Trex 800 Pro HV and DX8

[canadien007]

Note: Before you read on, please understand that the only goal I am trying to acheive it to set up my heli for scale flying and possibly AP.


just got my used 800 in the mail a week ago and im finally getting time to set it up on my radio.

I dont have much experience setting up helis and fbl controllers.

i am trying to follow the manual for the radio settings. the manual talks about "general flying" and talks about what sort of throttle curve to set. it also mentions to have -5 to +10 degree pitch with 0-2 degrees at mid stick.

what sort of pitch curve do I set for general flying, NO 3D?

ill be putting a naza h on it, any help is welcome.

if someone can provide me a with a SPM file, thatd be great!

[JohnTC02]

When I used my DX9 for scale flying my pitch curve was 31,51,64,80,95. Hopefully this will give you a starting point.

Depending on what you have set for your total pitch when setting the heli up mechanically the lower number of 31 will give you a negative pitch of around -3 to -6 degrees and the 95 will be around 9 to 12 degrees.

[canadien007]

Originally Posted by JohnTC02

When I used my DX9 for scale flying my pitch curve was 31,51,64,80,95. Hopefully this will give you a starting point.

Depending on what you have set for your total pitch when setting the heli up mechanically the lower number of 31 will give you a negative pitch of around -3 to -6 degrees and the 95 will be around 9 to 12 degrees.

first off thank you John.

How to adjust the maximum - and + pitch?

[JohnTC02]

You will adjust the pitch along with all other settings when you run the setup for your FBL controller, this will be your mechanical setup.

I only use the vbar and AR7200BX controllers, they are all different so you will have to look at the instructions for the one you are using.

[canadien007]

Originally Posted by JohnTC02

When I used my DX9 for scale flying my pitch curve was 31,51,64,80,95. Hopefully this will give you a starting point.

Depending on what you have set for your total pitch when setting the heli up mechanically the lower number of 31 will give you a negative pitch of around -3 to -6 degrees and the 95 will be around 9 to 12 degrees.

What was your throttle curve like

I have mine as recommended by aligns manual at

0, 40, 65, 85, and 100

[goodhunting]

Do not just simply copy someone's numbers in your Transmitter...

use pitch gauge to measure the actual pitch as each helicopter is different.

In the scale world people use general pitchrange from -2 deg on the low stick... 5,5 deg at mid stick (as the helicopters hover at this setup) and +11-12 deg at high stick ... just in case...

this will give you a docile and stable helicopter that will hover at mid stick and that still has enough negative pitch to descend quickly and enough high pitch to get you out of trouble if you ever get into it...

each radio is different... so is each helicopter so to setup the system to work as it should use the pitch gauge to measure the precise angles...

furthermore if you are using a FBL controller... such as Naza H then all this is done in the FBL controller and not in the radio...follow the wizard for that one. Watch a lot of youtube videos on how to set it up... seek help locally if available

gh

[JohnTC02]

Good advice gh.

To answer the OP's question my throttle curves were straight as I'm using the vbar gov, I now use the vbar control radio which doesn't use throttle curves.

No disrespect but one thing that is bothering me here, if you own a heli as big as the 800 you should know how to set it up mechanically and how to set up a FBL controller, if you are having problems doing this I wonder if an 800 class heli is right for you.

These big birds are very dangerous and you need a lot of experience with something smaller before moving up to a 800.

[canadien007]

Originally Posted by JohnTC02

These big birds are very dangerous and you need a lot of experience with something smaller before moving up to a 800.

I was thinking of purchasing a 450 and try to setup the naza on it to get some experience before slapping it on my 800. This way, even if I mess up, it wont cost me $300 to put her back in the air i suppose ....

[Woodsta888]

I agree with goodhunting.

With a 2nd hand heli (and an expensive 800) I'd go through the setup of the helicopter from scratch. You will familiarise yourself with the mechanics and have confidence that it wont fail mechanically. Whilst some builders are competent other that claim they are really are not. 2nd hand heli's I have bought I strip down and rebuild and have often found build mistakes on re assembly. With an 800 a physical failure can do alot of damage. 700 size + helicopters kill people.

I'd at least check

Gearing meshes between pinion and main gear and any bevel meshes in the tail drive train. Poor mesh will cause wear. Pinion end can strip gears.

Check that all swash control links are set as the lengths in the manual.

I'd check the servos are centred properly to give the usual 90 degree centres.

Then check the pitch with a pitch gauge is zero at centre stick.

The you can set the values (checking with a pitch gauge) for the pitch curves as per the manual.

You have some other choices too with a big 800. For scale you may consider flying lower headspeeds. Though you will ideally want a 'freewheel' capable esc to set lower throttle curves/idle up. Or as the 800's are so big you could putthe lipos in series to create a lower headspeed.

You wont want 3D headspeeds particularly and even on low headspeeds an 800 will still eat up the sky.

I'd check that the ESC is set for the correct number of cells if you are flying if different from previous owner.

Add in some expo to make it more docile around centre sticks and not so responsive required for 3D pilots. The HV servos will be quick so this will help here.

I think for the relative cost and peace of mind I'd go to my nearest club / hobby store and pay for someone to check it and fly it if I wasn't confident in FBL setup.

