One or two batteries for a twin ESC setup?

[mymonsterbeetleisbroken]

Hey everyone.

After owning my txt-1 for just over a year, i've become bord with its speed - or lack of it! []

I've been running it with a single Mtroniks RV11 esc, which works just fine with 2 motors, but limits me to pretty much stock silver cans only.

So, i've just bought another RV11, and i'm going to run a twin ESC setup.

No idea what motors i'm going to go for yet, maybe something around 17 turns...

Anyway, i was wondering what the best battery setup is for a twin esc setup?

I could either run each esc with its own stick pack - the txt-1's got space for 2 packs in the battery holder,

or i could make a Y power lead, and power each esc from a single pack.

What setup would you consider to be best?

The only thing that concerns me with the twin battery setup is both batteries need to hold the exact same capacity, or one motor will die before the other. I've got a peak charger so i guess it i could charge them to the same level?

So many questions lol [] 

[BiggusDitchus]

When I had my TXT, I used a twin esc set up (like I do in my Twin Detonator now) I ran 2 batteries.  Just Y lead the esc's into the reciever (remembering to remove oo cut red wire  one of the esc's servo plug). The problem I found then was the power from 2 17 turn motors each powered by a 8.4v pack was to rip upper links from mounting points at axle.

[modelmaniac]

When i had my Clod, i ran a twin motor/twin battery ESC.

It was by Kyosho and think it was called a Perfex?

It had two battery leads already installed, with tamiya style connectors.

Sweet ESC and the Clod really shifted, didnt do much for the "handling" though!!!

Modelmaniac[6]

[Rabiedmushroom]

I'm glad someone else is asking simple questions about slightly modded twin Clodified motors! I posted this query in the Electrics section only today asking for some advice:

http://tamiyaclub.com/CS/forums/34/ShowForum.aspx Help!

Haven't sorted my motors to plug into it yet (obviously!), but my splendid new Novak SuperdutyXR has 2 battery leads so you can run either one or two packs. All you do to swap between 1 or 2 is follow the instructions to make up a little lead to short the unused lead out if running only one pack. We've tried it on Alex's same ESC on his TXT and it works great, so he can choose either enormous ooooomph or longer runtime.

Sorry that comment won't help your Mtronics discussion, but thought I'd mention it whilst on relevant subject.

 

[rhenbelz]

If you are set on running two standard ESCs instead of one dual-motor ESC, then go with a battery to each. You will have very low runtime with a single battery and the draw on it may damage the battery or at least heat it up. The capacity difference between two packs isn't really going to make any difference as long as the packs have the same specified capacity. A pair of GP3300s for example will work fine together if you peak charge them.

[mobias]

Hey everyone.

After owning my txt-1 for just over a year, i've become bord with its speed - or lack of it! []

I've been running it with a single Mtroniks RV11 esc, which works just fine with 2 motors, but limits me to pretty much stock silver cans only.

So, i've just bought another RV11, and i'm going to run a twin ESC setup.

No idea what motors i'm going to go for yet, maybe something around 17 turns...

Anyway, i was wondering what the best battery setup is for a twin esc setup?

I could either run each esc with its own stick pack - the txt-1's got space for 2 packs in the battery holder,

or i could make a Y power lead, and power each esc from a single pack.

What setup would you consider to be best?

The only thing that concerns me with the twin battery setup is both batteries need to hold the exact same capacity, or one motor will die before the other. I've got a peak charger so i guess it i could charge them to the same level?

So many questions lol [] 

 

For all twin motor monster trucks like the TXT-1 and Clod there is an extra level of (usually expensive) complexity to running them that single motor vehicle owners just don't have to worry about. Going down the twin ESC route for your TXT is a good one especially if you're on a budget. I've got two Mtoniks RV-15's in my TXT and generally they work fine although I did blow one last summer.

As far as a twin battery versus single battery set up is concerned you have to look at the pros and cons of each one. Its not actually true that a single battery set up gives you much less run time.  Remember batteries are heavy, you're putting an extra heavy object into an already heavy truck, that extra weight just requires more energy to move it. It is true that having a single battery set up punishes the battery more with over heating etc but then again, as I found when I had a twin battery set up in my TXT last summer, having two hot batteries right next to each other didn't help matters either. Also there is the TXT's handling to consider. The TXT is already a notoriously top heavy truck, by having two batteries instead of one up there in the chassis you're only making matters worse. Although it does help the TXT pop wheelies which is fun, but again that extra weight just punishes your truck more.

