RC4WD Archives

1/14 Mercedes-Benz ZETROS 6×6 Truck

by Craig | Apr 8, 2022 | RC Construction, RC Reviews, RC4WD

An RC Heavy Hauler!

This is the 1/14 scale Mercedes-Benz ZETROS 6×6 truck with remote-locking diffs and two-speed transmission. It might be smaller than the real thing but don’t lets its size fool you: ‘heavy duty’ is its middle name!

A 6000mAh 3S LiPo Gives This Rig an Hour Runtime!

A Truck of Many Names

It’s sold under a few names: JD Models, JDM, JD Concepts, Team Raffee and RC4WD. Regardless of badge, this is a 1/14 scale model of the Mercedes-Benz Zetros 6×6 truck. The Zetros is made in 4×4 and 6×6. Occasionally you’ll find it in 6×4 configuration and there are even a handful of 8x8s out there. The 4×4 variant is most commonly seen in 1/1 scale and the 6×6 isn’t far behind. You might think of the Zetros as the offroad answer to Mercedes-Benz’s Actros, a very capable on-road workhorse.

We sourced ours from Hong Kong, care of a small company called ‘HIGHWAY TOY Store’. We’re not sponsored but they have been excellent in both shipping and after-sales support for the numerous vehicles we’ve bought from them. Our unit came well packed and communication was good throughout the transaction. It sells on AsiaTees under the Team Raffee badge. If you’d prefer to buy directly from the USA, once or twice a year RC4WD runs discount days and you may be able to nab a bargain on this truck then. Worth keeping an eye out!

Sizing Up

This model weighs 7.5kg (16.5lb). Its dimensions are 734mm long, 230mm wide and 273mm high. It has a front-rear wheelbase of 482mm with front-middle axle of 365mm and middle-to-rear axle of 115mm. First gear ratio is 1:64 and second gear ratio is 1:16.

What It Isn’t

Despite having remote locking diffs and a heavy-duty drive train, the Zetros 6×6 Truck is not a rock crawler. The suspension is hefty and clearly capable of supporting significant weight. When loaded with enough weight on its hitch plate the rig will work nicely across uneven terrain. Physics works both ways though, so when running without a trailer the truck will be bumpy!

Another factor affecting the truck’s progress on uneven terrain is its clearance. Specifically, the lower-hanging componentry along the mid-area of the chassis. You’ve got a couple of hydraulic oil tanks (empty and unused in default configuration) and a ladder. Things can be removed, but the truck is just so pretty you’ll understandably probably want to keep it all attached. This means its break-over angle is poor. Again, this is not a rock crawler. With that expectation set up-front, the off-road performance this truck can deliver is actually quite good. More on that in a moment.

Ready To Run (Well, Not Quite)

The vehicle is advertised as being a RTR (Ready To Run) model. Experience dictating caution, we spent two evenings going over all the screws in our model to ensure everything was secured before running. Be aware that it needs thread lock applied to nearly all screws, wherever there’s metal thread. Many parts arrived only loosely attached, some nearly completely apart. But even if things are firmly installed, without thread lock it is inevitable that the screws will work themselves out over time.

Zetros 6×6 Truck Fix

As well as securing your screws with thread-lock, the other ‘gotcha’ with this truck relates to a design shortcoming rather than pre-assembly oversight. Namely, the drive shafts are strong but poorly secured. The universal joint has a hinge block in center that would commonly be secured by a set screw, as many manufacturers commonly do it. However, the units on the Zetros 6×6 truck are secured by a pin with E-clip at each end. It is strong, but unsuitable for off-road use. Those E-clips are exposed on the outside of the shaft collar, so if either of them are bumped by rock or stick passing underneath, they have a tendency to pop off. Once that happens, the whole assembly rapidly falls apart! It can be very frustrating and we had this happen twice on our unit. Not good!

To address this, we surmised the E-clips needed to be captured/covered and prevented from popping off. One could replace the shafts entirely, but it seems a waste, as they’re otherwise solidly made and should outlast the truck. So, our cheap workaround was to wrap a few layers of TESA Tape (or other automotive fabric tape) around the assembly. This way, even if they get knocked by a rock, the E-clips should remain snugly in place. After months of off-road driving since then, it’s been sufficient.

