Vertical play in main gear hub

[Rob43]

Hey fellas...

I am building my X50. Mostly built. I've noted some axial play of the main gear hub on the one way sleeve. The main gear can move up/down, maybe 1mm or so. Is this normal? Like it needs another spacer between the main gear hub, and tail drive gear hub. I noted there is one already included and didn't see any notes about it or additional spacers.

[tat2spyder]

yeah mine had play too. i bought another shim to stick in there. part number PV1340

[Rob43]

Thanks for the tip. Think I will do the same. So, you put the additional shim between the two gears? Looks like it could also run on top of the main gear under the one way sleeve flange.

[tat2spyder]

Put it between the two gears. The manual says to put one there, just throw in another one

[skytrekin]

I have been flying mine with just the one shim and haven't noticed any ill effects. But thanks for the P/N for the shim. If I ever feel like it needs to be gone I will order one.

[Rob43]

I ordered them, and removed the shaft and gears so I can install another one.

[bjames]

Im experiencing vertical play in the main shaft as well but will the shims resolve this because I was thinking the collar with the set screw on the top of the frame area might be the culprit as well. I was not sure how to properly install that upper collar with the set screw, wondering if I did this wrong?

[Rob43]

OK. There are a couple of sources of vertical play involved here.

1. If you can move the main shaft up and down, then it relates to the main shaft collar position. It's possible the collar can be positioned with the set screws aligned with the groove in the shaft, but the shaft can move up and down....

If this is the case, simply loosen the set screws, and push the shaft downward while tightening the set screws (using the access holes in the carbon frames on each side) in a manner which pushes the collar upwards against the bottom of the top bearing block.

I found that the groove in the shaft is still wide enough that you can position the shaft and collar for no vertical play.

2. If the shaft is not able to move up and down, they likely you're seeing vertical play of the main gear on the one-way sleeve. There seems to be some vertical play caused by the spacing of the top of the tail drive gear hub, and the bottom of the main gear hub when the main gear is lifted so it can rest against the "flange" on the top of the one-way sleeve. It's possible this may cause no problems as the main gear stll meshes properly. However, a solution is to install an additional spacer below the main gear, adjacent to the one which is already included with the kit. Part number PV1340. This was my issue.