450 Play on servos and Main Gear?

J

jcfernan51

Member
I have a question, I was hovering the heli for the first time in 6 month. I removed the 3GX and installed the AR7200BX, put new bearings and greased the thrust bearing in the main rotor assembly, and replaced the shaft in the one-way bearing. I thought it was all tight. While I was hovering I noticed the heli was not as solid as before so I checked the servos and main gear and they have play. please see video.

http://youtu.be/hHEmiET7s68
 
Lee

Lee

Well-Known Member
Looks like you need a shim (washer) between the main gear and the top bearing mount.
Maybe it fell out when you were fixing things.
As for the servos, a little play is ok, but if they are really bad, just buy a set of new gears for them. That should fix it.
 
trainrider06

trainrider06

Active Member
Check your main bearing blocks also to see that they are installed correctly....I had that problem on my 500...turns out my bearings were installed incorrectly....My main gear did that same thing....also your main gear and tail drive gear will start getting a gap in them allowing them to rock like that....what may be happening is one of the main bearings in the bearing blocks is coming out of its mount in the block.........i found out the hard way...lol
 
J

jcfernan51

Member
Thanks for the reply, I am sure I have the shim in but I will take it all apart and check the bearings also. I did not realized there is wrong way to install the bearing I thought they were symmetrical.
 
J

jcfernan51

Member
Status. I took the rotor apart and added a second shim and now there is no more play. I remembered the shaft came with two shims one thinner than the other, I guess I needed both. In the process I noticed I was able to slide the blade holder in an out. I disassembled the rotor head and discovered that it was missing a shim between the bearing and the thrust bearing when I compared the parts I removed to the diagram.
I also took the servo with the most play apart and inspected the gears. They looked good. When I bought this Heli (used) it had Hitec HS-65MG which by the way I fried using the 3Gx (analog vs digital) so I have three servos to take gears from. Before I disassembled the 656MG I checked and the servo was solid so I figure I swap gears. The slop got better in the 5065MG but it is not as solid as the 656MG but at least it matches the other two.
I took the Heli for a hover today and it is much improved.

Thank you all for your help.
Juan
 
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