brushless Wheely king rat rod build

[Luke den Bak]

here's my wk build. I use it mainly as a basher, but it has been a crawler at one point. After a couple of months running it stock i decided to go brushless after seeing my friends slash go 90km/h.

heres what it is right now

[/URL][/IMG]
sealed bearings all around
level3 rc on axle servo mounts
level3 rc steering links
4 wheel steer using a y cable and a servo signal reverser with a hobbyking servo and the stock servo
axial 2.2 rockster beadlocks with the stock tires
wheel base extension using GPM lower links and flipping the link mounts

[/URL][/IMG]
home made skid plate on front axle

[/URL][/IMG]
home made center skid plate
home made sway bar in the rear(made from high tensile fencing wire)

[/URL][/IMG]


i bought a used castle creations sidewinder 5700kv system from that same friend and it ran for about ten minutes before the tranny blew up. apparently, the clicker clutch had stripped out. i bought a set of hardened steel tranny gears from rc4wd and i thought that would be the end of buying drive train parts.

But, i was very wrong. the die-cast ring and pinion gears stripped out very quickly. i read somewhere on this forum that axial wraith ring and pinion gears could fit in wheely king axles. i pondered for a while about whether a 43/13 gear ratio would fit rather than 38/13 which is the stock ratio. i decided to buy the 43/13 gears because i figured it would be great to have a little bit more reduction to reduce torque twist and since the 5700kv motor didn't offer a whole lot of torque. it turns out that was a bad idea. when i maxed out the throttle those gears would grind and no amount of shimming would fix it completely and eventually, they stripped out as well.

[/URL][/IMG]
i guess the gears couldn't mesh properly because the ring gear was a larger diameter than the stock ring gear. i then bought 38/13 helical ring and pinion gears and those seem to mesh pretty well.

I also experimented with diff lockers not knowing that they would destroy the axle shafts:evil:. I went back to open diff and replaced the stock axle shafts.

once while i was rippin around on a beach, a piece of sand got lodged in between the teeth of the rc4wd hardened steel spur gear and locked up the motor. the system got so hot that, after a couple seconds of pulling on the throttle and wondering why my truck wasn't moving, bright orange flames started licking out from underneath the body. The esc got pretty cooked as you'll see in the picture.

[/URL][/IMG]

At that point i decided i should turn it into a crawler while i looked for a deal on a new sidewinder system. most of the work was already done, i just needed a crawler motor. it was pretty fun as a crawler and MAN could it climb steep inclines.

At this point the stock body was pretty messed up so i picked up a proline 1950s chevy truck body and decided to make it a rat rod. i soldered together a roll bar and hood stacks from copper tube that i cut off of an old air conditioner. to get the rust look first i took a dremel to the fenders and other parts of the body to make rust holes. i sprayed the inside of the body with tamiya red brown. then i sprayed that same red brown on the outside on the spots where i wanted there to be rust. while that paint was still wet i sprinkled salt of varying grain sizes on those wet spots. remember to take off the protective film if you do this yourself. then i sprayed matte black over the salt and chipped the salt off when the paint was dry. then i sanded the rust spots to make them look more real. as this body gets used and scratched up the outside paint will scratch off and the inner rust colour will show through.


Right now im in the process of changing it back to a basher. im just waiting for a new sidewinder system to be shipped in and then all i have to do is assemble it and shes ready to rip.

 

[clod booster]

Sorta fixed all those for you.

Looks like a neat build, very MadMax Rictus Erectus.

 

[Luke den Bak]

Thanks man

 

[Luke den Bak]

the new sidewinder system finally came today. got everything installed. last time, i was really fighting high temperatures so i found some 12 volt fans that im running right off the 3s lipo. those should keep it cool.

[/URL][/IMG]
took it for a quick test run and rolled it and broke off some of the hood stacks. i think if i shorten them, that wont happen again. i cant really reinforce them either tho, because i dont have any more copper tube.

[/URL][/IMG]
got some more parts on the way:
cheap non-brand name aluminum shocks (ill see if these dont break right away)
hex hubs
a steel drive shaft( you can see in the previous posts that the front driveshaft is different than the rear. the front one is aluminum and i seriously doubt that it will last very long)
metal gear servo
some tie rod ends

 

[Luke den Bak]

took it out for a spin the other day and encountered a problem. after taking some fairly abusive impacts, the paint cracks and flakes off.

