Which tail part is broke?

[Mimbulus]

My 130x has a "tail issue" and I cant figure out what is broken. I have aftermarket ali tail grips, but all else is original plastic.

Without any rotation / power applied the servo moves the tail rotors as expected.

As power is applied and rotation increases, the tail shaft slides so that it protrudes out to the left side of the tail case. The end locking "nut" (with the two screws holding the tail shaft) is locked securely to the shaft - but is not "locked" to the tail case - hence the sliding action.

Not having a "working" version to compare against - I am not sure which part has broken to allow the shaft to move.

Any suggestions please?

Thanks

[Mike Sanders]

The tail shaft shouldn't move. It should be fixed and the slider should move along it, actuated by the link which is pushed and pulled by the servo push rod.

Check that you have the tail shaft bearings in properly and that you have the little alloy tube on the shaft between the two bearings. This prevents the gear from moving.

[trexamanic]

i have a tail box for a 130 x and i had a similar issue. it was like i had lost something plastic out of the end of it.
I will post a pic up in a bit.
If it moves the tail case aint working

[Mimbulus]

All the pieces seem to be in place. The tail shaft is a "snug fit" in the bearings, but moves if when at high speed you yaw the aircraft left after which the shaft remains "extended". As far as I can see, the bearings are fully home. I've stripped it down and reassembled. I've added some pics of before and after. I just can't see what's causing the movement. I am minded to replace the tail shaft and bearings.

Could the mixing of the aftermarket Aluminium tail grips be creating "unbalanced" forces the other plastic components don't like? Perhaps I should get some plastic grips as well!

What do you think?

[tomatwalden]

I think you've rounded-out the plastic tail gear on the inside.

The inside of that gear should have a "D" shaped hole - which is how it binds onto the tail shaft. The tail shaft itself is D shaped until where it meets the gears, at which point it becomes fully round and therefore should NOT be able to slide further into the gear itself (as it clearly has done in your photo).

The fact that the shaft has gone through the gear means that either the shaft has been manufactured wrong (with a D shape that's too long), or more likely that the inside hole of the plastic gear has simply rounded out.

EDIT: You can see the change from D shape (flat bit) to fully round on the image below...

[Mimbulus]

I think you've rounded-out the plastic tail gear on the inside.

You are right. I have. I stripped it down again and it's round. So round in fact it looks as if it were made that way! It's a tight fit and so the rotor still spins very effectively - which is what got me.

Cool. Parts on the way! Many thanks

[tomatwalden]

Cool.

BTW, you had the bolt at the end on backwards too. The cone shaped side should be facing the bearing with the flat side on the outside.

[Peteski]

Good spot Tom!

[trexamanic]

well done Tom.

[Nick_C]

Use a metal bevel gear,they dont round out

[trexamanic]

Use a metal bevel gear,they dont round out

I am rounding of teeth on the front option gears like crazy at the moment.
They seem to be softer than chess these days. No reason for them to do so but they are. i end up with metal dust all over the back of the pitch servo.
New bearing new frame, tail etc etc .
get about 10 flights then they are wearing to the point where a tooth will slip if you know what i mean. It makes the heli twitch.

[Mike Sanders]

I know a lot about a twitching 130x. After a lot of replacing parts all four gears are now metal.

It still doesn't fly perfectly for very long but it is items other than the gears that cause the problems.