ceramic bearings

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jeff baham

Well-Known Member
Joined
Aug 10, 2002
Messages
1,257
have anyone used the ceramic bearing and if so, how or they. i' was told by boca bearings that they will last longer than the regular bearing. help me please.
 
I wouldn't bother Jeff - heard too many horror stories. WIB swiss bearings are my 1st choice.
 
jeff baham said:
have anyone used the ceramic bearing and if so, how or they. i' was told by boca bearings that they will last longer than the regular bearing. help me please.
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NO! NO! NO! NO! NO! NO! NO! NO! Is that clear enough?? :p

Just get the WIB's from Ron @ Racecraft. I had enough problems with regular bearings from Boca ( I will not buy from them again) let alone the issues with ceramics. For openers they wear out the bearing races way too fast. :blink:
 
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Not what they are all made out to be. They are not forgiving at all. One lean run and you are in deep Poop. Dunk the boat in southern water and you will be changing them. Use Ron's bearings.
 
The fact that they are so tight you can't hardly spin the when they are new should tell you something. One run and they are free. The silicon nitride balls are way harder than the race so what do you think is wearing? The race which is intended not to wear. Silicon nitride can withstand alot of heat but when they overheat, they let go in a big way. When they do let go, tiny particals get buried thoughout the motor. So you change the bearings and they let go even faster because nothing you can use will wash the particals out.

When I worked @ Coors Technical Ceramics, the Haas CNC machines we used only lasted 1/4 of their expected life because the bedways couldn't withstand the punishment of the ceramic dust.
 
I would only recommend Boca bearings for the competition :p sorry Boca

Ceramics are really good bearing for some applications. The ceramic's strong points are in acceleration and top end. I think some of the “longevity” issues associated with the ceramics are coming from the use of cheap bearing races. I have some motors with Novarossi 16000 series races and WIB 607 races that are balled in ceramic and they are holding up as well as any steel sets I’ve ever had.

It also helps to know people who actually know what they're doing with the ceramics ...the type of person that can give the proper C clearance and ABEC rating when they ball a set of bearings for you.....It takes specialized equipment to measure those size differences (millionth range micrometer).

Some 1/8 On-road guys use them and JP On-road motors come stock with them but they are expensive (around $100+) / set. Most of the .21 drag racing guys use them....I dont know many boat heat racing guys that use them.....I have thought about using them in a heat-race boat but haven’t due to the cost/ benefit ......benefit being small for a boat that doesnt rely on the ability to spin up quickly (arguably a negative for a boat)

Last I heard Ron B was doing some research on the Ceramics…..I’d like to see what he has to say about them too. B)
 
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I had a conversation with Ranjit Phelan about them (pylon racing guru) and he said they have some good aplications like turbines but for our use - forget it. Some of the mega dollar Pylon engines have them fitted but a lot of them get ditched in favour of more conventional bearings.
 
jeff baham said:
have anyone used the ceramic bearing and if so, how or they. i' was told by boca bearings that they will last longer than the regular bearing. help me please.
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What application are you planning on using them for?
 
i reconmend ron byrd bearings also i have been using them for over a year now and no problems with them.
 
I swear by conventional HIGH Quality Bearings and that is one thing you really wont find at Boca therfore the Ceramics they sell are even worse.

This is not a sales pitch as Jeff Baham is one of my customers so he knows the Quality I have. I am sure he is just looking for that extra edge but quite frankly just any old Ceramic bearing isnt going to give you anything but trouble. With that being said I have in conjunction with a well known Car Motor Guru developed a Hybrid Ceramic Bearing with super High Quality Ceramic balls in WIB Races and Retainers. I have had a test set since May in Ron Drakes 3.5 Nova Rossi Outboard which he won all his Heats running away at the Internats taking first place in Heat Racing, in the Oval TT he blew off because the boat accelerated so hard off the turn and he at the same time releived tenion on the rudder a bit to quick making the boat lift, NO Time Last Place. At this point he thought his bid for US-1 was over and I told him it was not over all he had to do was go out in SAW TT and take first to win with the knowlege of what everyone else did in Oval. Well he went out in SAW TT and beat everyone by a landslide: US-1 in both 3.5 and 7.5 Ob Tunnel he runs my conventional bearing in the 7.5 OB. He also wins every Race in Florida with the 3.5 boat running away. We have tried to go for the records at two Record trial events but radio gremlins and or the water was to flat for the boat to break free of the grip of the water and he still barley missed breaking the record for SAW and Oval, if some one had sneezed he would have broken them. Long story short these bearing which are still in his motor are holding up well and we may offer certain bearing sets as ceramic to our customers in the future but for now they are still in R&D as far as boat motors go as I want to be sure that if I sell it the Qualityand longevity are there like the WIB conventionals that I sell! The biggest advantage in these is as Kevin states they are good for quick acceleration and top end so they work really well in RC Drag Cars. The advantages in boat heat racing are there but they really shine in SAW and Oval TT's.

