RCM Pinion idea

[kneedeeppow]

i have been using rcm 14t and 15t pinions in my brushless mooge since its creation about three months ago.i have been breaking quite a few pinions.one was due to my motor mount being loose but the others have been a bit odd.nothing loose,nothing bent.after taking my trug away on holiday with me where i got to do alot of driving and tweaking the set up i noticed a possible issue with the smaller pinions. they are hollowed out in the center which makes them weak and the teeth prone to snapping off. i broke my last available 15t two weeks ago and put in a 17t which doesnt have the hollowed out center section.since installing the 17t it hasnt missed a beat.the trug has taken some mean hits(the 8 metre kicker at arccc is vicious) and the pinion has held up far beyond what the smaller ones did.
maybe making the smaller pinions without this hollow area will make them alot more durable? just a thought

[Sammus]

First I've heard of it, food for thought though. That said, I have a 11T I use from RCM and can't see any hollowed out bit to speak of except for the shaft bore and the set screw. It's served me well over the years :)

[kneedeeppow]

Originally Posted by Sammus

First I've heard of it, food for thought though. That said, I have a 11T I use from RCM and can't see any hollowed out bit to speak of except for the shaft bore and the set screw. It's served me well over the years :)

here is a pic of one of my bung pinions. the hollow section i mean is directly under the teeth.i know there is need for a hollow for the bore.

[jokerjustin]

they are hollowed out about .25 of an inch from the gear end..

[phildogg]

I also had a 15t mod 1 pinion broke a tooth off,same kind you speak of. I emailed mike he sent a new one. I never had it happen again. I have several of his pinions,no other problems with them.
phil

[magman]

I have a dozen or so RCM pinions I use on 5 vehicles w/not a single problem

[RC-Monster Mike]

This type of failure is relatively uncommon, but it happens(and not just to my pinions). I replace these pinions when they fail like this. It is a simple matter of math, as there is no such thing as 100% success rate. I have easily sold 8,000+ hardened pinions over the last few years so a 1% failure rate would yield 80+ failed gears(haven't seen even half this many failure total). The weight reduction pocket doesn't span the entire width of the teeth(pocket depth), and is simply not a factor in this failure.
Every so often, a gear gets passed through production either without getting hardened enough, getting overhardened or otherwise out of spec. You were simply one of the few. Send it back and I will replace it. :)

[bdebde]

So Mike, will all of your future pinions have this "weight reduction pocket"?