trex 450 se v2

[kmagjr]

Im new to this fun, have built my trex 450 se v2 have it set up and I tried to fly it this morning, and when it gets off the ground, it jumps up and down like it is having a seisure. Is there anybody that can help me? Oh yea the first flight did not end well.

[OC Heli Tech]

1st what radio and what is ur throttle cures and pitch curves

2nd, how many degrees are you running?

[nmdesertracer]

Do you have any + expo in your radio? Im a newbie and im running +30% to slow the action down.

[Andy01]

More info would be helpful.

When I started, my first "flight" did not end well. Went back to the sim, and used Radd's method, which helped a lot for fine control.

Colin

[Starcruiser]

Possible causes;

Wind impacting lift
stiff links
TX has ratchet spring installed on throttle/collective
low battery (LVC)
slipping one-way
Slipping or loose pinion
head links loose?

these are the areas I suggest you review.

[kmagjr]

my radio is a JR XP7202, JR DS285MG servos,JR DS3400G tail servo,Futaba GY401 Gyro,
Throtle curve is normal 0-50-80-90-100 Idle 1, 100-95-90-95-100
Pitch curve nornal 40-45-50-75-100 Idle 1, 0-25-50-75-100

[Andy01]

I assume you have rebuilt the heli and checked everything over on the ground - checked pitch (both collective & cyclic), looked for damaged servo gears, bent or loose linkages, loose electrical connections etc etc.

I found that when starting most of the "heli being out of control" was actually the pilot because I was not used to the sensitivity of the sticks, especially compared to my previous coax heli. That is where I thought that Radd's method helped.

As asked above, are you using expo & how much pitch (especially cyclic) do you have ? What is your headspeed ? A high headspeed with no expo makes for a VERY twitchy 450.

Colin

[Starcruiser]

I would concur with the Expo and new pilot statements.

This is why those who start on smaller heli's, like the MCPx or 250 sized do better when moving to the larger ones, your senses are sharpened due to how quick they can be versus the larger heli's.

For your 450 I would suggest you check and document the overall collective pitch range, should be about +/-11° (symmetrical) to start, some like it around 10, and cyclic should be around 6 to 8° to start. Expo should be at 20 to 30 to soften the stick response. this will make it easier on you to learn. Put on some training gear and try the Radd's course to start, this should assist you in tuning your stick skills. At the very least the training gear will allow you to maiden the heli with a smaller chance of a crash.

[dl5973]

Originally Posted by Starcruiser

I would concur with the Expo and new pilot statements.

This is why those who start on smaller heli's, like the MCPx or 250 sized do better when moving to the larger ones, your senses are sharpened due to how quick they can be versus the larger heli's.

For your 450 I would suggest you check and document the overall collective pitch range, should be about +/-11° (symmetrical) to start, some like it around 10, and cyclic should be around 6 to 8° to start. Expo should be at 20 to 30 to soften the stick response. this will make it easier on you to learn. Put on some training gear and try the Radd's course to start, this should assist you in tuning your stick skills. At the very least the training gear will allow you to maiden the heli with a smaller chance of a crash.

I have been flying the trex 450 for years now and still run 30% expo on aile and elev.

expo is your friend its not just for newbies

[kmagjr]

Thank you to all the replies. I now have my expo set to 30% and will set my pitch. This weekend is when the weather is good and I can try this again.

[latte]

Meanwhile it could be a good idea to reference check your head-build with the manuals. Maybe you have something backwards?

[kmagjr]

Checked all moving parts today. Ready to try it again. I have the expo at 30% but am questioning weather I should slow the head speed down or not, and how slow to bring it down to.

[Starcruiser]

2400 to 2600 would be ok to start IMO. But try it out with what you have it set at and see how it behaves. it will seem twitchy to you, do not hold the sticks for corrections but bump them to make small corrections otherwise you will chase the heli and end up crashing. Just my .02

[salrica]

Originally Posted by kmagjr

Checked all moving parts today. Ready to try it again. I have the expo at 30% but am questioning weather I should slow the head speed down or not, and how slow to bring it down to.

I would check the head, for example dampeners and linkage measurements .
Check for grease on dampers and on feathering shaft.
What pitch do you have on mid, low and high stick?

[nmdesertracer]

Its better to have higher head speed and use less pitch for take off and hover. Then low head speed and more pitch for take off which will make your tail twitchy. I just switched from aligns white fiber blades to the 325d pro blades. I didnt think blades would make that much of a difference. Im going back to the fiber blades for now. There 20g heavier then the pro blades. Practice on a sim on the throttle cut switch it will save you $$ in a crash!!