Play in mainshaft to gear ???

[Kev Mallin]

Hi Guys
Just doing a rebuild after a small crash. Changed the main shaft, (old one was bent) it’s back together using all new hardware but I have play in the main shaft. I hadn’t noticed this before.
I’ve checked the new parts against the old and they are all the same size ect.

Can one of you do me a favour and hold your main gear then looking from the top grab your blade grips and rock them CW &ACW, can you let me know how much movement you’ve got.

It seems to me that the main shaft is turning slightly in the main gear, I’ve checked the old shaft and it’s the same, if this is standard stands a good chance that this is the reason for the shafts snapping.

Let me know if you can, I want to fly tonight.

[utahbmxer]

I think it's normal. Mine had a lot out of the box I remember. I have since rebuilt it 3 times and I just snug the main gear bolt up a little more, not a lot but just enough that it isn't noticeable unless you grab and turn. Out of the box mine was loose enough that just by turning the helicopter the head would spin a few degrees.

They could probably make the holes in the shaft a little smaller, I bet it would reduce the broken shafts that others are getting. (have yet to break one, knock on wood.)

[Kev Mallin]

Thanks for the info, I’ll just nip it up a bit.

I can go play .

[rc18]

The main shaft and main gear hub both have too much play. Hopefully a 3rd party will develop replacement parts.

[Kev Mallin]

Need more bits, servo stripped. bu88er no 300x flying tonight.

[65L88]

Originally Posted by rc18

The main shaft and main gear hub both have too much play. Hopefully a 3rd party will develop replacement parts.

My 450s and my 500 have the same relative amount play as the 300X, the difference is, the play in them is damped by the OWB, so it's not as noticeable. This damping action (or lack of in the case of the 300X) could possibly be a contributor to the shaft breakage....

[Chris Gardill]

Originally Posted by 65L88

My 450s and my 500 have the same relative amount play as the 300X, the difference is, the play in them is damped by the OWB, so it's not as noticeable. This damping action (or lack of in the case of the 300X) could possibly be a contributor to the shaft breakage....

That's an interesting thought and you might be on to something there. I hadn't ever really paid attention to what the OWB did for that issue on the bigger helis but at least my 450 behaves with a similar amount of play but the bearing almost completely masks it.