Common mistakes are reversing servo directions in Tx's when it should be in the software. You will need to learn the DJI NAza FBL unit well if going alone. I'd visit the DJI NAza FBL thread for some help.

Good luck, be careful and triple check that the control surfaces react as you expect BEFORE flying.

[canadien007]

Thanks everyone for the great advice. I think ive gone in deep over my head with a heli this size.

I had a question regarding the travel direction of servos. If i give right aileron, the servo arm should go up right.

[goodhunting]

Don't look at the servo arms... Look at the direction the swash tilts... If you want the helicopter to bank left then the swash should move left as well...

Gh


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[canadien007]

Originally Posted by goodhunting

Don't look at the servo arms... Look at the direction the swash tilts... If you want the helicopter to bank left then the swash should move left as well...

Gh


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OK, I tried for maybe 1.5 hours to get the servo to move in the right direction but no luck.

tried reversing and everything but just cant get it right.

[goodhunting]

OK... first of all ...all the adjustments MUST be made in naza nad not in transmitter. When you reverse the servos... do that one at the time. Do not reverse two or even all three as this will not get you the results you need. Bear in mind that when setting up naza...in the step to reverse servos... you need to "experiment" just a little... to get it all moving right.

Trex helicopters "increase power" as the swash moves up... the movement of the helicopter is determined by the movement of the swash plate leveler. if swash moves left... the helicopter will "tilt" left. if it moves backward... then the helicopter will "tilt" backward...

don't give up hope... play with it and experiment...

gh

[canadien007]

Originally Posted by goodhunting

OK... first of all ...all the adjustments MUST be made in naza nad not in transmitter. When you reverse the servos... do that one at the time. Do not reverse two or even all three as this will not get you the results you need. Bear in mind that when setting up naza...in the step to reverse servos... you need to "experiment" just a little... to get it all moving right.

Trex helicopters "increase power" as the swash moves up... the movement of the helicopter is determined by the movement of the swash plate leveler. if swash moves left... the helicopter will "tilt" left. if it moves backward... then the helicopter will "tilt" backward...

don't give up hope... play with it and experiment...

gh

ok so all the settings in the Tx has to be "normal" not "reversed".

Theres a section in the dx8 under swash mixing when the aileron, elevator, and pitch are all at +60, I leave them the way they are?

[goodhunting]

The FBL units work independently. Consequentially you do not change anything in the tx. They NEED the swash to be set for 1 servo only.... No internal mixing at all.

Best advice is to create a brand new model and start setting everything from scratch. Read the instructions for Naza H.... It tells you what the setup for the transmitter needs to be.

Then follow the setup instructions in the naza software. DO NOT skip steps...

It should be fun...

Gh


Sent from my iPhone using Tapatalk

[canadien007]

Originally Posted by goodhunting

The FBL units work independently. Consequentially you do not change anything in the tx. They NEED the swash to be set for 1 servo only.... No internal mixing at all.

Best advice is to create a brand new model and start setting everything from scratch. Read the instructions for Naza H.... It tells you what the setup for the transmitter needs to be.

Then follow the setup instructions in the naza software. DO NOT skip steps...

It should be fun...

Gh


Sent from my iPhone using Tapatalk

Makes sense now. i had 3 servo configuration in my radio. going to change that see what happens.

well atleast that's how my naza m is. didnt even think about that!

[canadien007]

Originally Posted by goodhunting

OK... first of all ...all the adjustments MUST be made in naza nad not in transmitter. When you reverse the servos... do that one at the time. Do not reverse two or even all three as this will not get you the results you need. Bear in mind that when setting up naza...in the step to reverse servos... you need to "experiment" just a little... to get it all moving right.

Trex helicopters "increase power" as the swash moves up... the movement of the helicopter is determined by the movement of the swash plate leveler. if swash moves left... the helicopter will "tilt" left. if it moves backward... then the helicopter will "tilt" backward...

don't give up hope... play with it and experiment...

gh

have yoi worked with a naza h?

[canadien007]

Originally Posted by JohnTC02

When I used my DX9 for scale flying my pitch curve was 31,51,64,80,95. Hopefully this will give you a starting point.

Depending on what you have set for your total pitch when setting the heli up mechanically the lower number of 31 will give you a negative pitch of around -3 to -6 degrees and the 95 will be around 9 to 12 degrees.

Okay so at low im showing -6 degrees, mid -2 degrees, and high its at 11 degrees.

[goodhunting]

Yes I do have a naza H controller... But mostly fly others.

If you want a docile helicopter for gentle scale flying then set up your pitch for -3 at low stick 5,5 at mid stick and +11 to 12 at high stick...


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[canadien007]

Originally Posted by goodhunting

Yes I do have a naza H controller... But mostly fly others.

If you want a docile helicopter for gentle scale flying then set up your pitch for -3 at low stick 5,5 at mid stick and +11 to 12 at high stick...


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Since you own a naza, I have a question for you. In the setup menu when it comes to point where you have to select the % of pitch, th3 defualt was at 50, I brought it down to 45% to get to -5, 2, and 11. If i brought the pitch percentage to 100% it was crazy numbers like -15 at low and +26 at high! is this how im suppose to do it?

The other thing I did was decreased the lower end.travel to get -5 degrees and decreased higher end travel to get 11 at high.

One thing.worth mentioning though is that I get +6 degree pitch close to 60% throttle. is that ok?