CTX-5FBL a proper coax - Page 2 - RC Groups
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Feb 07, 2015, 12:00 AM
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Gregco10's Avatar
Thanks I see it now, 3 main servos control both rotors and the yaw servo the top rotor alone.
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Feb 07, 2015, 02:56 PM
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I made a video, not upto Marks standards but I did one, maybe I'll get a buddy to make one with me next week. Meanwhile, sorry to all those in the frozen North or the flooded west, Florida is a nice place today, if a trifle windy.

CTX 5FBL (3 min 20 sec)

Did you notice the non spinning auto just before the end and my pathetic attempts at backwards flight in rate mode

You can see the heli a bit better in full screen mode
Last edited by Peter Wales; Feb 07, 2015 at 03:08 PM.
May 06, 2015, 08:22 PM
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CTX-5 for sale

I have a CTX-5 that I won at a fun fly. It is for sale for $450 brand new in the box and un-opened. Send me an e-mail for any more info. Thanks
May 09, 2015, 12:54 PM
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Pity I don't live in the States. Hope you find some buyers?
No one is posting anything about this machine. I would love to hear some operational experiences from flyers out there. Quirks, handling, durability, flight times etc. Come on guys!
May 09, 2015, 11:26 PM
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Atomic Skull's Avatar
Seems they now have a 4 blade version of this?

May 10, 2015, 06:43 AM
mono's Avatar
Description from Sovereign website...

EP500 RC Helicopter
This is a 2-in-one model.
It comes from CTX-5, a double chain safety design. Its structure may be transferred into flybar or flybarless simply. That means every user just like own two mechanics but; take one model price.

So it comes with the bits to make it flybar or fbl, though I'm not sure why anyone would want to put the flybars on it. Makes it look like its predecessor, the helibaby.
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May 11, 2015, 03:50 AM
Cá bhfuil an linn snámha?
spykez's Avatar
I guess it is less costly in terms of blades, and more on head parts if you put it in.

Memory is hazy but I think the flybar model was on the site listing at about the same time I posted the find on helifreak.
Aug 31, 2015, 12:56 PM
rdf430's Avatar
I just ordered one of these. should be in Canada soon, couldnt wait for the KA-32 fuse. I wanted to fly this and see if it will be worth putting $500 fiberglass fuse around it. with the way the Canadien dollar sits... it could be more then $500
Dec 21, 2015, 01:06 PM
RC helicopters since 1985

Finally got one too

This is about the only group on the 'net that talks about this pretty little Coax "Kamov", so I joined today.
Yes, today my CTX-5FBL arrived in the mail. It's built but never flown. I'm setting it up with a BeastX, but am a little confused by the minimalistic manual.

Could you help me set it up properly? What are your recommendations? I'm especially wondering how to prevent the tailgyro from going into"negative" so it will spin itself senseless.
Love to hear from you!
Dec 22, 2015, 08:00 AM
Registered User
Set the beast x up with minimum gain on the rotor and 80-90% on yaw.

Fit the blades and create a pitch curve on on3eof the bottom blades 0-5-10 degrees. Now set all the bottom blades at exactly 5 degrees at mid stick. The pitch is not important but they must all be as close to each other as possible.

Put the gyro in rate mode and center the travel of the yaw spider on the top. Equal travel is important. Now set the top pitch at 7 degrees which will be close to optimum.

The throttle curve should be a straight line 0- 100%

Spool the model up and see which way you need to adjust the yaw trim to keep it still. Adjust the pushrods on the top so that the model will stay stable with no yaw trim.

Do not worry about it going negative, you s=dont have that much travel on the yaw control. Now you can set the heli up as any other with dual rates, expo etc to suit yourself.

We quickly ditched those plastic blades and had some CF ones custom made. they will come from Eastcoastvario.com if you cant get 3 blade sets locally.
Dec 22, 2015, 12:36 PM
RC helicopters since 1985
Thanks Peter, I will apply your settings tomorrow and report back!
Dec 22, 2015, 01:38 PM
RC helicopters since 1985
It's evening here, just thinking out loud. Peter, would it be better to fit a ZYX instead of the BeastX? As I have quite a lot of them on spare aswell I wouldn't mind.

What is minimum gain, 10% or off (0%) completely? If one needs to dial the gain of the head back, does one even need a cyclic FBL system at all?

Found this vid!

KA32 Short flight 2015 12 13 (3 min 48 sec)
Dec 23, 2015, 12:54 PM
RC helicopters since 1985


Following Peters' advice I made some adjustments on the CTX. But I also made some alterations that, in my experience, were better than stock. For example I made the servo arms on the swashplate all the same length, the 16mm setting proved to be non-negotiable for the BeastX so I changed the rear swashplate link to accomodate a 13mm setup on all 3 servos. Now the BeastX was fully OK with it. I also found the rod that links to the spider too long, as-std the mixing-links of the spider were not horizontal mid-stick so I changed this and re-adjusted the blades. For this reason the spider "hat" was removed.

From Peters' story I understood that the top blades needed more pitch than the lower set, in reality it was the other way round and I think Peter made a little mistake writing it down. In any case a difference of about 1.5 degree was spot on like he said.

To adjust this I used a state-of-the-art test"bed", a contraption commonly known as a spinning cheese plate. Now I could rev the 'copter and find out optimum "tail" trimsetting after I temporary disabled the tailgyro.

In my small garden I had some gentle liftoffs and now the tail stays calm on about 50% rate tailgain. The beastX cyclic gain had been set to 25% for the first hops, but now it's set back to std. mid setting and the CTX doesn't seem to mind (yet).

When time and weather permits I will do some more testing on the flying field!

Thanks for now, Marco.
Dec 23, 2015, 07:11 PM
Registered User
Look forward to seeing your ctx5fbl fly. I hope to acquire one soon myself so i am following this thread closely as a knowledge base. I really like Kamov's and the ctx is perfect platform. In meantime I am flying my Teryx 450 with custom KA32 fuse .

Skyrush Terxy 450 FFF for a coax (2 min 42 sec)

Skyrush Teryx 450 scale KA-32 fuselage with onboard camera (5 min 53 sec)
Dec 29, 2015, 03:05 AM
RC helicopters since 1985
Well, yesterday I flew the CTX on the RC airfield for the first time and I have to say: What a great little machine!
As it was a bit windy it is a bit of a handfull lifting off at first, but after some getting used to it, I was flying it around fuss-free and almost "like nomal". I tried to up the gain of the BeastX cyclic, this calms it down in hover but creates some nick oscillation in flight. So the best setting was back to standard setting, that's how all my BeastX's are set when the geometry is correctly chosen.

It makes a great humming noise flying past. It becomes unstable (dolphining) when you go too fast forward, but I think this is down to the soft blades. I defo will fit carbon FBL blades later!

Will post a good vid soon. Happy with it!

Greetings, Marco.

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