Big Rock The Fat Rock

[Rottster]

I know weight is bad, I used to drag race motorcycles and power to weight is key. But I also have 3 Jeeps and crawl here in Colorado and weight can be a good thing in the right place for the right reason. I got back into the hobby after I bought a friend a Traxxas for helping me move my shop and was amazed at what they are now capable of. I was totally blown away and we damn near put a hole in the wall of my new house, lol. 10 years later I picked up a cheap brushed Legeandary, broke a few parts, but it was (and still is) great learning tool.

Fast forward a year and here I am with a Big Rock BLX V3 and damn it was fast. I broke a bunch more stuff (all my fault) and started my build for my style of driving. I really thought the odd toe out on the front wheels out of the box was weird, but thought "OK, they know what they're doing" even though I'm an 35 year experienced mechanic/machinist, lol. Not so much. All great stories have a beginning and I'll start there to avoid any confusion.

At this point, it was all about body protection with the Traxxas roof rack and Kraton Wing.

 

[Rottster]

Another view of the Kraton wing mod and body trim.

 

[~Kaos911~]

Love the Big Rock! Mine takes a beating from me learning in the beginning and it seems to be the truck everyone wants to drive when I have it out at family events. So far I have only replaced a CVD due to slipper being too tight, a slipper assembly from it being too loose, replace a steering knuckle and glued a shock shaft back in the cup.

 

[grihn]

Weight isn't inherently bad, it just depends on what you're doing. As you already mentioned, lighter is better for drag (to an extent...too light is a thing), and added weight in the right places is excellent in a crawler. But, speed running is another place where some extra weight in the right places is a huge benefit. Look at Bonneville cars in the 1:1 world...most of them are pretty heavy and drivers regularly add 200-400 lbs rear bais depending on the condition of the flats (most of those cars are not AWD), and an off road basher is another place where some added weight can be a benefit to keep you closer to the ground over bumps and mole-holes if you aren't trying to jump it.

I like your Big Rock, that roof rack looks awesome. And welcome to the forum!

 

[SlooDon]

Big Rocks are certainly a blast. Enjoy it. I’m loving mine.

I have rigs, all for different uses like crawling, trailing and competitive crawling.

The Big Rock was my first, in awhile, “fast/basher” type truck and I’m hooked again!

 

[JKWoods]

The Big Rock is still my favorite go to all around basher.

 

[Heatwave]

Looking good! I love the kraton wing in the rear, really help with the look and makes it resemble an outcast! Glad to hear you're enjoying the hobby just as much as I am!

 

[Rottster]

Love the Big Rock! Mine takes a beating from me learning in the beginning and it seems to be the truck everyone wants to drive when I have it out at family events. So far I have only replaced a CVD due to slipper being too tight, a slipper assembly from it being too loose, replace a steering knuckle and glued a shock shaft back in the cup.

Everything I broke was a result of my poor driving skills, not the design itself. I love this thing, but me being me, I just can't leave well enough alone.

Weight isn't inherently bad, it just depends on what you're doing. As you already mentioned, lighter is better for drag (to an extent...too light is a thing), and added weight in the right places is excellent in a crawler. But, speed running is another place where some extra weight in the right places is a huge benefit. Look at Bonneville cars in the 1:1 world...most of them are pretty heavy and drivers regularly add 200-400 lbs rear bais depending on the condition of the flats (most of those cars are not AWD), and an off road basher is another place where some added weight can be a benefit to keep you closer to the ground over bumps and mole-holes if you aren't trying to jump it.

I like your Big Rock, that roof rack looks awesome. And welcome to the forum!

Got that right, any weight I add I try to keep low as possible. Even motorcycles at Bonneville add weight low and to the rear (on the rear swing lever) for stability. I'm generally ripping up grass and dirt and any jumping I do is just for distance, not skate park stuff.

Big Rocks are certainly a blast. Enjoy it. I’m loving mine.

I have rigs, all for different uses like crawling, trailing and competitive crawling.

