Big Rock "MONSTER" Big Rock v3 Poland

[LK80]

Hello Arrma Family!

I want to introduce my Arrma Big Rock.

It's my first RC car ever (excluding cheap toys with 0/1 steering) - when searching for the specific model to buy, I have walked this path:
1. Maverick Quantum+ Flux [inexpensive(+), good looking(+) but a bit fragile(-) I gave up on it seeing a lot of YT videos with destroyed trucks after few minutes of run]
2. Traxxas Hoss [2x price of Maverick, much better durability(+), TSM(+) but not impressive in jumping/flips (-)]
3. Arrma Granite [1,33x price of Maverick, durability at Traxxas level if not better(+), better jumping/flips performance(+)]
4. Arrma Big Rock [same price as Granite, ~same durability (+), better handling (+), jumping/flips performance worse than Granite, but better than Hoss]

So ended up with Big Rock v3 as a first RC to learn driving, make mistakes, giving a hard time to the truck.
I believe there are not much of better choices, if any...
(and not only myself but also my 8yo son will be driving this monster)

What I added to stock truck is:
1. replace wheels (already in LHS) for Granite's dBoots Fortress MT
2. rear wing from Typhon 3s
3. front bumper from Granite
4. roof protection (Traxxas 8917)
5. hood protection (ARA480017)
6. body stickers
7. additional LOUISE UPHILL MT wheels (for learning to drive on tarmac and not destroy Granite wheels)

"Service zero" I did so far:
1. slipper clutch adjustment
2. radio calibration and servo end points adjustment
3. anti-corrosion grease into applicable locations
4. bought spare servo + 25t servo saver in case stock servo will become dead (as many of you experienced)

I think it's now ready, or have I forgotten something important before first run?

Pictures before first run:

 

[Wheels007]

Sweet rig. After the Granite tires are burnt, get Proline Badlands MT's. You'll never go back

 

[Ginglehopper]

Hello Arrma Family!

I want to introduce my Arrma Big Rock.

It's my first RC car ever (excluding cheap toys with 0/1 steering) - when searching for the specific model to buy, I have walked this path:
1. Maverick Quantum+ Flux [inexpensive(+), good looking(+) but a bit fragile(-) I gave up on it seeing a lot of YT videos with destroyed trucks after few minutes of run]
2. Traxxas Hoss [2x price of Maverick, much better durability(+), TSM(+) but not impressive in jumping/flips (-)]
3. Arrma Granite [1,33x price of Maverick, durability at Traxxas level if not better(+), better jumping/flips performance(+)]
4. Arrma Big Rock [same price as Granite, ~same durability (+), better handling (+), jumping/flips performance worse than Granite, but better than Hoss]

So ended up with Big Rock v3 as a first RC to learn driving, make mistakes, giving a hard time to the truck.
I believe there are not much of better choices, if any...
(and not only myself but also my 8yo son will be driving this monster)

What I added to stock truck is:
1. replace wheels (already in LHS) for Granite's dBoots Fortress MT
2. rear wing from Typhon 3s
3. front bumper from Granite
4. roof protection (Traxxas 8917)
5. hood protection (ARA480017)
6. body stickers
7. additional LOUISE UPHILL MT wheels (for learning to drive on tarmac and not destroy Granite wheels)

"Service zero" I did so far:
1. slipper clutch adjustment
2. radio calibration and servo end points adjustment
3. anti-corrosion grease into applicable locations
4. bought spare servo + 25t servo saver in case stock servo will become dead (as many of you experienced)

I think it's now ready, or have I forgotten something important before first run?

Pictures before first run:

View attachment 145026

View attachment 145027

Welcome! The 3s line is great and that truck looks awesome!

 

[Wakko]

Sweet rig. After the Granite tires are burnt, get Proline Badlands MT's. You'll never go back

What size? Do they hold up on road? OP: your truck looks great...I'm stealing the bumper/wing/roof rack idea.

 

[Wheels007]

What size? Do they hold up on road? OP: your truck looks great...I'm stealing the bumper/wing/roof rack idea.

Size 2.8. You could go on road with them, but they're meant for off road. If you're on roading I'd suggest on road tires. They'd grip the surface better. I'm sure someone could suggest good on road tires for the BRCC.

 

[Javage]

4. roof protection (Traxxas 8917)
5. hood protection (ARA480017)

Wow that looks great on there, I may just have to steal that setup.

 

[LK80]

first run yesterday evening (50% power) - truck did well, very stable & easy to drive...

runtime:
- on 2s 8800 mAh 50C battery was ~45 minutes (@ 50% power) - I was expecting a bit more, but...
- battery had 3,79 V per cell after LVC ended running - that's a bit dissappointing...

According to spec, BLX 100 has LVC set @ 3,4 V
Do you know if anything can be done to fix it and let the battery go down to 3,4 V @ LiPo mode?

I know that solution is to put ESC in NiMh mode, and use LiPo alarm - that is what I will do, but is there any way to fix LiPo LVC to 3,4 V as it's designed to?

 

[Edough13]

first run yesterday evening (50% power) - truck did well, very stable & easy to drive...

runtime:
- on 2s 8800 mAh 50C battery was ~45 minutes (@ 50% power) - I was expecting a bit more, but...
- battery had 3,79 V per cell after LVC ended running - that's a bit dissappointing...

