Buildthread: RJX Xtreme EP90

[Laurens]

Because my Estratus didn't fly as well as expected, I have bought another heli. The main reason the Estratus didn't fly as well, is because of linkage geometry and the maingear. The maingear couldn't cope with all the power from the E setup. Instead of spending a lot of money and time on it, I decided to buy another heli instead, and put the Estratus on the shelves for a while.

My choice for a more proven heli was the Xtreme EP90 from RJX. I've seen it flown by Jurrien Saelens and Michael Daris, both 3DM contestants. This heli has been designed by a German engineer, and its produced in China. This is a very promising combination, a well designed heli for low costs.



The frames are made of either carbon or glassfiber. Because the choice of this isn't that important, I've chosen the GF frames. Whats new to me are the breakaway tabs. These are mounted between the canopy posts and the main frame. Instead of damaging the frames, only these cheap tabs will break.

The lower frame is only for mounting the battery. Really light and simple.



The upper frame carries all the electronics and gearing. This is a lot stronger.



The maingear is made of delrin, CNC cut. It also features a helical cut of about 15 degrees. This results in a quiet heli with a friendly sound.

Because I went for flybarless straight away, I got the FBL head. This is a simple but very effective design.

There are 2 choices of taildrive. You can either choose the torque tube tail, or the belt tail. Because I'm a bit lazy I picked the torque tube. The belt will need some adjustment when the temperatures change. Even though its cheaper to crash, the torque tube is easier.

The setup is exactly the same as the Estratus:
- Futaba BLS 451 on swash
- JR 8900 on tail
- Mikado Vbar
- Kontronik Pyro 700-52
- Kontronik PowerJive
- Hyperion 12s 4200
- Edge 693 FBL

And more pics:

[arroxfive]

do you have more detailed building pics?

thx
Steven

[Laurens]

What kind of pics are you looking for?

[arroxfive]

the FBL head and the bearings of the main gear

thanx

[Laurens]

I'll try to make some tomorrow.

[Mercuriell]

Good job Laurens, looks very sturdy! Have you flown it yet?

[Laurens]

I have flown it a lot, but lately I don´t have any time to fly at all. I crashed it 7 weeks ago, but so far I haven´t even checked whats damaged. The army is a lot of fun, but it also takes up almost all my time.

Maybe in december I´ll fly it again, I´m not in a hurry.

[garfield2412]

hi Folks,

the title shows "BUILD-Thread" but most of the pic's are ready-Heli pics...

i'm building an 2009 X90EP this winter and i'll post pics from every step.
mybe 1-2 a week, i'm not in a hurry, the weather is bad for heli and LiPos.




any sugesstions for my build are welcome (like ESC/Motor combo, servos or anything else)
thought about:
- Scorpion 4035-500, 12s @ kontronik jive HV 80 (maybe HV 120+).
- Savöx 1258MG on swash, Savox 1290TG on rudder.
- Microbeast as Flybarless System
- 4000mah or 4500mah 12s (2x6s) packs (Turnigy nanotech)

[arroxfive]

Hi !,

My setup : motor -scorpion 4035-500
esc -Castle creations Phoenix ice 85 HV
swash -Savox 1257 TG
rudder -Futaba BLS 251 with stepdown
FBL -Beastx
bec -Castle creations BEC Pro
lipo -12S 4000mAh 30C

still waiting for my microbeast...en this for almost 6weeks

i'll post some pics soon

[garfield2412]

hi Folks,
i got pretty straight forward today.
built the main frame step 2-2 - 2-4.

don't want to critic Laurens, but he did some variation from the manual!

1. 4 washers @ front servo mounts arne not manual like
2. you don't have to mount the bearing @the main-shaft, the bearing is for the motor-pinion
3. receiver/gyro mount: he mounted the wrong part or did some mod?

please compare the pic's from my build with the manual and Laurens pic's and mount like you want. but you will miss some washers for the next step when mounting like Laurens.

greetings from Germany

[garfield2412]

Originally Posted by arroxfive

Hi !,

My setup : motor -scorpion 4035-500
esc -Castle creations Phoenix ice 85 HV
swash -Savox 1257 TG
rudder -Futaba BLS 251 with stepdown
FBL -Beastx
bec -Castle creations BEC Pro
lipo -12S 4000mAh 30C

still waiting for my microbeast...en this for almost 6weeks

i'll post some pics soon

thx for posting your setup.
i heared beastx is waiting with delivering because they ship V 2.0 software beasts beginning tomorow! (source: German beastx forum)

[garfield2412]

the build goes on!
(way to fast, it's early winter season! i have to slow down! :-) )

[garfield2412]

and more build pics
swashplate installed and a little bit level-work

maingear installed


the whole success of the day

[garfield2412]

Tail Boom and Tail Rotor

[arroxfive]

nice pic's...fast building, you have you maiden before Xmas :-)

[garfield2412]

Originally Posted by arroxfive

nice pic's...fast building, you have you maiden before Xmas :-)

Thanks!
jeah, it's pretty going forward to fast!
but i have to wait for x-mas-money for servos, microbeast and motor so there is a natural stop ;-)

progress of the day: Tail-Boom mount
PAY ATTENTION! I think there is a fault @the manual (v1.0) Page 32.

The rotation of the belt is displayed wrong compared to the picture @ step 7-3

mounted like page 32 and got an wrong spinning tail rotor! changed belt rotation and now spinning my main rotor clockwise and the tail rotor spins also clockwise ! like shown on figure 7-3.
compared to other pic's @the web and to Laurens pics with the edge blades this seems to be right like shown at figure 7-3!



and in the 2010Kit there are 2 bearings, 1 long screw and 2 small "crossmembers" (don't know the right word)
they are for the belt mount @the tail-case
like shown here

pretty huge baby compared to my 450 and also much bigger than my 600 roxxter 33SE

[garfield2412]

and some more progress..
some tail built (look at those screws and nuts going through the tail-brace) litte mod by me like suggested in the manual!




and finaly the canopie. i think you can hear me curse all over the world when mounting those f#**#*# rubbers! boild them 5mins but they where so hard to put in!


but the beauty of this canopie/heli made me so happy that i have forgotten this f#*#*#* rubber-action after 2min :-)

[Laurens]

I think you're right about the rotation off the tail.

[arroxfive]

i wonna share the following : maybe is my fault but i forgot to loctite the elev arm, so the setup of the beastx went wrong.
it was because the waiting of of the microbeast...now i'm thinking if i forgot something else...


for the elev arm
you can't thread them with loctite before you did the mechanical setup for your head
so you have to do it after (F) Setting the tail sensor direction and (G) swashplate servo centering in the beastx menu

everything turns out fine and the installation of the microbeast is very simple !

[garfield2412]

Originally Posted by arroxfive

i wonna share the following : maybe is my fault but i forgot to loctite the elev arm, so the setup of the beastx went wrong.

hi,

i thought about my previous setup and tested what i did! puhhh.. not fixed! --> lucky!
but i think i will forget this too if your therad wasn't here!
--> i'm writing an note right now.
i'll install my servos maybe next year.

what about your beast: allready on 2.0 ?? ;-)
beastx is cool, simple setup and running verry well!