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Old 12-02-2016, 03:49 AM
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fyrstormer
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Join Date: Mar 2014
Location: Maryland, Near DC, USA
Posts: 3,209
Default Build Complete: Axial SCX10 II

My first "scaler" is done.



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.



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.)



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:



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.



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.



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.



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.



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 www.ledcalc.com, 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:



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



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:



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.



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.

Last edited by fyrstormer; 11-24-2017 at 05:22 PM.
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