What's the deal with my name?

[OptimaMan]

Some dude asked me about my name - why is it OptimaMan? Well, back in the late 80's, Kyosho Optimas once ruled the 4wd off road buggy scene. I had a couple of chain drive 4wd optimas and belt converted ones too. I then got the Optima Mid and Turbo Optima Mid. It was definitely WAY ahead of it's time. The Optima Mid uses the "stealth" tranny of the RC-10's with the ball diff on the bottom, an idler in the center, and a pinion on top with a slipper clutch (very rudimentary - but it prevented gears from breaking and U-joints from popping). It was just "backwards" because it was 4wd so the motor was mid mounted. I used to drive that thing forever w/o problems. As a matter of fact, I used to RACE it in off-road as recent as 2 years ago (2002) against the 2wds and would keep up and actually win - but on rough tracks, it didn't stand a chance due to the older suspension that didnt' have as much travel or long a-arms.

Recently, I sold allllll of my Optima and Optima Mid parts on ebay (I think I got close to 1000 bucks for it all) and got started into the brushless stuff that way. Oddly enough, they're almost collectors items and some of the good condition stuff sold for more than I originally paid for it!!!
So, don't toss out the old stuff - wait a few years and sell it on ebay!

-OptimaMan

[Popop]

Sad to know you sold all your Optima stuff
Actually both my Alien Mid4 and Ultima trannies hold insane power !

[OptimaMan]

The Optima Mid tranny could probably hold a ton of power too. I used to have 32 pitch Robinson Racing hardened steel gears in it. With a ratio of 2.64:1, that was an awesome tranny. NEVER ever had problems with gears breaking. Sigh... but I had to clear out to buy brushless!

[robnjr]

Hey OptimaMan, I’m a big vintage Kyosho fan. Got a few MIDs (and an original Ultima), and I’m rebuilding a few more MIDs (with stadium type truck conversion). I just ordered a Novak SS, and was thinking of giving it a try in one of my old MIDS….What do you think? Will the old Optima power train hold up to the Super Sport? I don’t see why it wouldn’t, since like you said, they got a pretty rugged power train, but just looking for a second opinion. Thanks.

[OptimaMan]

The MID drivetrain is very rugged. If you have ball diffs and setup the slipper so it slips just slightly, you can put almost anything to it. I've run my mid with 12 cells in series with 12 and 13 turn motors. I've run it with 9 turn singles. I've never ran brushless because I didn't have it when I got brushless, but I'm sure it can easily handle the brushless.

[robnjr]

Hmmm, I’m kind of surprised that you think that ball diffs are stronger on these vintage cars. I’ve snapped more than one on my Ultima and Optima Mids (the long thin shaft/joint that the hex screw passes through breaks). These were the Option House original ball diffs, maybe there are stronger replacements? Since these incidents, I’ve gone back to regular gear diffs with the extra heavy 30000 weight Kyosho diff grease (gives a nice limited slip). Never had a problem with the gear diffs, and I don’t have to worry about rebuilding them as nearly as often as the ball diffs. And yes, I KNOW they’re not as efficient as ball diffs, but I’m not racing, just looking for reliability and low maintenance (I’ve got enough work rebuilding “new” vintage cars, not fixing the ones I already have). As you probably know, rear diff access on an Optima Mid isn’t exactly easy (and don’t get me started about a belt replacement due to the glued-on belt guards!)

By “slipper clutch” I assume you mean the wave-washer and protector plates on the spur gear. Interesting, I never know these were supposed to normally slip, just under extreme circumstances they’re supposed to protect the drive train. Are you saying I should loosen the wave-washer pressure to allow “normal” slippage???

PS: this may be getting a little off topic (although it does relate to a brushless motor application). Let me know if we should take it elsewhere. Thanks for the info. Too bad you sold all your vintage stuff. Those cars are really becoming popular now.

RN

[OptimaMan]

No, don't let the gear protector slip - it's only supposed to slip to prevent gear damage, universal joint snapping, etc.

In addition, it's interesting that you've had trouble with Kyosho's ball diffs. I've had a couple of Optimas, couple of Ultimas, Optima Mids, and even the Lazer ZX and NEVER had a ball diff fail on me - except it gets a bit gritty if I didn't maintain it. However, those bevel gear diffs - I've had the hex nut come loose in many instances and the outdrives will just spin. So, that's weird... but a bevel gear diff isn't any less efficient than a ball diff - probably more efficient in the turns if you ask me. The ball diff was nice for the drivetrain because it also acted as a backup "gear protector" if it wasn't overtightened.

The maintenance - yeah, that was horrendous. I used to use servo tape for the upper belt cover instead of glue so I could reuse the belt cover. It was such a pain in the butt that I just totally took my time and SEALED the whole drivetrain so it was just about watertight so I RARELY needed to take it all apart.

One thing about that MID trans - it was REALLY efficient. I still believe it was a more efficient tranny than the Losi XX4, XXX4, Lazer ZX, and other belt 4wd buggies. Oh well...