Have you ever wondered exactly what you get for your very low outlay with some of HobbyKing’s models? Not taken the plunge because you weren’t sure? Well flail around in darkness no more and let me enlighten you.

(note that the battery shown in the pictures is NOT provided with the model)

Intro…

When buying for young people, or newbies, there’s always the problem of how much to spend on someone who ultimately may or may not be interested in the hobby. Therefore it makes sense to go cheap, however, in the not so distant past, to ‘go cheap’ meant buying some pretty sub-standard kit and hoping for the best (that it wouldn’t break within the first 2 battery packs), but hey, at least a lot of money wasn’t wasted, right?

On the other hand, is it a good idea to give someone their first taste of RC at the lowest level? I wouldn’t want anyone to think that a sub $150 car is representative of what the hobby has to offer, so it’s a double edged sword. The solution is simple of course! Decent quality for cheap…but is it doable?

Of course it is. You just have to compromise in the right areas and not compromise in the critical areas. So let’s take a look at this recent entry from HobbyKing, a company that is rapidly cornering the ‘low price, high value’ market. Have they solved the age old riddle with their ‘Rattler’?

HobbyKing itself is quite the phenomenon, I realise it probably existed in some guise long before it became mainstream, but in the last 5 years or so, wow, what a surge into the spotlight. I’m sure for a lot of you, as for me, my main business with HobbyKing up to now has been for cheap lipos (or should I say ‘correctly priced lipos’, but that’s another discussion). My personal focus isn’t often on the budget end of the hobby and I have yet to try any of their models first hand, so I’m particularly glad to have the opportunity to finally make a meaningful comparison and let you guys know what the car is like and what I think about it.

About the Rattler…

The Rattler is available as a brushless RTR (review sample is RTR – Ready to Run) or ARR (no radio supplied, Almost Ready to Run). In name, it is a 1/8th Off Road Buggy. I’m going to get the obvious negative out of the way here at the start, although it shouldn’t really be much of a surprise at this price point…this is not a ‘true’ 1/8th buggy in the sense we have come to expect. It does not have 3 differentials, it has a 36mm motor (albeit a 4 pole unit), not 42mm, and the ESC is rated for 2S and 3S, not 4S to 6S like a 1/8th. Don’t groan too much though. True 1/8th cars need all that power to move their significant weight. The Rattler is noticeably lighter than a racing 1/8th e-buggy ready to run, so in and of itself, 1/10th size electrics shouldn’t be a significant issue, especially given that 4 pole motor. Suffice it to say that this is a 1/8th car in physical dimensions only, everything else on the car is typical of 1/10th size.

Out of the box

The box itself is decently attractive. It also plies us with our first tidbits of info about the car, for example, the kv of the motor (2700 in case you are wondering), the fact it’s a 4 pole (nice), the speed controller rating (40A). Yikes, but I’ll reserve judgment, since amperage requirements in recent years have got out of control and are nowhere near the much lower realities, this ESC may well be fine in this lightweight application, we shall see very soon. Other standard stats like dimensions etc, but lastly and interestingly, a servo rating; 9kg. I think this may be the first time I’ve seen a servo rating on the outside of an RTR box. Not a bad inclusion at all, and a decent selling point; 9kg/cm (about 125oz-in) is right around the minimum acceptable spec for a car like this and better than a lot of RTRs. It’s nice to know that it’s something that won’t require immediate replacement, as it does on many other budget RCs. It’s no powerhouse, but it will allow the car to handle as intended, it shouldn’t be struggling to turn the wheels.

Inside the box, the car is suspended on the edges of its tires. It’s not a bad design, and the wells that the tires sit in are also round to spread the load on the bottom third of the tire, but it might have been better to have the tires fully suspended. There are no flat spots or malformations on any of my tires, but then this is a new review sample, when they’ve been sitting on the shelves for years, it may be a different story.

A separate compartment contains the radio box (a retail box of the well-known budget 2.4Ghz radio, the HK-GT2E), I’ve never seen a retail box included with an RTR radio. Usually they come in white unmarked boxes, so that was a nice surprise.

