RunRyder RC
WATCH
 4 pages [ <<    <     1      2     ( 3 )     4     NEXT    >> ] 5648 views POST REPLY
HomeAircraftHelicopterAntiques or Out of Business › GMP Cobra being revived!!
02-04-2008 12:04 PM  10 years agoPost 41
HeliAdict

rrApprentice

Texas

My Posts: All  Forum  Topic

A modern gyro is about the same as mechanical when it is in rate mode. With the parts situation being what it is, why risk the mechanics for electronics.

PM  EMAIL  GALLERY  Attn:RR  Quote
02-04-2008 04:42 PM  10 years agoPost 42
baby uh1

rrVeteran

St. James, Mo.

My Posts: All  Forum  Topic

Gyros
DON"T! I tried that on my Kalt whisper and ended up breaking my skids. The Mechanical gyros are difficult to use and even more difficult to tell if they are working properly. Mine seemed to work but couldn't keep the tail still and even worse was eratic!
So don't risk your rare bird on old tech that barely worked when it was new.
Huey

PM  EMAIL  GALLERY  Attn:RR  Quote
02-04-2008 07:36 PM  10 years agoPost 43
heli_headcase

rrKey Veteran

Hovering around Atlanta

My Posts: All  Forum  Topic

Mixing Levers...
The balls on the sides of the mixing levers in the head allow more collective/cyclic range without binding.
That's pretty smart. It's the first time I've ever seen or heard of such a modification.

Here's the 'official' mixing arm upgrade, parts from the Falcon 888:

The pushrod goes from the elev and air servo to the lever and then to the bellcrank/lever. This creates a parralelogram and eliminates interaction. The 1st Hirobo Eagle used a system very similar.
The only interaction was an unwanted elevator trim change with collective movement. Everyone today (please don't tell me I'm wrong here) is flying with a computer-based RC transmitter with at least one free programmable mix available. Just make Pitch as the master and Ele as the slave and play with the mix percentages until the swash stays level at full collective extremes. The first X-Cell 50-60 heli's had this very same problem and I mixed it away.


HHC

So many heli's - too little time...

PM  EMAIL  GALLERY  Attn:RR  Quote
02-05-2008 12:10 AM  10 years agoPost 44
GMPheli

rrElite Veteran

W. Bridgewater, MA USA

My Posts: All  Forum  Topic

Yup, I'm sure you could mix it out. You would need to mix out the ail too. I am flying my GMP's with an old Futaba Super Seven that has only one free mix. And I use it on a couple of machines (modified Legend and modified PHI Hurricane) for my 3 servo 90 ccpm. It only has 2 servo 90 built in. I would have one free mix on my Competitor which is non ccpm

PM  EMAIL  GALLERY  Attn:RR  Quote
02-05-2008 05:22 AM  10 years agoPost 45
heli_headcase

rrKey Veteran

Hovering around Atlanta

My Posts: All  Forum  Topic

Oops...
Yup, I'm sure you could mix it out. You would need to mix out the ail too.
That's right. The X-Cell has 'balanced' aileron rods off the servo that are the source of the collective motion whereas the GMPs have a single, forward connected rod to both cyclic servos.

Now if the Cobra and Competitor were configured with the control system of the Hirobo Shuttle...

That's different!


HHC

So many heli's - too little time...

PM  EMAIL  GALLERY  Attn:RR  Quote
02-05-2008 04:34 PM  10 years agoPost 46
RAK402

rrElite Veteran

Alhambra, CA

My Posts: All  Forum  Topic

The Cobra and Competitor were derivatives of the Hirobo Falcon 808/707.

The original Hirobo models had "I" levers mounted at the pivot point of the collective arm, with intermediate pushrods.

There was no interaction with the original Hirobo designs. The "I" levers were left off for simlicity sake and, if memory serves because the collective arm was inverted on the Competitor in order to elminate a 90 degree bellcrank mounted to the front, vertical frame member between the collective servo and the collective arm.

The original "I" levers were plastic with a brass bushing. Optional levers, and those on the 808EX were metal with ball bearings.

PM  EMAIL  GALLERY  Attn:RR  Quote
02-05-2008 08:27 PM  10 years agoPost 47
aristo1963

rrApprentice

goldsboro nc usa

My Posts: All  Forum  Topic

those old birds are great.

PM  EMAIL  Attn:RR  Quote
05-07-2008 01:01 PM  10 years agoPost 48
baby uh1

rrVeteran

St. James, Mo.

My Posts: All  Forum  Topic

Almost made my maiden flight Sunday. After breaking in the motor I attempted to hover and the clutch lining came out of the heli.
I don't know if they came installed in the kit or if the previous owner installed the lining but the glue didn't hold.
Is there a special glue to install clutch linings?

Thanks

PM  EMAIL  GALLERY  Attn:RR  Quote
05-07-2008 01:06 PM  10 years agoPost 49
Roger Oxe

rrApprentice

EDFE, Germany

My Posts: All  Forum  Topic

Hello baby uh1,
5 min epoxid glue...

"Model Makers are mostly normal human beings, only their childhood dreams are growing up again

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-07-2008 02:18 PM  10 years agoPost 50
jczankl

rrKey Veteran

AZ

My Posts: All  Forum  Topic

JB Weld is another good one!!

