Are Zippy Lipos safe with a Castle MMM Speedy?

[Chadworkz]

Wow, I must say, I am now thoroughly confused and scared to death...heh!

A few details;
I have a nitro 3.3 Revo that I converted to brushless using Mike's RCM motor-mount and custom carbon-fiber Battery/ESC/RX trays that I made. It has the V3 MMM/2200kV combo running through the nitro transmission with a forward-only conversion, Pro-Line Bow-Tie MTRs on Pro-Line 23mm ½" off-set Velocities, a ton of carbon-fiber, titanium, & other lighter-than-stock parts throughout...and I am also planning on running the brakes & reverse via the motor.

I was planning on running a pair of Zippy Flightmaxx 4S 2650mAh packs in parallel for 14.8v @ 5300mAh, but am now questioning that choice after reading this thread, but wanted to ask a few questions before I make my final decision.

I am not a speed-freak, and I am not going to race, I just want a quick truck that is reliable enough to bash around the yard, in the chert-pit, and do jump-tricks off of my ramp...maybe 35-40mph max. Right now, besides the batteries, my biggest question is gearing, and about the transmission...

...is the overall gear-ratio of the nitro Revo transmission any different than the E-Revo transmission? If so, what spur and pinion would you guys suggest for my setup and what I want out of the truck, as well as if the ratios are the same for both transmissions? Like I said, I don't want all-out speed, just 35-40mph and reliability enough to do what I said above. As for the batteries I chose, I believe they will work just fine for my needs, but I really want to make sure before I damage something, and I would really appreciate help from you guys since you really know your stuff.

Thank you so very much for any help you guys can provide, it will be much appreciated!

P.S: I am going to run a set of Mike's V3 1/8 Revo Hybrid Diffs (buggy ratio) in the future, so I may need some help selecting a spur/pinion for that setup as well...

[fastbaja5b]

Originally Posted by Chadworkz

Wow, I must say, I am now thoroughly confused and scared to death...heh!

A few details;
I have a nitro 3.3 Revo that I converted to brushless using Mike's RCM motor-mount and custom carbon-fiber Battery/ESC/RX trays that I made. It has the V3 MMM/2200kV combo running through the nitro transmission with a forward-only conversion, Pro-Line Bow-Tie MTRs on Pro-Line 23mm ½" off-set Velocities, a ton of carbon-fiber, titanium, & other lighter-than-stock parts throughout...and I am also planning on running the brakes & reverse via the motor.

I was planning on running a pair of Zippy Flightmaxx 4S 2650mAh packs in parallel for 14.8v @ 5300mAh, but am now questioning that choice after reading this thread, but wanted to ask a few questions before I make my final decision.

I am not a speed-freak, and I am not going to race, I just want a quick truck that is reliable enough to bash around the yard, in the chert-pit, and do jump-tricks off of my ramp...maybe 35-40mph max. Right now, besides the batteries, my biggest question is gearing, and about the transmission...

...is the overall gear-ratio of the nitro Revo transmission any different than the E-Revo transmission? If so, what spur and pinion would you guys suggest for my setup and what I want out of the truck, as well as if the ratios are the same for both transmissions? Like I said, I don't want all-out speed, just 35-40mph and reliability enough to do what I said above. As for the batteries I chose, I believe they will work just fine for my needs, but I really want to make sure before I damage something, and I would really appreciate help from you guys since you really know your stuff.

Thank you so very much for any help you guys can provide, it will be much appreciated!

P.S: I am going to run a set of Mike's V3 1/8 Revo Hybrid Diffs (buggy ratio) in the future, so I may need some help selecting a spur/pinion for that setup as well...

No matter what you do someone somewhere will say it's wrong. I have run a converted Revo with a MMM speedy and a Medusa 36-60-2000 motor and it was fine that was running Reedy 5000mah 20C Lipos (2 * 2s packs)

so your set up should be ok from what I can see.

I think on 5/6s it's more critical than on 4s unless you gear down severely but then of course you risk an undergeared motor so either way ur stuffed lol!

My converted Revo, 4s Lipo stock spur and 14t pinion with the 2000mah was a handful but it was super reliable (now in the hands of a mate who is known to be a magnet for breaking things, but he hasn't yet!), yours should be even quicker, although with the extra torque of the MMM motor, I'd explore putting in the Robinson Racing metal gears inside the transmission!

Good luck with the project!

[Finnster]

Personally I think the whole thing is a bit of CYA from castle, and I would only really be concerned about it if I was pushing my system to the limit. What you are doing will not, and that just fine.

My first revo conversions used a MM on 4 and 5S and ran 10C batteries. they had no problems, but I didn't abuse them either. Decent batts and setup and it will be fine.

As far as gearing goes, use this calc of BrianG's IDK all the ratios, but its quite easy to just use the drop downs to get what you want. FWIW, I used 3.5v/cell and 6.7" sized tires to get the speeds I was seeing on my radar gun using maxx mashers. YMMV, but it gets you close. Aim for 40 and a ~32K rpm motor and you will be golden.