So, the box and packaging are decent, not that this is something that is really important, but it’s nice to see it, especially at this price point. I remember back in the day, often receiving OFNA stuff in completely unmarked boxes with no manual to speak of. Things have moved on a fair bit in terms of doing better business in the last decade or so. Boxes on shelves, pictures on the internet, it doesn’t matter, what you get in your hands is what counts and it’s always that bit sweeter if it looks good before you open it.

Also in the box are the wing (attaches with 2 clips, included with the wing in a little cellophane bag) and a full assembly manual. The car is already assembled, but having the manual means it can be completely disassembled and reassembled if you are one who likes to do such things (I am, so for me, this is a great and important inclusion).

The car once out of the box is pretty big. It’s about the same size as a 1/8th buggy, naturally, but the chassis and body are slimmer. It’s not the most attractive buggy body I’ve seen, but it isn’t bad. The paint design is ok, pretty generic. It does grow on you though as you get used to it, and it’s not ugly by any means, somehow it has character. Beauty of course is in the eye of the beholder, so if you disagree, I’d love to hear about it in the comments.

Have to mention a mildly amusing fail, though I’ll forgive them, because maybe they were rushing to get review samples ready. I hope so anyway, cos there are very few other good excuses for… Failing to take the body overspray film off before applying the stickers. Yup, that’s right. Epic fail. Never mind, hardly a deal breaker.

Specs:

Length: 460mm

Track width: 270mm

Height: 150mm

Wheelbase: 325mm

Weight: 2.15kg

Motor: 540 size sensorless 2700KV 4 Pole

ESC: 40A brushless

Servo: 9kg steering

Wheel size: 110x55mm

Wheel hex: 12mm

Battery Tray Dimensions: 142x46x24mm (MAX battery size)

Required:

4 x AA batteries for transmitter

2S-3S 5000mAh lipoly battery

Features in detail



Starting at the back today, we have a composite wing which the user has to initially attach with the supplied clips (keeps the box size down). The wing is quite thin plastic, but if you consider that a lot of models these days, including a few premium ones, use lexan wings, if durability is your goal, you’re already ahead of the game. It’s not quite as sturdy as a Proline 1/8th wing of course, but then it doesn’t cost 20 bucks to replace either. 😉

The wing mounts to the rear shock tower, which is made of plastic. I really don’t know what to expect from these composite shock towers until I run it. They’re quite meaty and seem quite strong yet also somewhat flexible. These and a few other load bearing parts seem to be made of a different composition of plastic than others, so I expect some kind of extra strong plastic has been used here. I‘m interested to see what happens, as shock towers are traditionally a weak point on any buggy that exposes them in this way.

Suspending those big wheels and tires, is a set of fairly large bore, long travel shocks. The plastic bodies are threaded and secured with alloy caps. The spring rate and oil selection seems well suited to the weight of the car with the battery in it. They’re actually really nice in action, I can see the crawler community liking these as capable budget shocks.

The shock towers attach to a typical bulkhead/diff holder assembly, which is the focal point both front and rear, everything attaches to it, including the upper and lower A arms, as well as the top deck of the chassis. Attaching the arms in this way reduces adjustability (no roll center, more limited camber and no anti squat adjustments), but offers the neat advantage that they are identical front and rear, as well as symmetrical. This is great, as it means when ordering replacements, you don’t care front or rear, or left or right, only upper or lower. This is also a significant saving on manufacturing process as well as simplifying the building process meaning money saved all around, including in the hobbyist’s pocket.

Essentially, the entire major front and rear assemblies (bulkheads, diffs, arms, shocks, shock towers, knuckles, hinge pin holders, bumpers, wheels and tires) are composed of the same parts front and rear. Some are arranged in reverse in comparison to the opposite end, but all parts are common, continuing this theme of cheap to replace, easy to produce spare parts. The only exception to this is that the front and rear control arms (steering links on the front, toe links at the back) are different; the front items are impressively, fully adjustable, reverse threaded turnbuckles. They’ve even been assembled correctly!! At the rear we find a slightly different and less adjustable arrangement involving a ball cup threading into a molded piece. I think this has something to do with the ‘Active Toe System’ that is alluded to in the blurb on HobbyKing.com for the car, though quite what it does or why this is better than using the same turnbuckles in the rear, I cannot fathom. It’s a curious decision not to go with the same turnbuckles as in the front, further enhancing this symmetry of parts, as well as providing better and more intuitive adjustability. The rear toe links are slightly adjustable as they are, but this seems like a missed opportunity.

