Spektrum DX6i with Spektrum's AR7200BX on a T-Rex 450 Pro DFC

Tony

Staff member
The wind taking the heli up is called Translational Lift. Means the blades are getting very clean air and it's more efficient at producing lift.
 

Doum066

Member
All right.. so here i am, a while after the last post on this thread...

This post is gonna be a little long, to give you a little bit of my flying backgroundd, so you can understand how i do feel.

as i stated on another thread i started, i recently crashed trying to move my bird... I'm fine when it gets to hover, any direction, i even prefer nose in, i kinda like the challenge of it. But since this bird is my first CP Heli as i could say, i do have over by now, about 70 hours or even more in Phoenix 4 Sim, but in real life, the only other heli i flew before was my old E-Flite Blade CX, which i only flew inside an did inside circuits, then i got myself an E-Flite Blade 120 SR, which i also, flew inside, but since it's a little bit more tricky as a Single Rotor Fixed Pitch and how my appartement is made, it's too tough to fly it inside, so back then, i flew it / hover inside for about a week at the beginning of winter, then i got Phoenix 4, not to mentioned ever since i got the sim, i never flew my 120 SR....

So all that to say that, for a first CP Heli, a T-Rex 450 Pro DFC when moving, is a total demon for a beginner, even though i'm sure the fact i had a BeastX instead of the 3GX made it easier to start with. So about one week and a half, since i felt confortable hovering with it, any direction, i tried to get it moving... and with a curve which wasn't suited for me.... so it lasted about 3 minutes, when i tried to turn it back with a bank turn, it hit some tree branches.. i almost made a clean turn, but i kinda needed about 2-3 feet to clear my turn... so not to mentioned what happened, some stuff are Scratch and Sniff, some other are Fish and chips, some say don't drink and drive, but that day, what i did was, Smash and Crash ;)

I then 2 nights ago, came up with a thought... That the BeastX comes with a setting option/menu, which is Control Behavior. In this menu you got a few options, if i am not mistaken those are; Normal, Sport, Pro, Expert and Transmitter. By default it's set on Sport... so i came up witth he idea that, since it's a really sensitive bird.. if i do add some positive Expo it might tame the bird down a bid.... so i though, to try out Normal settings, and see how it does react, might be easier for a beginner, but when you set up on of those 4 presets, it is recommended, if not,forbidden, to use TX Dual/Expo, so that's where the Transmitter option comes in play, it allows you to use your TX settings. So i made some reading on the web, since i wasn't sure which one to use, Normal preset or Transmitter settup with rates i can adjust.... so i went for a settings with the TX.

I wasn't able the try it out yet, it was freaking windy these days, so i tried to enter the exact same settings in Phoenix, even in the same i was more confortable with the settings, even though the T-Rex 450 3Gx doesn't feel the same thing at all as a DFC 450 Pro in real life, but still makes me feel a difference.

Today the wind has finaly calm down, i might be able to try this settings has hovering, see how the controls react....

I'm curious to know, for some of you guys using the same setup (450 Pro DFC + AR7200X) and remember when you first started, some hint and tips, because that bird is a nasty one to start with, way more nervous and sensitive than a flybar one etc....

I even made a little video on youtube, to show that as for as it is now, i'm doing not bad in the sim... and not being able to move inr eal life, kinda frustrate me.. at the point i am mostly wondering if i'll ever be able to... but we'll see with some settings that tame the bird down a bit.

So i changed the settings in the sim for the exact one i have in real life, which is;

Collective Pitch Range : -11,7 / + 11,2 (that oscilating digital pitch gauge, plus the fact you can only adjust ball link one full turn at a time, makes it tough to be on perfect pith you want)

Throttle curve : 0/60/75/75/75

Pitch Curve : -5,7 deg. (25%) / -3,7 deg. (34 %) / 0 deg. (52%) / 5,2 deg. (75%) / 11,2 deg. (100%)

Dual Rate : D/R 80% and Exponential +20%

Phoenix 4 R/C Sim - T-Rex 450 Pro Circuits - YouTube
 

breeze400

Spagetti Pilot
If your running this in normal mode then your throttle curve should be liner. 0-25-50-75-100. Pitch curve I would set at 45-48-50-75-100. This is the correct curves for any heli once you go to IU1 or IU2 ( Idle Up ) then you can play a little. 80-78-75-78-80 100-95-90-95-100 throttle and 0-25-50-75-100 pitch curve. Pitch curve in IU1 or 2 is the same the throttle you can play with a little. Throttle hold should be the same had IU. You can fine Tony's article on setting up blade pitch under the arrivals section- Setting Proper Blade Pitch!