According to spec, BLX 100 has LVC set @ 3,4 V
Do you know if anything can be done to fix it and let the battery go down to 3,4 V @ LiPo mode?

I know that solution is to put ESC in NiMh mode, and use LiPo alarm - that is what I will do, but is there any way to fix LiPo LVC to 3,4 V as it's designed to?

No there is no way to adjust it unfortunately. I'd guess it's because the batteries have really bad voltage sag under load as it dropped from ~3.8v per cell to under 3.4 to trip LVC and on 50% is crazy. I'm guessing battery is cheaper brand and quality?

 

[LK80]

I'm guessing battery is cheaper brand and quality?

Well actually it is not. I have it from LHS and it was proposed to me as quality battery.
2nd run yesterday and after LVC I've measured 3,72V with rather soft running (still 50% power) just before LVC.
At the moment I don't have access to any other LiPo to make a comparison, hunting for gens-ace-r-spam Bashing Pro 3s 8000 100C, but it's not in stock for a long time...
This is my current battery:

 

[Edough13]

Well actually it is not. I have it from LHS and it was proposed to me as quality battery.
2nd run yesterday and after LVC I've measured 3,72V with rather soft running (still 50% power) just before LVC.
At the moment I don't have access to any other LiPo to make a comparison, hunting for gens-ace-r-spam Bashing Pro 3s 8000 100C, but it's not in stock for a long time...
This is my current battery:

View attachment 145367

Never heard of it and only place I can find that brand is from Poland. Just because LHS says it's good doesn't mean it's good are you checking voltage the minute it hits LVC or are you waiting a few minutes until you can get it out and on to a charger? If your not checking immediately your not getting a valid reading as lipos can recover and balance with a short rest. I suggest getting a voltage alarm for a few bucks and set it to 3.4 and see if it sounds as LVC kicks in and then see if battery recovers to 3.7 after a few minutes. Trust me I have a couple packs that I can run 5 mins and they trip LVC but check them a minute later they read 3.7-3.8v per cell. It's because they are cheap and can't handle the load.

 

[LK80]

Never heard of it and only place I can find that brand is from Poland. Just because LHS says it's good doesn't mean it's good are you checking voltage the minute it hits LVC or are you waiting a few minutes until you can get it out and on to a charger? If your not checking immediately your not getting a valid reading as lipos can recover and balance with a short rest. I suggest getting a voltage alarm for a few bucks and set it to 3.4 and see if it sounds as LVC kicks in and then see if battery recovers to 3.7 after a few minutes. Trust me I have a couple packs that I can run 5 mins and they trip LVC but check them a minute later they read 3.7-3.8v per cell. It's because they are cheap and can't handle the load.

I agree - it does not seem to be a global LiPo brand, maybe you're right and quality is poor.
Thanks for the hint, I did voltage measurements on the charger after getting back home => 10-15 minutes after LVC.
I do have LiPo alarm, I will try it today as you suggest...

 

[LK80]

I have lost my LiPo alarm during first ride... now i have another one and I have prepared better to not to loose it again.
It fits perfectly to the hole in the rear wing and even looks nice, giving some tail red light:

 

[Enferius]

Quick question! How did you mount the roof skid? I was looking into one myself but wasn't sure how people were mounting it. I know on the Maxx there's a support under the body it mounts to so I wasn't sure if I should buy that too and modify it to fit just in the roof of the truck on the under side.

 

[LK80]

Quick question! How did you mount the roof skid? I was looking into one myself but wasn't sure how people were mounting it. I know on the Maxx there's a support under the body it mounts to so I wasn't sure if I should buy that too and modify it to fit just in the roof of the truck on the under side.

I used screws from Traxxas 8917 set and nuts from ARA480017 as spacers. No backplates:

 

[Enferius]

Aw sick! Thank man! I actually have the body post protectors on their way to me from Horizon so that works perfectly. I'm in the process of converting my BRCC into a Kraton without the 4s setup and need something to protect my Kraton body. I scratched up the BR pretty good already. Here's a glimpse shot of my build below.

 

[evberkel]

Aw sick! Thank man! I actually have the body post protectors on their way to me from Horizon so that works perfectly. I'm in the process of converting my BRCC into a Kraton without the 4s setup and need something to protect my Kraton body. I scratched up the BR pretty good already. Here's a glimpse shot of my build below.

View attachment 151242

are those proline wheels with 17mm hex? Did you use hex adapters? did you do this for wider wheelbase and more stabilit? (I’m new at this and allready converting my Senton to a big rock)

 

[*420+3RC*]

Nice ride.

 

[Enferius]

are those proline wheels with 17mm hex? Did you use hex adapters? did you do this for wider wheelbase and more stabilit? (I’m new at this and allready converting my Senton to a big rock)

The wheels are 17mm, yes. The hex adapters are from Hot Racing. They're 12 to 17mm adapters with a +10 offset. The car will still roll but not as much as it did when stock.

 

[evberkel]

Tnx. I was making a calculation for a 100% conversion but that’s way to expensive i discovered.... so maybe I’m gonna sell the senton and get the big rock or make a trade or something.

 

[evberkel]

Decide to do the conversion ordered all I need to convert the senton in a big rock with the badlands