The front and rear bulkhead assemblies are screwed to a basic composite shallow tub chassis with a stamped alloy top deck. I use the word basic not in a derogatory sense in this case, this is one of the beauties of this car, there’s no over-engineering. The chassis layout is one of the simplest I’ve seen; battery on one side, motor at the back, closed electronics box at the front and that’s all there is to it.

The alloy top deck provides good front to rear rigidity, while the composite nature of the tub gives good lateral flex, this should make the car progressive and predictable even over very rough stuff.

At the back of the chassis, the steel (yep, steel) spur gear pokes through the top deck. Just in front of that is a cast alloy two piece sliding motor mount. I really like these simple motor mounts, this is a good one with a good range of adjustability for large and small pinions. Speaking of pinions, the one supplied is also steel. The gears are MOD 0.8 pitch and feature a 17T pinion and a 48T spur. The drivetrain is also all steel, with planetary oil filled diffs front and rear.

Mounted to the sliding piece of the motor mount is a blue Hobbyking 4 pole 2700kv 36mm motor. There’s little to comment on here, its a sensorless unit. The motor should be adequate for the application, but we’ll talk more about how the car runs later. Of slight concern is the lack of information about the speed controller. I can’t find anywhere, any ratings for the ESC (even on its manual page), except the claim on the outside of the box: 40A max load, which sounds low for a car like this. I had to check the Rattler’s page on hobbyking.com to determine if it could take 3S batteries.

That conveniently brings us to the battery tray, which definitely cannot accept 3s batteries in its default out of the box state (see battery dimensions, then find me a decent 4000mAh+ 3S that fits…good luck). Personally, I’m expecting to get more out of this car running it on 3S, however, I do not possess any 3S batteries that will fit in that tray (or more accurately would allow me to close the tray flap/cover/thingy). Even the 3S battery that Hobbyking kindly sent for use with their reviews is far too big for this car. It’s a silly design that even when used with an appropriate 2S battery is still bad, failing to hold the battery down with any conviction and generally feeling loose. It would have been far better (and cheaper, surely?) to use a standard velcro strap solution, allowing any height battery, while maintaining the lateral dimensions, this would allow most 3s surface packs to be used with ease. To see how I personally solved this little conundrum, see the Extra! section right at the bottom after the video. If there’s anything this hobby has taught me, it’s never to despair; with a dremel and some duct tape (or in this case, just a little re-purposing of some existing parts), you can fix anything in the universe. 😉

The super clean looking layout of the chassis is down to that large electronics box that keeps all your wires tidy and out of the way as well as the majority of dust and water out, though there’s a vent for the ESC to get air, so there’s no way this is waterproof, but it looks like it should provide some protection. The aforementioned vent for the ESC is very small and I can’t see anywhere else for air to go in or out, so it’s going to be trying to get in and out through the same tiny grille and won’t be doing a great deal of effective cooling. We’ll have to keep an eye on that, especially with 3S running. The little port on the top that features that smart cable routing is a genius touch, keeping everything looking tidy at all times.

On the subject of ingress of foreign materials, it’s worth mentioning that the bottom of the body hugs the chassis sides quite well, so a strip of velcro will also provide a good seal to prevent ‘stuff’ getting into the chassis pan, as well as negate the need for the fiddly body clips; this is something I will definitely do on this model.

Inside the radio box you find exactly what you would expect to find, a servo, a receiver and an ESC. It’s not cramped in there, and the ESC is positioned to make access to the programming button easy. The servo horn however is particularly thin; I definitely feel this is an area which could be improved. It doesn’t need to be alloy, though that would be nice, it’s just the stock one is very small, thin and pathetic looking. The geometry of the steering system however, is perfect. Many times on RTR models (and not just low budget ones), we see uneven steering throw. The right angles in this system ensure exact same steering throw both sides at the same speed, despite the jaunty angle of the servo on the chassis; it’s reassuring to see this wasn’t ignored.

