MBX-5 going BL. Center diff question.
 

Hello all,
I've been using this site for research for well over a year now and just now registered(bout time eh?). I will be following up with a full report after my initial question in the coming weeks. I'm converting a Mugen MBX-5 to BL LiPo. I know I need to swap out the Mugen diff for a plastic spur compatible diff. I would like to use the stock center CVD's. What would work as far as drive cup dimensions and length, or are they all the same?
Preliminary plans are MM controller, 5S MaxAmps 10Ah and NEU 1515/2.5D but more on that later. Thanks, Stephen.

welcome... jeeze it's about time, lol.

I'm not sure exactly what the differences are in a Mugen. I would think there is a way to use the stock diff, CVDs etc. You may have to change out the one bearing that fits on the center gear, if you use a Kyosho plastic one, but that should be it.

Maybe I'm missing something?

That will have some killer runtime.... +30 minutes easy.

Should be wicked fast too... 5s and that 1515.... :004:

i believe the holes in the moogen diff cups are located different then the ones in the mp7.5/777 cups.

Use a hot bodies buggy/truggy diff(which accepts the kyosho plastic spur) and the Hot Bodies center bulks(same hole pattern as the Mugen). This combo will drop right in. Drop me an email if You would like me to provide these parts for you. :)
rcmonstermike@gmail.com is the quickest way to get me through email. :)

And welcome to the forums. :)

Yeah, you must likely need the diffs internals as well, since the HB uses 4 mm cross pins. (i thought the Mugen used 3mm X-pins?) anyway; the HB uses 4mm pins, and 6mm outdrive cups.

yes - the whole HB diff is needed to make it work. :) Mugen diffs are smaller overall (shorter end to end, as well as smaller shafts, etc.). Fortunately, they use offset center bulks, so the HB bulks allow a direct drop in of the HB diff. :)

Can the MM handle 5s for the long hall. I heard of a few people using 5s but, will it hold up over the long run?

We'll see if my E-lst will outrun your buggy. Ha ha. :)

If you are planning on running 5s as your every day setup IMO you would probably be better off with something designed for that voltage. The MM will run it, but thats pushing it. There are a few on this forum that run the MM on 5s regularly, but for relaibility you should go for something rated for higher voltage.

The MM and the Neu isnt necessarily the best combo either. The MM can have some cogging problems with the Neu motors. CC is working on a software update for the MM to fix this, but no ETA on that yet. IMO the MM is best paired with a standard 2 pole motor until they get that ironed out.

Thanks to Mike and everyone else. I'll get the HB stuff on it's way. Now to the fun stuff. First off I should point out this will be a race buggy for racing with the "nitro guys". I really want to run the Neu motor because of their efficiency and US made. I also think the MM is the cats meow. Ya I've also been waiting for the MMM but want to be rolling by late march or so of THIS year LOL. Well I guess I will stick with the Neu. So is the Quark monster pro 125B(heat sinked) and the Neu 1515/2.5D the ticket or is there a better setup for the money? I want to be able to run a 20 min. main so I figure the 5S 10Ah will be more than enough. I take 4200Mah on 4S in a 10 Min race with my 10.5 lb G2R with the HV6.5 and I'm sure it's not near as efficient.

If you definitely want to run 5s, then an ESC like the Quark125B or one of the BK Warrior ESCs might be a better choice (need an LVC for the Warriors though). Like was said, the MM will run 5s, but you're pushing it. The Quark has an easy to mount case, has a lot of programming options, built-in LVC, etc. There are some people (me included) who have issues with cooling, but an extra heatsink is easy to add. And it runs the Neu perfectly fine. Downside is the price.

If you're running 4s, the MM would be the best bet, providing Castle comes out with the software fix when using Neu motors.

I'm sure I don't need 5s for racing. I just figured the higher voltage would be more efficient and run cooler. What's the word on the update for the MM 4 pole compatible? If they come out with it soon I would consider running 4S with it. MM is great let alone Castles customer service.

