Noob Question for you tech guys.
 

Is there a way to run 2 smaller brushless motors with 1 mmm esc. Can you run them in parralel or series or something or would it not work and fry the ecm or batteries. The reason i ask is i just bought a used g-maxx chassis and a single speed converted tranny and I want to use both side of the motor plate instead of one off to the side. I have seen some of the vtwin setups but apparently its not the way too go.

Twin motor setup.
 

A lot of guys just do not like or recommend V-twin setups due to the added weight issues. The arguement is why put two motors on when you can purchase one motor that will give you the same or more power than a v-twin system. You can use the Novak Super Duty XR ESC to run two motors. There are a few other ESC's that will work, and I am sure that you will soon get a ton of responses for this both good and bad points. Good luck with that RIver. You may have read some of my responses as I am building a SuperMaxx right now with Twin Dewatl 18v 970 motors. It has been done before, but I wanted the experience with that setup anyway. I am using the super duty myself.

Nope, that's not going to work I'm afraid. In a nutshell, sensorless brushless ESCs use back-EMF pulses from the motor in order to know what position the rotor's in, so that they can drive the motor. Trying to run two motors on one ESC would result in two "sets" of back-EMF pulses, which would totally confuse the ESC and probably end up frying it. In theory it's possible if the motors were completely synchronised (identical KV and rotor start position), but simply getting hold of two motors with identical KV is nigh impossible.

In short, two motors on one ESC isn't going to happen I'm afraid. Twin VXL systems work, but they're an inefficient way of doing things; the two motors will always be fighting each other slightly because they're running on the same spur, and it's also a heavier solution. Plus, with two motors, you'll always get lower total efficiency than with one high-quality motor...and the VXL motors are already run hot. Lastly, it's more expensive.

Besides, two motors are completely unnecessary; one large motor can easily provide enough gumption. It might not look perfectly symmetrical, or as "cool" as two motors do, but you'll enjoy the lower cost, higher efficiency and greater simplicity of just one motor. Efficiency is *everything* in a brushless setup.:yes:

Edit: Just saw Jerry's post. RiverMaxx, the SuperDuty XR speedo that Jerry's talking about is a brushed-only controller. You can run twin brushed motors easily, but not brushless. I thought I'd try to avoid any confusion there. :yes:

Oh yes it will.
 

[QUOTE=Dagger Thrasher;254006]Nope, that's not going to work I'm afraid.

The Novak Super Duty XR is a brushed sensorless ESC

With the toque these brusless engine make I didnt think weight was reallly an issue especially if you put the engines towards the front where its needed most because of the excessive wheelies.

You can run 2 bl motors off one bl esc. They have to run the same pinion size on the same spur, so in an emaxx it is doable. You do have to sync them to each other, I am a little fuzzy on the technique. The up shot is that it is simpler and often the same price to run one motor with one esc. A dual motor dual esc setup like the vtwin is an option. Most do not care for it, and a MMM combo with the 2200kv motor is a better choice.

I found some spec on that novak jerry. Maybe someone can interpret it for me. Will it even work with brushless what would be a good set of brushless motors too run? I am just exploring all my options this is not a for sure thing. How about 2 2200kv motors?lol:diablo:
SPECS: Voltage input: 6 to 14 cells (7.2-16.8V) On-resistance:0.0011 ohms
BEC voltage: 6.0V/3A Weight: 4.03oz (114g)
Maximum current: (forward) 400A (reverse) 180A
Case size: 1.75" x 2.17" x 0.85" Rx wire length: 10.5"
Batt wire length: 7" (both) Motor wire: 13"
Wire Gauge: 14 Yellow (+), Blue (-)
Single motor limits @ 6 cells: None
Single motor limits @ 10 12 or 14 cells: None (550 size only)
Dual motor limits @ 6 cells: 10 turns
Dual motor limits @ 10 cells: None (550 size only)
Dual motor limits @ 12 and 14 cells: 12 turns (550 size only)

Even if you were to run the motors on a common spur gear, the minute differences in gear mesh, kv values and other minute differences when the esc is switching 2 motors at hundreds of times a second... If you want to run 2 motors, your going to need 2 speed controllers... The Only problem is that you now have 2 systems transforming your battery power to heat (esc and motor), limiting runtime compared to that of a single system.... Best bet is to get a high efficiency motor (neu, CC, Medusa) and be done:intello:

Not true - Linc is correct - You just need to sync the motors and esc.