[/URL][/IMG]
i would be kinda ok with this if it was just the outside layer, but the inner rust colour cracks off too and you can see right through the body. i guess for now ill just repaint the cracked spots until i figure out a better solution.
another little update: im ditching the copper tube exhaust pipes. im gonna pick up some plastic tube from a hobby store which i figure will look more realistic anyway and will be lighter too.

 

[Luke den Bak]

Since the wheely king is so tippy ive been trying to figure out ways to get a lower center of gravity. what ive come up with so far is a prototype for a new chassis layout.

[/URL][/IMG]

[/URL][/IMG]

[/URL][/IMG]
I plan to put the battery box underneath the motor. the only problem with that is that it messes with the upper Y link in the front. i think ill just have to rearrange the geometry there. there also a lot of things to figure out like how to mount the battery box in its new position and new shock towers(the plastic that im using is too thick for the stock ones).

 

[Luke den Bak]

an update: i built 2 frame pieces based off of the prototype. i drilled multiple mounting holes for the front suspension to see what works best.

[/URL][/IMG]

[/URL][/IMG]

 

[Luke den Bak]

its been a while since ive posted but some major progress has been made. The chassis is now complete and fully operational. the cheap shocks came as well as a new driveshaft. The shocks really surprised me. i only paid 16 bucks for all 4 of them and they're actually put together pretty well. The springs were also stiffer than stock which is good because the rig is much heavier than stock. the only problem with the shocks was that there was hardly any oil in them. so, i put some 10w-30 engine oil in them and that seems to work well in the cold. when the oil is room temperature it doesn't really do much shock absorbing. Does anyone know if there is a trick to filling shocks with fluid without getting an air bubble in the fluid? anyway, the low cg and the new shocks really help it stay upright. i also used the stock shocks to make an unorthodox sort of dual shock set up in the front. the body is also a lot worse now ... i took it out for a rip in the snow and took some hard landings. a steering rod also got busted when i ran into a little tree. i guess the cold makes the aluminum really brittle.
well, here it is

[/URL][/IMG]
here's an action shot

[/URL][/IMG]
i have a little question for you guys. how much does a typical rock crawler weigh? my rig weighs 7 pounds ish and it says that the sidewinder system is rated for 5 pounds. the sidewinder system definitely has enough power to make it move, i'm just worried about the esc getting really hot. there's not really much i can do in the way of weight reduction and i dont really know if the fans i installed will keep it cool or not.

 

[groovethumper]

I really don't know what a stock crawler weighs(5 pounds ish?). My Crawler king is closer to 9-10 pounds. I wouldn't worry about it too much. Just keep a vigilant eye on temperature, and gear accordingly. Plus you have fans on everything. Which does help a lot.

That's awesome, one more person besides myself who uses motor oil. I use straight 30w, the kind you put in a compressor. Works great and doesn't freeze up as much in the frigid Manitoba winters.

 

[Luke den Bak]

some carnage:

[/URL][/IMG]
As you can see the bearing in the axle case got mashed and allowed the pinion gear to move around and tear up the side of the case. its not actually a big deal tho i just neede to replace the bearing. if this keeps happening ill probably buy a steel scx10 axle case cuz cheap ones can be found on ebay. im pretty sure that the wheely king differential will fit in one of those. ive also decided to ditch the four wheel steer. i found out that it is WAY more controllable without because the rear steer flings the back end around and the rig either flips or spins in circles. if i do end up buying an scx10 axle case ill get some good hard straight axle shafts so i can have locked diff in the rear.
i improved the suspension aswell. before the shocks weren't cushy at all, so i took the shock shafts and pistons from the stock shocks and put them into the new shocks and that was remarkably better. the pistons from the stock shocks made a better seal and had smaller holes in them. i didn't really like the way i had mounted the shocks, so i changed it... then i broke it. sorry i dont have any pics of what it looked like when it was intact.

[/URL][/IMG]
the reason it broke was because i drilled the mounted holes waaaaaay to far into the plastic and a weak spot was created.

heres a sick picture of the rig about to do a mud drag

[/URL][/IMG]
if there's anything it does really well, its mud drags

 

[Luke den Bak]

i repainted the body. not really happy with the result, the paint that did not flake off shows through the the new paint so now the surface isn't smooth. doesn't really matter tho, half the time it'll covered in mud anyway.

[/URL][/IMG]
it sorta adds to the beater look tho... im not sure what to think of it

[/URL][/IMG]
i have yet to buy polystyrene tube and make the stacks