Axial Scorpion AX10

build tip

An extra instruction sheet is included to highlight this but I missed it and had to turn to the web for the answer, so to save you the trouble… When installing the output gear at the front of the diff, ensure it is properly seated in there. You’ll know if it’s not as the diff mesh will be incredibly tight. If this happens, use some pliers to pull the output gear forward so it sits further into the axle and diff casing (this also saves you having to undo the axle case again).

shocks and turnbuckles

With the diffs built you begin the slightly tedious task of putting all the turnbuckles together and building the shocks. This task is made more pleasurable as you get to admire the gorgeous green anodised aluminium turnbuckles which are all etched with the Axial logo and help to make this a really distinctive looking kit. The plastic bodied shocks are a little bit of a disappointment and about the only thing in the kit which doesn’t exude quality. They are fully functional oil filled dampers though and do the job perfectly well. If you really want to up the ante however, Axial offer some gold coated, hard anodised shocks as an upgrade or any T-Maxx sized shock will fit straight on.

Now that all the turnbuckles and shocks are made, the rest of the truck starts coming together remarkably fast and the last technical part is to build up the gearbox which provides the permanently locked four wheel drive. Again it’s important for a crawler to have a locked gear box and ensure power is sent evenly to the front and rear. Attached to the front of the gear box is a machined aluminium motor mount and 87 tooth spur gear.

The gear box assembly is mounted to a plastic plate which sits at the bottom of the two U shaped vertical chassis plates. This keeps the motor (once it’s installed) nice and low to reduce the centre of gravity. Once the turnbuckles and shocks are attached to the vertical chassis plates, the basic foundation of your rock crawler is in place!

electrics

Steering is accomplished by mounting a servo (a Hitec 645 in this case) to a plate on top of the front axles. Two turnbuckles are then used to take the servo movement to one wheel and then from that wheel to the other - a simple yet very effective design that means there’s minimum slack in the steering and the servo is kept low down to reduce the centre of gravity.

battery pack

Now here’s a bone of contention among the rock crawling crowd if ever I saw one! As you might have gathered by now, everything on a rock crawler needs to be kept as low as possible to reduce the centre of gravity, yet in its stock form, the Scorpion has the battery pack sat right on the top - the worst possible place! You may wonder why Axial have done this, well it’s so people like you and I can get going straight away because this set-up allows you to slap a normal 7.2V stick pack straight in.

If you want to get serious with your crawling or just start tackling tougher terrain then you’re going to need to move the battery pack. Fortunately Axial have now released a revised front servo mount which allows you to sit the batteries on top of the front axles, alongside the steering servo. The official part is really made for a LiPo battery pack, however you can achieve the same thing by putting three or four cells either side of the servo, shown here in this picture we borrowed from rccrawler.com (an excellent website for all crawling info).

novak make it easy

So here’s where I really started to feel a little out of my depth, as not only are we using an electric motor instead of a nitro engine, but you ideally need a dedicated crawling motor and ESC if you want to do this properly. Fortunately CML Distribution who bring us the Scorpion in the UK also deal with the distribution of Novak and they have just released a new dedicated brushless crawling motor and ESC called ‘The Goat’, and like their other products it’s pretty much idiot proof.

Having a brushless crawling motor may at first sound like a bizarre concept (well it did to this nitro-loving RC fan). I mean it’s not as if we want to achieve extreme speeds with it! However a brushless motor is actually ideally suited to this application due to its instant throttle response and explosive torque which combine to give you amazing low speed drivability. There are two motors available, the Crawler 18.5 and the Crawler 21.5, both are pretty similar; the 21.5 just goes slower but gives even more torque.

We used the Crawler 18.5 brushless motor although the supplied ESC can also be used with brushed motors if you so desire. When you have a package like this Novak Goat, you can throw all your worries out of the window because Novak do all the work for you. In this case they even provide the motor and ESC with all the wires soldered on - I really wanted to find someone at Novak (preferably a fit young busty blond receptionist) and give them a big hug.

With the Goat coming as such a readymade package, it’s just a matter of fitting everything in, securing the wires, and you’re ready to go. Well you need to set the ESC up but that again is a completely painless process and done with just the push of a button.

There’s a whole host of set-up options in the ESC which you can work your way through but its standard set-up will get you out and crawling in no time at all. If you do want to explore the options further, the Goat ESC will allow you to alter;
Drag Brake – Raising this setting makes the motor slow down more without pushing the transmitters in the brake/reverse direction.
Dead Band – Raising this setting will increase the ‘free play’ or the distance your trigger must move before forward drive or braking will begin.
Minimum Drive – Raising this setting makes the motor start at an even stronger or higher level so it takes off more aggressively.

In order not to over-complicate things, I didn’t go overboard with these settings, however after an initial test run I did increase the drag brake and reduce the minimum drive. I did the latter as being a nitro driver, I wasn’t used to such instant throttle response - well that’s my excuse, others will just say I’m heavy handed!