Mad Bull (first Tamiya build)

[briscaF1 71]

Hi all,

Something arrived today...surprisingly quick as I expected it to be snailed. Rubber capped ball race kit arrived on the same day, too.

Progress may be a little slow as my son wants to assist in the build. Since he's 4 and a half, work may be confined to weekends but I'd like him to understand the process and I doubt it will take long to put together.

More pics to follow...

[Nitomor 2122]

Excellent, looking forward to it.

[Theibault 1535]

Sweet! Hope you guys have fun building and running this.

[Badcrumble 4201]

Enjoy! I can't wait until my son is old enough to really get involved in a build.

At two he's already fitting chassis halves together and taking a keen interest. 

Not too long until the weekend...

[Effigy3 1267]

Awesome!  Start 'em out young I say.  Sure do love build threads.

[briscaF1 71]

Happy that when I got in from.work last night, the first thing he asked to do was to build the car.

He had a look at the manual and scratched his head a bit which is good as he was thinking.

I think I'll cut out/trim most of the parts (we've let him properly saw stuff for a while but a craft knife is maybe going too far) and he can screw them together.

I notice that the steer tower isn't lubed. I can get this silicon based grease from work (in pic) but is it a good idea to apply a small amount to these swivels etc? Or will it be a dirt magnet? The grease is thick in application but thin when warn.

Will keep it coming....

[GregM 1109]

You can use a very thin film of grease. I'd suggest either the supplied small grease that came with kit, or Tamiya cera grease HG. Make sure to check for wear and dirt over time.

The suspension arms should be left dry.

[briscaF1 71]

Picked my lad up from school this afternoon and his first words were...."Can we work on the car when we get home...?"

Began to solder my tagged battery pack last night but the batteries in a "brick" config won't fit in the MB so have unsoldered to make what I'd call a stick (2 lots of 3). I'll do that later to avoid any burnt little fingers.

The build has started in earnest. My son particularly likes measuring things and reading the numbers off the calipers.

 

[briscaF1 71]

No grease on counter shaft - am relying on the bearings.

Below is the gearbox before the screws are tightened up. Rubber ended bearings in place.

First time builder so I made a mess of mixing the bags of screws up...that'll make things interesting later on...but I hope not. The calipers should help in that regard.

[Nitomor 2122]

At each step is a key of the items needed, the scale is 1:1 so just match the screw up against the key, if it is drawn white it's a silver screw, and if solid filled it will be a black screw.

Great to see your little one is getting into it, how cool for you both...

 

[briscaF1 71]

To be honest, he did say he was bored during the initial part of the gearbox build.

He's gone to bed now with strict instructions for me to carry on. So it's pint and radio on in the kitchen time. Just like the 1970s..!

[TurnipJF 9190]

My Mad Bull had an addendum with the instructions indicating that the gearbox should be grease-sealed around the front where the motor goes. Might be an idea to do the same?

[briscaF1 71]

There's not much grease so I may end up doing that with some of that ABS sensor lube I have which I think is zinc based.

[briscaF1 71]

The diff is a bit rough. It spins but it's surprisingly noisy!

[briscaF1 71]

Also, is there much point in running the motor in? I used to do it in some water but that was 30 years ago.

Is it required these days?

[Darat76 265]

Were you spinning the diff with the gear box screwed together? If so did you fit the shim plates between the large bevel gears and the diff cases? 

As for motor running, some say yes, some say no. For me I attach new silver cans to either my dremel or drill and just spin the shaft while doing some surfing or researching on my computer, that allows the commuter to wear down a better contact patch in the brushes before putting power through the motor, once in the car gentle use of the throttle, brake, and reverse for 1 full pack to finish bedding the brushes if I want max life and performance from a silver can. 

With a new brushless motor I'll run it at no more than half throttle on a 2S lipo (so voltage to the motor is 5v or less) for about 5 mins, after that they get hammered lol 

[briscaF1 71]

I did fit the 9mm shims and dabbed them with some grease. In fact, I put quite a bit of grease inside it. 

I was spinning it with one half shaft in. Now it's in the gearbox with both shafts in it feels smooth. Noisy but the gearbox casing acts like an echo chamber. I think it's OK - just never built a car with a diff before because the oval stocks I raced had a solid rear axle.

I guess these motors are fairly cheap to replace and I'm not racing it so I'll leave it in terms of running it in. I'll just take it easy, as you suggest, for the first pack.

Cheers 

In terms of this grease seal at the motor, there is a cardboard shim between the motor and gearbox. Is this a Tamiya mod so grease is not required ? I didn't see an addendum anywhere.

[TurnipJF 9190]

The cardboard bit is a heat shield to stop the motor from melting the gearbox plastics if it gets too hot. No grease needed there.

 

The addendum refers to grease between the gearbox halves to stop dirt/dust getting in through the small gap that is left between them when they are put together.

[briscaF1 71]

Ah, I see. I didn't see anything about that in the instructions.

I did grease the seal but didn't use a lot. Just a smear along the edge.

Tagged battery pack has been re-soldered and taped up - it even fits in the MB battery carries which is a bonus. Radio gear, ESC, steer servo tested on the kitchen top.

Looking good so far. He'll be pleased that it runs, I think.

Then he can help me put the guts in now all the hot irons etc have been removed.

[briscaF1 71]

Battery pack isn't my finest work but it'll have to do

[Nobbi1977 1793]

Looking good. First upgrade is CVA shocks followed by a LiPo pack.

[briscaF1 71]

I think I'll run it with the standard ones at first just to see what they're like - serves as a good base for comparison, too.

But, when the time comes, are there any recommendations on the make of CVAs? Just want something functional and maintenance free...

Also, there is a mod for the steering on this with the ball caps etc. Is there a min thread length for the balls or will "standard" ones suffice? If I order some stuff, I might as well do it all in one go.

LiPo I'm a bit nervous of for the moment particularly charging. I suspect it's no more risky than charging a laptop or mobile up but that can perhaps wait a while since I have two NiMh packs to go at.

Thanks,

D

[Nitomor 2122]

Nice work, now clean that mess up before the missus starts lol!

ps. Lovely solder station, my mates dad had one of those weller temp controlled solder stations but I couldn't find that model when I was looking so ended up with aoyue or however its spelt!!

[briscaF1 71]

I had the old faithful out before the Weller - an old RS iron with a tip that you could shovel coal with.

Think I nabbed that Weller when they there throwing about 30 into the skip. If only I'd rescued the lot .... They'd be worth a few quid now.

Not familiar with the make you say - are they good?

Decided on a colour scheme - Gulf livery. Light blue with orange stripe as it just happens to be the same as. the colour scheme on a 'Frozen' character bag he likes.

Although that could easily change yet!

[Nobbi1977 1793]

16 hours ago, briscaF1 said:

I think I'll run it with the standard ones at first just to see what they're like - serves as a good base for comparison, too.

But, when the time comes, are there any recommendations on the make of CVAs? Just want something functional and maintenance free...

Also, there is a mod for the steering on this with the ball caps etc. Is there a min thread length for the balls or will "standard" ones suffice? If I order some stuff, I might as well do it all in one go.

LiPo I'm a bit nervous of for the moment particularly charging. I suspect it's no more risky than charging a laptop or mobile up but that can perhaps wait a while since I have two NiMh packs to go at.

Thanks,

D

Sticking with the budget nature of the model I fitted the DT-03 hop up pack dampers.

standard balls work well. I used the hi torque servo saver if I remember, this comes with spare balls that are useful