Checking grease on thrust bearings in head?

[BruceW]

After every few flights I notice a small thin line of grease on the main blade that must have sprayed out from the thrust bearings in the head. When I assembled the grips, there was a good coating of grease applied but I just wanted to get feedback from others if they have checked the thrust bearings after X flights and what was found. I have not taken mine apart yet but they still feel very smooth.

So far, I've logged 28 flights at 5:30-6 minutes/flight (~2hours 40 minutes total).

[OICU812]

Yea best thing to do and "maybe" you already are.... is to use a heavy automotive grease that you would use to do your ball joint and u joints. Even with the high outer forces it retains well within the thrust cups. ;)

[BruceW]

I used TriFlow synthetic grease which is fairly viscous. Its also used on my mountain and road bikes.

http://www.triflowlubricants.com/Synthetic/synthetic.html

EDIT:
I also made sure to turn the thrust cups outward to catch and hold the grease due to centrifugal forces. Maybe I will take the grips apart and check just for the sake of it - on a rainy day.

[OICU812]

You mean you have the balls towards the head block correct? That is correct way.

[BruceW]

Well you can see the balls from both sides of the ball holder but it was put in so the flanges of the ball holder point towards the head block. Kind of like a little bowl with the open side aiming towards the head block. Hard to describe...

http://www.helifreak.com/attachment.php?attachmentid=35830&stc=1&d=1200550999

[OICU812]

Yes that is what I meant, open end to the headblock, nice diagram though :D

[murp]

I have about 5 flights on my Logo 5003D and I tore it apart to check the thrust bearings and both the tail and head thrust bearing grease had dried out! I was using a generic lithium grease I got from a local hardware store.

I was able to clean up the head bearings and reuse them; this time I used a motor assembly lube (more viscous than grease but not as light as 3-in-1). The tail thrust bearing was ruined though and I am now waiting on a replacement.

I should have done some more digging before I assembled it I suppose.

[BruceW]

What the heck, I'll take it apart later tonight and check the dampening rings as well then I'll post some pictures of what it looks like after 30 flights.

[BruceW]

Glad I decided to check the bearings. They weren't really dry but one side must have had more wear than the other because of discoloration of grease (and it was fairly thinned out). Also found the balls on the mixing arms were starting to unscrew. I think I'll put some CA on them tomorrow.

Here are pictures of the bearings in each grip and then one of them cleaned up before being repacked. The o-rings are in good shape and show no sign of wear.

[OICU812]

Are those the standard dampers? I suggest to anyone when they are ready to change out their stock dampers to run the #3092 ones, they really tighten things up nicely on the head and make it crisp. :D

[BruceW]

No, they are #2756 (medium hard). Maybe I'll get those next time or the new K&B hard dampeners. They seem to be the hot ticket right now.

http://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=7021

Also need to get an extra battery and other misc items next week. Right now its a toss up with getting the EVOlite 6S 5350 (700g) again or trying the TP V2 6S 5000 (726g). The EVO25 6S 5000 seems too heavy (800g) with these other choices out now.

[dahld]

FWIW, I've always used (25+ years) automobile wheel bearing grease, most recently the synthetic stuff, and have never had a problem with thrust bearing wearing out. My Logo 10 has 469 flights on it, and having regreased the bearings only twice in the time, things are still running smoothly. Much of the excess grease does fling out very quickly after greasing them, but a thin film of lubricant is all that's needed I guess. That being said, bad crashes (are there ever any good ones?), especially when the head speed is still real high on impact, can damage the bearings, and they should be closely inspected after such an event.

[zguy]

No, they are #2756 (medium hard). Maybe I'll get those next time or the new K&B hard dampeners. They seem to be the hot ticket right now.

I noticed a significant improvement with the hard dampeners. Please let us know if you try the K&B as this is the first I heard that they work in the Logo.


Also need to get an extra battery and other misc items next week. Right now its a toss up with getting the EVOlite 6S 5350 (700g) again or trying the TP V2 6S 5000 (726g). The EVO25 6S 5000 seems too heavy (800g) with these other choices out now.

Funny, I just ordered an Evolite 6s 5350 to compare against my Evo25 5000's. FYI, both my Evo 25's weigh 764g w/ Deans.

I'm still having less than great results w/ TP packs (2200's) even the V2's they replaced.

[zguy]

FWIW, I've always used (25+ years) automobile wheel bearing grease, most recently the synthetic stuff, and have never had a problem with thrust bearing wearing out. My Logo 10 has 469 flights on it, and having regreased the bearings only twice in the time, things are still running smoothly. Much of the excess grease does fling out very quickly after greasing them, but a thin film of lubricant is all that's needed I guess. That being said, bad crashes (are there ever any good ones?), especially when the head speed is still real high on impact, can damage the bearings, and they should be closely inspected after such an event.

Same here :thumbup:

I used some auto bearing grease (dark green?) and after 80 flights still looks brand new.

[BruceW]

Funny, I just ordered an Evolite 6s 5350 to compare against my Evo25 5000's. FYI, both my Evo 25's weigh 764g w/ Deans.

I'm still having less than great results w/ TP packs (2200's) even the V2's they replaced.

That's good to know about the weight of the EVO25s. The Flightpower site said 800g so I just went with that. I'll stay away from the TP.

Thanks,
Bruce

[BruceW]

Looks like I'll get some automotive grease. The Triflow grease is actually thinner than what I originally thought but works for a while.

[Mercuriell]

That's good to know about the weight of the EVO25s. The Flightpower site said 800g so I just went with that. I'll stay away from the TP.
Bruce

Mine is 755g with Deans - runs pretty good with this - I'm getting 6:40 though from evo 25 4350S so this is my favourite pack so far (haven't tried EVO Lites)