D/R and Expo even I need help with! Lol. But this is where you tame down you machine from! If your curves are not set right your bird will never fly properly for you!
 

Lee

Well-Known Member
@Sam
A linear curve in Norm mode is not ideal for a steady helicopter, as the throttle and pitch are both constantly changing. Having the throttle as he has it 0,60,75,75,75 will mean the throttle is steady and only the pitch changes, therefore the heli is less prone to bouncing up and down.
Throttle hold should NOT be the same as ID1. Throttle hold should always be 0%

I would up your Expo to 30% from 20% if you are finding the bird twitchy.
 

Doum066

Member
@Sam Thanks for your reply, i really appreciate.

Yep, i did made my blade pitch settings, as i said, it's almost perfect, as what a turn (you need a complet turn on the ball link so the A stays outside) allow me, the difference between both blades is more or less ,5 degree, at mid stick, 50 % one blade is oscillating ont he digital pitch gauge, from 0 to -.3, my other blade is oscillating from 0 to +2. Servos were almost pefectly align 90, when i rebuild my bird, i took all 3 servos, and with the servos resetting to center position, i was playing around with the servos horn, if one was a bit too off from center position, i would then turn the horn 180 degree to see how it is centered ont he other side (knowing i need 2 servos with horn poitin at o o'clokc, and one horn poitin at 3 o'clock, i turn, changed gorns froma servos to another, until i get 2 horn at 0 o'lock and one at 3 o'clock as much possible as i could, then aligned all 3 servos, using a ruller i then align all 3 servos with the mddle hole of the servos, where we put in the sscrew, and trying to get as much as i could a pefect ligne from all servos middle hole and horn's ball ling, when this done, i then use my BeastX menu where we set up the swashplate level, and adjuste each servos center position with the BeastX built in sorta trim. I didn't had much to adjust. When finished rebuilding te Heli, time came for swashplate leveling, i then went back int he same menu as before, and with my swashplate leveler in place, only one of the 3 servos, needed 1-2 turns to level up the swashplate, when this done, i then checked the blade pitch, and only one needed a few turn on it's grip arm ball links... and it was almost perfect as mentionned at the top of my reply. And to make sure i'm as close as possitble to 0 deg pitch, i take off my swashplate stopper plate, this is where i then put my digitial pitch gauge. this is the only place i'Ve found that makes a perfect level with the heli, then i zero my pitch gauge there to make sure it is at the same level as the heli, and not at for exemple, the table by putting the gauge on the table to level up the gauge... i'm a little bit perfectionnist... professional bad habbit. :)

And the reason i don't use a 45 deg lenear pitch curves on idle up is simple, the 0/22/50/75/100 willl then use the full collective pitch range, meaning, i get -11,6 deg to + 11,2 deg... 11 deg negative pitch for a beginner.... freaking scares me :) The curve i set, gets me more or less -5 deg, which is not that bad, 40%-45% shouls bring it down to around -2 deg. which is i think, dangerous, making you get used to not much negative pitch... and i wonder if it's a bad thing to learn....

The Expo, is a sorta way like a joystick deadzone on a computer, it kinda reduce the sensitiveness around the stick's center, so it feels like sensitive and robotic.... What kinda made me crash is, i was using the Sport built in settings of the BeastX, and i am not sure it has much positive expo, so a slightly move on the stick makes the bird really sensitive.

@Lee Thanks also for the reply.

