RunRyder RC
WATCH
 1 page 289 views Post Reply
Home✈️Aircraft🚁HelicopterHelicopter Main Discussion › SHIELDED OR OPEN BEARINGS
08-29-2020 09:05 PM  26 days ago
Topic Vote0Post 1
MattJen

rrElite Veteran

UK

MyPosts All Forum Topic
SHIELDED OR OPEN BEARINGS
Hi Folks,
Hope everyone is well, I was wondering which is better for main mast bearings, shielded ( not sealed) or open?
All The Best
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-29-2020 09:35 PM  26 days ago
BeltFedBrowning

rrKey Veteran

Kansas City

MyPosts All Forum Topic
I have helis with both types. The open ones are on electric helis and I find them easy to lubricate.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-29-2020 09:42 PM  26 days ago
balsabasher

rrVeteran

Central Ohio, USA

MyPosts All Forum Topic
Shielded helps keep the grease in and the dirt out. If you have a "The Greaser", shielded bearing can be relubed.Blades; what goes around, comes around!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-30-2020 12:22 AM  26 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

Two different arrangement for two different applications.

Shield bearing, work on dirty condition and it is to protect the bearing.

Open bearing, work within a mechanism than lubricate by itself with oil or grease, like a gear box or something like that.

So, on RC helicopter DON'T use open bearing.

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-30-2020 12:37 AM  26 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

BTW, it doesn't matter if your rc helicopter is glow or electric... Sand and dust came from the dirty ground...

So, watch the ground before intent a hover or a landing!

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-31-2020 02:17 PM  24 days ago
wjvail

rrElite Veteran

Meridian, Mississippi

MyPosts All Forum Topic
💎Sustaining Member
I use rubber sealed bearings. I use them on just about everything. That includes motor bearings, control bearings and shaft bearings. I install them and then fly them until they show signs of wear - which in many cases is never. As a generality, I don't lube them. I checked the other day and both my Raptor 30 and 50 are approaching 70 hours flight time. Both have rubber sealed bearings in many locations.

Consider Boca "Green Seal" bearings. The principle of, "the right tool for the right job", certainly applies to bearings so Green Seals aren't the only choice. But when I think about replacing bearings, I first consider rubber sealed.
https://www.bocabearings.com/search...erial:greenseal

One man's opinion... Adjust to taste...

"Well, nothing bad can happen now."
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-31-2020 06:48 PM  24 days ago
wjvail

rrElite Veteran

Meridian, Mississippi

MyPosts All Forum Topic
💎Sustaining Member
I just reread post number one and find myself asking why you ruled out sealed bearings. Your question was shielded or open and my go-to has always been sealed. Is there something I need to know about?"Well, nothing bad can happen now."
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-31-2020 06:59 PM  24 days ago
MattJen

rrElite Veteran

UK

MyPosts All Forum Topic
HI GUYS
thanks for the replies and comments.
There was no real reason, on my old turbine machine which i bought in 2006 in the manual it was open bearings, i put open bearings in, it was 3 bearings on a 15mm shaft.

The ones currently on there are shielded and are fine all these years later, so I was just wondering the difference..

All The Best
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-01-2020 02:06 AM  24 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

Good point about turbine application.

Bearings are always some sort of electromagnetic noise emitter.
So the metal shield, ZZ, could be a problem in some applications.

I like the idea of shield bearing using no metal or rubber.

But, remember...

Metal shield are for high rpm application.
Rubber shield are for low rpm application.

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-04-2020 09:37 PM  20 days ago
utahbob

rrVeteran

St. George Utah

MyPosts All Forum Topic
While we're on the subject how about our electric motor brgs.; I always put a drop of oil on the top and bottom brg. of my Scorpion motors before a flying session..Scorpion recommends it; but my flyin buddy who runs Align motors says he doesn't because his bearings are "pemanently lubricated"..I say that thin oil gets in anyway..what do you guy's think?I do a great decending funnel!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-04-2020 10:24 PM  20 days ago
fastflyer20

rrKey Veteran

N. Tonawanda, NY

MyPosts All Forum Topic
There is a thin gap between the shield and inner race of shielded bearing where oil can get in. Sealed bearings are exactly that, sealed. Grease should not leak out and oil should not be able to get in. If you start oiling shielded bearings, do not stop. The oil slowly washes out the grease so oil will eventually become the only lube and it does not last long. Very unofficial, but I have tried both ways and it seems like the bearings last longer by not oiling. I have a Scorpion in my 380 that has 1000's of flights on the original bearings with zero maintenance.Tom
CAUTION - my posts are based on my experiences, yours may be different.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-04-2020 11:59 PM  20 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

That is correct.

Bearings on high rpm, must be lubricated with grease and not oil.
Oil on bearing at high rpm, it is going to spread out of it.
It is useless.

