Transmission block

[sookainian]

I notice my Transmission block bearing is lose. It can move it front and back. Even when my collar and pinion gear is screw tightly to the tail rotor shaft, i still can push the whole thing back and foward.

What should i do ?

[sookainian]

Does this happen to you guys before ?

It is dangerous to fly it 'lose' like that ?

[WayneBrown]

remove the bearing, apply green locktite and reseat.
Wait 24 hours and fly.
this will solve the issue.

[angelob]

Just a thought, but would the bearing block work out if the flange was facing the delrin coupler? My reasoning is this - with the flange facing the delrin coupler, the bearing is not only held in by loctite but also by the torque tube and boom assembly.

Maybe someone has already tried this? It would suck for the bearing to come loose like this.

Angelo

[WayneBrown]

whats the real difference in it being trapped by the collar or the delrin cup? Either way you will be subject to metal to metal contact between the bearing and the block which can't have a good outcome.
This appears to be one of the monday morning/ friday afternoon QC issues, just locktite it in and go on.

[sookainian]

Can i use blue locktite ? It is writen on the back of the bottle saying ' Medium strength '

[Rada70]

for that kind of job, I rather use green or red locktite.

[WayneBrown]

you really need green on this.
If you've built a trex and have anything left in that little bottle, use that.

[sookainian]

Means the green is stronger then the blue ?

[WayneBrown]

green is more permanent. It requires heat to remove it, so yes it's better in this instance.

[sookainian]

ok thanks

[Wayne]

If that bearing is loose, I'd suggest sending it back to Min Air and getting one that is correct. It should not be that loose. Or, call up Min Air, speak to Jeff, and ask him what to do.

Wayne
www.flymha.com
Miniature Aircraft

[Dr.Ben]

FYI possible causes:

Hole in block slightly overbored.
Anodizing slightly thin on the part.
Combo of 1 and 2
Failed loctite that allowed the bearing to loosen and wallow out the hole.

Reloctiting the part is fine as long as the bearing is no looser than a glide fit into the hole. If the hole is oversized enough to allow bearing movement laterally, then replace the block (and the bearing if it broke free and wallowed the hole).

Ben Minor

[capebob]

Be very careful that you get the right Loctite. There are two green Loctites that are generally available to the modeler. The first is Loctite 290 which is medium strength wicking thread lock and is not satisfactory for securing bearings. The Loctite that you want is 680 retaining compound.

Bob