S.S.Bearing- What to Do about it??

[patterndude at comcast.net]

You found roller bearings that fit an OS140RX???  Please provide a reference.  
THis would be an amazing find.  I disagree with you that these wouldn't handle 
the thrust load.  On the contrary, our bearings carry almost no thrust load.  
They handle radial load almost entirely.  I would think a roller bearing would 
be a great solutions.  As evidence to this conclusion, look at what Zenoah, 
Desert Aircraft, and other gas engine mfg do - they use roller bearings.  These 
engines are designed for far more life than modelers put on them and the 
bearings are never changed.
--Lance

--
District 6 AVP
www.aeroslave.com
> In a message dated 8/5/03 4:18:50 AM Pacific Daylight Time, rcaerobob at cox.net 
> writes:
> 
> > 
> > Assuming that OS doesn't offer a solution to lubrication of the rear bearing 
> > on the 1.40, what other options are available?
> >     What mods could be made to the crankcase to permit more oil flow back 
> > there?
> >     Would increasing oil content of fuel make any difference?
> >   
> > If the real core problem is undersizing of the bearing for the load 
> > application the motor endures, then a real fix would be a redesign of the 
> crankcase 
> > to use a larger and wider bearing.  Pretty unlikely that would happen, I would 
> > guess.
> >     So what's the solution besides keeping the bearing suppliers 
> > well-funded??
> >  
> > Bob Pastorello, Oklahoma
> > NSRCA 199, AMA 46373
> > <A HREF="mailto:rcaerobob at cox.net">rcaerobob at cox.net</A>
> > <A HREF="http://www.rcaerobats.net/">www.rcaerobats.net</A>
> >   
> > 
> 
> Continued - A larger bearing is a double edged sword, larger bearing means 
> larger balls and larger diameter races and thus higher surface speed, between 
> the balls and races at a given RPM.  I'm not enough of a mechanical engineer to 
> say where the trade off is, but I know in other engines larger bearings have 
> not solved the problem (OS .61).  The solution is a tapered/timpkin bearing, 
> I've tried to find a match, but no success, the problem is that we are using a 
> ball bearing in the wrong application, auto manufactures tried this for years 
> on wheel bearings, tapered bearings solved the problem.  I can get roller 
> bearings that fit, but they will not stand the thrust load.  Again, stainless 
> has 
> worked for me, several different engines and I have a lot of data/experience, 
> many thousands of flights on mine and others engines, most recently the OS 140 
> and believe me I've tried all the "fixes"  Interestingly I just changed the 
> bearing in a new OS 140 RX, just because it had 140 flights and I was planning 
> to go to a contest this weekend, bearing seemed fine.  Turns out that it is a 
> stainless bearing, with the seals removed (I've never found a stainless without 
> seals).  The bearing was fine, no corrosion, I jumped the gun.  No for the 
> rest of the story I had this engine apart for other reasons and it was a year or 
> so back so it's possible that I just changed the bearing because I was in 
> there, but I think I would remember and I keep pretty good records so that is a 
> doubtful answer.  It will be interesting to see it the new engines start 
> showing up with stainless bearings or if this was a fluke, maybe they were out 
> of 
> bearings at the factory and used the bearing from the EFI or...
> 
> Bob 
> 
> Bob
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