The Good Stuff!

Minor issues out of the way, let’s focus on what makes this model great! The diffs are enormous and feature remote diff lock by cable actuation. The truck comes set up with a three-position switch on the radio that’s connected to two servos. It cleverly achieves two different functions on the one switch:

High and low speed (more on low speed in a moment); and,
Locking and unlocking all three diffs.

It works really well and transforms the truck when the going (or towing) gets tough!

The high-speed gear delivers a moderate walking pace at top speed. That’s with the included 55-turn brushed 540 motor and also with the similar speed 1200kv brushless unit we’ve later installed (HobbyWing Fusion 1200kv). Second gear drive ratio is 1:16.

Low speed is where things get interesting. The Zetros 6×6 truck model features a somewhat unusual transmission. High gear is standard fare and 1:16 ratio is fairly typical. However, when you see a number like 1:64 for first/low gear drive ratio, you’ll appreciate why the truck employs a planetary gear set for such a huge reduction. The torque this thing puts out is incredible and the accompanying low-speed capability made possible is just perfect for a heavy tow rig like this! All gears are steel and all moving parts have been consistent and reliable in our testing so far. Again, we’ve had ours for 7 or 8 months at time of writing this article.

Cabin Fever

The drive train is wonderfully tough, but that’s not all to love with this machine. The scale cabin features integrated and functional spare wheels mounted on a swing-out bracket behind the rear window. There’s ample clearance for most scale trailers on the hitch plate behind it and they just look great. The cabin itself is plastic and is coloured silvery-gray. This is not paint but the plastic itself, which is good news for scratches and longer-term aesthetics. Both doors open, as does the hood, under which is an aluminium battery tray and the model’s radio and ESC.

Inside the cabin is a scale interior, with three seats and a full dash. The steering wheel and pedals are convincing and the dash controls look good even unpainted. There’s room to fit a 4” to 5” action figure/driver.

Trim and Terrific

The mirrors are realistic, as is the trim around the hood and the guard bars around the lights. Empty but functional light buckets and a snorkel round out the scale fittings. Aside from the integrated light buckets, these external trim items need to be installed after you get the truck. Presumably this is because they are too fragile to reliably survive shipping. Thankfully, installation is easy to do. The only weird part of the cabin/hood piece is the headlights, which are coloured amber rather than clear or white. It’s a strange decision but it isn’t distractingly bad, just noticeable.

Bumper to Bumper

The front bumper is plastic. There’s a bash plate underneath it that is metal. Both pieces look good and both are made of the most appropriate material for their function. You want a bit of flex on the upper, main bumper, while the metal bash plate is protecting the sway bar-cum-lower linkage in front of the axle, which you do not want to break!

At the other end of the rig are a set of four metal mud flaps. They’re attached by tiny screws in a somewhat complex assembly. The threads on a couple of ours were stripped from over-tightening at the factory. We tapped a larger thread and installed bigger hardware but found the metal quite soft. Second repair attempt was simply using a longer bolt with locking nut on the other side. Both methods will work. Be prepared for yours to take damage either in transit or during driving – they’re fragile and not a great design from a durability point of view. They certainly look the part and the rear-facing ones have light buckets in them, ready for your light kit if you so desire.

The bumpers and mud flaps round out what is a fabulous looking scale body. The twin, shiny chrome fuel tanks that double as actual, functional hydraulic oil tanks look brilliant. Also completing the distinctive look is the prominent pair of spare wheels. Speaking of which…

Wheels and Tires

This is a 6×6 truck with twin dual wheels on the rear axles. There’s an additional pair of functional spare wheels mounted up top. That’s 12 aluminium wheels and heavy-duty tires for this Zetros 6×6 truck! The wheels feature attractive, black metal hubs and the tires are super firm. There is some air inside, but its only from the moulding of the tires. There are no foams and they hold their shape due to the sheer amount of material in their carcasses. For a heavy towing truck, the wheel and tire choice is completely appropriate. Tread pattern is good for an off-road capable truck and besides all that, they just look fabulous.

