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Revolution Models . CarbonXtreme . Midland Helicopters

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e-Minicopter Joker > Main shaft thrust bearing
 
 
andrei
Heliman
Location: all over the place

Can anyone point me to a schematic or advise me where exactly the thrust bearing upgrade is supposed to go on a Joker CX?
Thanks,

Andrei

registered user
04-25-2008 10:09 PM
 
 
East Coast Scale
Key Veteran
Location: Taxachussetts

Directly below the top bearing block on the Joker.
Joe
04-26-2008 01:32 AM
 
 
nooobsVeteran - Location: Toronto, Canada -



Below is on a Maxi-Joker2
04-26-2008 01:03 PM
HOMEPAGE  
 
 
Gerd
Senior Heliman
Location: Vellmar/Germany

It also works on a Joker CX and Joker 2, when you only or most fly "normal" (with pulling rotor), with pushing rotor (inverted) the load is completely on the lower radial bearing and the thrust bearing is then out of function. But of course this is causing no damage.
04-26-2008 08:46 PM
 
 
andrei
Heliman
Location: all over the place

Thanks everybody.I wont be doing any inverted flying, just slow forward and hovering.
Here is my horse, almost ready to rumble.
I had to extend a little bit the main tail boom in order to accomodate the cranked tail by using the standard lenght belt.
I wanted to be able to use some 830mm blades and 120mm tail blades at very low rpm and after the first trial it looks like it might work just fine.



registered user
04-29-2008 12:41 PM
 
 
fionn
Heliman
Location: Ireland

Main boom?

Hi,
How did you extend the long boom?
I just cut a long boom with crushed ends down to 844 to use the shorter belt (part no 286 - 1800mm) as was intended.
Your tail rotor will have a lot of leverage with the full length boom + the cranked tail extension
Fionn.
04-29-2008 01:00 PM
 
 
andrei
Heliman
Location: all over the place

fionn,
I just added a short piece of boom pipe wich i glued and reenforced with some bolted carbon brackets on the inside.The main belt that came with cranked tail kit was shorter than the original one and i would've had to shorten the boom thus the main and tail blades wouldn't have cleared one another.
The leverage is a good thing in my opinion since HS is barely above 1000RPM wich doesn't give the tail rotor a whole lot of authority.
With the standard lenght boom and 710mm when i increased the throttle/pitch suddenly i would get the heli spinning counter clockwise.
I hope it will work better now.
I'm also using an ACTRO 24-6 on 8S in the quest for increased flight time.
I fly mostly FPV.

registered user
04-30-2008 04:02 AM
 
 
fionn
Heliman
Location: Ireland

Boom

Thanks for that, Yes I understand the clearance issues.
I split and glued some of the offcuts inside the ends of my booms to prevent crushing when I shortened the tail boom for the shorter belt.
I wonder would it be better to have the joint at the tail or the body when extending the tail boom? My heart tells me the tail but someone with mechanical engineering knowledge can possibly give an authorative answer.

I have an FPV setup myself (Headplay + BW Wireless) but havent tried it on a heli just yet. I like how I can set them up so that I can just look into the goggles to preview shots atm.
04-30-2008 08:51 AM
 
 
rroback
Key Veteran
Location: Irvine (UCI), Ca

interesting. that thrust bearing upgrade is different then mine. Mine doesn't have that collar, but instead has a tube that goes from the bottom of the thrust bearing, to the lower bearing in the frame.

Rhett... There's no power like E Power!
04-30-2008 04:57 PM
 
 
HawkEyeMedia
Senior Heliman
Location: Fort Worth, Texas

Is the thrust bearing an upgrade? Niether of my MJ2's have the thrust bearings, just a tube that goes all the way from the lower bearing to the upper one.

Mark LaBoyteaux
HawkEyeMedia.com
04-30-2008 08:05 PM
HOMEPAGE  
 
 
littleman
Veteran
Location: state college pa

yes, the thrust bearing is an upgrade designed for heavy lifting MJ's
A.J.

Proud member of Teams Minicopter Acrobat and CYE
AIM minicopter3d with questions
04-30-2008 08:42 PM
HOMEPAGE  
 
 
nooobs
Veteran
Location: Toronto, Canada

FYI...

The schematics does not exist. It is made up from MJ2 and CX manuals. (as Andrei was asking).
05-01-2008 10:51 AM
HOMEPAGE  
 
 
andrei
Heliman
Location: all over the place

Haven't had the chance to install the thrust bearing yet i was too impacient to try the new blades.
I made the mistake not to check them for ballance, wrongly assuming a 300$ set of blades would come factory ballanced.
The shaking wasn't too bad but enough to make the LG do the hula.It is connected to the frame with rubber dampeners.
After messing with the radio trims and the HC's autotrim and several landings and takeoffs later i noticed the cranked part of the tail was somewhat twisted.
The crappy glueing job i did couldn't take the torque and the vibes i suppose.
There are two CF brackets on the inside but they are not strong enough from preventing some twist once the glue gave up.
It's a narrow spot and i'm not shure what to do about it.
I need to use some sort of a collar something like those used to clamp the radiator and vacuum hoses.
Still no other dammage so i'm a happy camper.For now.



registered user
05-01-2008 12:45 PM
 
 
Gerd
Senior Heliman
Location: Vellmar/Germany

You will say that you have lengthened the tube using a short piece of carbon tube and glue?