Everyday Heat Racing I still recommend the lower cost conventionals like I sell but if you feel the need for something extra then they will cost you double as it is not a cheap process nor are the ingredients to concoct these babies :D

As I stated I am not at this time selling any ceramics they are still being tested but I do stock WIB Conventions bearings if your interested.

Ron
 
As TimD already stated, some FAI pylon racing engine manufacturers use ceramic ball bearings. For instance the dominating F3D pylon engine - the Dutch MB .40 - is a true masterpiece featuring lots of refinements making this engine apparently unbeatable.

It is a very nice example of the "reduce moving & non-moving parts approach".

It handles rpms up to 35K without probs - and this is a 6.5 cc engine! Keeping in mind those engines run only full throttle ceramics seem to be a good choice in this particular rpm regime and application.

http://home.kabelfoon.nl/~fiorimet/Index.htm

View chapter "Crankcase"

View attachment 3746
 
I am running Boca ceramic bearings in my K&B 45 outboard SAW engine and they are great. I am spinning the engine almost 29000rpm and have dunked it many times. I run 60% nitro with 14% oil and have made several "lean" runs. The bearings are still good as new. I will swear by them and plan to put them in more of my engines and reduce the amount of oil I run. They are new technology and some of you older boaters are afraid of change.
 
I wanted to ask Ron at Race Craft about the bearings their runnin' in the model

turbines. I started to modify an "Old/New" Yellow Aircraft F-16 and was (at the time) going to use a 12lb trust "Ram" turbine. That Turbine was capable of Turning

200,000!! No-Kidding,,I think those were Ceramic bearings :huh: (Ram 500)

Is it better lube in the turbines or the water in the boats thats killin' them :huh:

Still have the F-16,stopped production to finish a Balsa USA 1/3rd scale Stearman

with a RCS 215 , 5 cyl , 4 stroke "Radial".

The F-16 is for sale with a set of Scale $700 air operated landing gear
 
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From my own expereience ceramic Boca bearings were a disaster for my last P80 EXR.Impossible to fit the crankshaft troughout it so I decided to return the set to Boca.They sent to me a new pair that definetevely was a mess to fit the crankcase so I would not spent my bucks (US120)with myths.

Swiss ones will meet the necessary requirements for our application!

Therefore my sons use ceramic bearings in their downhill skates for more than year without any problem.

Gill
 
Have to agree with the rest of the guys..Isn't worth the money you spend on them and have them mess up your engine too..
 
krpnova said:
I will swear by them and plan to put them in more of my engines and reduce the amount of oil I run.
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The bearings are not the only part of the engine that requires lubrication and most probably not the first thing to fail as you reduce oil content in your fuel. I would think the most critical areas (especially in a K& B) is going to be the big end of your rod and (correct me if I am wrong) the actual piston/liner. I really cant see running ceramic bearings alone allowing you to run less oil in the fuel.

krpnova said:
They are new technology and some of you older boaters are afraid of change.
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There is a difference between being on the leading edge and the BLEEDING EDGE of technology!!! Right now it appears that ceramics have little exposure to RC Boating and lets face facts - most facts and fugures are "Bikini numbers". (What they show you is very appealing, but its what they hide that counts!!!)

I have had people assure me that steel cage bearings are rated to 50,000 RPM and above.... and they are right :unsure: but it is the imbalance of the engine and the constant acceleration / deceleration that vibrates the cage apart causing the cage to distribute itself evenly through your engine.

The RC Boat environment is different to just about every other RC environment in so many ways (or those pylon engines would be in boats right now) and bearing successes and failures with both traditional and ceramic materials will lead to more R & D and more information and more EXPERIENCE!!!!

Once someone comes up with the right ceramic bearing package for us boaters (including how they may affect our maintenance or installation procedures) then I am sure that they will become commonplace in boating. Just now there is little experience and a lot of anecdotal evidence around of the benefits and drawbacks.
 
Another thing to consider is high percentages of Nitro. Not it's corrosive effects, but what the engines run like with it in the fuel. It is hard on engine parts due to it's explosive nature when the motor is burning it. Especially if you use PO in it to set it off.

Pylon engines race with a control fuel - 20% oil, 80% methanol. no nitro. Bearing life is a lot better than a marine engine running 50% plus nitro - as are disk rotor faces, rod bushings etc. Craigs example of bearing rating is an example of this.

Also - I agree that reducing oil content for the sake of bearing change is going to show up in other areas such as rod bushings, crank / case seal and piston and liner wear.
 