Electronics

The truck ships with a 55-turn brushed 540 motor, a 9kg steering servo and a pair of 4.5kg shifting servos for high/low and diff lock duties. The ESC (Electronic Speed Controller) is a HobbyWing WP-1060 with integrated 6v/3a BEC (Battery Eliminator Circuit), which powers the radio and servos. The radio is a 6-Channel DumboRC system. The high-low/diff lock function is located on the 3-potision Channel-4 thumb switch.

The ESC is waterproof, as is the motor. However, the servos and radio gear are not, so keep that in mind if you plan any extended outdoor adventures. The radio transmitter requires 4x AA batteries and the truck runs best on a 2000mAh to 2500mAh 3S 25C+ LiPO battery. It would run acceptably on 2S or even NiMH stick packs and there’s sufficient room in the battery tray for up to 5000mAh 2S LiPO or 3500mAh NiMH stick packs. For best results use a 3S LiPO. We’ve been using 2200mAh 3S 30C packs and the truck has been perfect.

Lastly, there are several spare channels on the included radio receiver. These will be welcome if you have a trailer that needs a channel or two for tipping, support legs, third axle, hydraulics and so on. The radio suits the truck and possible intended uses perfectly.

The Driving Experience

Our initial video review (as shown above) was all about the truck itself. Because of our drive shaft problems, we never really got a chance to showcase much actual driving! We’ve been enjoying the truck for some months since that initial review and it’s running beautifully. It seems timely we make a follow-up video that covers all the main elements of operating this big rig outdoors. In the below video, we cover high and low speeds, diff lock, steep ascents and descents, side-hilling and even some mild rock crawling.

We also discuss towing. However, as we have yet to find a suitable trailer to use with this truck, all driving so far has been done with the hitch plate empty of load. That makes for a rougher ride with those super-firm rear leaf packs, but the heavy diffs and ultra-low center-of-gravity have made up for any shortcomings in smoothness!

In short, the truck is a pleasure to drive and it looks fantastic on the trails. Catch the video for the longer answer!

Let’s Torque About It

Once we got the drive shafts sorted out, the next thing to improve was power efficiency and torque. The included 55-turn 540 motor was definitely appropriate for the big truck, but we wanted a more broad speed range and better battery life (though it’s pretty good for brushed, already). We installed the all-in-one HobbyWing Fusion 1200kv motor and ESC in place of the 55-turn brushed motor.

The Fusion gives unparalleled smoothness and control at low speeds, even under load. This is thanks to the FOC (Field Oriented Control) system HobbyWing employs in their Fusion and AXE line of brushless systems. The motor spins according to your throttle input and is computer-controlled to maintain that speed even under load. More traditional brushed, sensored systems will slow as load is applied, requiring you to increase throttle signal. The FOC systems instead will boost power to the motor to ensure it delivers exactly the RPM you ask of it, regardless of load. It’s a bit of an acquired taste and maybe not for everyone, but on a heavy truck it’s just fun, fun, fun. Very satisfying to see this thing inching its way up a stupidly-steep hill, or to exude buttery smooth control down a steep rock face!

Water, Light & Sound?

Power system aside, the other upgrade you may consider down the track is to install a waterproof servo set. The default equipment is fine and the steering strength is ample for this kind of model, but you’ll need to keep the truck dry above axle height. You’d also want to waterproof the radio receiver for wet running.

A light and sound kit might be last on your upgrade list. There’s a premium version of the truck out there that includes these, but is hard to find. Besides that, it’s worth noting the all-metal gear drive train sounds pretty good on its own when running, even under no load. There’s a lot of sound under throttle, but it’s a pleasing pitch and it sounds like there’s a lot going on inside. It’s quite a fun rig to drive and again, it looks fantastic.

The Verdict

If you want to add a 1/14 scale truck to your stable with off-road capability and/or heavy towing capacity, the Zetros 6×6 truck should be on your short-list. Regardless of vendor, its cheaper than the other off-road (ish) options from the likes of Hercules Hobby, Tamiya, JDM and LESU. Price isn’t the only attraction; this thing is absolutely capable. Decent price and performance, plus it’s gorgeous? This one is easy to recommend!

Where to Get It

The Team Raffee 6×6 model is available here & the TR 4×4 model is available here. Both these links are from the ever-reliable AsiaTees online store. Alternatively, you can find the truck on the Highway Toy Store here. Lastly, it sells under the RC4WD Sledge Hammer badging here.

