Blade 400 3D - Airborne without crashing!

[dam74]

Darryl,Sometimes it can be easy to mistake a wagging tail for one that is just vibrating from something that is bent as I found out myself on my Blade 400.On closer inspection the tail rotor shaft was slightly bent,It doesn't take alot for the tiniest bend to make the tail vibrate as it spins at such a high RPM.Hope this helps.
Cheers Grant.

You talking about the tail boom as there is no tail shaft on a blade 400 it's belt driven.

[Grant85]

You talking about the tail boom as there is no tail shaft on a blade 400 it's belt driven.

Well my Blade has a tail rotor shaft so I should hope your's does too because if it doesn't then I don't have a clue how you have attached the tail rotor hub,grips,blades etc

[dam74]

That is refered to as a tail boom from all the spares lists that I've looked at both from Century and Eflite A shaft is used to drive moving parts

[Holst]

That is refered to as a tail boom from all the spares lists that I've looked at both from Century and Eflite A shaft is used to drive moving parts

The general convention for helis is that a torqe tube is what is used instead of a belt (inside the boom) and the tail shaft is the shaft that the tail blade grips are attached onto.
In your case this shaft has the pully for the belt attached.
On a torque tube heli this shaft has a beval gear that is driven by a corresponding gear on the torque tube.

Century and Eflight manuals may say different, but they are probably translated from chinese :P

The tail boom generally refers to the tube that connects the tail of the heli to the main body.

[dam74]

Holst are you refering to the shaft that comes out of the tail gear box onto the tail grips?

[Holst]

Holst are you refering to the shaft that comes out of the tail gear box onto the tail grips?

Yes, this is what I would refer to as the tail shaft.

If this shaft is slightly bent it can cause vibrations (which was the original question)

A bent tailboom is unlikely to cause such problems. (unless its very bent)

[dam74]

Ahh yes after re-reading I now remember the Century website refering to the drive inside the tailboom as a torque tube (or something to that effect). My bad Holst but I was confused and thought Grant was refering to the boom. Ok will take a look at the tail shaft to see if it's bent but not sure how as I don't recall having a tail rotor strike.

[Holst]

Ahh yes after re-reading I now remember the Century website refering to the drive inside the tailboom as a torque tube (or something to that effect). My bad Holst but I was confused and thought Grant was refering to the boom. Ok will take a look at the tail shaft to see if it's bent but not sure how as I don't recall having a tail rotor strike.

Its easy to check, just rotate the blades and see if there is any wobble (you might need to remvoe the bladeholder and tail slider)

They can come from the factory pre-bent

I check mine before I fit them to make sure they are straight.

[dam74]

Cheers Holst/Grant, will take a look at this tonight as my MSR spares haven't turned up. Kind of peeved with Wonderland Models, won't use them again. Ordered on Wednesday and they still haven't arrived. The order was supposedly dispatched on Friday which is poor seeing as it was ordered Wednesday evening. Should of been processed Thursday morning and dispatched by evening mail. Now that Sussex Helis have the parts in stock will be ordering from them from now on.

Darryl

[dam74]

On another note the gain on the default gyro is sitting around 45-48% (not sure if this is the correct way to read it).

Does that sound like too much or does it all vary a lot between helis?

[Holst]

On another note the gain on the default gyro is sitting around 45-48% (not sure if this is the correct way to read it).

Does that sound like too much or does it all vary a lot between helis?

It will vary between helis and different types of gyro.

You want to run the gain as high as possible untill the tail of the heli wags quickly in the air, then reduce it by a few % and you should get a stationary tail that is responsive to tail imputs and will hold the heli against the wind (if you are side into the wind)

[dam74]

Ok cheers Holst. On another note the tail rotor looks a bit suspect so going to strip and take a look.
Hmm can't seem to remove the tail rotor blade grips hex head seems to be in between sizes?

Wondering if last week when I had the motor wind up and I had to go in with the motor hot whether the tail rotor was hitting the ground or my feet. Haven't managed to get at the shaft completely yet to look at it but don't think it's right.

[dam74]

Going to change out the complete tail shaft and tail rotor pitch slider. There is quite a bit of burring/elongation of the diameter of the shaft so can't remove it without damaging it. Tried forcing but couldn't get it through the bushing? and bearing. So I'll take it to work and file the old shaft down to remove the burr. Think it will be safter to order the spares.

[Holst]

Going to change out the complete tail shaft and tail rotor pitch slider. There is quite a bit of burring/elongation of the diameter of the shaft so can't remove it without damaging it. Tried forcing but couldn't get it through the bushing? and bearing. So I'll take it to work and file the old shaft down to remove the burr. Think it will be safter to order the spares.

If it looks dodgy then replace it.

If you cant get the bearings off you can cover the face of the bearing with some tape (to stop dirt from getting inside) and then cut the shaft with a hacksaw and remove it that way.

I had to cut the tailsaft and mainshaft after my last major crash

[dam74]

Yeah if worst comes to worst I'll get my junior hacksaw or grinder onto it