Build Complete: Axial SCX10 II
 

My first "scaler" is done.

http://i.imgur.com/vuXOqSt.jpg

I've been going back and forth about creating a build thread for it, because I feel like the SCX10 II is so good out of the box that there wasn't really anything I needed to improve significantly, but there are a couple things I'd like to show off anyway.

http://i.imgur.com/6CRmkkN.jpg

First of all, I replaced the stock aluminum links with SSD's titanium-upper/steel-lower link set, to add some weight down low and to put a more durable surface on the underside where the truck will be scraping against rocks. (I hate dragging aluminum across rocks.)

http://i.imgur.com/hds3i7e.jpg

Second, I beefed up the axles a bit with SSD diff covers to help protect against rock damage (they are aluminum, which contradicts what I just said, but they're *really good* aluminum, so that's something), and brass Beef Tubes axle weights, which you can see peeking out from inside the c-hubs. Here's a clearer view:

http://i.imgur.com/767cFKG.jpg

I normally use AquaCraft Grim Racer Speed Grease on all the sealed gears in my builds. However, since the SCX10 II has nifty hypoidal diff gears which scrub their teeth together as they rotate, I opted for Tamiya Molybdenum Grease for the diff gears instead, to reduce wear. Hypoidal gears in real cars also require special lubrication to avoid premature wear. The rear diff was assembled with a Vanquish tight-fit locker to reduce slop, but I left the stock locker in the front because that little bit of slop significantly reduces drivetrain shudder when the steering turns sharply and the U-joints rotate unevenly.

http://i.imgur.com/154r7nL.jpg

The motor is a Tekin Pro 30T, with a Sunon CPU fan stuck on the endbell using MuchMore Racing endbell-fan mounts, as I do with all my brushed motors nowadays to help the commutator handle the massive amperage provided by LiPo batteries. The transmission is fitted with a SSD 2-speed kit, but I'm not talking about that because it's REALLY noisy in high gear, so I'm running it as a single-speed until Axial gets their act together and releases their own 2-speed kit.

http://i.imgur.com/icenyrj.jpg

Most of the actual work on this truck, besides the initial assembly of the kit, was soldering. This truck has SO MANY WIRES, because it has no less than 10 LEDs festooned across it, plus that cooling fan, and the Y-harness that powers the fan and LEDs from a single port on the receiver.

http://i.imgur.com/pepPKar.jpg

Here's a closeup of the wiring for the bumper. The bumper itself is a Pro-Line wide bumper, which fits perfectly with the Jeep Cherokee body, and gives me a convenient mounting point for a couple Axial light buckets in addition to the built-in corner lights. The rear bumper is stock, partly because it fits the body better than the Pro-Line rear bumper, and partly because it has rear marker lights built-in whereas the Pro-Line rear bumper doesn't.

http://i.imgur.com/oVi3CfR.png

I'm not a big fan of those prefab rectangular light bars that are so common nowadays; it's an odd nit to pick, but they don't look very scale to me, even though I know they are also available for real off-road trucks. Instead I build my own lights using old-style 2-wire LEDs and whatever light buckets will fit. I use a very simple driving mechanism for my LED lights; each LED has a resistor, which is selected based on calculations provided by Current limiting Resistor calculator for leds, based on the voltage provided by the ESC, the voltage-drop across the LED (also called the "forward voltage", which varies depending on the color of the LED), and the desired amperage that I want the LED to receive. (10mA is good for marker lights, but if you want useful illumination in front of the truck you'll need to go up to 40mA or higher, which is hard to do with cheap LEDs.) White LEDs have a voltage-drop of about 3.2-3.6 volts, so they have to each run separately, because most ESCs provide power between 4.8V-6V, so two white LEDs connected in-series will require more voltage than the ESC is providing. However, I was able to connect the twin corner lights in series because amber LEDs have a voltage-drop of about 2.4V each and the Axial AE-5 ESC provides power at 5V. That was nice because it reduced the amount of wiring I had to run to each corner light assembly.

But what's the deal with those springs on the front body mount posts? Well, that's the bit I'm really proud of with this build:

http://i.imgur.com/psuJQEd.jpg

They are Losi Mini-T springs, wired into the lighting harness, and they match up with these:

http://i.imgur.com/wCvoia4.jpg

They are quick-disconnect electrical contacts to power the headlights on the body, so I don't have to futz with unplugging anything when I remove the body to adjust something or to install or remove the battery. And here's the result:

http://i.imgur.com/UJ3xlkW.jpg

The lighting on this build is a convergence of my RC hobby with my fancy-flashlight hobby from a few years ago. The headlights are lit by Nichia DS warm-white LEDs for a more realistic look, while the off-road lights are lit by some custom-ordered cool-white LEDs that have 5 emitters crammed together into each LED so they can handle more power and produce more light. I was a little concerned that the two different tints would look weird together, but when I flipped the switch and saw the result, I was very happy.

http://i.imgur.com/zMic7yY.jpg

So there's my Axial SCX10 II. I'll add the Axial 2-speed kit when it becomes available, but as far as the rest of the vehicle is concerned, it works better than I thought a 1.9" scaler could, and I'm glad I bought it.