Moving to the front, I already mentioned the only difference compared to the rear, and it’s those steering links. Very nice proper reverse threaded turnbuckles. This neatly takes us into what is arguably the finest feature of the car. Adjustability. The genius decision to use PBS (pillow ball or pivot ball suspension) immediately and innately provides free access to camber and a degree of track width. With the turnbuckles providing toe, you’ve got the really important settings covered, though again this makes the omission of turnbuckles on the rear toe links a glaring one.There’re no roll center adjustments here, nor droop, or even caster, but you’ve got what you need to tune to a surface and the natural droop setting is perfect anyway. Combined with the threaded bodied shocks, this is definitely one of the more adjustable RTR models around. The shock towers and A arms also provide multiple shock mounting positions both top and bottom to further extend the options.

Finishing off the features section, miscellaneous worthy mentions include the sealed oil filled diffs, they have a fairly thin oil in them from the factory which leads to a good deal of unloading and wheelspin, but you could always put something thicker in there. Additionally, the model is ball-raced (bearings) throughout, with the exception of the steering system. The hinge pins are captured, which is always a nice feature; C-clips are finally starting to disappear, even in the RTR segment. All the hardware is hex variety, no Philips heads here.

The drivetrain is exactly what you’d expect, dogbones all around. They could actually have used a little more bolstering in the drive cups, the bones slide in and out a good deal. It’s not a problem, but it’s not very reassuring either; nobody enjoys looking for dogbones that popped out at the bash spot, and how much would it have cost to put 8 o-rings in the cups just to reduce some slop? They gave me no issues during running, just saying.

The wheels and tires are oversized even compared to contemporary 1/8th buggy tires, they are noticeably wider. The off white nylon wheels have an unfinished look to them, but the material feels reassuringly strong and flexible. The tires include foams, are already vented and very securely glued to the rims. Pin spikes are always a good choice for an off road basher, these tires will work great everywhere, though they’ll probably wear out pretty quickly.

Enough talk. Let’s ride…

As soon as we arrived at the bash spot we got going. I strapped the 2S pack in as my helper fired up the camera.

Immediately, I was impressed by the car’s pure stability, I knew it would be an easy drive with that super flexible chassis, fat tires and soft shocks, but the thing really was planted. The out of the box setup is ideal for the beginner, very easy to handle. As you can see from the short video, the car did not want to flip over. I think I flipped it only twice the whole session, despite the super rough ground. There was a lot of off power oversteer with the out of the box setup (those diffs really need thicker oil), but this was manageable once I got used to it.

The performance on the 2S 5200mAh 30C Zippy Lipo that HobbyKing kindly supplied for use with this model (excellent workhorse batteries for any level of hobbyist at a great price), provided performance far above my expectations. The gearing is very nice for 2S, giving sharp throttle response, quick acceleration and a satisfying if not earth shattering top speed (hey, it’s a 2700kv motor. On 2S, it was never going to be a speed demon). It was certainly more than fast enough on the rough ground where I normally run. My assistant, new to the hobby, was impressed how fast it was, so I guess that’s the reaction you can expect from this vehicle’s main target audience, it certainly is a fun car to drive, easy and quick.

When I tried a 3S battery (battery tray modification required), I was surprised how quick the car was. It suddenly becomes waaaaay too much for any beginner. Unfortunately, I don’t have this on video as I couldn’t get more than about a minute out of the car on 3S before everything slowed to a crawl. I assumed it was the ESC getting hot (thermalling), so I opened the receiver box flap thing to get a bit more air to the fan, but it didn’t seem to make any difference. It is possible that my battery was at fault, though I had no issues with it last time out. To be completely honest, I will not be running this car on 3S anyway, regardless what the problem is, it’s just too much power for what is really quite a soft car, I feel that expecting consistent, consequence free 3S performance at this price point is just being greedy. The performance on 2S is ideal for the target audience of the model anyway, and satisfying still, even for me as someone used to much faster models.

Did it break? Well, technically no, but yeh, it broke. lol. I didn’t have high expectations, naturally. I was always going to try to avoid major incidents with this car, so with a little trepidation, I handed the controller to exactly the kind of person that this model is aimed at. While a mature individual, my friend has little to no experience with hobby grade RC, and promptly crashed it head on into a curb. That’s fine, these things happen, and it didn’t seem to have suffered much, if any damage. Within a few seconds we realized the error in that assumption as there was a loud clacking noise on acceleration. Removing the body, I can say I was pretty surprised to see the damage below.

