Direct drive with outrunner

[AngelowDoom]

Hi, im building a SCX10 and im thinking about dropping the transmission all together and just mount the driveshafts directly to each side of the outrunner, since both sides are spinning. Has anyone tryed it before?

[EeePee]

Over the years I've seen it a few times. Though they were always sensor less out runners. Now with sensored out runners it seems a bit more feasible than before.

[STANG KILLA SS]

without the gear reduction, i could see torque being an issue
stock transmission is like 16:1 total reduction i think

[K.O.M.]

Yup, the stock transmission is 16:1 with the 87/14 spur/pinion combo.

I'm all for simplicity, but then you're left with just the reduction in the axles, for a final drive which is roughly 2.7:1. Yikes! My FWD touring car isn't even geared that high.

Now for building something with Losi or Kyosho worm drive axles, I could see that as an alternative. You would still need a primary reduction, of at least 4:1 to overcome the inherent inefficiencies of worm driven gears, but would like to hear your findings if you go through with the experiment.

[EeePee]

Come to think of it, first time I saw it was with custom worm gear axles. Search for threads started by rbgerrish.

[Joshs4x4toyz]

I had an lcc which I ditched the trans with an 1100kv outrunner (i believe maybe 1300). SDH on here has it now running maybe 90/22.... Been forever since I messed with it but we ran em a couple weeks ago and runs like a champ still.

[WHITE-TRASH]

I can only imagine how fast it'd be with no gear reduction. The ax transmission is 2.6:1 if I remember right and without that bit of reduction my exo hauls absolute ass with 4.9:1 from the 1/8th scale trans, taking that away, even with a low kv outrunner would be crazy fast.

[Liv3mind]

Look up JENS's losi build In the lcc area, he just got his running with no granny and an out runner. There is video and pics "thumbs up"

[Joshs4x4toyz]

Originally Posted by WHITE-TRASH

I can only imagine how fast it'd be with no gear reduction. The ax transmission is 2.6:1 if I remember right and without that bit of reduction my exo hauls absolute ass with 4.9:1 from the 1/8th scale trans, taking that away, even with a low kv outrunner would be crazy fast.

Hypoid and worm gears are quite different. lcc trans ratio is around .86:1 and axles are 25:1 I believe . With that outrunner it crawled like a goat actually. Too slow for me anymore, but it was a very impressive for its day lol

[rbgerrish]

I had fun with that a million years ago. I had a few versions- the first was one large outrunner with dirveshaft outputs on each end feeding worm gear 25:1 axles. Then I tried 50:1 worm gear axles, and that was better. Then I switched to 2 small outrunners next to each other, each feeding one axle so I could have electronic dig. That worked well, but it was pretty heavy. Eventually ditched the setup due to parts availability for those custom axles. You could do a similar setup with Losi worms, but be sure to get a low overall gear ratio ir it wont crawl well...

[Undefined]

Originally Posted by EeePee

Over the years I've seen it a few times. Though they were always sensor less out runners. Now with sensored out runners it seems a bit more feasible than before.

I thought sensorless outrunners produce the most torque in low rpms and have very little cogging from what I remember? Maybe i'm wrong...

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