I think Sam meant, that the Pitch curves on idle-up and the throttle hold pitch curves on idle-up be the same. And indeed that is the reason i'm using this throttle curve, it spools up than when flying lowering the stick only changes the pitch and not the throttle. Once more foncortable i will be able to raise up the 75 points. I might indeed try 30 %, i was just able to fly, was way too windy outside, but i went down at the shopping mall and went in the underground parking lot, was able to fly my 4 packs... ok those darn supprt concrete beams scares me lol but i wanted to try those settings, and simply moving forward and back, was way less sensitive. I might try 30 % as for what i read on some forum, 30 % Expo is almost what the BeastX built in preset Normal uses.

But i really need to calm down.. i'm still shaking like crazy when slying, specialy since my crash :)
 

Lee

Well-Known Member
I know sometimes people say to use a linear throttle curve in Norm, but from my experience and the people that I have told to try the flatter throttle curve, it has all be positive feed back. But as with everything, it comes down to personal preference. Give it a try Sam, you will find the heli much more controllable :D
But the throttle hold should always be 0% as i said and i'm sure Tony said. so when you hit throttle hold, the throttle is cut. Maybe it was just the way it was written that confused things.
Hope that i make sense :D
 

breeze400

Spagetti Pilot
Ok I understand what your saying. I was reading from Tony's blade pitch set up guide this morning in the article section it says pitch on the th should be same has IU. But throttle should be 0's I miss read it. Lol sorry!
 

Doum066

Member
Well here i am, after a few more packs with some changes and i think i almost have something there... well for what i could try in an underground parking lot :p I felt a little more safe and start simply flying forward, folowing as much as i could as a challenge, the parking yellow line, then about 30-50 feet in front of me, stabilized her back into hover, than bringing it back to me (tail in that was, didn't felt safe to go in nose in as i bring her back for now.), then stabilized her back, hovering, and sending her back forward etc... i did a smal change in the Expo, i made it +25 for now, and maybe next time try +30 as Lee mentionned, we'll see. and the other change i made was, creating my Idle Up settings almost like my normal one, the only diff is, for the throttle curve, my normal is 0/60/75/75/75 and i made my idle up one 75/75/75/75/75 since the bird start to lift around 55-60% stick input, the the throttle is already at 75% since 50 % stick input, so no variation as i switch it... i find it really important as a beginner that it doesn't kick up when you switch it to idle up... it scares me ;P

So once the bird start lifting i can switch to idle up, and i'll be able to hover, move without any throttle variation... So far it tamed it down quite a while.

So for those interested beginner or what ever, here is my setttings :

1- AR7200BX or BeastX Parameter Menu Setup / Menu B - Control Behavior, i selected Transmitter (Blue Solid) which allows to use Transmitter's D/R Expos setings.
2- D/R Expo: 80%, Expo +25% (Same for Normal and Idle Up settings)
3- Throttle Curves: (Normal 0/60/75/75/75) (Idle Up 75/75/75/75/75)
4- Pitch Curves: (Normal 25%/34%/52%/75%/100% in degress is more or less -5.7 deg./-3.7 deg./0 deg/+5.2 deg./+11.2 deg) (Same curve for Idle Up and Throttle Curve)

As for the % and the degrees of pitch settings, mine are based on my pitch blade range which is more or less -11.7 deg. / +11.2 deg. There is not much difference on both Normal and Idle and that's for one purpuse, it's to get to know the bird before asking it to give all it got. :) The flat throttle curve on idle up will give smother hovering or flight since only the pitch will be affecter as stick input, the throttle wil be a straight 75 %.

I know it's a boring settings, but i rather learn slowly, but safely, i spent already enough on for a first crash. :p

Take care :)
 

Tony

Staff member
Just to clarify, I have started telling people to use the 0 60 75 75 75 t-curve because of stability. It's like flying in idle up, but without all of the negative pitch. Just a much more simple bird to handle, and when the pilot does get to using IU1 and 2, they are mostly used to it and are not scared by the sound of the blades spinning really fast.
 

Doum066

Member
Well, seems iM' having a little issue for now, when i add some rudder input, the tail start shaking, if i land, then take off again, it seems ok, if i re-add throttle it starts shaking... and it doesn't seems to make this every time... i'm wondering if it's the gyro fighting the wind.... but it never made that much shaking... I guess if it does that again, i should try to put back the BeastX at his default settings of Control Behavior with Sport settings, and use my settings with no D/R Expos... see how it does....I've tried to set back my tail servos end points.... still does it... that's mainly the changes i've made, that and the new tail servo. To much gyro gain, or not enough, not sure if it could be that.

