good news and bad news

Saturday June 26 ( bad news day) it became obvious that a bearing in my Magnum 36 died and I dared not fly it again with that noise coming from what has been otherwise an excellent engine. Only 220 flights so somewhat dissapointed. Today June 28 (good news day) I found a new replacement bearing in a bearing store in our town so for less than $15,I got the engine once again useable. And then received an Email from Randy Smith saying that a replacement engine was already in the mail. I am pleased to let everyone know because that kind of service should be rewarded. I guess that for $69.95 (the cost of the engine) one should not be too upset if the occasional bearing goes prematurely .Be happy that weve got some very nice suppliers in this hobby. Keith V.

Just out of curiosity, never having done this before. What do you do to get the right bearing at the store? Did you take the old one with you? Were they able to tell that it was a "C3 clearance" bearing?

No, I only knew that the bearing was 24x12x6. and ignored the clearance factor, Since entering this hobby I've replaced maybe 15 or so bearings based on size only and had no cause to be sorry, they all have lasted as well as the original equipment. Maybe I have just been lucky,eh? or are they not that critical? I have often had to buy shielded ones and remove the shield but that's no biggie. I know that speed fliers are much more critical .Also since this bearing had absolutely no numbers or markings I didnt have much choice. Keith V.

I guess you might get away with putting a C3 bearing in an engine built to accept CN clearances, but not the other way round. A qestion of tolerances. I have a new engine ready now, (Metamorph 60 Stunt). Assemble it with a CN bearing, it locks solid. C3 and it's fine, dare I say - superior quality? When I get photos sorted I'll post details.

What kind of fuel were you using how much oil, caster or syn. How much nitro.

Carl; 10% nitro 11% synth 11% castor GMA Powermaster Keith

Keith,

This is interesting. During the Regionals my Magnum said goodbye to the rear bearing. This was the first Magnum bought 2 1/2 years ago and had over 80 hours of run time. Since I had 2 other engines bench run for 2 hours each, just bolted in another one and everything was back to normal.

Since my early combat days I've always used a mixture of Klotz and Castor for lubrication (50% Klotz & 50% Castor-- 20% total) either mixed my own or bought Sig. This mixture of oil with any amount of Nitro up to 50% has always worked best dispite the claims of all the other "Miracle Oils" It also seemed to produce more power for any given Nitro content. Wonder if the lubrication led to an early dimise of your bearing? Just a thought

Keith,

Exactly what failed in your rear bearing? Most of the time the problem is a crapped out retainer, and I've got a really cool fix for that.

I have broken the actual balls in ball bearings, but only a couple times and in heavily loaded RC Pattern motors at that.

The bearing was really good except one ball was rough ,as if it was too soft or something and the outer race had one little depression, so the bearing felt good except every 2 or 3 rotations it would hit a rough spot and almost jam up .very strange and I suspect it was probably a faulty one from new. No Name or markings on it, Very likely used because of the low price rather than the quality. Keith

Chinese ball bearings are lacking, tis true. These engines run good, but you'll please not run them at high rpm, 'cause the bearings won't stand for it. The Speed Limit Combat guys replace them, first thing. Good bearings are available from Boca Bearing, correct grades, high-zoot if you want. Steve