GAUI/Empire
Xpert Servos
PowerMaster Fuels
YS Engines
Graupner
Castle Creations
Scorpion Motor
VTX Blades

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
05-07-2008 06:12 PM  10 years agoPost 51
GMPheli

rrElite Veteran

W. Bridgewater, MA USA

My Posts: All  Forum  Topic

Make sure you rough up the inside of the bell. I crashed a PHI Hurricane because the clutch liner came unglued. It was slipping, and it didn't have the punch it usually had and I couldn't figure what was wrong untill the liner fell out in flight. The clutch shoes bent out and hit the metal of the bell and it glitched like crazy!!!

PM  EMAIL  GALLERY  Attn:RR  Quote
05-08-2008 12:51 AM  10 years agoPost 52
baby uh1

rrVeteran

St. James, Mo.

My Posts: All  Forum  Topic

WOW,
Thanks for the info guys. It really helps to hear what others are using as this is my first nitro and I'm kinda lost sometimes on the details.

Huey

PM  EMAIL  GALLERY  Attn:RR  Quote
05-08-2008 12:51 AM  10 years agoPost 53
uh60

rrNovice

Hopkinsville, Ky - USA

My Posts: All  Forum  Topic

GMP Cobra Start Shaft Extention
Hey guys
Where can I get a starter shaft extention with the rubber cone insert for my cobra? Thanks....The one Tower Hobby had is discontinued..

Matt

PM  EMAIL  Attn:RR  Quote
05-12-2008 12:03 AM  10 years agoPost 54
RadioFlyerMk

rrApprentice

Trenton, Ohio,

My Posts: All  Forum  Topic

OK....I have located some hard to find screws I needed...so my build should get back under way here soon.

-----------------------
"I'd rather hover a Heli......than fly a plane"

PM  EMAIL  GALLERY  Attn:RR  Quote
05-12-2008 02:30 AM  10 years agoPost 55
baby uh1

rrVeteran

St. James, Mo.

My Posts: All  Forum  Topic

Hello, I got my extension from Tower but I think that it is a Century part so it might be available from them. If I see one somewhere I'll post it here.

Good luck

PM  EMAIL  GALLERY  Attn:RR  Quote
05-13-2008 02:15 AM  10 years agoPost 56
marcw

rrApprentice

Southern California

My Posts: All  Forum  Topic

you could also convert to a standard hex start adapter...especially if you also fly modern helis

PM  EMAIL  GALLERY  Attn:RR  Quote
05-13-2008 04:30 AM  10 years agoPost 57
TMoore

rrMaster

Cookeville, TN

My Posts: All  Forum  Topic

DON"T! I tried that on my Kalt whisper and ended up breaking my skids. The Mechanical gyros are difficult to use and even more difficult to tell if they are working properly. Mine seemed to work but couldn't keep the tail still and even worse was eratic!
So don't risk your rare bird on old tech that barely worked when it was new.
Huey
I still have quite a few Airtronics SG 1 gyros that work quite well. In fact, I would wager a guess that they will work just about as well as any piezo that is used in rate mode. The trick is knowing how to set one up. It's not the same as a modern gyro.

Everything that y'all are going through with these GMP builds, a lot of us went through with the same stuff back in the day so I can sympathize.

TM

Delayed Response Operator Not Engaged
AMA SECTION 336 = Good
Drones = EVIL

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
06-23-2008 03:42 AM  10 years agoPost 58
baby uh1

rrVeteran

St. James, Mo.

My Posts: All  Forum  Topic

IT LIVES!

Flew five tanks through the Cobra today! The motor is breaking in and the setup is getting better but the Telebee 701 gyro doesn't quite work right. I don't know if I have a gyro or servo problem but it doesn't hold well and with the sensitivity at 90 it barely works.
I guess it's time to get a 401.

Huey

PM  EMAIL  GALLERY  Attn:RR  Quote
06-23-2008 04:15 AM  10 years agoPost 59
marcw

rrApprentice

Southern California

My Posts: All  Forum  Topic

GY401 Works Good on these with S9254 Servo
You will just need to run a bit more gain than you might be used to because of the relatively low tail rotor RPM.


PM  EMAIL  GALLERY  Attn:RR  Quote
06-30-2008 03:26 AM  10 years agoPost 60
baby uh1

rrVeteran

St. James, Mo.

My Posts: All  Forum  Topic

OK after a dozen flights I have the Telebee working and the tune up is getting close. The problem with the gyro is that the remote adjustment isn't working. I adjusted it at the gyro sensor and it works.
This thing rocks! It is so stable compared to my 450s it seems easy to fly! The motor is running better and better and longer and longer on a tank of fuel and it really moves!

WOW!

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 4 pages [ <<    <     1      2     ( 3 )     4     NEXT    >> ] 5648 views POST REPLY
HomeAircraftHelicopterAntiques or Out of Business › GMP Cobra being revived!!
 Print TOPIC  Make Suggestion 

 9  Topic Subscribe

Monday, December 10 - 5:23 pm - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

The RC discussion world needs to consolidate. RR is now one choice for that. Its software is cutting edge. It hosts on-topic advertising. Help RR increase traffic buy making suggestions, posting in RR's new areas (sites) and by spreading the word.

The RunRyder Difference

• Category system to allow Rep/Vendor postings.
• Classifieds with sold (hidden) category.
• Classifieds with separate view new.
• Answer PMs offsite via email reply.
• Member gallery photos with advanced scripting.
• Gallery photo viewer integrated into postings.
• Highly refined search with advanced back end.
• Hosts its own high end fast response servers.
• Hosts thousands of HD event coverage videos.
• Rewrote entire code base with latest technology.
• No off-topic (annoying) click bait advertising.
Login Here
 New Subscriptions 
 Buddies Online