Mad Bull Build

[ALEXKYRIAK]

Will keep the text light, just some pics of my first Mad Bull Build. Not finished yet but I love this car, love the stance, the chunkiness, the width, the fat tyres, the streamlined skinny body. Final colour scheme will be black, silver and red. Will fit new shocks/dampers, have already fitted ball race bearings, steel pinion, and Sport Tuned motor.

 

Wild Willy 2 wheels and tyres:

 

Front suspension on (it feels so wibbly!)

 

Rear gearbox with Sport Tuned motor fitted:

 

Front and rear suspension fitted:

 

Savox Servo:

 

Wheels fitted:

 

 

 

 

With body fitted:

 

 

 

 

[ALEXKYRIAK]

Ok, so I attempted painting the shell. TS Black. Sanded and "keyed" it, as per some tutorials online. Was using 300 grit paper, finest I could find. Primed it with White, 2-3 coats. Not sure if I've done this wrong but after 3-4 coats of the Black I can still see the effects of the sanding. I might have b*llsed this up bigtime.... might've been the fumes getting to my head.. ...  will post same pics I a few days.

[ThunderDragonCy]

I'm no expert having only painted one shell but 1200 Grit is incredibly fine. Almost feels smooth. 300 might have been too much but wait for someone with more experience to confirm. Mad Bull shells are less than £7 at modelsport UK. Might be worth getting another and just using that one as a runner basher shell?

[ThunderDragonCy]

PS - I found 1200 Grit on eBay. 

[Darat76]

300 grit is coarse, and used for shaping, you should be in the 1000's for keying a body, which is wet and dry paper

the number (300 in your case) refers (from memory) to the grain count per square inch of paper.

 

You can still save this body, basicly you need to start with around 1000 grit wet and dry, and wet sand the paint with a block until you get a smooth finish, you will likely burn through to the primer, just try not to burn through the primer to the body, if you start seeing primer and the paint surface isn't smooth, start going up in grit count to 1600 plus, keep an eye on the primer, if you burn through it, clean the body, and lay a few more coats of primer and keep going until your happy with the surface, then apply the color, polish till your happy, and enjoy

 

[Effigy3]

I use ultra-fine grit sanding sponges.  I find the sponge works into the crevasses of an R/C body quite well.

 

[ALEXKYRIAK]

Thanks guys, very much appreciated. Gave it a another look this AM. Still looks as bad as it did last night... no overnight curing magic...! This one is well and truly being chalked up as a total noobo mistake. I very much underestimated the effect this sanding would have on the final finish.

 

I'm also glad I got this mistake done on this shell and not the more complicated Monster Beetle that is next in line in the build list.... I will try to save this shell, but will probably also go for another if they're as cheap as that at MS. Someone said somewhere on this forum how they feel spoiled by the easiness and instant perfection of lexan when compared to hard body.... I'm certainly with you on that one.

Cheers.

[ALEXKYRIAK]

So I am going to attempt to fix up the suspension on this car using the sloppy steering improvement mods described elsewhere in this forum.

Will heat shrink the tips on the ends of the suspension arms. Steering mod will come later with ball cups and ball studs, just need to get the parts  

For the shocks, I can put on DT-03 CVA damper set 54567, the CVA short and mini shock II set 50529/50520, or use the kit shocks from the re-re Monster Beetle.  

[TwistedxSlayer]

I used DT03 shocks setup but found the springs waaaaaaaay to soft. I used TT02B springs on the front and the DT03 springs on the rear. With hind sight ill be going with DF02/03 shocks and springs if i need to get some more for a MadBull.

[wilsonian]

This is how I ended up fixing the steering

 

 

I had to dremel a little away from the tower and tub so it wouldn't catch.

 

[ALEXKYRIAK]

On 29/04/2017 at 7:25 PM, TwistedxSlayer said:

I used DT03 shocks setup but found the springs waaaaaaaay to soft. I used TT02B springs on the front and the DT03 springs on the rear. With hind sight ill be going with DF02/03 shocks and springs if i need to get some more for a MadBull.

Oh ok I might give the DT-03 set a miss then!

However I do have two spare Hotshot springs lying around and a bottle of Tamiya Blue damper oil. Could try using these in front but this may be way too hard...

I was reading another Mad Bull thread (really detailed and very useful but cannot remember who wrote it!) and he was saying that the rear should be super soft to help in landing the jumps. He advocated 100cst/10wt damper oil  

Guess I'll go for the cva mini shock set II and cva short shock set II for now.

[TwistedxSlayer]

Ive just got normal tamiya oil in mine. Unsure what wt that is and it works great

[ALEXKYRIAK]

Hope this is still current: 

[ALEXKYRIAK]

So I had a go at the heat shrink mod to the pivot tips at the ends of the suspension arms where it mounts to the tub.

