RC10Talk - The Net's Largest Vintage R/C Community

This place is full of insight and discussion. It would be nice to have a thread where random RC mysteries(or not so mysterious things...) can be discussed.

I'll start.

Why did it take so long for the now standard three gear tranny to be, for the most part, universally adopted?
there were all these manic designs before hand with multiple gears(diff on top, diff in the middle), bevel gears, chain drives, belt drives, direct drives and so on. why wasn't the incredibly simple, efficient, and effective three gear tranny adopted right from the very beginning? those early transmissions were so delightfully over engineered!

My first RC was a Kyosho Outrage. I HATED that tranny. I kept destroying that weird idler/spur gear/dust cover mount nonsense. I was so much happier with my next car. A RC10ce and its perfect stealth tranny.

I've actually wondered that myself. Even for the time, It wasn't exactly high-tech.

I was wondering the same. I noticed that on my Sand Scorcher, it has a 3 gear tranny and I'm sure it was like that way before the RC10.

Would it be fair to say the RC10 popularized it or was someone else responsible?

mip's 3 gear was my eye opener as srb's weren't exactly on my radar.
associated then popularized it by creating the stealth and making millions of them.

The Outrage transmission was from the Ultima, and that was an evolution of the transmission used on the Scorpion/Tomahawk. That transmission design, with most of the gears outside the trans case, was very popular back in the day....you saw it on several Kyosho cars, Ayk cars, the MRP Pro110, and the Traxxas Bullet. They only had one extra gear reduction compared to the Stealth so they weren't too far off in design....especially after you upgraded them with a ball diff. What they lacked most was a slipper clutch.


The 6-gear's design came from the design of pan car differentials which were probably the smoothest diffs of the time.

The SRB transmission was most likely the starting base for the 3-gear design but it didn't have a diff until Thorp and MIP started making them for the trans. From that we got the MIP SP-1....and from the SP-1 we got the Stealth.

Has there ever been an instance of RC tech making it's way into full scale cars?

I vaguely remember one of the RC tire companies(I think Proline) testing out full size foam supported tires on a Nastruck style full scale racer.

I vaguely remember a video with some off road race truck builders saying that they had basically taken some of their ideas straight from rc's.

As I'm thinking, I can only come up with two designs that seem to be strictly RC that might work in full scale. Ball diffs and the CVD/CVA style of universals. I can't really see a ball diff holding up to full scale power but it would be cool to see that type of design in a full scale car. The CVD/CVA seems like it would be pretty practical in a full scale design if it already hasn't been tried.

I guess I'll post this simply because since I first saw your user name I've had this song stuck in my head. Thanks!

[youtube]Xf1YF_MH1xc[/youtube]

Rootdown4594 wrote:As I'm thinking, I can only come up with two designs that seem to be strictly RC that might work in full scale. Ball diffs and the CVD/CVA style of universals. I can't really see a ball diff holding up to full scale power but it would be cool to see that type of design in a full scale car. The CVD/CVA seems like it would be pretty practical in a full scale design if it already hasn't been tried.

I remember reading in RCCA that the CVD drive was taken from full size cars. But that was 20 years ago, I could be mistaken.

THEYTOOKMYTHUMB wrote:I guess I'll post this simply because since I first saw your user name I've had this song stuck in my head. Thanks!

[youtube]Xf1YF_MH1xc[/youtube]

haha yeah. im a big fan

8rad wrote:

Rootdown4594 wrote:As I'm thinking, I can only come up with two designs that seem to be strictly RC that might work in full scale. Ball diffs and the CVD/CVA style of universals. I can't really see a ball diff holding up to full scale power but it would be cool to see that type of design in a full scale car. The CVD/CVA seems like it would be pretty practical in a full scale design if it already hasn't been tried.

I remember reading in RCCA that the CVD drive was taken from full size cars. But that was 20 years ago, I could be mistaken.

you could be totally right. when I first saw the cvd style of universals I just automatically assumed it was an rc thing.

8rad wrote:I remember reading in RCCA that the CVD drive was taken from full size cars. But that was 20 years ago, I could be mistaken.

CVD has nothing to do with 1:1 cars. It's just the name that MIP called their rebuildable universal joints, and so CVD has become the standard description for any rebuildable universal joint.

The only constant velocity joints in r/c are the latest double cardan joints that are starting to appear in touring cars, and slider driveshafts with a universal joint at both ends if connected correctly.

terry.sc wrote:

8rad wrote:I remember reading in RCCA that the CVD drive was taken from full size cars. But that was 20 years ago, I could be mistaken.

CVD has nothing to do with 1:1 cars. It's just the name that MIP called their rebuildable universal joints, and so CVD has become the standard description for any rebuildable universal joint.

The only constant velocity joints in r/c are the latest double cardan joints that are starting to appear in touring cars, and slider driveshafts with a universal joint at both ends if connected correctly.

I didnt mean the term CVD but rather the different construction of the MIP joint itself from what was common at the time. But like I said I may not be right about that and I have little knowledge of how full size cars are made.

A 1:1 car constant velocity joint is made up of two halves with a ring of ball bearings connecting them. The balls fit in grooves in the joints so the joint can move, kind of like a ballrace but with the tracks going from side to side instead of around the axle. This is what they look like. It would be really neat if they could be made small enough to fit in r/c, but you would be looking at very fine tolerances to get everything to work smoothly.

MIP CVDs are mistaken as proper cv joints though, due to the name and they do look similar when built up. Strangely enough the nearest we had to a proper CV joint in r/c was the Tamiya Frog and Fox hex joints, which worked until the torque wore the points off the hexes.