I believe you mount the motors to the spur with pinions attached but not tightened. Then use a 1.5v battery accross two phases to align the motors - Only the shaft should rotate as pinion locked agains spur.

Then tighten the pinions down.

IMO not worth the trouble unless you happen to have the motors laying around. Not only do you to do this on setup, but anytime a you change the spur and if a pinion grub screw comes loose - pretty much anytime the mesh changes at all.

Is it possible? Yes.

It is practical? Not really.

Better off getting a single motor setup that is the right size. Setup and wiring is much simpler.

[QUOTE=JERRY2KONE;254007]Sorry Jerry, I was referring to RiverMaxx's first post. I must admit, I always thought that, for two brushless motors on a single ESC that the KVs had to be identical (e.g: if one motor was 2253KV exactly, then the other would have to be also), but obviously I'm wrong on that part. Still, it's tricky and a bit impractical to do.

RiverMaxx, the Super Duty XR is a brushed-only ESC; totally different technology to brushless. It won't run any brushless motors I'm afraid. You're wanting something along the lines of a Mamba Monster, which is a big, powerful brushless ESC (but can also run brushed motors if you wish).

So let me guess that novak i posted specs on wont work with a brushless setup. What brushless motor is equal to a 12 turn 550? Because I have know idea what those numbers mean. Sounds like I am going to go with the mmm combo and wait till the slipperential comes out so It can be symetrical. Thanks guys Btw will a g2 chassis work with a UE mono block?

Dont worry river.
 

Don't worry River you will get the hang of this all in good time. It is a little bit overwhelming at first, but some of it starts to sink in as you try different things on your own. Good thing is that there are quite a few very knowledgable guys on here that have already been through what you are feeling right now. Lean on them and they will lead you in the right direction. Trust in them and try the single brushless motor setup first. Then if you still want to explore the V-twin setup you will have learned enough to go that route with little trouble. I am glad to see that you are digging into this though.

By the way has anyone noticed the thread on (New parts). I posted up in there to let everyone know that UE is back in business. I know some of you know this, because I saw you on UE earlier. He is making up some monoblocks to start with to see how the response goes. He is being bonbarded with requests for other parts as well. We shall see.

Yea I will pick it up sooner or later. Yea he must need money. He made a batch about 1 1/2 years ago and they sold out. I will believe it when i see it if he makes other parts.

MetalMan can make you a centerdiff drive unit that will work on the FLM and GorillaMaxx 3906 chassis- may require a little trimming/clearance work on the inside of the chassis rails to allow room for spurs bigger than 44tooth I believe. No slipper with that unit, but the centerdiff acts as one in a manner of speaking..

I like sysmetrical too, but one must learn to embrace the Asymetrical sometimes :yes:

Do you have any samples of his work. I think a 44 tooth might fit just right.

Samples, no- just PM him for details really, far quicker and easier than rooting around this place for burried threads and such. What you're after is one of these basically:

http://www.rc-monster.com/forum/showthread.php?t=10233

There are a few variations in shape depending on who makes it (Serum has an older version in a G2r revo, but the basic design in the same).

Mike is also starting on his in the next couple of weeks - YAY!

info
 

Yes Sir I exchanged emails with monsterMike on this ver subject just before Xmas, and his response with this was that he is going to have some of these made up and hapefully have them in the store sometime shortly after the New Year 2009. So there are several of usstanding by for his release on the Maxx truck center diff mount. I would expect that we will hear something or see themon the RCM store page within the next month or so. There are two of them out there that I have seen. One is SSSConcepts,and the other is Harold's(Paralysed). They look really good, and should solve a lot of issues for some of us in getting rid of the tranny all together. Mike is also planning ot release the Slipperential pretty soon. He has shared with us that he is finalizing all of the patent pending issues and trying to take legal steps to protect his design. So 2009 is a good time to start into this RiverMaxx.

Yes, that exactly what I want I guess I will wait till mike gets them made. Now that I have a g2 chassis I think the build will go alot easier. I just cant decide which bulkhead setup I want to use. I was thinking about using a mono block with the g2 chassi and vbs with 8 spidersand racerx with setbacks or ga's with sweestrobes and rpm truetraks I cant decide and I will have too pull some peices off my nitro trucks.:gasp:

Sounds pretty good.
 

