcome bud
Remember training gear!

 

[Tony]

I think I'm done with the setup.. Is there a way to tell? The settings I'm not sure I got right is rudder endpoints and governor.

Also, both satellites are blinking, is this expected or should there be a solid light? Anyways, I spooled up on the floor and it seems very stable so I guess its time to take it outside. Any final tips before I go out and fly this thing into the ground?


To the people who helped me with this build, especially Tony and Marius: THANK YOU!

The blinking lights on the Satellite Rx's means the Tx lost bind to the Rx. Meaning you unplugged the helicopter and left your Tx on then plugged the heli back in. As long as it's a slow flash, and it doesn't happen after you fly, or worse, when you fly, you will be fine.

The end points on the rudder, you know you have it right if the slider goes all the way to each end without binding. If it binds or doesn't reach the end of travel, then you need to do it again.

The governor needs to be OFF. There is no reason to run one on an electric heli, especially when it was made to work with all of the electronics it came with.

Just make sure your training gear is on good and the skids are up off the ground, spool up slow and take your time. Make sure you have an open area and if there is grass, make sure it's mowed very short. Starting out it's best to start out in a parking lot or the like. If you click on the articles button above, I have a how to fly series that shows step by step what you should do. It worked for me so I thought I would make videos on it.

 

[flysolo]

First flight was a disaster!

It's still in one piece but just barely. As soon as the skids came of the ground the tail started to go crazy, rocking superfast back and forth. Now I changed the gyro channel from Gear to AUX2, changed the heli size from large to small and tried to set the rudder endpoints up better.

Second try tomorrow

 

[breeze400]

Turn your gain down! It should be about 65%

 

[stokke]

What value do you have set in your Tx gyro settings?

 

[flysolo]

It's set to 40% on the Tx now. When I was outside I tried to lower the gain on the Tx but nothing changed. I think after reading some forums that it was the wrong channel and the settings didn't have any effect.

 

[stokke]

Well you're good on the gain then.
The AUX/GEAR "problem" is correct when using Spektrum equipment.
Rudder gain has to be on AUX.

Hope you work it out

 

[murankar]

Its been a few days since I last logged in and want to help someone other than myself.

After many broke zip ties on training gear I finally changed up my method of attaching. If a zip tie breaks it can cause the heli to tilt to one side. In turn maybe cause the main blades to grind on the ground. I have a video of the very thing happening.

My solution to that was to use the strings from the inside of 550 cord (parachute cord, military grade). I wrapped it many times then tied it off. Once done I melted the knot so it would stay tied.

The down side was I could not case the heli to transport it. It did save some money though.

 

[flysolo]

After many broke zip ties on training gear I finally changed up my method of attaching. If a zip tie breaks it can cause the heli to tilt to one side. In turn maybe cause the main blades to grind on the ground. I have a video of the very thing happening.

I experienced this first hand yesterday, or similiar

When the tail was freaking out so did I and tried to put it down to fast. My zip ties didn't break but I broke the training gear, the thing that holds them together, and the blade tips just touched the ground and shaved off a millimeter. It was really close to tilt over and do some real damage but I got away with just a small part taken off the blades.

I've been flying a mcpx for two months and feel pretty comfortable with orientation and stuff but the pure size, sound and force of this thing makes it feel like I'm starting over from scratch.

Thanks for your advice, gonna have to do something about those training gears today after work.

 

[flysolo]

Second attempt just finished. What a difference from yesterday, this is how it should have been from the start.

I did 3 packs of simple hover, it's so stable I can't believe it. No vibrations at all and no crazy tail behaviour like the first time, the only thing is that the tail is drifting very slowly to the right(head left). It's a very slow drift, maybe 45° in 30 seconds but I'd like to get rif of it.

After searching a bit it seems like it's better mechanical setup of the tail that is needed, must be doing it wrong somehow..

