Big Rock Big Rock “Bone Crusher”

[walking_target]

Arrma Big Rock v3 which was new to me a couple of weeks ago second hand. It was an absolute bargain at £180 GBP - they are going for £300+ over here.

So far, it has:

• Hobbywing EzRun 4000kv motor
• Typhon shocks all round fitted today - which needs some nitro fuel tubing to stabilise

I think it needs some different tyres as it is quite squirmy at speed and the pivot balls are shot and need replacing which is next on the list.

Anyway, love it as will my son which is what this one is aimed at.

 

[parcou]

Enjoy...nice....!

MX Badlands 2.*" are a popular pick for this rig and gives it a nice widen stance... A lot of us are running the Typhon shocks on the Big Rock but the stock springs are too soft. The factory shock springs are even stiffer than Typhon....so I would suggest changing the springs first this rig is heavier and as stated the springs for Typhon are too soft for this. Lots of post about it...

Enjoy...

 

[walking_target]

Changed the shock oil to something a little heavier today which I think will make a difference.

Have also changed all of the pivot balls throughout which has tightened everything up - was very sloppy and to be fair, the guy I bought it off said it needed doing.

 

[walking_target]

Couple of nice improvements today:

Have done the Outcast wing mod which looks really good and was easy enough to do.

Added some lid skids.

Finally, changed the rear Typhon shock springs to Talion versions which are a bit harder. Made a huge difference to the handling

 

[Gosraider]

Yo,

I love big rock, this is my next purchase. The hold is beautiful

 

[walking_target]

Too much?

Prepping for some replacement wheels and tyres…

 

[palmryde]

Nice set up I have a couple questions about your upgrades, own one myself although stock.
1. Typhon shocks all round fitted today - which needs some nitro fuel tubing to stabilise, where did you use/put the tubing?
2. Typhon 6S shocks springs on the rear need stiffer springs? Do you have the p/n for the Talion rear springs. Are the fronts ok with the stock front springs? 50 wt about right?
Thks

 

[walking_target]

where did you use/put the tubing?

Top of shock where the screw goes through into the shock tower. I ended up using the servo rubbers instead which work really well - no slop so pleased with that.

Do you have the p/n for the Talion rear springs.

Yep - I am using AR330501 which are the 5.4lb version which seems to be great. Much improved over the Typhon ones.

Are the fronts ok with the stock front springs? 50 wt about right?

Yeah the fronts seem to be fine. I am using 1000CST shock oil which is the Arrma standard weight.

 

[Mycloud]

Too much?

Prepping for some replacement wheels and tyres…

View attachment 170430

View attachment 170431

Nice big tires! What tires did you use?

 

[*420+3RC*]

Nice truck! I like what your doing with it.

You can use the Axial bushing for 7.5mm cap. I run 60 wt in my shocks. I have ZD Racing 115mm in front and stock rears. Sets the truck up high. Badlands mx 2.8.

 

[walking_target]

Wheels on today and took it for a cheeky lunchtime bash to see how they go - much more stable than the stock wheels.

 

[*420+3RC*]

Nice set up I have a couple questions about your upgrades, own one myself although stock.
1. Typhon shocks all round fitted today - which needs some nitro fuel tubing to stabilise, where did you use/put the tubing?
2. Typhon 6S shocks springs on the rear need stiffer springs? Do you have the p/n for the Talion rear springs. Are the fronts ok with the stock front springs? 50 wt about right?
Thks

View attachment 170433

You can also get axial bushing for 7.5mm shock caps.

 

[walking_target]

Having some overheating issues so this is Stage 1 - 3D printed ESC mount which allows a 30mm fan on the BLX 100 which has a bit more blow than the stock 25mm.

Then have some motor fan mounts coming which will allow 2 x 30mm fans - that’s Stage 2.

 

[*420+3RC*]

Having some overheating issues so this is Stage 1 - 3D printed ESC mount which allows a 30mm fan on the BLX 100 which has a bit more blow than the stock 25mm.

Then have some motor fan mounts coming which will allow 2 x 30mm fans - that’s Stage 2.

View attachment 171253

View attachment 171254

View attachment 171255

View attachment 171256

Your the first person, that I have seen anyway, make a mount for the blx 100. That's awesome! Have u run tested them? If yes and it worked......u happen to be selling any??

 

[walking_target]

Your the first person, that I have seen anyway, make a mount for the blx 100. That's awesome! Have u run tested them? If yes and it worked......u happen to be selling any??

I can’t take any credit, it is just a print of this file that a local chap did for me:

https://www.thingiverse.com/thing:4913202

I have mounted it and fired it up and the air flow is considerably greater than before but I haven’t run it yet. Testing report to follow!

Need to get the motor cooling sorted first

 

[*420+3RC*]

I can’t take any credit, it is just a print of this file that a local chap did for me:

https://www.thingiverse.com/thing:4913202

I have mounted it and fired it up and the air flow is considerably greater than before but I haven’t run it yet. Testing report to follow!

Need to get the motor cooling sorted first

Ok thank you. Yes please update. I'll have to find someone to print me 1. Our library has a 3d printer......but do I take my own material in?? Total dumby in 3d prints

 

[walking_target]

No idea mate - all I did was search facebook marketplace for a 3D printing service…

 

[walking_target]

Added the motor fans and a 3D printed steering guard to help prevent stuff getting in there which jams the steering up

 

[walking_target]

So, the cheap fans I used initially were, to use a technical term, shite.

Replaced with Rocket versions and we are much improved. Hopefully, this will help this beastie remain a little cooler.

3 x 30mm fans - one on the ESC and two on the motor.

Other than what I have done, I am not planning on doing a massive amount more on this truck till I break something.

Here’s the fans:

 

[walking_target]

The older child has decided this truck is going to be called “Bone Crusher” which I quite like.

Tinkering with motor options for this truck - the HW 4000kv is a bit high and I think it is missing some grunt. Considering a cheap Surpass one which have the same specs as stock but for a fraction of the price.