Finally..... Fixed my tracking problem.

[psilo]

I have had a problem with my tracking the last few times out. Initially thought it was the pesky screw in the cnc flybar holder (the usual culprit). But having tightened and threadlocked I was still getting tracking drift from too high to to low. So, replaced the o rings, checked all linkages and basically rebuilt the head from scratch only to find the problem still there :mad:

Today, I suddenly realised there was one thing I didn't check (always the way!). The thrust bearing. I forgot the last time I rebuilt to check the diameters of the two washers that form up the thrust bearing. On the plastic head the larger aperture goes nearest the head, on the CNC head it is the other way round with the smaller diameter washer nearer the head (i.e inside the blade holder). So, whipped out the feathering shaft and found that on one side I had the large aperture washer inside the blade holder DOH! Then to my real surprise found that the other side had 2 large apertures and no smaller aperture thrust bearing!!! Rebuilt with the correct parts in the correct places and finally she tracks beautifully again. Hoorah!! :happyd

So, if you are having problems with your tracking, or even if not, don't forget to check which way round you are putting in the thrust bearing components when you rebuild your head.

Gerd

[Jonnyheli]

Gerd you are right. You should always check the thrust bearings are put back the right way after changeing the feathering shaft or whatever.

I always make sure I put them right. To make sure which one has the biggest inner race just put it on the the feathering shaft and it should wobble more thn the one with the smaller one.

-Jonny

[mnwizard]

We had a "discussion" about those darn washers a while back. As I recall some of us didn't know there were 2 different sizes.

[psilo]

I remember now. Had forgotten all about it to be honest until this tracking problem. It was when I was looking in the manual for a part number when I noticed it and thought DOH!:arggg:

The strange thing is that for the cnc head it says to put the smaller aperture on the inside of the blade holder but for the plastic it says to put the larger, don't understand why it is reversed?!

[Crossfade]

Thanks for letting us know what the problem was, Every since my last crash with my mini titan i have also had this problem, I put in a new feathering shaft and a new main shaft and i still have this tracking problem, it's so bad right now that my mini titan want even lift off the ground, I make the adjustments to fix the tracking but within a few sec's tracking is back out again, I know my raptor 50 has the big washer and the small washer, The big washer goes toward the head and the small one goes to the outside, I wonder if my mini titan also has the big and small washer and if this could also be my problem, i'm gonna check.

Thanks

[mnwizard]

I remember now. Had forgotten all about it to be honest until this tracking problem. It was when I was looking in the manual for a part number when I noticed it and thought DOH!:arggg:

The strange thing is that for the cnc head it says to put the smaller aperture on the inside of the blade holder but for the plastic it says to put the larger, don't understand why it is reversed?!

My theory is that there has to be some give to allow movement in the dampers so the inner diameter of one washer is a little bit bigger. I don't think it matters if they're in the inner or outer position, as long as both sides are the same, otherwise the blades will each track differently.

Anyway that's my theory and you have to admit that it sounds good. :)

[Heli Yea!]

Yea,
Sounds good MN but it is important to make sure that the open side of the bearing faces the larger hole and the closed side faces the smaller one. It seems to me that the balls go in the tracks better and has a smoother motion. I tried the other way round and the bearing wore quickly and I had to replace them. I haven't tried to reverse the washers to see if that has any effect, but it seems the smaller washer fits in the inside cnc blade grip with a perfect match to the hole in the bearing inside the grip.:thumbup:

[psilo]

Yep, that is exactly as the manual shows it for the CNC head. The smaller aperture washer goes in the cnc blade grip with the closed side of the bearing facing it then the larger aperture next.

[mnwizard]

Yep, you guys are right, I forgot about that.

I guess I'm not trashing enough feathering shafts ! :)

[john_pullen]

I got to be honest and say I had no idea the thrust bearing washers were different sizes (er! it's in the manual). It's hard to spot the difference visually but if you put them on the feathering shaft and wiggle them you can easily find the larger one. I have had tracking problems (plastic head) even with align blades so hopefully this will resolve my problen. Thanks Gerd!!