Missing ball from thrust bearing

BMPnumber1 · 01-14-2011, 03:56 PM

So I'm getting the K4 ready for repair and I am taking apart the blade holders and feather shaft when I discover an odd fact. The thrust bearings (as seen here) is actually missing a ball from the bearing from the undamaged blade holder (or the part of the feather shaft that did not bend). I've checked my work area and there is no ball there or any of the surrounding area, so... did they install a bearing with a missing ball? Will this prove harmful re-installing the bearing like this? Should I order a new set?

My engineering gut tells me to buy a new set and install. My cheap SOB gut tells me it will be fine, we're not doing 3D flight--just learning.

Which side should I listen to?

Big Tonka · 01-14-2011, 04:13 PM

Hi BMPnumber1 you should always get into the habit of never accepting anything other than 100% from the parts on a heli most of us have tales of horror from taking risks with parts that aren't 100%, on average a blade tip is travelling at 250 mph + when at hovering speed, a blade comming off at that velocity becomes a missile ( imagine doing blade traking at eye level and the blade comes off ). Dont want to be the all doom and gloom but keep it safe.
BT

chrismechanic · 01-15-2011, 04:49 AM

hi all...bmp, sounds like you need a new set of bearings..or you could just loose a bearing out the other side to keep the balance but i doubt that is a good idea.
chris.

KeithT · 01-15-2011, 07:03 AM

Nope - I don't think it is either.
BT is spot on imo. Only 100% perfect to your knowledge - what I mean is, things go wrong you don't know about - don't add to the risk by installing something you KNOW is wrong. It is a good habit to check and test everything and repair if in doubt.
I know some do, but I don't even subscribe to straightening shafts. For what it costs, replace it!
And incidentally, those balls are not free to drop out - they are machined in, so I doubt you could repair it anyway.

Wrench 54 · 01-15-2011, 09:51 AM

Bad things happen to these helio's at the most unopertune time even when everything is 100% spot on, to take the chance on a part that is not 100% is not a good idea, the forces that are involved up in the head and tail rotor when spun up are un-imaginable to most, safety is the #1 thing with these helio's, they sure can hurt you in just a blink of an eye------Wrench

01-14-2011, 04:13 PM	#2
Big Tonka Registered Users My HF Map location Join Date: Mar 2009 Location: Shrewsbury, UK	Hi BMPnumber1 you should always get into the habit of never accepting anything other than 100% from the parts on a heli most of us have tales of horror from taking risks with parts that aren't 100%, on average a blade tip is travelling at 250 mph + when at hovering speed, a blade comming off at that velocity becomes a missile ( imagine doing blade traking at eye level and the blade comes off ). Dont want to be the all doom and gloom but keep it safe. BT __________________ Jumping from heli's was almost as much fun as flying them. BuzzFlyer Buzzfly K2 and all the purple bits,3900 brushless,30Amp esc Copter X 450 now with Align Airwolf body kit

01-15-2011, 04:49 AM	#3
chrismechanic Registered Users My HF Map location Join Date: Feb 2010 Location: Margate, England	missing bearing hi all...bmp, sounds like you need a new set of bearings..or you could just loose a bearing out the other side to keep the balance but i doubt that is a good idea. chris. __________________ trex 450 pro-fbl-scorpion 2221-8-custom motor mount-beastx-tarot head-beam e4 swash trex 550e-castle 100 ice-bec pro-alloy tail control arm- 550mm blades-beastx-compass 6hv head-2mm side frames futaba T8FG--R606FS/R617FS

01-15-2011, 07:03 AM	#4
KeithT Registered Users Join Date: Nov 2008 Location: Over here in Blighty	Nope - I don't think it is either. BT is spot on imo. Only 100% perfect to your knowledge - what I mean is, things go wrong you don't know about - don't add to the risk by installing something you KNOW is wrong. It is a good habit to check and test everything and repair if in doubt. I know some do, but I don't even subscribe to straightening shafts. For what it costs, replace it! And incidentally, those balls are not free to drop out - they are machined in, so I doubt you could repair it anyway. __________________ Raptor 90SE + 50 TitanSE Both with BeastX and RJX heads MD500 with 450pro/5blade head/3G/Scorpion electrics MD530 - fuse only - 'in progress'

01-15-2011, 09:51 AM	#5
Wrench 54 Registered Users Join Date: May 2009 Location: Jax. Fl.	Safety First Bad things happen to these helio's at the most unopertune time even when everything is 100% spot on, to take the chance on a part that is not 100% is not a good idea, the forces that are involved up in the head and tail rotor when spun up are un-imaginable to most, safety is the #1 thing with these helio's, they sure can hurt you in just a blink of an eye------Wrench

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01-14-2011, 03:56 PM	#1
BMPnumber1 Registered Users Join Date: Dec 2010 Location: Virginia	Missing ball from thrust bearing So I'm getting the K4 ready for repair and I am taking apart the blade holders and feather shaft when I discover an odd fact. The thrust bearings (as seen here) is actually missing a ball from the bearing from the undamaged blade holder (or the part of the feather shaft that did not bend). I've checked my work area and there is no ball there or any of the surrounding area, so... did they install a bearing with a missing ball? Will this prove harmful re-installing the bearing like this? Should I order a new set? My engineering gut tells me to buy a new set and install. My cheap SOB gut tells me it will be fine, we're not doing 3D flight--just learning. Which side should I listen to?