Blade 450 wont take off after repair

[def19]

Hello guys - I had a minor crash with my Blade 450-
The damage:
1. a bent flybar
2. one of the main rotor blades was missing a small piece
3. the linkage rod/pushrod was off the ball link from the bell mixer arm

Repairs:
1. New flybar - with old paddles
2. New set of wood main rotor blades
3. Pushed the linkage rod back into the ball link of the bell mixer arm

Problem: The heli was flying perfectly before the crash, now it will spool up nicely, no noticeable vibration but the heli won't take off at mid or full throttle.

[Epoweredrc]

Check make sure none ur servos are stripped and or other links are bent dum ? But u did install paddles right way? Hey ive done it

Sent from my ZTE-Z990G using Tapatalk 2

[def19]

Hello -
- I checked the blades and paddles by comparing them to pictures and they look good.

- I tested the servos and they appear to be moving around with no problem or weird noises

- All the links appear to be ok – not bent or broken.

What I have found since then is that the blade pitch is off. For some reason the pitch at low stick is at 0 and high stick is at +5. (before I had them at +3@ L and +7 @ H – this worked perfectly just for low hovering while I am learning)

Now I am trying to understand why would the blade pitch would change so drastically... I am thinking the swashplate may be at fault here, but before taking the head apart I wanted to check for zero degrees of pitch at mid stick - but after reviewing the how-to videos I am still unsure how to go about it. (I guess there is some setting in the radio that I have to change before I do it??)

Any thoughts?

Thanks

-def19

[celltech]

Did you replace the feathering shaft?

YouTube

YouTube

[nbisme]

Originally Posted by def19

What I have found since then is that the blade pitch is off. For some reason the pitch at low stick is at 0 and high stick is at +5. (before I had them at +3@ L and +7 @ H – this worked perfectly just for low hovering while I am learning)

I would do the following:
Radio: put normal pitch curve to a linear 0-25-50-75-100, make all travel adjustments 100%, dual rates 100% and expo INH. Set all trims and subtrims to 0.

Put transmitter at mid stick and ensure servo arms are close to 90 (on FB, use subtrim to get exactly 90). This will ensure that a mid stick position on the radio = mechanical middle on the head.

Then see if your link lengths close to what is outlined in this thread: http://www.helifreak.com/showthread.php?t=368517. This should get you in the ballpark. Go from there.

p.s. you'll get many varying opinions on the best setup for beginners, etc. IMHO, a beginner should set up the heli the same way an advanced person would. Take advantage of idle up and collective range. Don't teach yourself bad habits.

It won't be long before you're flying those anyways, so you might as well jump right in. It you want to tame it down, just reduce your idle up flat throttle curve to 70 or something like that.
IMHO it's more intuitive to learn on a zero pitch at mid stick pitch curve and a flat throttle curve than some non-intuitive linear throttle curve with non-symetrical pitch curve.

[def19]

Celltech- thanks for the advice. I dint see any vibrations so I dint think that was the problem - but I will keep it in mind.

mbisme - thank you for the step by step instructions and the link to the the thead with the links lenth. I will give that a try and see what I can find.

-def19

[def19]

Hi mbisme - after checking for zero degrees of pitch at mid stick with the radio settings provided - I was able to find that both main blades have incorrect pitch degrees (Blade1 / H +11 / M +1 / L - 8) (Blade2 / H +14 / M +3 / L -11) as oppose to the recommended H +10 / M 0 / L -10.

I have also uncover a bad servo.
I haven’t check for the rod links length.

Question - At the hobby store I was told I need to go through a "Mechanical setup" - does this procedure only involves the swashplate setup and leveling? Or are there additional steps pertaining to other components in the “mechanical setup” procedure?

Thanks

-def19

[Imzzaudae]

This is the video you need to see.

YouTube

YouTube

[Excalibur3]

I twisted two half turns out on all my swash linkages front and sides and it fixed the problem. Somehow the servos all moved and they weren't damaged hope this works for you too

[Excalibur3]

Ok thank you

[def19]

Excalibur3 - thank you for the advice. I am actually in the process of mesuring and adjusting the servo linkeages as I am having trouble leveling the swashplate.

-def19