450 I am a happy man

Diederik

Member
I started building my third 450 about 3 months ago with all the bling stuff, ally this, ally that, CF this and CF that, you catch my drift? The build also included an FM as orientation is something I have always had problems with. The other 2 I also build my self and they fly 100% correct, ( I love building, flying is ok) I have up to now not been able to get this heli to fly, it is a HK450GT,

Initially I had cheap HXT 900 servos on it, just over half throttle they would start jumping up and down, I rebuild, ran the power wires one side and servo wires on the other side, same thing, thought FM was causing problems, removed it, same thing, though Walkera ESC was the problem, replaced it with a Turnigy Plush and still the same problem, bought Hitec HS-65HB servos (wow they are not cheap) same problem, swapped motors from one of my other helis, a Turnigy Typhoon 2218, same problem, stripped al the movwable parts today, and spun the motor after each bit got cleaned and put back, bit by bit..........................PROBLEM FOUND...........CF TAILBOOM........it was causing such vibrations that none of the electronics were working properly, replaced it with a normal one and spun it up inside the house, it seemed ok.

Now we are having a terrible windy,stormy day, but still thought.......stuff it, the heli doesn't know there is a terrible wind blowing............it made for challenging hovering..............BUT..............for the first time this heli flew 100%, wow I was happy, for 1 battery pack she flew and did everything exactly the way I told it to do.

Must admit, a lot of the stuff I tried was from trail and error I read on this here forum, IOW to everybody here who have had problems and to every one that has helped those members.....here is a BIG THANK YOU........all of that is what helped me sort my problem.

Now I can for the next 2 hours teach my 10 and 11 year old sons how to build helicopters, the are both busy with 450's, we do this every Sunday for 2 hours
 

Lee

Well-Known Member
I spent 5 months searching for a vibration on my HK450GT. Found the same thing as you, CF boom was the culprit. Changed it back to an ally one and Bingo, problem solved. 5 months for a 5min fix GRRRRRR!!!!!
 

Paulster2

I am El Taco!
I spent 5 months searching for a vibration on my HK450GT. Found the same thing as you, CF boom was the culprit. Changed it back to an ally one and Bingo, problem solved. 5 months for a 5min fix GRRRRRR!!!!!

Not to mention all the $$ you threw out there trying to find it, either!
 

DAL2855

Banned
Are the CF booms really that much of an issue? I just installed one yesterday on my HK450GT but haven't gotten it to the point of being able to spool it up yet and just found this thread! I might wanna consider putting the ally boom back on it if it's gonna cause problems like this!
 

Lee

Well-Known Member
I had one carbon boom that worked perfectly and one that caused huge vibes. It all depends on the thickness of the carbon, how you clamp it down (tight, loose) The boom supports (tight or loose). Just see how it goes. If you have bad vibes then you know what could be the issue. When i say vibes, mine were to the point of shaking the heli to bits in 30 seconds if i had kept spooling up.
 

Westy

LEGEND
is it the CF vibing or ... Static build up? Carbon is a great conductor.... some say earthing the CF solves a lot of static build up ... this is really predominant on belt drive systems as the current builts up from the friction transfer from the rear tail sprocket into the nylon belt.
 

Slobberdog

Well-Known Member
Carbon fibre does not transmit vibes well it will bounce any vibes in the fuselage back into the fuselage instead of using the tail boom as damper,

we had the same problem on the harrier jump jet, wings were cracking so they put a carbon wing on it, stopped the cracking but the vibration from the massive engine then had no where to go so the fuselage started cracking instead.
 

Slobberdog

Well-Known Member
Yeah it was done

Hawk
Harrier
Tornado
Spitfire

And jet engines as well.

The good old days...............
 

Diederik

Member
My son is insisting that he wants he CF boom on his Heli, so we put one on. When the heli is ready to fly, (in a month or 2 (he is 10 and builds for 2 hours every Sunday on his heli as they race RC cars and also do a masiive amount of quad and bike riding)I will check again and see what and why the CF causes a problem, in the meantime I do not have the "want" to try it on my helis again
 
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