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I have three RC10 6 gear transmissions. The video is of the best one that spins the longest. 3 seconds. Someone once mentioned it could do 16 seconds. BS. I have ABEC 7 bearings through out plus the black delrin gears. The metals gears have been ground down. The case has been shaved down a little so no moving parts make contact with the case. It even has an 80 tooth aluminum spur gear. I know of no way to make this spin longer other than using a larger steel spur gear. But no way are you getting 16 seconds from this tranny. 3 is the best I can do.

Honestly, I've never believed the 15+ second spin time by hand. I have never seen a 6 Gear in a video or in person that has spun that long. And Jim Halsey says 30 to 45 seconds in "The Winning Edge."

I've seen almost 10 seconds but that was by using compressed air to spin the transmission up to high speed and then letting it coast. It's quite possible that all this time we've been thinking "spun up by hand" when in reality is was being spun up to ludicrous speed using an air compressor. Having never been let in on that secret could be why for years we've chased the mythical spin time without knowing that a key piece of the puzzle had been left out.

Did you clean out the stock grease from the bearings? That will cause a lot of drag. Some will run them dry or use a real light oil. Also removing the dust shields from the inner side of the bearings will help also.

http://www.google.com/url?sa=t&source=web&cd=8&ved=0ahUKEwj7-uCCzZvLAhXESSYKHcCMBJ4QtwIIMDAH&url=http%3A%2F%2Fm.youtube.com%2Fwatch%3Fv%3DRepARd6db7c&usg=AFQjCNHshQcaGvIvXGgQAci8Rb9LLfBlpA&sig2=RUqB6Omek8oKT9NWqU8W1g
Abec 7 have more tight tolerance compared to abec 5 which is mostly used in off-road. German made bearings spun more freely compared to china made bearings.

I've wondered about this as well. I seem to remember various techniques used to improve gear mesh. 30 seconds is a long time. it would be great to see someone that can replicate and report on all of the improvements needed.

- Limestang

also something to keep in mind is that a newly rebuilt trans. is alot 'tighter' than an old wore out one. I have some really nice spinning 6 gears but have no clue to how old they are. They are all old used ones so pry wore out

Todd

TOLITS wrote:http://www.google.com/url?sa=t&source=web&cd=8&ved=0ahUKEwj7-uCCzZvLAhXESSYKHcCMBJ4QtwIIMDAH&url=http%3A%2F%2Fm.youtube.com%2Fwatch%3Fv%3DRepARd6db7c&usg=AFQjCNHshQcaGvIvXGgQAci8Rb9LLfBlpA&sig2=RUqB6Omek8oKT9NWqU8W1g
Abec 7 have more tight tolerance compared to abec 5 which is mostly used in off-road. German made bearings spun more freely compared to china made bearings.

I don't think the standard bearing that we buy for our RCs is an ABEC 5. I think they're ABEC 1s. I bought them from Boca Bearing. Don't know if they're German or China. They were close to $100. I hope for that price they were German.

I didn't take the covers off or remove the grease. Boca offers grease and oil. They told me I don't need to add oil. So I tried them the way they came. Then I oiled them real good with their speed oil. They improved greatly.

here's my new built 6 gear with no work done to it...and bushings. Just for comparison sake
sorry about the audio, I was apparently enjoying some Ricky Bobby
[youtube]IeBWoZ-ruw8[/youtube]

32 pitch spur!

If you want the bearings to spin forever, do what DHood said. If you don't like tearing your car down after every other race to redo your bearings, don't do what DHood said. Basically.

Yeah they used to use much better bearings than most available today. I did a save type clean up of a nice and tidy team car recently and the transmission in it spins forever.. Way longer than anything else I own for sure.. Classic Jason,do what dhood says or don't do what dhood does

Wonder if they are spinning bare trans with spurs only or entire rear with wheels minus pinion...

I think 15 seconds is entirely possible, 30 seconds may be a bit of a stretch but I wouldn't rule it out totally.

i think this is a just one of those mythbusters deals. the issue you have gets kind of complex, but it boils down to the moment of inertia for the transmission internals. In order to get something to continue to rotate for many seconds, you need to have mass to maintain your inertia.

think of a front wheel assembly; two bearings, one wheel, one tire. spin that fella with good bearings and it will spin for quite a while. many revolutions. Now take the tire off, and repeat, it will spin for less time. now just visualize one bearing on the axle, spin the outer race, it won't spin more than maybe once or twice, it has very little mass therefore very little inertia.

i would bet all those quotes of many many seconds were in system, with axles, bones and rear wheels.

Here's one I found, canned air and a stealth connected to the driveshafts but no wheels.

[youtube]WbkqcfuXYP4[/youtube]