There is a special lubricant liquid that you can use to put grease inside bearings.
This product has grease with high volatile liquid. You put 2-3 drops and should be enough.

Check this link...
https://www.triflowlubricants.com/

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-05-2020 01:50 AM  20 days ago
wjvail

rrElite Veteran

Meridian, Mississippi

MyPosts All Forum Topic
💎Sustaining Member
Rojoalfa Bearings on high rpm, must be lubricated with grease and not oil. Oil on bearing at high rpm, it is going to spread out of it. It is useless.

There is a special lubricant liquid that you can use to put grease inside bearings.
This product has grease with high volatile liquid. You put 2-3 drops and should be enough.
Rojoalfa But, remember...

Metal shield are for high rpm application.
Rubber shield are for low rpm application.
I wonder about some of these comments...

Study the link below. I chose this particular bearing entirely at random but I believe it is reflective of many rubber sealed bearing.
https://www.bocabearings.com/produc...-2gs-3-l55-4103

A few items to note.
-- The rated RPM for this particular bearing is 68,000 RPM. That would hardly be sufficient for the hot section of a gas turbine (which can exceed 200,000rpm) but certainly sufficient for (almost) any other model application. I'm not certain what qualifies as "a bearing at high rpm", but looking at the specified rpm for most rubber sealed bearings suggest that they are adequate for every part of a typical glow, gas or electric model helicopter.
-- Notice that the rated RPM for all bearings is higher using oil vs grease. Possibly this is a translation issue but bearings will almost always be rated for a higher RPM with a less viscous lubricant. Is it possible you've interchanged the words "oil" and "grease"? When you say "This product has grease with high volatile liquid. You put 2-3 drops...", did you mean oil? Grease isn't applied as drops.
"Well, nothing bad can happen now."
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-05-2020 02:13 AM  20 days ago
utahbob

rrVeteran

St. George Utah

MyPosts All Forum Topic
I would think grease in a high rpm bearing would cause some heat buildup..I'm no expert..but I have logged alot of flights using thin oil on my motors and have never had a bearing fail..I do a great decending funnel!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-05-2020 03:33 AM  20 days ago
Rojoalfa

rrKey Veteran

Punta de Mata, Monagas-Venezuela

MyPosts All Forum Topic
/
/

On the contrary... Absence of grease cause a lot of problems on bearings.

Of course, a premature failure on bearings could happen any time.

Lubrication, bad instalation procedure, manufacture problems, worn out issues...

/
Saludos cordiales,
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-05-2020 10:39 AM  20 days ago
balsabasher

rrVeteran

Central Ohio, USA

MyPosts All Forum Topic
Guys just to clear this subject some;
Grease is a semisolid lubricant. Grease generally consists of a soap emulsified with mineral or vegetable oil.[1] The characteristic feature of greases is that they possess a high initial viscosity, which upon the application of shear, drops to give the effect of an oil-lubricated bearing of approximately the same viscosity as the base oil used in the grease. This change in viscosity is called shear thinning. Grease is sometimes used to describe lubricating materials that are simply soft solids or high viscosity liquids, but these materials do not exhibit the shear-thinning properties characteristic of the classical grease. For example, petroleum jellies such as Vaseline are not generally classified as greases.

Greases are applied to mechanisms that can be lubricated only infrequently and where a lubricating oil would not stay in position. They also act as sealants to prevent ingress of water and incompressible materials. Grease-lubricated bearings have greater frictional characteristics because of their high viscosity.
If you let grease sit around long enough, the oil will start separating out of the grease, and the base material will start "drying out".
Blades; what goes around, comes around!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-05-2020 01:26 PM  19 days ago
utahbob

rrVeteran

St. George Utah

MyPosts All Forum Topic
Thanks for that explanation!..that explains why the grease I use in my rotor head thrust brgs. Is always dried out when I take them apart every 6 months!I do a great decending funnel!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
09-05-2020 02:08 PM  19 days ago
wjvail

rrElite Veteran

Meridian, Mississippi

MyPosts All Forum Topic
💎Sustaining Member
Balsa... Thank you for the education.

As I mentioned before most bearings have a higher RPM rating using oil than grease and I believe the issue is that the higher viscosity of grease at higher RPM causes the bearing balls to begin skidding. That can lead to an assortment of problems including flat spotting of the balls, heat, contamination of the grease, retainer failure, etc.

As I said before, I use rubber sealed bearings much of the time. They have been assembled in a sterile environment, come packed with an appropriate grease, and their shielding results in the factory grease being retained while allowing little or no foreign matter to enter the bearing.
"Well, nothing bad can happen now."
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 289 views Post Reply
Home✈️Aircraft🚁HelicopterHelicopter Main Discussion › SHIELDED OR OPEN BEARINGS
Print TOPIC

 5  Topic Subscribe

Friday, September 25 - 1:26 pm - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online