In my TXT I reckon I've worked out the best compromise on a budget for speed and torque versus battery run time and ESC punishment at low speed crawling. Two RV-15's (17 turn limit) powering two Tamiya RZ 23 turn modified motors coming of a single 3300mah battery.

I totally recommend this set up for anybody with a TXT-1. I did have two 17 turn Venom motors in my TXT and yeah they gave it a fair amount of speed and acceleration (although I wasn't much impressed by the Venom's torque generally) but they did drain batteries like there was no tomorrow and also I had to leave the batteries for ages to cool down before charging them because they get so hot. It didn't add up to much driving action.

The Tamiya RZ or BZ motors are cheap (off ebay anyway) and are very well made (they also look good to in anodised colours). But most importantly they do offer a decent amount of speed and battery run time. On top of that if you use RV'11's or RV'15's with them you can also do a bit of slow speed crawling, which is always fun with the TXT. Put 17 turn motors in there and any slow throttle stuff will push even the RV-11's to the edge of what they were designed for - you'll see white smoke fairly quickly if you don't keep it at around full throttle, the big wheels and sheer weight of the TXT put a lot of demand on your ESC, even the higher rated ones.    

[rhenbelz]

Mobias makes some good points but I disagree on a few.

The TXT is already a massive truck, but it's not one you should really worry about weight on. People run these as crawlers with a single stock motor just fine. The truck is suprisingly efficient for its size. Batteries don't really weigh much in relation to the rest of the truck.

I would have to recommend my setup actually... a pair of no-maintenance 550 Mabuchi motors. $11 for a pair of new motors can't be beat, and they run fine at 7.2v or 14.4v. I run 14.4 and the power is nuts. I have a pair of GP3300 packs side by side in the stock tray and they never get even warm. Runtime is great, I'm getting about 15 minutes to a charge with really hard driving. Wheelies are too easy and I get plenty of speed with no handling issues. You could put in the motors and run them on 7.2v for a while, then upgrade your ESC and go 14.4v when you feel like it.

The TXT is just an awesome truck... it was made to take lots of power and does just fine with it.

 

[mobias]

When I was new to my TXT last year and was posting very similar questions to the main one posed above pretty much all the long time TXT runners who replied said to avoid a dual battery set up unless you were wiring them in parallel and going for masses of power like with a brushless motor set up.

I know different set ups give different drivers different experiences but I do believe that weight is an issue with the TXT hence the reason you can buy very expensive light weight chassis parts and axles for it. All that weight does after all accumulate and a second battery just adds fairly considerably to it. Also as i said earlier the handling issues are inarguable, the TXT just becomes even more top and back heavy, though you can get round the latter by reversing the chassis.  I don't think the TXT is industructable, there are a few weak points on it are only magnified by any extra weight. But of course this is an area where again as with any Tamiya RC different people have very different experiences.

At the end of the day it does depend on what you want from your TXT. If you just want masses of all out full throttle power then obviously certain options and certain considerations, like weight, kind of go out the window to a certain extent. For massive motors or brushless set ups you obviously  need two batteries and thats the end of the story. But personally I like a balance of power and crawling ability hence the set up i went for as mentioned earlier. The TXT is easily as much fun going slow as going fast, at least for me.     

[mymonsterbeetleisbroken]

Cheers for the replies people [H]

It sounds like the twin battery setup would be ok then, rather than pushing a single pack to near melting point. (i've had enough melted batteries in the past when using MSC's!)

I'll counter the weight issue by adding some spacers to the rear shocks. High speed cornering wasn't something i had in mind as i'm running the truck with 4 wheel steering - but its straight line speed is useless at the moment with the silver cans so thats really what i wanted to improve.

Have any of you changed the pinion size when adding different motors, or is the stock gearing ok even with faster motors? 

edit - I've just read your new reply Mobias - now i'm wondering which option would be best!