One Last Thing

Like the Zetros model? Enjoy playing with Lego? We’ve got an RC Lego Zetros to show you, too! Check it out here: https://youtu.be/moggvEgLaP8

Craig Veness

RC-TNT

Craig has been into radio control since the 90s and into RC crawling since about 2010, when a Losi MRC started the obsession! Now it’s all rocks this and crawl that and upgrade all the things! …You know how it is, right? Welcome home 🙂

RC4WD Trail Finder 3 RTR w/Mojave II Hard Body Set

by Craig | Apr 2, 2022 | RC Crawlers, RC Reviews, RC4WD

RC4WD Goes Back to Its 80s Roots

RC4WD has released the Trail Finder 3, after enjoying a decade of leaf-sprung, scale dominance in the 1/10 RC hard-body crawler arena. The Trail Finder 3 is certainly different to its predecessor, the Trail Finder 2, but it isn’t necessarily what you’d call “new”. We’ll get to that below as we take a closer look at RC4WD’s latest hard-body scale crawler and trail truck.

Out With The Old…

…and in with the, er, same? Well, yes: the Trail Finder 3 rocks the Mojave II Hard Body Set, same as on the Trail Finder 2 (see our TF2 video here). It’s finished in a new color – glossy white – and comes with a few choices of decals on the sticker sheet. The body is molded from ABS plastic and features a black flat bed and various scale trim pieces, such as side mirrors, wipers, chrome door handles and an intricate multi-piece front grille. There are light buckets front, side and rear, ready to be populated with an LED light kit if desired.

What’s actually new here is how the body sits higher on the Trail Finder 3 than on the Trail Finder 2, plus the glossy white finish and a windscreen sticker that says ‘RC4WD TRAIL FINDER 3’. And that’s about it. There are no wheel arches, so looking from the side you can still see into the chassis and through the other side. The body also suffers from the same clumsy 4-screw plus two body pin mount points as employed on the Trail Finder 2. So far, we could be looking at a minor model update for the Trail Finder 2. Perhaps we’ll find something new and improved underneath the familiar Mojave II body!

Department of the Interior

There is a dash and steering wheel in the body, but that’s about it. With the missing wheel arches, the body seems a little empty. Wheel arches would help to make the vehicle feel more ‘solid’, but even so, you can still see wiring and components when looking down through the windows and windscreen.

Thankfully, Tamiya makes a lightweight interior that includes a new dash and bench seat. For a few more dollars, there’s also a plastic driver model available that bolts right in. It installs without issue in the Mojave II body as the dimensions are identical to the Bruiser and Mountain Rider bodies for which it was originally designed. A coat of paint, 5 screws and you have an interior that helps complete the scale look of the Trail Finder 3 – without really harming its rock performance. That’s a win!

(The part number for the interior is TAMIYA 19000315 and the driver is TAMIYA 54416).

Trail Finder 3 Updates

Immediately obvious are a few changes over the Trail Finder 2:

Steel C-chassis rails instead of CNC-cut aluminum rails;
Wider rails in the rear, tapering to a more narrow front, instead of the Trail Finder 2’s parallel rails. This is also now more like the Toyota Hilux on which the TF3 is modelled as well as going back to its roots, being the same tapered rail profile as on the Tamiya Bruiser;
An updated layout for servos and battery plate;
Stonking great 22R faux engine that looks fit for a truck rather than a small car;
Mid-mounted steering servo with bell crank, taking a step back four decades to the Bruiser’s design from the 80s (but it’s somehow worse than that!); and,
Plastic cross-braces on the chassis rather than the cut alu struts of the TF2.

Geared Up

The Trail Finder 3 RTR w/Mojave II Hard Body Set comes equipped with a 2-speed transmission and integrated transfer case in the one unit. This is a change from the Trail Finder 2, which included a 2-speed transmission and separate transfer case in the kit and a single-speed transmission and the same separate transfer case in the RTR model. You can install an 11, 12 or 13-tooth pinion on the motor in the TF3, but that’s it for tuning by gearing.