 

[stokke]

When you put on your rudder pitch link (the long one), did you make sure you had mechanical center on the slider?
When the rudder servo is at 90 deg, the slider (for rudder pitch) has to be as centered as possible.

 

[Adam]

trying is never wrong. turn your gain on gyro up until you get wag in tail then lower it just a little. if you still have drift it does not hurt to go back through the gyro rudder setup through the 3gx. think I did that one a good dozen times and my tail is solid

 

[flysolo]

Can (should) I use sub-trim a all on the tail rudder or is that a no-no?

 

[coolgabsi]

Subtrim yes

Trim no

Subtrim only through FBL gyro though. No tx subtrims..


You have a dfc right? Did it come with the new design main bearing block?? it looks different than the pro and pro v2.. Mind positing the pics of how you mounted stuff?? Just for my info.. Nothing related to your issue

 

[flysolo]

Subtrim yes

Trim no

Subtrim only through FBL gyro though. No tx subtrims..


You have a dfc right? Did it come with the new design main bearing block?? it looks different than the pro and pro v2.. Mind positing the pics of how you mounted stuff?? Just for my info.. Nothing related to your issue

Ok, cool.

Sure, I can post some pics. I recently split up with a girl and she took all the foto gear with her so I have only my telephone.. Not sure if I got the new bearing blocks but I guess so. Pics will be up in a minute

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The quality is not great, let me know if you want more and of what and I'll try to make them more sharp

 

[flysolo]

More pics

 

[flysolo]

Trying to understand everything about the gyro now. I'm using a Dx8 and 2 sats.

There are 2 screws on the 3GX. When to use them?

On the Tx when I go into gyro there are two percent values. They are the same, 42% currently. Why two? Flip a switch to change between the values or they set different things? Seems like I can only change both at the same time.

Ch. is set to Aux2 it has to be when using 3gx with 2 sats?
Sw. What is it? It's now set to On

 

[Adam]

Your two screws on the 3gx one is for ail gain and one is for elev gain an adjustment that you can kind of compare to lowering your gain on your tx for a tail wag. As for the dx8 i will let someone else answer that one since i fly with dx6i. But to get HH mode on your gyro you have to be above 50% i have mine at 62 but everybodies will not be the same.

 

[Tony]

Adam, he has the DX8 not the DX6i. His gain goes from -100 to +100, not 0-100. Anything in the positive is HH anything in the negative is Rate mode.

Your gyro should not be on Aux2, it should be on the gear channel or gyro channel. I know mine was anyway. and you can change the switch that will change it. The aux2 switch is a two position and the gyro is a 3 position. The two different values are the two different gains you can set to that switch (3 on the gyro switch). Watch my videos on this helicopter, I'm pretty sure I went through this setup in there. Makes me wish I still had my helicopter so I could just punch up everything and test it out. But I don't...

 

[flysolo]

Your build videos were great Tony, they've helped a lot and I also found the ones you did on the Dx8. Gonna go back and watch them again and see if i missed something.

About the Aux2 I'm not gonna argue against you it's just that on my first attempt I lowered the gain and it did not seem to have any effect. When searching the webs a lot of questions about that show up and they pretty much state Aux2. Gonna connect to the pc and see what happens if I change it.

Some of the things I try to read up on now is not strictly related to getting the 450 in the air, just trying to understand the 3gx gyro and the dx8 settings. Did you by any chance know what Sw is for? It can be set to Inh, On or to a switch nut I'm not sure what it is.

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When you put on your rudder pitch link (the long one), did you make sure you had mechanical center on the slider?
When the rudder servo is at 90 deg, the slider (for rudder pitch) has to be as centered as possible.

Yeah, it was pretty off on my first attempt but now it's centered as far as I can tell

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Your two screws on the 3gx one is for ail gain and one is for elev gain an adjustment that you can kind of compare to lowering your gain on your tx for a tail wag.

Ok, thats good to know. I'm gonna leave them on their defaults since I havn't had problems with ail or elev, just the tail.