By:
Brandon Wilcox, Thomaston CT
June 29, 2007
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pictures to open high resolution image in new window.
When the Wheely King was first announced,
it looked like HPI was making a really nice 2wd basher,
aimed at newcomers to the hobby. The truck looked like
a real monster truck, and included everything you needed
to run. It was fully RTR. Within a couple days of being
announced, the guys over at rccrawler.com started talking
about how great the axle’s looked for use in their
RC rock crawlers. After some new pictures were released,
it looked like the Wheely King had a good base for a
rock crawler, and with a few modifications, could become
quite capable. In this article, I show you 5 cheap and
easy steps to turn your Wheely King into a capable RC
rock crawler.
1. The very first thing you need to
make your Wheely King a good crawler is give it full
time 4wd. (If you already bought a newer 4wd Wheely
King, you can skip this step.) HPI makes a 4wd conversion
kit that is a drop in for the stock truck. The part
number is 87602.
This only takes about 15 minutes to install after the
wheels and tires are off the truck, and everything is
dissembled. Instructions are included with the kit.
While the axles are still open continue to step 2.
2. Step 2 is very important,
in rock crawling, you want as much traction as you can
get, and you do not want any of your wheels to slip.
You need to lock the differentials. Some people use
JB weld or hot glue, but these methods are messy and
can break under extreme use. For my differentials, I
went with http://www.rcguy.com
diff lockers. For only a couple dollars more then JB
weld, you can have quality aluminum diff lockers that
wont break, no matter how grueling the conditions are.
RCguy diff lockers come with instructions and are very
easy to install into your axles. The diff lockers are
precisely machined out of aircraft grade aluminum, and
are very strong. These will not be breaking anytime
soon.
3. Once you get your axles back together,
its time to stretch the Wheelbase of your truck. The
stock wheelbase is great for bashing and pulling wheelie's
all day, but we want to rock crawl, so we need to stretch
the wheelbase out to 12.5 inches. 12 to 12.5 inches
is the magic number, if you ever feel like competing
in the future with your truck, the USRCCA has a 2.2
size class, and one of the rules is the truck must have
a wheelbase of 12.5 inches or less. Here is a parts
list of what you need to stretch your wheelbase:
Traxxas
#5139. 118mm. (For lower links) (2)
Traxxas
#5138. 108mm. (For upper links) (2)
Tamiya
#9804179 Upper/lower suspension stays (1)
Traxxas
#4951x Half shafts (1)
First, you need to rotate the stock suspension
stays that your shocks attach too. Instead of having
them face up on the axle, they need to be rotated so
that they face the side. This will be used to mount
the shocks, and also to mount the lower links. Next
you need to take out the old upper link mount plate,
which is made out of plastic. When you take it off you
see 2 holes. Mount the new Tamiya suspension stays there,
they are a direct fit. This is where your upper links
attach too. Next mount the new Traxxas links as shown
in the picture, the longer ones for the lower links,
and the shorter ones for the upper links. Now that you
have a longer wheelbase, use the Traxxas half shafts
to connect the axles to the transmission. In order to
fit properly they need to be trimmed about ¼
of an inch off both the male side and the female side,
to allow the truck to articulate freely. Now mount your
shocks as shown in the picture, the top can be placed
in the stock position, or angled as shown in the picture.
The bottoms will be on the inside of the mount you rotated
before. Look at the pictures; they are worth a thousand
words.
4. Now that you truck
is back together, we need to install better steering.
The stock steering works ok for bashing, but now that
we've stretched the wheelbase and locked the differentials,
we will need much better steering. I went with the new
http://www.rcguy.com
steering kits. They bolt up securely to the front axle,
and are very durable. Not only do they look great, but
they can use the stock Wheely King parts for the steering
links. Definitely a must have for anyone upgrading their
Wheely King, and at a incredible cost as well.
5. The last thing we
need to do to make a good crawler is get rid of those
hard stock tires. I choose to go with one of the better
tires out there, Pro Line Moabs. They are 2.2 in size
and are well proven in the rock crawling community.
I cut the foams in a star pattern, with flat edges,
so the foams would act like fingers and wrap around
the rocks. I also narrowed them slightly.
There you have it, 5 easy steps to convert
your Wheely King into a capable crawler. The truck works
great, and is much improved over the stock form. The
transmission is mounted vertically still, and this makes
the center of gravity still pretty high. I think in
the future I will either try to mount the transmission
horizontally, or possible replace the transmission with
something smaller. Have fun with your new rc rock crawler!
Sources:
http://www.rcguy.com/
http://www.hpiracing.com/
http://www.towerhobbies.com/
