Thunder Tiger MTA4 S28/MGT 4.6 Brushless build (with centre diff) Updated 25/03/14

[MAZ]

Hi all, I've been wanting to do a brushless monster truck build for awhile and today I picked up a Thunder Tiger MTA4 S28 monster truck

First impressions - its bigger than I thought which is pretty cool, the servo seems a bit exposed being at the bottom of the chassis and I'm really not liking the gearbox.

I'll be cleaning it up over the next few days, checking the diffs and taking out the gearbox completely

So yeah, that's it for now, any advice, tips etc will be greatly appreciated

Cheers

Edited March 25, 2014 by MAZ

[MAZ]

Just had a quick clean up and took out the gearbox and motor

[MAZ]

With a truck this size I thought these would be a bit more beefy?

[jari]

Nice. Another MTA4 brushless...

 

I've got one ready to do, just no time to do it got the motor mount, a 4082 leopard and ezrun to go in it, an s50 gearbox with FOC kit and battery tray. So all the bits ready, just no time:( Still lots of detail, and don't know what I'll do for wheels, tyres and shell.

 

 

As you point out the hex are a little bit small... I can't figure out what to do with them on mine. Either leave as is and see how long they last... the axles are long enough to get two nuts on, so you can tighten and threadlock them on.

 

or try to replace.

 

The axles are only 6mm, and the bearings 12mm outer, 6 mm inner. I think the common size for 17mm hex buggy style is an 8mm axle. and the only bearings i can find that are 12 outer, 8 inner are 3.5 width. Tiny and probably wouldn't survive sustained use. 

 

There used to be some good conversion threads on monstergt.com- but that seems to have disappeared and been eaten by ultimaterc.com. A common mod there was to use the RPM knuckles and drill out to 16mm, then combine with 8mm axles of your choice and 17mm buggy hexes. The rpm knuckle bearing is 15 outer, 6mm inner. 

 

Another option is ST-1 knuckles - bigger bearings, but changes the geometry and needs longer driveshafts or cut down the arms. 

 

Or go with tmaxx knuckles.

 

I've got one thing left to try on mine - I got some thunder tiger 17mm buggy hex  which fit a 6mm axle. They *nearly* fit so with some grinding might be made to fit stock 6mm axles.

 

so what motor/esc is going in yours?

 

and are you keeping gearbox or going to do a centre diff?

Edited August 18, 2013 by jari

[jordan_bench10]

savage 17mm fit staright on these guys 

[MAZ]

I first got interested and in doing a monster truck conversion when a fellow member on here said they were getting an mta4 specifically to convert to brushless. I had a dig around, asked a few questions and one thing that I instantly didnt like was the gearbox, especially the s28's as it has plastic gears.

Having picked up my mta4 yesterday and seeing the bulk of the gearbox it just reinforced my view on the gearbox I dont want it in there. With that in mind, I figured I'd try putting in a centre diff - probably one from a hyper 7 or the ST (I have both)

I havent got a clue how to fit it but I'm hoping to find a way

As for the brushless set up - probably an Xerun 150a esc and a leopard 4282 motor (not sure what kv to go for yet though)

[ollietheox]

Just to add a note about the hex's, you can also get 23mm direct replacements.  Pretty sure they have them on the MS website.

[MAZ]

I've been having a quick look on modelsport for parts, nothing special but I was surprised to see that the diffs were around

[DreXeL]

Yep, the diffs are silly money. My son has one and has been running RWD for a long time due to blowing one of the diffs and not buying another one due to the cost.

[Mr. Doktor]

http://www.ebay.com/itm/MGT-8-0-DIFFERENTIAL-front-or-rear-gearbox-25081-25082-25080-Associated-20502-/370851907704?pt=Radio_Control_Parts_Accessories&hash=item56587f0878

are MGT 8.0 diffs the same? they are much cheaper on ebay...

[chrisreilly]

Strange and great, came here to make a topic on this very subject. I am sick and tired of my Nitro S28 and Nitro in general, i love taking the car out, for fun, but the constant stopping and starting and the odd breakages here and there is spoiling the fun for me.

 

I REALLY want to also convert mine to brushless, however i have ZERO idea how to do it and what to buy, is there any full kits available to buy? 

 

I suppose the couple shells and parts that i would no longer need would fund the conversion? 

 

Any help appreciated. 

 

Thanks

[jari]

mgt 8.0 diffs are i believe the same.

 

the diff itself (not the case) might be shared with other team associated cars and trucks. - MGT diffs will be the same though no easier to get hold of. Might be the case that the buggy and truggy diffs are the same? We need someone who has both to take a look!