Please note: The end of the tailboom (before the tailgear flange begins) is the most stressed area of the whole helicopter with the highest amplitudes when you have any vibrations?

So please do not try this again, it´s really dangerous.
05-01-2008 02:55 PM
 
 
andrei
Heliman
Location: all over the place

"You will say that you have lengthened the tube using a short piece of carbon tube and glue?"

Yes Gerd that's what i did.
It is also held by 2 CF plates on the inside wich are bolted to both sides of the boom.You can almost see the one on the oppside side of the boom in the picture.
Today i fixed it by wrapping some tough canvas tape and impregnated everything in epoxi.
And to try to put a little bit your mind at rest, i am only flying above grass in a field where there is no one or anything under the heli.
If anything should happen and the tail fails in the air and the heli comes down and crashes into the grass, i will be the only one to suffer a heart attack and die of pain and suffering.

registered user
05-01-2008 06:16 PM
 
 
flyboy
Elite Veteran
Location: NorCal

Danger Buck!

With your elevated LG you should consider going with the straight boom. Problem solved. Less weight, less parts much more rigid. Nice ship other wise.
FB
05-01-2008 08:11 PM
 
 
fergus
Veteran
Location: Ireland

Andrei

Quote 
I had to extend a little bit the main tail boom in order to accomodate the cranked tail by using the standard lenght belt.

If you are using the standard belt then how come the standard boom would not accomadate it?

I don't like to stick my nose in here but this is a disaster waiting to happen in my view. Take the twisting issue as a warning. This extension WILL fail. Please listen to Gerd and maybe save yourself a costly repair bill or worse.
Quote 
i am only flying above grass in a field where there is no one or anything under the heli.
The two people on the bench behind you in the picture may not hold the same view!

Posted with the best of intentions.

Regards

Fergus

If you see a smoke trail from my heli get an extinguisher EPOWER
05-01-2008 10:25 PM
 
 
nooobs
Veteran
Location: Toronto, Canada

Andrei

Please STOP.

That bird stores a lot of power. Believe me. I've crashed several times already within the last 4 months. I've seen the amount of dirt that can get picked up even when just hovering low.

The cost of damages will outweigh the cost of your tail modification.

Your heli is elevated due to the AP landing gear. There is a high posibility that your heli will tip over in case of a crash. Just look at all the mods you've put in. Just imagine if you damage your Profi?

Just trying to prevent a heart attack...


Quote 
i am only flying above grass in a field where there is no one or anything under the heli.

What do you plan to shoot with your camera at this low altitude?
05-01-2008 11:12 PM
HOMEPAGE  
 
 
andrei
Heliman
Location: all over the place

Thank you guys for the good advice and goodwill and i hope i didn't give anyone reason for concern.The 2 people on the bench are 30 yards away, i'm only flying about 15 yards away from me on two directions(east-west) and there is absolutely nothing under or anywhere near or in the path of the flight.
And i'm only hovering and very slow forward flight.
The unorthodox job i did seems to hold just fine after some 60 minutes of flying.
I've always modded everything and maby not in the most engineeresque way but most of the time it served me just fine.
Two days ago before i had a chance to mess with the failsafe setup, after several failed atempts to get my 2 laptops to cooperate with the HC software i've experienced a pilots most feared scenario when the heli gets a mind of it's own and starts acting funny and not listen to radio command inputs.
I regained briefly control over it but not long enough to allow me to bring it down safely.
It hit a tree on it's way down, wich tree helped brake the fall fairly well.
Still the aftermath is costly enough.
One of the main blades is broken, the tailboom fractured behind the midpoint where the 2 struts converge and clamp, the skids in front of the first LG strut are broken, one cyclic servo had shaved gears, the Pentax z750 i'm affraid is history.
I suspect the interference had something to do at least in part with the 2.4Ghz video Tx wich untill that time i haven't had turned on.
There might also be a chance that some RC Boaters about half a mile away might've been on the same channel but i'm not shure about that.
I hope to put everyones mind at rest regarding the home grown exension.Since the boom is in two pieces and the main blades are history i can only use a shortened one and the shorter belt as Gerd intended it, so there is no more chance of something giving way up when flying.
Maby it is for the better that it happened this way.



registered user
05-05-2008 09:44 PM
 
 
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e-Minicopter Joker > Main shaft thrust bearing
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