450 Align 450 thrust bearings

[Eggy 71]

I've been doing a little maintenance on my 450. I had a minor crash, barely dinged up the blades but bent the main shaft slightly. I replaced the main shaft and thought I'd check and lube the thrust bearings while I had the head apart. The blade grips moved freely before but has some resistance now that I put it back together. I've cleaned and reassembled the thrust bearings twice and still no change. I really can't figure it out but thought I'd just replace the bearings and be done with it. I've got two questions if anyone can help:
1) could I have bent or slightly crushed the thrust bearing when I reassembled ?
2) my LHS can't get align parts so would any thrust bearing that fits a 4mm feathering shaft work?

 

[Tony]

If they got into a bind, then the balls could have caused small pits to form in the steel races. Could be because of the crash, could be because of not being installed properly, or could be a very small piece of dirt. Make sure you have all of the shims installed and there is no play, but they are not too tight.

And you will need to get the thrust bearings for your helicopter. There were two that I know of for the 450. One is for a feathering shaft that has been necked down at the end and the other is for a completely straight shaft.

You could just order a kit like this. I think this is a canadian supplier but not sure.

450 Feathering Shaft Set H45H005XX

 

[Smoggie]

If you broke the blades and bent the main shaft the it's very likely that the feathering shaft is also bent. A bent feathering shaft will make the bearings feel tight. To check the feathering shaft remove one blade, put an allen key into the screw head and rotate the feathering shaft. If the opposite blade 'wobbles' as the shaft turns then the shaft is bent. Repeat for both ends.


As a point of interest... if the grips feel notchy to turn that's usually the inner radial bearing not the thrust bearing.

 

[Eggy 71]

I got another feathering shaft just in case. I only chipped the end of one blade. The original was still dead true but changed it anyway. The weird part was the grips were good after the crash. It was after I disassembled lubed and replaced the thrust beatings is when it stiffened up. It does seem notchy though. I guess I should get a full set of bearings to be safe. I must have damaged them somehow reassembling. The open end of the ball bearing part should face in, correct?

 

[jcfernan51]

correct and also pay attention to the bearing race themselves. Some are labeled IN or OUT but in case they are not one of the two on each side should have a smaller inner diameter which goes on the outside.

 

[Eggy 71]

Update on the tight thrust bearing. I pulled things apart again and did a thourogh cleaning of all parts and the inside of the blade grips. It turns out one of the washers between the outer bearing and the thrust bearing was ever so slightly bent. You can't tell without magnification. I only caught it as it showed slight change reflecting light off its surface. All I can suspect is it doesn't allow equal pressure on the between the outer bearing and the thrust bearing. My LHS had all kinds of washers but not one that would work. I did have 2 with a smaller outer diameter and thinner so I put them together as a makeshift fix. Anyone know of businesses that would carry tiny washers and screws like that. I hate the thought of ordering another thrust bearing and paying about $12 in shipping just to get this one washer.

 

[Tony]

Have you by chance looked on ebay local to you?

 

[trainrider06]

Those Align blade grips can be maddening! I ran into an issue a while back when I switched over to the XX shaft/bearings
I had the notchy grips while turning, and some had said as long as you pull them apart then turn em that it would be ok because centrifugal force would pull them out and they would rotate freely. But that just wasn't good enough for me. What I discovered is those silver spacers between the blade grip, and head assembly, can be of a different thickness! Once I got the right combination of spacers in it they tightened down tight and the grips turned buttery smooth afterward!
Also you'll find on some of those that you'll be able to pull the grips apart after assembly and get a bit of movement. I ended up getting a Tarot head/grips for it, and now no problems! Those Tarot heads are really pretty nice heads, and cheaper than the Align's!