In my opinion that sounds like a pretty good setup. Your choices are right on the money and if all goes well you will have a nice truck for your first BL conversion RIver. You seem to be rolling right into becomming a real Brushless dude here at RCM. Good luck and keep us updated with your progress. Good luck RM.

Only if you use the G1 rear end or cut the G2 rear end. I have a G1 rear end with mono. The driveshaft you'll need is 110mm. You can buy the titanium 110mm shafts from UE.

Whats the diffrence beteween the two. I thought it was only the lower chassis plate was different. I also thought the g3 cassis had the different upper plate that required you to use the front flattened out skid in the rear which wouldnt work with a mono. Question is, should I use a mono block or buy a g3 upper plate and use a front skid which would be cheaper stronger and better over all to lengthen the wheel base a little. Lets see mono is $65 upper plate is ~ $25 and a rear aluminum skid is $19 and a used titanium one is $25 so ~ $50 compared to about $90 for mono with ti skid. Mono would be stronger for sure and I could use any normal ti skid. Descisions decisions.LOL

All things concidered, the G2 chassis (when fitted with the extended rear upper plate and extended rear lower skid) is the same length as the regular G2 chassis fitted with a monoblock- theres only like 1/8" difference. My advice would be to just pickup the G3 rear upper plate and rear skid, no need to mess around modding parts or hunting for extended skids. I've never had any durability issues, and I've flipped my truck more times than I care to remember..

Does rc monster sell it in kit form? Or do I have to get that from the gorilla website. I was thinking about using my 3mm thick ga skids and for that I would have too run a monoblock. I wonder if a hardcore rear titanum skid would work I really dont like aluminum skids.

Sell what in kit form exactly?

You can buy the parts you need from gorillamaxx themselves as spares, just look in their spares section under the G3 chassis- you will need the skid and rear upper plate. RCM doesnt sell the spare parts, just the whole chassis. I honestly wouldnt worry about needing a Ti skid on the rear, though a trimmed down item would fit over the top of the gorillamaxx ones nicely (just use the 4 holes that attach it to the underside of the bulks, and trim off the rest if you use a normal length skid). The aluminium skids of the gmaxx chassis are very short, not like a normal skid that is inclined to bend if you hit something- take a look at the photos of my truck to get a better idea of what you're dealing with:

http://www.robotwars.00server.com/gmaxx.html

I have been studying your truck among others very closely these past few days. BTW nice build. What I need to know is what length is the rear drive shaft pin to pin. Lito say 110mm but I have seen others say different. If it is 110mm I could get titanium ones from ue.

River, my gmaxx with mono uses a 110mm rear dogbone. I used to have a 108mm dogbone but have to use 2 o-ring on each cup to remove the fore and aft play. I measured the distance and bought the 110m titanium dogbone from UE and it fits like a glove. No o-rings were needed on the cups.

Anyway, can you post a pic of your chassis?

Hey lito what length is the front shaft? . That is awesome I can use a titanium shaft with the mono. I wonder if there is a difference of shaft length with the g-maxx chassi extension Neil said 1/8" in length between the 2. I bought it from billy trucks he gave me a pretty good deal . A similer one sold for over $200 a couple of hours before. I dont know how to tell if it is a g2 or g3 I guess the g3's are longer and the g1 lower plate is flat. Heres a link the the auction. http://cgi.ebay.com/ws/eBayISAPI.dll...m=160310588005

I saw a gentlemen about 3 weeks ago that was running a MMM with twin Velineon motors hooked to it on a 3905 Emaxx. He had fried both of his VXL-3 controllers and had the motors laying around with a MMM to use. The truck ran awesome on 3S. So I would have to say.....yes it can be done. Is it the most efficient way....probably not.

The front uses the same length dogbone for the e/t maxxes; 57.5mm. There's a bit of play so you'll need to put one o-ring for each cup. 59mm would be the ideal length if you decide to have one made by RCalloy.

I can't see the picture from work.

Cool!! I have a few extra front stock length ti shafts.

Besides
 

Besides the O-rings you can also use some silicon fuel tubing to buffer the gap in each drive cup. It really does the trick and since you are still a nitro guy I am sure that you have some laying around. Good to see that you are having fun figuring this build out for BL. Have a good one.