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From what I read....all the guys that were using them (present company included) are having good results with them. I'll continue using them in some of my motors....but I get my ceramics from a very trustworthy source. I admit that I wont spend $100+/bearing (dealer cost) to put them in a mono or a tunnel boat because I don’t personally see a benefit......most of the motors that have ceramics installed are $600 + motors and are the best motors made.

Should qualify the above by saying that the ceramics don’t make them the best motors, but help them to perform in the range for which they are intended. I guarantee that they guys that are running +$600 motors aren’t the same guys that can’t tell if they’re overheating their motors, or if their motors are being run without enough lubrication.
 
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izitbrokeyet? said:
From what I read....all the guys that were using them (present company included) are having good results with them.    I'll continue using them in some of my motors....but I get my ceramics from a very trustworthy source.  I admit that I wont spend $100+/set (dealer cost) to put them in a mono or a tunnel boat because I don’t personally see a benefit......most of the motors that have ceramics installed are $600 + motors and are the best motors made.
Should qualify the above by saying that the ceramics don’t make them the best motors, but help them to perform in the range for which they are intended.    I guarantee that they guys that are running +$600 motors  aren’t the same guys that can’t tell if they’re overheating their motors, or if their motors are being run without enough lubrication.

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Can you tell me exactly where your Ceramic bearings are giving you an advantage over say WIB Bearings, why your ceramics are working (say better than the other ceramic bearings described in this thread), what you have to do to maintain them and which applications they will and wont work in (maybe even which motors they will or wont work in)????

I dont have these answers and I am not sure if you can definitively answer those questions and I am not meaning that as a slur against you but these bearings are relatively new and what little research and testing has been done into Ceramics in RC Boat engines I think it will take some time until we can confidently answer those questions.

My reason for asking these questions is to highlight the general lack of knowledge on Ceramics. Ceramics may be great in some circumstances but totally inappropriate in others. Like my steel cage analogy (but they are rated to over 50,000 RPM and dont fail for hundreds of hours continuous use!!!! how can they come apart with only a few hours running in a boat!!!)

I say get as much information as possible - test - discuss - test again - discuss again....
 
Craig,

When people refer to ceramics they are referring to the balls in the bearing set. The balls are actually made of a material called Silicon Nitride SI3N4. It is a High Fracture strength material for the toughest high-temperature applications. The person that said something about overheating must not have known this…or maybe his ceramic balls skipped the “how to behave like ceramic bearings 101 class. The material has a low coefficient of thermal expansion and high thermal conductivity this gives them excellent thermal shock resistance, and it has some of the best chemical resistance properties out there. The silicon nitride material is stronger than most metals and maintains it’s strength properties at temps where steel has the strength of cheese.

Please go back and read that my ceramic bearing sets are actually WIB 607 series bearing races that are fit with ceramic balls. I also have Novarossi 16000 races that are fit with ceramic balls. I also believe I stated the types of boats I wouldn't use them in. If I didn't; I'll edit this post to be inclusive.

Ceramic bearings are clearly documented as having lower rolling friction and lower break-away than steel and require less lubrication. Anyone who says that Boat Engines are a different animal will only convince me by providing me with the new set of Physics laws that their special boat motors obey. Ceramic bearings are used increasing by top Cyclists, top Skaters, they are used by Larry McBrides top fuel Kawasaki and Greg Anderson's Prostock car. They are being used successfully by some people in here. Again…everyone in here that said they were used were having positive results. The only bad results I read were from people who weren’t using them…..or qualified it by stating that they were using an inferior bearing...I still havn't decided on how to respond to the fact that there was a metal retainer in a ceramic bearing set...sounds like another Boca Econo-power triumph of salesmanship to me----Not unlike putting steel temporary 45mph steel wheelies on your Porsche rather than RZ rated tires.

The physics of the performance advantage comes from the lighter balls. The ceramic balls are 40-60% lighter than standard bearings. This is simply a direct reduction of rotational mass that will spin up. Without going into a dissertation for you about rotational inertia, and angular velocity I would hope it suffice to offer up the analogy of the skater who simply brings in her arms to spin up angular velocity by reducing her moment of inertia…….a little more detail would be that any change rotational velocity requires a torque input that would reduce the net application torque available at the shaft.

Anyway, I’m not here to sell you a set of bearings….I would recommend that you read what was posted and try to select the advice you take wisely. Good ceramic bearings for hobby use are not widely available. I suspect lots of sets will be sold / have been sold to people who don’t have the wherewithal to figure out if they have a good set of bearings or an expensive piece of junk……It’s like anything else: everyone in here has a computer and should take the time to educate themselves rather than Nod Their Head, Say Yes Master and blindly take another dose of bad advice.
 
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