NewB CC01 Question

[Sleazysmurf208 1]

Hi all,

I just recently picked up a CC01 kit (Isuzu Mu Black Metallic).  This is my first CC01... I can’t wait to play with the full time 4 wheel drive, and from what I’ve been reading, it’s a tinkerers dream, with the ability to do a lot of mods to it.  However, I’d like clarification on two things:

1.) Locking the rear and/or front diff:  what situations have come up where it was a good decision to lock the diffs?  I’ve read it’s good to lock them if you need more power.  But what circumstances would make it a good idea to do it?  Is it just for getting better traction?  My intention is more for trail riding and less climbing, so I don’t know how I could tell if locking them would be of any benefit

2.) Motor speed / turns:  From what I’m reading, it’s preferable to use a motor with turns of 27 or higher.   What is the main reason behind this?  I’m used to putting the fastest possible motor in a rig, and even now have a Super Hornet, Fighting Buggy, Blackfoot, and Mud Blaster II all with brushed and brushless motors with turns of 15 or less.  So is this truck more of a leisure ride type of vehicle, or is it a capable machine that if I wanted to, I could throw a 12 or 15t brushless motor in it and tear up some trails?
 

 

[TurnipJF 5371]

1. As with a full-size 4X4, locking a diff means that if one wheel loses traction, it and its opposite (which hopefully still has grip) will keep turning, rather than the available power all going to the wheel with no grip, turning it uselessly. You would thus lock the diff(s) if driving on terrain where one wheel is likely to lose grip, causing the rig to come to a halt.

The downside is that the turning circle suffers, especially if the front diff is locked, so on mine I have locked the rear diff and slowed the front one with putty. This gives a limited slip effect, giving much the same benefit as a locked diff but with less of an effect on the turning circle.

2. The CC-01 can be made to go pretty fast, but it tends to roll over when asked to turn at speed. However it is rather good at picking its way slowly over scale-appropriate rough terrain (about 1/10th the roughness of what you would attempt with a fullsize) and for this, low-throttle control is very handy. A higher turn motor facilitates this.

 

[Juggular 3444]

Before anything, I'm sure you know about the rear axle needing some bushings? 

[1] Limited Slip Differential(LSD) would be the 3rd option.  If you are in US, I'd recommend "Bad Horsie Diff Lock."  It's ultra-sticky grease of a sort.  a) The problem of unlocked diff is differential-unloading.  If the left wheel loses traction, then automatically the right wheel lose power.  You've seen people having to push their 1:1 cars in slow, mud or on ice.  That's mostly diff-unloading.  b) The problem with locked diff is that it makes it easy to flip the truck on high-traction area when turning. That's why differential was invented in the first place.  Also, locked front can break the drive cups on hard surfaces.  

LSD is best of both worlds.  Subaru is best at making LSD, which is why their 1:1 AWD system does so well.  You can give that your RC car.   If you are not in US, I'd recommend "3Racing Ultra High Viscous Differential Oil."  Use sparingly so it won't seep out and gunk up other gears.  If one wheel loses traction, the other wheel still has like 1/2 power.  On hard surface, it still allows differential action, so it would not flip.  I've used "Bad Horsie Diff Lock" like 20 years ago in my Wild Willy 2.  To this day, if WW2 gets stuck on a tree root, one wheel touching the ground can get it out of the situation.  Or you can use "Tamiya Diff Clay," this will almost lock it.  

1) Lock Both if you NEVER drive on tarmac.  If you drive on tarmac with big sticky tires, you could break front dog bone or drive cups. 

2) Lock rear, use Tamiya Diff Clay for front.  Almost crawler, but front won't break even if driven on tarmac.     

3) Use Tamiya Diff Clay on both.  Perfect for a trail truck.    

4) Use Tamiya Diff Clay for the rear, but use "Bad Horsie Diff Lock" or "3Racing Ultra High Viscous Diff Oil" for the front.  More relaxed front axle will make it easier to drive on tarmac.  

5) Use "Bad Horsie" or "3Racing Ultra Diff Oil" for both front and rear.  Weaker on crawling, but more easier on tarmac.  

6) Use "Bad Horsie" or "3Racing" for the rear and use Tamiya Anti-Wear grease.  Even easier on tarmac, still capable for trail blazing.  

7) Use "Tamiya Anti-Wear Grease" for front and rear.  Very weak LSD effect, but better than included Tamiya grease.  

8) Keep both open if you drive on tarmac only.  (I never do this. Even for on-road cars, I use "Tamiya Anti-Wear Grease" on the driving axle)  

Of course, there are few more combinations... It's up to you to choose.  

 

[2] Motor choice depends on the terrain.  Something like a 55 turn would drop the RPM down to half.  The silver can has 14000 RPM, while 55t would have 7000 RPM.  It has lower torque too. But it only uses half the current, so the battery should last much longer.  If you are crawling, you would use low RPM more often anyway. "Controlling" is easier.  

Imagine you want to increase only by 500RPM.  The trigger movement you'd need on a silver can would be 1/28th.  If the trigger moves 28mm, you'd need to move 1mm to increase 500RPM.  But if you are using 55t, trigger movement can be 2mm.  It's just so much easier for "control." 

Unlike buggies, CC01 has high center of gravity.  Just like SUVs easily rolling over, CC01 is the same.  For a wide-open gravel field where you could use more speed without rolling over, you could use faster motors like Sport Tuned.  If you are running it on a narrow trail through a woodland, slower 35t would be better suited. You can't get the speed because it's narrow and winding. You might as well get better control.  

 

[Sleazysmurf208 1]

Thank you both.  I didn’t even consider doing an LSD and will go that route.  

I did see someone else just post about the additional bushings/spacers for the rear axle, and will definitely do that.

[GooneyBird 820]

Here's how I used a bunch of spacers to make my rear axle all nice and smooth.

For the record, I use my CC01 as a trail rig, taking it along with me on 2 hour+ long walks, and I take 2 3000mAh NiMH packs with me. I usually end up swapping them about 90 minutes in, and the remainder of the second battery lasts the rest of the walk. The 55t motor hardly uses any power! 

Also, my front diff is fully unlocked, and the rear diff is fully locked. While it's gotten stuck once or twice with all wheels losing traction I've yet to come across a situation (on normal trail driving, think 1:1 offroading instead of rock crawling) where the Paj gets stuck due to wheels unloading.