This was not a hard impact, but it wasn’t a light one either, no plastic was broken, just a scuff on the bumper, the hit was directly head-on into the curb.

Unfortunately, as you can see above, the car underwent a minor redesign with new and sexy curved parts. I thought the day was over right there when I realized that not only was the top deck banana’d in a fun and interesting way, but also the center driveshaft. Not wanting to admit defeat after less than two full packs, I decided to see if I could straighten anything with the limited tools I had brought with me.

Imagine my surprise to discover that I was able to straighten not only the top deck without any difficulty whatsoever, but I was able to bend the driveshaft back into shape as well, with my bare hands! I had straightened both perfectly without any flat surface, just careful bending with my fingers. On the one hand, these parts are going to bend if you so much as look at them funny. On the other, they are ridiculously easy to fix in seconds. It’s hard not to see it as a bonus when you consider that this amount of damage would have ended my day with many other models.

Once bent back into shape and reassembled (6 screws all done), the car was as new again. The parts did not bend again throughout the day, despite an additional minor encounter with a rock some time later (that one’s in the vid below). Remarkably, the car suffered very little from this apparently significant damage, it ran just as it did before.

The radio gear performed mostly admirably. As is so often the case (or curse) with RTRs, the less said about the servo, the better. It works, that’s about the kindest thing you can say really. In its favor, it seems to have plenty of torque, but is very, very slow. Not unexpected, but still disappointing. The radio itself was a standout part, needed zero fiddling, and worked perfectly.

Verdict…

So, as stated at the top, what exactly do you get for $149? I am able to report (and it sits well with my view of the universe that this adage still rings true) that you still ‘get what you pay for’. The car is soft in every way, plastics and metals alike, but that gives two important advantages…easy field repairs and even easier handling. The cleverly simple design, the ease of repair, the cheapness of parts are all ‘good things’. The out of the box performance and handling are also no less than ‘excellent’ for the money.

The car looks good, is a good size, and feels very direct and nippy. In the end, the electrics that I had minor concerns about didn’t even blink on 2S. No heat issues whatsoever in motor or ESC, both cool to the touch even after extensive running, another testament to low real world requirements as far as amperage handling goes. In this mid weight car with a 4 pole motor, the 40A ESC proved more than adequate. Quite what was happening on 3S for me, is still under investigation, though I note from surfing around that others have had this model working fine on 3S for longer than I did, as well as others also referring to ESC thermal protection problems. In any case, as mentioned, I don’t think 3S is where this car is at anyway, there’s no need to strain it in that way to get a good deal of fun out of it.

When you take the overall package, and the price, combined with the good performance, it’s hard to complain, between some excellent points and some bad ones, we arrive at a decent middle ground somewhere between acceptable and good, leaning toward good, and at least we can confidently say that this is probably the best full size, fully RTR RC you can get for less than $150. Good job HK, you pretty much nailed it, this is a fun car for anyone, just be a bit careful with it. 😉

Summary

Hits: Highly adjustable, strong powerplant, good performance, good looking, good radio, steel drivetrain.

Misses: Weak materials bend easily, steering servo, stickers applied to overspray film, battery tray.

Availability:

http://www.hobbyking.com/hobbyking/store/__75465__H_King_Rattler_1_8_4WD_Buggy_RTR_.html

Running Video

Extra!

So, I said I’d let you know how I solved the battery tray problem…the pieces of plastic that stand up on either side of the battery tray, which effectively hold the battery laterally, have a track going through them, they almost seem as if they were designed with lipo straps in mind. Unscrew these parts from the underside of the chassis, thread your velcro strap through the right amount to get a good grip on the battery you want to fit, then tighten the plastic parts down again (slightly longer screws are a good idea, I’m even considering drilling them through and using a small m3 nut, just to make sure, since they are now taking the majority of the weight of the battery).

You will need to remove the circlip that holds the existing battery tray arm cover thing, so you can slide the pin out and get rid of it. You can see the result if you look again at the picture of the damaged top deck above, a standard velcro strap solution. One strap isn’t ideal, but it is adequate, I had no issues all day.