 

Anyone really needs a diff I have spares - I have a spare truck for this exact reason. Or buy an ebay special and break one yourself. 

 

Great thing about this truck is all 4 corners are the same.... and both diffs the same. means a spares truck can go a long, long way. Not like my Hyper TT where the front and rear arms and left/right are different... grrr..

[MrPug]

The simplest conversion (and the one I did) is to find a used s50 and convert it to forward only and lock it into second gear. Then you just need to buy a mount and that is basically it. The stock s50 gearbox is up to the power and works very well. The s50 also has 23mm hexes rather than the 14mm s28 ones.

[Tug]

Bubbles did a nice conversion, you could try PMing him for advice, or search for his thread, "The Bruised Carrot".

[DazzaClio]

Bubbles did a nice conversion, you could try PMing him for advice, or search for his thread, "The Bruised Carrot".

Yeah which I bought and finished off.

Op there's a few pictures etc here down page 15 if you want to look:

http://www.msuk-forum.co.uk/topic/71808-brushless-mta4-brand-new-slash-4x4-and-another-new-slash-4x4/page-15

Thanks.

[MAZ]

just trying to get an idea of what type of centre diff will fit and work in the mta4, got a youtube clip here:

its only short but if you pause it you can see it quite well

 

 

I'm just wondering if I could do something similar with a hyper 7 diff and a brushless mount like this http://www.modelsport.co.uk/absima-brushless-conversion-kit-for-ethnic-hobao-hyper-7-ansmann-virus-terrier/rc-car-products/369638

Edited August 19, 2013 by MAZ

[jari]

the vid you link to is talked about on ultimaterc.

http://ultimaterc.com/forums/showthread.php?t=177288&highlight=center+diff

The guy has made a few of the mounts and sold them on.

 

He uses the design work from this aussie thread:

http://www.ausrc.com/forum/showthread.php?29783-Another-Associated-MGT-8.0-brushless-conversion

and video:

Very much the high tech approach.

 

 

Whereas this is the other end - more low fi craft with what's at hand approach!

Mega thread on rc-monster:

http://www.rc-monster.com/forum/showthread.php?t=25581

[MrPug]

The new Team Associated Rival (their version of the brushless MGT) uses a centre diff, so you could maybe get some of those mounts/centre diff. I did have a quick look and the chassis is different, so you'd probably have to cut it and drill new mounting holes etc.

Edited August 20, 2013 by MrPug

[MAZ]

I've just joined the UltimateRC forum so I can see whether that guy has some more motor mounts - although I cant actually pm him yet as I'm on post validation to begin with. Bit annoying....

[MrPug]

Ha, I only just realised I've already told you about the Rival in a PM... doh

[MAZ]

Ha, I only just realised I've already told you about the Rival in a PM... doh

Yeah but now everyone knows so it could help in the future

[MrPug]

Yeah but now everyone knows so it could help in the future

Yeah hopefully. I have an affection for factory builds. :-)

Sent from my Nexus 4

 

Edited August 21, 2013 by MrPug

[MAZ]

*update:  I've joined another forum  - ultimate RC to get in touch with a member about a brushless motor mount for the mta4, i think the mount looks fantastic

 

Hopefully he'll get back to me soon on whether he still has/makes the brushless mount mounts

 

[chrisreilly]

How much is the conversion set to cost you? 

[jari]

Been looking at the CVA's again yesterday and tonight.

 

The associated rival is an electric version of the nitro mta/mgt, with centre diff, and not sure what other differences (longer chassis?)

 

The CVA from the rival look like they are identical to the later MTA S50 CVA. i.e. they are 6 mm axle, slightly beefier than the s28 axle, and will take the 6mm hex. Breakers are starting to carry them on ebay.

 

The center diff is starting to appear too.

 

CVA:

http://www.teamassociated.com/parts/details/25768/ - gives the associated part number. 

wheel spin have them:

http://www.wheelspinmodels.co.uk/i/194674/?gclid=CMfBp7vJj7kCFfLHtAod_0gAcw

 

a few found on ebay. AMain have them too.

 

going rate is $38 a pair new. then combine with the hexes.

 

On the Center diff:

 

found one:

http://www.ebay.com/itm/Associated-1-8-Rival-MT-TRANSMISSION-CASE-GEARS-Bevel-Center-Differential-/370852462670?pt=Radio_Control_Parts_Accessories&hash=item565887804e

 

dollarhobbyz - must be a breaker?  $40 plus shipping.

 

not sure that the rival diff is the right way to go though.