Plain Bearing Model Engines

Especially when you know that it was (you) who took the “Brand New” engine out of the box, diligently broke it in, carefully mounted it in your model, and lovingly oiled it after every use.

After all, you paid a premium for the engine because it had “Ball Bearings”. You buy a set of spares so that if you ever need to change the “Ball Bearings” you’ll have them on hand. You just never know when the guy that makes the “Ball Bearings” for you engine will quit making them rendering you engine useless. (The cruel agony of it all)

You tell yourself it’s got to be a real smooth runner, its got “Ball Bearings”. You don’t need or want to use too much oil in the fuel, its got “Ball Bearings” and you’ll just gum it up with Castor.

You ask six of your friends what they do to keep their “Ball Bearing” engines in tip top shape and they all give you the best advice they can. Use After-run oil!!!!!

So you buy six different kinds of after-run oil hoping to prolong its life span. There’s Mouse Milk, Super Slick, Pig Snot, Marvel less Mystery, Dead Dinosaur, etc. Then there is the Super Oil that you buy to put in the fuel because it’s “The best thing that you can do for your engine”.

I think the best thing that I can do for my model airplane engines is to buy them without “Ball Bearings”.

Sort of agree with the other things (for Stunt use, not for Combat), but I think the above is unlikely to happen. Just about all the engines I've researched use commonly available bearing sizes. The hard part is finding loose clearance bearings for the rear bearing, though.

If it works for you?? I don't understand... "you have to get the caster out"... My ST 46 is the same one I ran when I was 15 yrs. old and it set for 30 years and it still has the same bearings and runs fine. Thank you caster. ATF works about as good as WD 40 from week to week but I wouldn't trust it any longer. Please explain!!!

Actually he was probably alluding to the fact that castor oil will get gummy over a long period of storage.It won't ruin your motor, as in rusting it, but it can be a pain to get it out of everything to free up the motor.
On the other hand Rizlone or ATF never gets hard or gummy and if you make a 50/50 mix of the 2 it is everlasting
I have motors treated with this mixture for 20 years. They are still free and clean.
Actually C/L motors shouldn't rust because of leftover fuel in the crankcase as we run till we're out of fuel. Your much more likely to get bearing problems from the moisture in the air with an untreated motor then one with a good afterrun oil, which is something that you should do with all motors, even plain bearing motors need it.
Dennis

Anyways, George recomended Rizalone but said ATF was fine so it must be ok.

BOCA Bearings is there for a reason.

So lots of Floridians have the opportunity to drive on I95?

I've said it before, I'll say it again: Store your engines in a sealed container of kerosene.

I used Snap-on Air tool oil because we have it on hand at the shop. I'm just glad that I caught it before it made a mess. It's really no big deal, I'll make the necessary change.

Being a Non-Competitive Voter on all issues that don't concern me/Sport Flyer, I'll just buy Plain Bearing engines and not worry about it anymore.

I'm just so very happy that the OS FP.21 is a plain bearing. You know, The Engine By Which All Others Are Judged...(smiles)I store those in a strong box encased in concrete buried in the back yard.

Regards,
John Jolley
PS: The map is in a safety deposit box.

I think ball bearing-equipped engines are highly over-rated.

Yes, I know there are advantages. But in a great many cases I am not convinced the positives offset the negatives.

Back in my days of Combat flying, it seemed to me the power was so close to the same it wasn't worth the extra weight. And, as John notes, the extra maintenance. Even at that it wasn't unusual to grenade a rear bearing, and that tore other whirly bits up something fierce, meaning it took a lot more than just one bearing to get the engine back in action.

Truth be known, the BB engines were a little easier to start, and that's where the list of advantages began to get a little thin.

For CL Stunt a bushed engine can be made pretty light, compact, and less expensive, all good things. And we don't have serious issues with starting engines, particularly with--at least in the NW--a fair number using good techniques *and* electric starters.

Yeah, bushed engines have the reputation of wearing the bush to the point of uselessness. But that's really only a problem with the Fox 35. Personally, I know of no other engines with which bushing wear is an issue. It certainly isn't with O.S. engines, at least not in the Galaxy-class pieces John takes an oblique swipe at and I have a fair bit of experience with.

It's kinda like bushed rods. People see a non-bushed rod and think it's gotta be junk, whereas I think it's (potentially, assuming correct materials used) a terrific idea, one with which I have had documented success (RC cars with Picco 21s).

Same deal with a non-BB engine: Must be a cheapie. I'm not so sure about that...

