T500 Align metal tail grip pushrod forces

Test of pushrod forces and servo current of Align metal tail grips before and after custom chinese weight bolt and nut

Category:

Education

Tags:

• T500
• Chinese
• weights

[coomz92]

Hi,

This is very interesting !

How much you add to each blade grip (in grams) to reduce power consumption ?

Why Align don't do this for the "stock version" of their helicopters ?!

Tks.

[ROBRENZ]

Its not just the weight its where it is placed.

I dont know why they dont but I am glad they dont

[armolite]

Rob,

this is all very interesting but can you please tell me, would fitting these chinese bolts to my trex 600esp help eliminate tail wag ?

i have my gyro sensetivity as low as it will go and it still wags slightly, also sort of bounces a bit after turning in either direction.

Cheers.

Mike.

[ROBRENZ]

Weights will not make those problems go away. try moving your ball link closer to the center on your tail servo.

[wrxsavvy]

nice video! Rob wouldnt the tail being held down increase the servo current draw? Surely in the air it does not have that restriction.

[ROBRENZ]

The power to drive the tail rotor is greater when the tail is held still. The power to change the pitch of the tail blades is not affected. Except for tennis raquet effect forces it takes no virtualy no force to hold the blades at any reasonable pitch. The current draw change you saw will be the same in flight as in the tests

[alobar77]

Cont'd:...... and at 60deg of rotation, pulls 160 oz.

You can see this effect in your video, where the pull force from stock grips was 10x the CWM grips, but the amp draw was only 4x.

That's why this mod may help a setup, but with a decent tail servo is not necessary. It makes life alot easier on your linkages though!!!

[alobar77]

The best demonstration of this effect I've seen yet; good job, on this and the others.

But I think you overestimate the stress on the servo by neglecting to account for the tangential leverage the servo gets as it rotates away from 90deg and the effective torque increases (F=T/(r x sin^)). If the servo arm/disc was rotated 60deg over when pulling the tailblades to greatest pitch, they would have double the torque. So a 40oz/in servo with the linkage ball mounted 1/2 in. from center, and at 6

[feliu1968]

Hi Rob,

Thanks for the research and video. As you explained Align should have done a better job with those tail grip but they didn't. More power to you ;-)

Do I need to drill the grips or the weights are just installed using the existing holes and thread?

Where can I get them?

Thanks!!

[armolite]

Cheers Rob,

Ive got the ball as close to center as it will go, i also have the gain as low as i can get it on the gyro (curtis youngblood solid G) and im using a pretty fast tail servo (align DS 650).

the tailwag is almost gone so i guess ill just have to put up with it, ive seen other 600esp's with the same problem but nobody seems to know exactly what causes it.

thanks anyway.