The Big Rock was my first, in awhile, “fast/basher” type truck and I’m hooked again!

It's really a "do anything" rig!

Looking good! I love the kraton wing in the rear, really help with the look and makes it resemble an outcast! Glad to hear you're enjoying the hobby just as much as I am!

Thanks! I did quite a bit hand trimming to make it right in my eyes and yeah man, this is a blast.
Next 2 upgrades were Team Associated ball ends and Lundsford Titanium turnbuckles.

 

[Rottster]

Next were some typhon/kraton 6s shocks, I forget which, lol. getting old is fun. I am running 60W in each.... Spring rate is a little high, but time will tell.

M2C motor mount is a must do...

 

[Rottster]

Did a little differential work today.... Gear/oil check. Pinion and ring gears still look absolutely perfect, changed the oil in the diffs to 60 front and 30 rear..... I'm big on going in a straight line, I'll let you all know how it works out. Did a bearing check..... All good and also checked the slipper clutch. It was 1 turn out from the factory, backed it out another half turn.

Got some Pro-Line Badlands MTX HP Belted pre-mounted tires with 2 piece wheels with the 17mm insert. The difference was only a 3 to 4 grams, no-joke.

 

[Rottster]

Well, I had to do it.

 

[Rottster]

Added some more weight Fabricated some shock bushings and added steel/aluminum CV driveshafts.

Thought I'd give this a try on the axle sliders, CV joints and turnbuckle ends. Works great on my other "stuff".

 

[Rottster]

Did this to save the wing from further abrasion.

 

[Specialj79]

It looks like you can drive it pretty worry free of any breakage.Nice work on that there!I should of did some upgrades before putting the 4s in mine

 

[Rottster]

It looks like you can drive it pretty worry free of any breakage.Nice work on that there!I should of did some upgrades before putting the 4s in mine

We'll see as far breakage goes... It always comes down to the weakest link and I'm trying to keep it to the cheapest and easiest link to replace.

 

[Rottster]

Added in a 35 kg servo, 25 spline Arrma servo saver and set endpoints on the stock SLT3 transmitter. Interesting upgrade as the servo saver decided to blow up on me and that spring is STRONG. I found a tip on the internet and it saved me hours of mucking around to get it back together. Why would I go with such a strong servo on a 1/10th scale? Because I'm anticipating a move to a Radiolink transmitter with a 7 channel receiver... Stability and ABS capable as well as a Castle Mamba X Monster with an adjustable BEC voltage.

Now the next question you may ask is "Why in the world would you go with a Mamba?". I can answer that, the answer is I'm going with a Castle 1515, 2200kv motor, suitable according to their spec chart for 1/10 to 1/8 RC cars 15 lbs and under with battery and rtr. I'm at 9.2 lbs with tires and a battery so I'm on the lower end which should keep temps down and is coincidently the same advertised weight as the new 4s Arrma Kraton. Hmmmm.... I did buy a bunch of mod .8 pinion 5mm straight shaft gears, so this should be a fun experiment. Plus a set of belted silver Hoons for the street, lol. I know it's all about motor temps and I have some Fluke infrared guns at my disposal. I imagine you all will see me on the destruction page again, but what the heck?

 

[Rottster]

So what are my goals with the Fat Rock? A durable basher on 3s, insane basher on 4s and 70 to 80 mph on 6s with Hoons. Obviously with a battery/pinion/tire change for every scenario.

 

[Rottster]

 

[Rottster]

The Castle 1515 2200 Kv motor fits... At least with a M2C racing motor mount. I'm currently running a 21/57 but tested a 26/57 and there is plenty of room for proper gear lash. On 3S, 22/57 keeps me about stock in regards to top speed. Obviously I'll drop my pinion down on 4s.

 

[Rottster]

Got the EC5 connectors soldered on the Mamba Monster X ESC, no big deal. I actually went a little overboard on the solder in fear of everything I've read about soldering these motor connections and just used a little flat file to nip off the excess. I've been soldering since 1978 and it's no different. A good soldering station with "hands" never hurts either.