The real problem, of course, is customer perception. Y'all go out and just try to sell any kind of model aircraft engine with a non-bushed rod, a plain bearing on the crank, and you'll see what I mean. That the naysayers will have their heads in their rear ends won't help the bottom line of your business.

The trick to starting PB engines quickly- put a couple drops of fuel on the back of the prop driver. Prime the motor through the intake and flip it through 15-20 times until it loosens up and starts to snap over. Then hook up the plug and it should start in a couple of flips. When you are flipping it you can feel the fuel work through the main bearing and free it up, and then work up to the cylinder and free that up.

YAh.... and their turn signal flashing all the way !

Wasn't it fun pressing the cranks apart to replace those Kawasaki bearings?
Dan don't get me wrong, I love those little FP.21's as much as you do. I just like to needle you about them. Thanks Brett (smiles)

Maybe I'll try making a replacement "Ball Bearing" out of a piece of Bronze Bar Stock that I have lying around and Fugetaboutit.

Our engines also don't have to withstand anywhere near the abuse absorbed by a typical RC engine. Torqued starters, longer runs, lower oil content, etc. - all combine for much more abuse than a typical control line engine. Leakage out of the front side of a bushing case is a documented problem in RC (and with bearings). When it happens on a bushing engine, there's nothing you can do except replace the case.

There's also the obvious fact that bearings will allow a lower idle than a bushing.

It's not all "marketing" that causes the demand for bearing engines.

I suppose now all I have to do is convince someone to build a F2D motor with a plain bearing just to see how it'll run. Or get Henry to make one Nelson .36 with plain bearings.

On these particular engines, the ball bearings used are smaller and thinner than on sport engines, to save weight - and so we are told to keep a close eye on them. Plain bearings, if they work as well, would eliminate the worry.

It works for me so just thought I would pass it on.

Bruce

Does your treatment get rid of the rudder wiggle in the KAOS?

I live in central Florida, and the humidity hardly ever drops below 80% around here. My old ST's mounted on certain planes that may get flown once in a blue moon are fine. I use Marvel air tool oil. I've still got the same quart can I bought 20 years ago, it only takes a few drops. And mine is the old Mint scented stuff, so you could tell if the guys were maintaining their air tools. "Hey, Fred, your drill doesn't smell very minty, take better care of your tools!" Hah!

Speaking of rusty bearings and extra weight, how many of you out there have tried the ceramic bearings, and what is your verdict? How much weight did you loose? Did it run cooler? Smoother? I'm curious!

Eric V

I'm interested. How did you determine the necessary clearance, from the original bearing manufacturers bearing code?
Just for "Kicks" I'd like to "Try" and bush the bearing engine that made me crazy. How do the clearances differ from a Bushing Model Engine to a Bearing Model Engine?
Regards,
John Jolley
CNC Programmers Motto: Some parts must die so that the others may live.

C2
min 0 max 9

"Standard"
min 3 max 18

C3
min 11 max 25

C4
min 18 max 33

As you can see, there's a pretty large range that fits "C3", and a large overlap between "standard" and "C3".

What sort of cage did the ceramic ball bearings come with? I've heard its usually cage disintegration that causes damage when bearings fail. Are there other sorts of catastrophic failure (as opposed to gradual failure that you can detect before the engine is damaged)?

What about stainless steel bearings, by the way? BOCA offers some here and there. At least they won't rust, but I wonder if the steel is softer than the usual chrome steel.

Could the smell be camphor? This is from the Woodcraft site.

- Norm F.

Woodcraft Tips & Tricks

Rust Protection For Your Tools

Nobody likes to see rust on their precious tools. Here are some tried and true ways to stop rust.

Some people keep small blocks of solid camphor in their tool drawers. Camphor produces fumes that form a coating on the tools that prevents rust.Keep the camphor in small pill bottles. Drill a number of small holes in the bottle lids to permit the fumes to escape and protect the contents of the drawer.

Note: Be sure to read the instructions that come with the camphor because, under certain conditions, camphor fumes can be harmful.

If you store your tools in tool rolls, soak the rolls in kerosene and allow them to dry. The kerosene residue will protect your tools.

You can store your tools with small packages of silica gel. Silica gel is often added to cartons of electronic parts and drugs. It absorbs moisture and you can rejuvenate it by placing it on a lit light bulb for a couple of minutes.

Note: Do not leave the gel on the bulb over a couple of minutes because the paper it is packaged in is flamable.

>I think the smell is wintergreen. We used to use oil of
>wintergreen in traction compound for slot cars.
>Derek Moran

Then the KAOS is not moving out fast enough ... I should have more properly said, "tail wiggle," an infamous trait of a woundup, screaming KAOS.

Bruce