Re: Build Complete: Axial SCX10 II
 

i like the build...but i must say congrats on the front post lighting arangement...thats some serious thinking yet simple it how it works....awesome...

love that little rotary...lol...was that functional at one point?

Re: Build Complete: Axial SCX10 II
 

I second the lighting system, AWESOME idea!

Re: Build Complete: Axial SCX10 II
 

I'm going to try to replicate your front light wiring solution. So elegant

Re: Build Complete: Axial SCX10 II
 

Thanks! I had the idea for these spring-loaded contacts for about a year and a half, but this was the first time I actually got around to finding the exact parts I needed to make it fit. The Mini-T springs have the chrome sanded off in a couple places to allow solder to stick to the metal, and the springs have washers soldered onto the top to provide a matching surface for the contacts on the underside of the body. The contacts on the underside of the body are attached with 3M "Scotch" foam tape -- the really strong stuff that doesn't let go, not the removable stuff that we call "servo tape". Make sure to solder the wires to the contacts before sticking the contacts in-place, so you don't melt anything. The contacts themselves are eyelet connectors from Radio Shack.

And yes, the O.S. rotary engine was functional -- in fact it's unused, and could be functional again if I reinstalled the front plate. I bought several of them on eBay last year.

Re: Build Complete: Axial SCX10 II
 

Your lighting solution is legit! I wish i could solder LEDs as clean as you. Nice work!

Re: Build Complete: Axial SCX10 II
 

Love it! You've done a pretty dang respectable job of upfitting an RTR!

The spring contact for electrical is really clever, gives me inspiration to solve the issue I'm having on my similar system that uses magnets. Any issues with the lights flickering while truck bounces around?

Re: Build Complete: Axial SCX10 II
 

Decades of practice. :) I've been soldering my own stuff since at least 1996.

It's actually the kit version, I just bought an RTR body to put on it because I didn't feel like spraypainting. :)

No trouble with the lights flickering. The ends of the springs have so little mass that you'd pretty much have to drop the truck off the side of a building for it to hit hard enough to make the springs lose contact -- and if you did that, you'd have other problems.

Re: Build Complete: Axial SCX10 II
 

I appreciate the clean wiring job. I'm kinda with you on the light bars, too. The old style can lights just have more character to them. "thumbsup"

I like the way you wired your circuit into the spring. I've seen a similar setup where a guy had used magnets on top of the body posts to hold down the shell, rather than using clips. He had soldered wires to each of the magnets so that when the magnets made contact it completed the circuit.

Re: Build Complete: Axial SCX10 II
 

I considered taking the magnet approach, but I ultimately decided I wanted to use clips to keep the body firmly attached if the truck takes a tumble.

Re: Build Complete: Axial SCX10 II
 

Yeah its a neat thought, but I tend to agree with you.

Re: Build Complete: Axial SCX10 II
 

Now I'm going have to use your spring idea, it is brilliant

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Re: Build Complete: Axial SCX10 II
 

What an awesome light set up! Can I send you a few bodies to do for me? Also I like your tire choice. The Wildpeaks are such a great performer and are very underrated.

Re: Build Complete: Axial SCX10 II
 

I can't wait to do the 1/6 Dodge Ram body I have

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Re: Build Complete: Axial SCX10 II
 

Thanks! Unfortunately I'm going to have to decline your request to wire bodies for you; despite how it may appear, wiring is actually one of those RC-related tasks that I can barely stand to do, and the only thing that makes it worthwhile for me is being able to admire the result. If I started doing it for other people it would turn into a job.

Re: Build Complete: Axial SCX10 II
 

Testing the center of gravity and the articulation, admiring the running lights, and encountering the local wildlife:

http://i.imgur.com/gNUQGd5.jpg

http://i.imgur.com/kwh6VGs.jpg

http://i.imgur.com/Uu3RGPc.jpg

http://i.imgur.com/2vlCQZX.jpg

Re: Build Complete: Axial SCX10 II
 

did you get the bonuspoints for running over the bunny?

Re: Build Complete: Axial SCX10 II
 

O Man. I just realized your two towns over from me. I like your lil rock garden.

Re: Build Complete: Axial SCX10 II
 

Not anymore, I need to update my profile. I moved to MD a couple months ago.

Apartment living is all about finding ways to make-do with the facilities provided to you. :)

Re: Build Complete: Axial SCX10 II
 

Very nice build, wiring very neat.