Not sure if i've done it right or as per others but this definitely removes some of the play or slip that the arms exhibited. They are now firmly planted in their pivot holes. 

This is the heat shrink I used:

i cut small strips that matched the length of the ends of the arm pivot tips. The rear tip of each suspension arm is slightly longer than the front tip:

This is the front tip with the tube heatshrunk into place:

Arm on the right done with heat shrink, arm on left not done. Definite difference between them, no play at all on the right:

Both completed:

Haven't driven it, and haven't driven it without the mod either, so I won't be providing a comparison commentary, but this definitely helps reduce some of the sloppiness in the front suspension when manually moving the arms around  

Next up will be the springs/dampers and then the steering link mod.

[Dangerseeker]

steering mods, i dont know which solution is better...

 

 

 

[TurnipJF]

The heat shrink mod works well but the heat shrink needs to be replaced after a while as it wears. However it doesn't weaken the car at all and is fully reversible.

 

The ball connector mod also works well and is more resistant to wear, but you need to either grind away part of the chassis and shock tower or drill a new hole in the bellcrank, weakening the parts somewhat.

 

Personally I prefer the heat shrink mod. A new piece of heat shrink every year or so isn't going to break the bank, no parts are weakened, and should the Mad Bull ever become a collectable classic, the car can be reverted to stock form easily.

[Macinnis]

I'm trying to talk a friend into buying a mad bull.  Can anyone tell me if square hardcase lipo fit the chassis or do they have to have the rounded style?

[TwistedxSlayer]

@Macinnis

They gotta be the round type. You could move the electrics and modify the chassis to take a square type and lay it in the centre of the vehicle rather than the rear where it normally lives. Its a little more messing around but it is doable.

[ALEXKYRIAK]

So I've now mounted some shocks, put on the DT-03 with Tamiya hard oil on the fronts and regular oil in the rears. Feels more planted, yet to run it but will drive it before switching out to test a couple of other possibilities. 

 

[ALEXKYRIAK]

Also had a go at the steering link mod. I used some of the DT-02 turnbuckle kit, and the thread of a 3mm screw (I cut the head off using pliers to leave just the threaded rod). This has reduced slop by 50% but there is still some play in it. Compared to stock with this and the above modifications, the Mad a Bull feels alot more 'tight'. 

 

Turnbuckle kit from DT-02, kit part number 53828. I used two ballstuds and two ball cups from this set. ( A bit of a pricy mod component when you consider cost ratio of items used out of this pack...!)

 

 

Servo horn with screw and ball stud. 

 

3mm drilled hole to steering arm. Hope it's not too asymmetrical or weak... time will tell:

 

Ball stud and nut spacer on the steering arm:

 

All connected up with ball cups and threaded rod connector:

 

Will post back once I've run it to see if it's a success or a noobish pile of inept rc modifcationing....!

[TwistedxSlayer]

Looking good Alex

[ALEXKYRIAK]

Thanks TS. 

 

Just wondering a little bit more about the fact that there is still a little slop or play (although much reduced from before the mod), I tried to stiffen the connection between the servo horn and  the steering arm by adding the stock steering rod back in. This effectively triangulates the connection, or braces it. I made a minor tweak to the rod to avoid it clashing with the new screw head on the servo horn, bending the end of the steering rod up. 

 

The steering action now has zero play in it, feels really tight. I plugged it into the servo tester and it's got a great action. The steering rod and the new turnbuckle rod do not clash with each other  

Again, usual caveat of I'll judge its success or failure after running the car....

 

[GregM]

Nice! Is there still clearance between the rods and the servo housing for full steering lock to both sides?

[ThunderDragonCy]

Nice idea with doubling up the steering rods. 

You can buy ball nuts and those rod ends separately if you search for the part numbers so you don't need the turnbuckle kit next time. I got some m3 threaded rod off ebay for £1.20 for 30cm. 

Are you going to be able to use the steering turnbuckles from the e dt02 set on the mad bull?

[ALEXKYRIAK]

9 hours ago, GregM said:

Nice! Is there still clearance between the rods and the servo housing for full steering lock to both sides?

Actually at total lock on the servo tester the ballcup very slightly touches the corner of the servo. I will play with the setup to mitigate this. 

 

7 hours ago, ThunderDragonCy said:

Nice idea with doubling up the steering rods. 

You can buy ball nuts and those rod ends separately if you search for the part numbers so you don't need the turnbuckle kit next time. I got some m3 threaded rod off ebay for £1.20 for 30cm. 

Are you going to be able to use the steering turnbuckles from the e dt02 set on the mad bull?

Yes I should have done it your way! However yes I do plan to use the steering turn buckles, will have a go at putting them in next weekend. 

All in all the steering and suspension mod seems to be turning out quite nicely. 

I will peruse the forums but am also interested in adding proper steering arms onto my re-re Hornet.