I like driving the truck slow too, but it would be nice to know that when i really open the trottle, the power would be there to make people say "wooh thats pretty quick for a big truck!"... or something like that [] 

 

 

 

[mobias]

If you do run two batteries then spacers on the rear shocks are probably a good idea. As far as the steering is concerned your TXT will spend a lot of time on its side or even on its roof if you run 17 turn motors with 4 wheel steering AND have extra battery weight up there. With 23 turn motors you can almost get away with it with deft handling of the steering. Depends on how much extra speed you really want.

edit If you're desperate for all out impressive speed and crawling ability then really the only option in an expensive brushless system. Like I said earlier if you try any prolonged crawling with big modified motors you'll have your TXT in flames fairly quickly, as i did last summer trying my TXT up a pile of rubble with 17 turn motors in it.

The Tamiya RZ's I've got in mine give me all the top speed I really want, they're noticeably faster than the stock 540's but I wouldn't kid you into thinking the TXT wheelies off into the horizon.

Anyway once you've got your second RV-11 you can have fun experimenting with different set ups and see for yourself which one suits. Venom 17 turn motors and Tamiya RZ/BZ motors are dirt cheap off ebay.

ps I've never changed the pinion of my TXT but its probably worth experimenting with, if only the gearbox of the TXT wasn't such a fiddle to get apart everytime you want to change things about... 

[mymonsterbeetleisbroken]

Cheers mobias!

I'll try a few different types of motors, it sounds likea good plan to me []

Taking out the gearbox is possibly one of the most boring tasks i've ever done on a tamiya. The last time i did it, i undone the 4 screws that fix the gearbox to the chassis, and then undone the driveshafts. the gearbox just squeses out under the truck. The only problem was putting it back in again [] 

I almost bought a modded emaxx of ebay last year just for its brushless system, but got outbid at the last moment. Brand new brushless motor systems seem overpriced to me.

I guess if speed got the better of me i could try and find one of those New Era nitro conversion kits for the txt-1 [] 

Thanks again for the advice [] 

 

[mobias]

You can actually replace the motors in the TXT without taking the whole gearbox out, the only thing you need is a very long screwdriver.  Simply remove the chassis bracing bar just below the motors then use your long screw driver to take out the screws that hold the motor plate in place. You'll also need to remove the battery tray to get at that single screw which is on the other side. Believe me I've had my motors out about a dozen times in the last six months, this is by far the quickest and easiest method.

[slivic003]

Hi  I was just reading your issue on speed and motors to use . I will say from my own need for speed issues on my trucks , the best way to go is brushless systems . They can be a bit costly but in the long run they are worth it . I use all novak systems . I have two 350 high lifts both with brushless systems . I put a novak 4300 ss system in one truck and the speed and torque was greatly improved . Also my runtime on a 3000mah battery is great . On my other 350 I put a novak crawler motor system in it . I am still working on the truck ( waiting on parts from rc4wd to come in ) so I haven't gotten to run it yet . If you want speed and a good run time go with brushless if you don't mind spending a little $ ! Also check with me sometimes , I just sold 2 brushless systems on ebay pretty cheap ! I have a ton of r/c parts !

[mymonsterbeetleisbroken]

You can actually replace the motors in the TXT without taking the whole gearbox out, the only thing you need is a very long screwdriver.  Simply remove the chassis bracing bar just below the motors then use your long screw driver to take out the screws that hold the motor plate in place. You'll also need to remove the battery tray to get at that single screw which is on the other side. Believe me I've had my motors out about a dozen times in the last six months, this is by far the quickest and easiest method.

I had to remove the whole gearbox last time round to ballrace it and service it, but yes a long screwdriver is the perfect tool to get just the motors out.[]

I had to use the quick method around a week after i bought my txt-1. The previous owner hadn't tightend one of the pinion grub screws fully, so one of the pinions came off! Luckily it was on the side of the gearbox that has a moulding on the inside for the mammoth dump trucks extra reduction gear shaft. The pinion was resting against it and was still attached to the motors output shaft. Lucky! []

 

 

[adam1973]

Another system you could try is the Ezilla set up, cheap ESC £40.00 (lhs price), motors off EBay about £10.00 each.