- - - Updated - - -

Well, seems iM' having a little issue for now, when i add some rudder input, the tail start shaking, if i land, then take off again, it seems ok, if i re-add throttle it starts shaking... and it doesn't seems to make this every time... i'm wondering if it's the gyro fighting the wind.... but it never made that much shaking... I guess if it does that again, i should try to put back the BeastX at his default settings of Control Behavior with Sport settings, and use my settings with no D/R Expos... see how it does....I've tried to set back my tail servos end points.... still does it... that's mainly the changes i've made, that and the new tail servo. To much gyro gain, or not enough, not sure if it could be that, i can try to lower it at first, if i do remember, it's set tp 70% on my TX.....
 

Doum066

Member
It was indeed tail hunting, Gyro gain in my TX was too high, i had the same gain as my Normal mode, i had to turn down a bit my gain in idle-up mod.
 

Tony

Staff member
If you are flying in idle up, and you know where your gains are supposed to be set, change your gyro gain over to the F Mode switch. This way, you will have ideal gains on all flight modes. I still use the gyro switch, but putting it on the F Mode is just one less switch to flip.
 

Doum066

Member
If you are flying in idle up, and you know where your gains are supposed to be set, change your gyro gain over to the F Mode switch. This way, you will have ideal gains on all flight modes. I still use the gyro switch, but putting it on the F Mode is just one less switch to flip.


If i do understand right what you say, it's mostly how i am set, i have the D/R Combi menu set to F-Mode, so when i flip F-Mode switch, it changes my Gyro in mode 1, pitch and throttle curves in mode 1 same with D/R Expo, it changes to mode 1.
 

Tony

Staff member
ACtually you will go into your gyro menu and set your switch to teh F Mode switch instead of the gyro switch. As stated, I still use the gyro switch, but I know that if my gains are so tight that I need to change them, I can do so by flipping the gain switch first to lower the gain, then flipping the idle up switch to raise the head speed. I like having that 3rd option on my DX8 that is in rate mode allowing me to center the blades just before I spool up, resetting where the HH is looking.
 

Doum066

Member
Allright guys,

Since i already back then started a thread about my equipment, i'm having some kind of issue here, i crashed last week, soft crash but still, at first i thought i got disoriented since the bird got a bit too far from eye sight (darn those 450 outside get small quickly), after thinking about what happened that night, i then realised it might had been a problem while stripping the tail... the rudder didn't answer and i ended up unable to get her back, so i thought something had failed since i over passed my maintenance day from a few flights...

Then yesterday, i went back to the flying field, and bam i got a problem which right away reminded me what happened last time, the second i tried to give rudder to turn nose in to bring her back, all was maily fonctional besided the rudder, i was unable to bring her back since i wasn't sure if she was nose in or tail in... exactly like how i crashed last week... but this time i was able to bring her back.. when i had no control over rudder i thought something went loose or failed as it did last time, but nah.. when she got back a bit closer, i was able to use rudder once more, i landed, checked everything, all seem fined, i flew 1-2 pack after, while only hovering close by and trying out rudder a lot... no problem at all....

So what could it be? Is there a fonction i'm not aware of, i was getting a bit far away i do agree, but if i loose signal, wouldn't all input not working, not only rudder? The AR7200BX is supposed to be a full range RX + FBL system... is it my DX6i/DSMX loosing some signals, i'Ve got a DX8i on it's way (the DSMX version), should get it today or tomorow, since the AR7200BX is a 7 CH RX, should i get myself a satellite in case there odd signals/frequency problem in the field, or the DX8i better at range and stuff....

I'm trying to pin point the problem, in any case, i'll try to keep her as close as i can from me.. but you all know while doing circuits you always over turn one of the ends :S


Thanks
 

breeze400

Spagetti Pilot
There both the same RX dsmx. I'm not sure how to hook it up but, the manual says either the dsmx or dsm2 will work! Read your manual or go to horizon's websight and download it. Then read it. I'm driving down the road. Can't read it myself.
 
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