The only thing I've heard about the MM update is "soon". Then again, the MMM was supposed to be released "soon" as well, and we know how that's going...

it will be worth it tho, id rather have it be right from the first one sold over tere wrong and need updates and all that

i do hope tho the mmm is here soon, and the mm with 4 pole will be sooo cool

Well I think I have decided on the MM ESC. Should be here Monday. I don't want to take the chance with 5S. Gonna run 4S but may drop down from the 10AH batteries to the 8AH. I just want to be able to run a 20 min. main and after seeing glassdoctor's run last week That shouldn't be a problem. I've got several 4800 Orion/Kokam packs. Thought Id test run with those to see what it's gonna take for sure. So now on to the motor. I keep going back and forth on whether to run the Neu 1515/2.5d. and hope for the best while waiting on the update from Castle or just go with the Lehner 1940/9. But whats up with that shaft size? Also I don't seem to understand what the difference is in the Hi amp version. Any and all thoughts and criticism is more than welcome. Is there a better motor choice? I'm not looking for stupid fast. I've done all my calculations based on 40mph. My two main goals are: #1 to be more than competitive. #2 efficient. Later, Stephen

lets get him some help! He needs it LOL :) Looks like he just picked up a Neu 1515 2Y :)

Center-Diff Issues in BL Conversions
 

Hello all.

It's time for some of my patented ignorant-newbie questions:

Can someone please explain to me the issues with center-diff compatibility in brushless conversions? Why does SilentMonster need to swap out his diff gear? And why all the talk about replace the innards of his diff?

Are there some brands of center diff which require less modification? I'm considering using an XRAY or possibly a Losi 1/8th buggy for my conversion. Will these require special attention? Will the Losi's Imperial (non-metric) hardware cause headaches? Does anyone know about any issues that the new Associated RC8 might have? (I realize there's not much info on it yet.)

Follow-on question: What pinion gears are people using with the BL motors in converted 1/8th buggies?

Thanks again, everyone, for all your patience and help.

The problem is that stock nitro centerdiffs use steel spurs. The hardened pinions don't hold long on BL motors, that's the reason why everybody is exchanging them with plastic ones.

The inner gears of the mugen use 3.5mm shafts, over the normal 4mm shafts. the HB (which uses 4mm inner pins) is a 1:1 fit for the kyosho spurs. Since the kyosho spurs are fair cheap, it's easier/cheaper to use a HB diff with a kyosho spur rather than making an adapter to make a 51T ofna spur work. (the 51T ofna isn't a bolton, it requires an adapter)

Mmm?
 

Also, what's the extra "M" in "MMM" stand for? And what IS the MMM, anyway?

Serum,

Thanks for your reply. I like your signature.

Anytime Skeeler. Yeah, that signature has got a story behind it :p

The MM means Mamba Maxx, and the MMM means Mamba Monster Maxx, which is an esc castlecreations is working on. (stronger than the current MM, more current, higher voltage)

"And why all the talk about replace the innards of his diff?" Just to be clear, you don't swap out any internal diff parts. You just swap out the whole diff with the HB diff and just change the steel spur with the Kyosho plastic one.
"What pinion gears are people using with the BL motors in converted 1/8th buggies?" Right here from MIke. http://www.rc-monster.com/gears.php The Mod1 pinions. Most motors use 5mm shafts with the exception of the Lehner 1940 series.

Mike has the 4mm mod1 pinions for the Lehner. I have a MBX5 and use a kyosho center diff(the whole thing includung the posts). It fits directly in the MBX5 holes. Of course the kyosho plastic gear works on their diff. I have a
8ight I'm converting now and it takes the kyosho plastic diff with no other changes. Save yourself the headaches, JUST GO PLASTIC DIFF. I usually run a 12-13 pinion at my local track from Tower(century heli pinion).