The spur gear cannot be changed for a different size, as it’s custom-made for this transmission and features a second, integrated gear. Your only options to change vehicle gearing is to swap the pinion or to a different motor entirely. Even so, this is probably enough – the two-speed transmission gives a useful gap between slow crawl and fast trail drive, even on 2S power. It’s Good Enough for this vehicle’s likely intended purpose. If you need more variation in speed and control, some of the modern brushless systems are well up to the task, in the most extreme case. Stock equipment will be fine for most drivers.

Suspension of Disbelief

The Trail Finder 3 ships with leaf suspension front and rear. This is great for realism. There are 3 leaves in the stack and they’re attached to the Yota II axles with U-bolts. (On the Trail Finder 2 with identical axles, the leaves were attached directly through tapped holes on the axles. Those axle holes are present but unused on the TF3). For reference, the Tamiya vehicles had two rather than three leaves in their leaf stacks, whilst the Trail Finder platform has employed 3 leaves on both the TF2 and TF3.

The leaves look great but there are two problems. Both can be addressed, one more easily than the other:

The leaves are too stiff for the weight of the body. This impedes articulation. The easiest remedy here is to remove the middle or smallest leaf on each corner. Removing the smallest leaf will give a softer ride through the entire articulation cycle (ie. it’ll be softer from slight to maximum articulation), whilst removing the middle leaf will give softer travel at first, increasing to stiffer articulation at a higher point. Experiment to find what you like best – or even remove both the small and middle leaves if you like. Try, test, adjust as needed.
The bigger issue is one that affects both scale and steering: the front leaf suspension has the shackles at the front and the static mount at the rear. The Trail Finder 2 did this too, in stock configuration. Functionally, the leaves can still cycle but it means there’s a lot of slop in the steering. Not ideal. To fix this, you’ll want to move the solid mount to the front and the shackles to the rear of the leaves. Some cutting may be required – but make this one of the first things you do and you’ll find improvement.

Steering Me Wrong

If there’s one overarching design oversight with the Trail Finder 3, it’s this: sloppy steering. Seriously sloppy steering! The mid-mounted steering servo moves a bell crank that moves the steering link, which moves the behind-the-axle (BTA) steering. The original Tamiya Bruiser, Mountain Rider and Mountaineer worked the same way, though with a one-piece bell crank. Meanwhile, the TF3 bell crank is a three-piece design (just the bell crank!) and there is a LOT of movement in the lower arm on the bell crank. In stock form, there’s way too much movement in the front wheels. This needs to be addressed. We’ve tried tightening it further, but that results in binding.

There are a few ways to go about this. We could remove the mid-mounted steering entirely and fabricate a bracket for the steering servo to mount up-front like a more traditional CMS (Chassis-Mounted Steering) design. However, that may detract from the pretty look of the chassis and may introduce other problems with geometry. The better solution may be to try to improve the bell crank assembly, removing the slop in the lower piece on the crank pivot shaft. We’ll keep you posted on this – we’ll do a video for the TF3 with some fixes in the coming weeks.

The car drives okay in stock form. There is a lot of slop in the steering because of the bell crank issue and the weird backwards-mounted leaf design, as above. But these aren’t enough to ruin the truck. We’ve had it on all manner of terrain over March 2022 in preparation for our review video (linked near the end of this article) and for this article itself. The truck is fun to drive in stock form. Flawed, yes. But fun nonetheless!

Wheels & Tires

Wheels are the standard RC4WD OEM 6-Lug Stamped Steel 1.55″ Beadlock Wheels. They look great. They work well. No complaints here, they really suit the body.

The RC4WD Compass M/T 1.55″ Scale Tires are a nicer design than those that came with the Trail Finder 2. There’s more detail in the rubber and the lugs are all grooved for increased flexibility. The rubber compound is sticky enough and the included foams soft enough that the truck grips rocks well, despite the lack of articulation from the too-firm leaf suspension and the steering slop from the awful bell crank design. They are a big part of why the truck is still fun to drive, despite those two design issues.

Shafts & Skid

The plastic drive shafts RC4WD issued with the Trail Finder 2 for years were known to be weak. They’d break under the torque of even moderate rock crawling, let alone withstanding much in the way of abuse.

The new shafts on the Trail Finder 3 are one area where there’s improvement over the TF2. Though they’re still plastic, their design has more support material in places where it matters. They will still break with tougher crawling, we expect, but you should expect better performance from them before that time. However, anyone who drives their TF3 regularly will find themselves with steel drive shafts eventually. Keep this in mind when budgeting for the truck purchase.

Another area that sees improvement over the TF2 design is the skid plate. It’s no longer the low-hanging aluminium bulge as found on the Trail Finder 2. Instead, there’s now a nice, flat plastic skid under the Trail Finder 3 that is more broad and higher up into the chassis. The vehicle should slide over obstacles that saw the TF2 get stuck, so this is a welcome update.

Scale Engine is Weird

This one gets its own section. The 22R motor that sits under the hood is oversized. It looks suited for tractor or a bigger truck. In real life, there’s no way an engine this big would be found in a pickup. The engine takes up a lot of space, necessitating the mid-mounted location for the steering servo. There is a lot of empty plastic inside the 22R model and yet, the bearings within are tiny, save for one. If running wet, it seems these bearings may be the first point of possible failure. It’s a confounding design, honestly. Still, we’ll see how durable it ends up being. It’s running well so far.

So, the hood doesn’t open. The steering needs fixing. The bearings are concerningly small and the scale 22R engine is ridiculously huge. This adds up to considering removing the 22R entirely from the vehicle and putting in our own custom two-speed transmission. Then, we’d be able to fit the steering servo up-front with the gained room. We’ll have a play with this and get back to you. For now, it stays and it works well enough we can overlook it, monstrously large as it is!

Bit of a Stretch

The included XR3 3-channel 2.4GHz radio system hasn’t changed with this new release, besides minor cosmetic updates. Channel 3 end points are easier to set on the updated version, getting their own dedicated dials. It takes 4x AA batteries and is as power-efficient as any other modern radio. From a comfort perspective, it is lightweight and easy enough to use.

However, as with the included radio on the TF2, you really need two hands to operate it. The steering wheel is just too far away for any but the largest hands to reach with outstretched thumb. This may not be a problem for many, but for those of us who like to drive with one hand on the trails, it’s an inconvenience serious enough to warrant fitting fatter foam on the wheel, a 3D-printed thumb extension or outright replacement to a more comfy transmitter.

Trail Finder 3 Batteries

RC4WD provides branded AA alkaline batteries for the transmitter – handy! They also provide a universal NiMH charger and 3000mAh NiMH battery in the RTR package. This gives ample runtime and charges in about 5 hours from empty. It fits neatly on the plastic battery tray on the chassis and is perfectly suited to this vehicle. The ESC has a jumper you should change if you swap to using LiPO batteries. This will ensure the low voltage cut-off is activated to protect your LiPO batteries. (NiMH can be run flat without problem).

Manual & Stickers

RC4WD gets the manual pretty much right. It’s issued in multiple languages, wrapped in an attractive cover. There’s a sticker sheet included with two different designs to put onto the truck. The manual includes a page with a guide for where to apply these stickers, which is welcome and most helpful. There isn’t much in the way of troubleshooting for this RTR machine, but the internet and RC4WD after sales service is something we’ve used from Australia in the past – and they’ve been responsive and speedy in their resolutions. No problems here.

If we could add one thing to the manual, it would be exploded parts diagrams of all the gear in the vehicle. The TF2 shipped as a kit and RTR option for years. Getting the ‘kit’ manual on both variants can be helpful with servicing and parts replacement and it’s something that would have been appreciated on the Trail Finder 3 RTR.

The Verdict

We’ve travelled 3,000 miles with this thing over March. Driven it on the beach, rocky headlands, sandy trails, dirt trails and on our rocky comp test course. We’re looking forward to working on it and improving it, which will add to the eventual satisfaction of making our TF3 look and go the way we want.

Issues notwithstanding, the smiles per mile are such that we can still recommend it. The Trail Finder 2 was (and remains) an excellent scale choice, but the Trail Finder 3 adds a solid next page to the nearly 40-year heritage of the Tamiya Bruiser that started it all back in 1985.

It is not without its design issues but on the other hand, nothing here is bad enough to overshadow the strongest thing the Trail Finder 3 gets right: fun. It’s fun to drive! It looks great and it goes well. And for this hobby, that’s pretty much the whole point, isn’t it?

Craig Veness

RC-TNT