HOOBEN ELEFANT JAGDPANZER SD.KFZ.184

Hooben Elefant RC tank

07/06/13- This might have been a build article if only I'd built it, (and I'd love to claim that I did!) but I didn't-- I bought it. I wasn't in an RC tank phase when Hooben released the Elefant kit a few years ago in 2011, but I stayed abreast of the hobby enough to know about it. Back then I kinda-sorta wanted it, but frankly, the Elefant doesn't have the iconic aesthetic appeal of a Tiger I. Not being in an RC tank phase gave me a practical perspective: Where would I put it? Did I want to go through the process of buying expensive upgrades, then trying to figure out how to shoehorn and rig mechanisms that weren't designed for it? At the time, my remembrances of my last Frankenpanzer project I'd worked on (the Pzkpfw IV) were that it hadn't been the gratifying and rewarding success I'd hoped for. Plus Hooben had a sort of checkered reputation among forumites for the quality and fit of their kits, especially the T-55A. Some have reported horrible castings and occasionally missing or wrong parts. When you're in a DIY tinkering mood, that can be an interesting and gratifying challenge; when you're not, it can be seen as work, frustration, and time-suckage. I suspected that if I didn't buy when it was fresh from release, it would likely be very difficult to buy later, and at an inflated price-- if you could find it. Two years ago, the nays were stronger than the yeas, so I passed.

Well, now it's later. Since I'm in one of my cyclic hobby binges, the clarity of practical considerations has dispelled, replaced by the fog of RC tank-lust. As I expected, it's practically impossible to find in stock anywhere nowadays (the hooben.com site shows it and allows you to add it to their cart, but I doubt it's actually available. In fact, I've read that Hooben has abandoned the RC tank field due to meager profits.). Unlike the Tiger or Sherman tank, the Elefant isn't a hugely popular tank with versions made by every RC tank manufacturer and with a wide selection of upgrade parts. That means that if you find one and want to splurge on it, you have to do a lot of looking around for a shrinking supply of upgrade parts, and a lot of waiting around for those parts to arrive. I hate waiting for parts!

That's why the ready-To-rock eBay listing was so attractive. It already had the most useful upgrades: Kenny Kong metal tracks, upgraded black can 480 motors, ElMod electronics, ETO's metal cannon deck, ATAK zimmerit panels, and more. Someone had agonized over the infamously frustrating sections of the build --the wheels and suspension-- and figured out how to rig the recoil, traverse, and elevation mechanisms. Yep, to get everything all at once, the lazy man's way... how sweet it is! Assuming that I could find the upgrade parts, I'm not sure that I would have saved any money doing it all myself either, since doing fancy upgrades is not about saving money.

There's a downside to not building it yourself, and it's a pretty significant one. Most builder probably don't build strictly "by the book", which isn't necessarily a good or a bad thing. Many times it's a necessity, sometimes it's to improve functionality or accuracy, and sometimes it's because the builder didn't think a step or feature was important or worthwhile. In any case, when someone else builds it, you don't know the history or anything about the builder's level of experience or mechanical intuition. Did the builder put lock-tite where it was needed? Did the builder identify weaknesses in the manufacturer's design and address them? Did the builder make it easy to access parts that might need adjustment? When someone else builds it, you just don't know. There's also the matter of a previous owner who didn't build it, but who might have modded it to better fit their preferences. It's all part of the unknown history of the kit.

It's a damned fine-looking build though, and I do have a lot of respect for and confidence in the reputation of the builder. Interestingly, while waiting for it to arrive, I searched for information on the RC Elefant and stumbled across its build thread on a forum. Very cool read, with lots of information and insight. The builder's talent became evident in the collection of close-up shots in the thread, something I hadn't realized from the auction's photos. I'd been estimating its worth to me in terms of the cost of parts and the convenience of not having to build it, but once I saw the other pics, I knew that it had value as the work of an artisan; something that I might be able to learn from.

In fact, there are quite a few Elefant build threads out there for the price of a Google search. Many of them had great step-by-step photos and valuable construction insights. Once my Elefant arrived, I found these extremely helpful to me, along with the printed instructions included with the kit. They helped me understand what I'd bought and how it was assembled and how it differed from the build instructions. The manual was particularly interesting because it shows a vision of what the manufacturer/design team intended... but what wasn't actually shipped. For example, there's mention of a video system, and it looks like they intended to include Clark Model's electronics-- at least the instructions for operation show the same distinctive stick movements. (Oddly enough,they're much clearer in the manual's explanation than those on the Clark website). From the instructions, it seems like an outstanding kit, much more ambitious than any other tank I've encountered. Of course, reality doesn't always match what goes down on paper.

Hooben Elefant RC tank

The builder had installed ElMod's ECO electronics with the Blaster 4 sound board and CSI battle module. Coincidentally, I'd just replaced a failing (overheating) early version of ElMod in my Tiger and was missing its unique sounds. At first I was a little apprehensive, given my experience with the failed board. I'd also just learned about and ordered the Clark TK-22 board but hadn't received & installed it yet. I was wondering whether I might want to replace the ElMod with a Clark... all before even having seen or touched the tank in person. Hey, when you're waiting for something like this to arrive, you think of stupid stuff. Anyway, I was pretty stoked, waiting for its arrival.

It Arrives: The moment I'd been waiting for. It arrived in pristine condition, and as I held it aloft to admire it, I was a little surprised that it wasn't quite as heavy as I'd expected for such a big tank. Of course, it didn't have a battery in it yet, and I'd been accustomed to the handling feel of my other tanks with batteries. It's probably because Hooben uses fairly thin plastic, so despite its size, there's a fair amount of air inside. And wires, too. Basically, my first impression from handling it was a sense that it was more delicate than my other tanks, and that's a good thing to know from the start.

Disassembly: It took me a while to figure out how to get the sucker open, but it turned out to be relatively simple: Two screws at the rear and the rear of the turret section lifted; I pulled the turret back from the tabs tucked under the front deck. The front deck was secured by strong magnets.

Fitting the Battery: At this point I was just exploring, but was also trying to fit a battery to test it out. I knew that it was set up with Deans plugs, and I had a LiPo with Deans plugs ready and waiting. I saw that the tank had a battery compartment, accessible from the bottom. I tried putting the LiPo in the compartment, but it didn't fit; I also tried a NiMH with a Dean's adapter, but it didn't fit either because of the tank's short plug and the length of my battery wires. Clearly, it was meant to fit the previous owner's specific collection of batteries, but not mine. There was surprisingly little free space inside despite being such a big, voluminous tank on the outside, so I couldn't place the battery inside either. I was looking at some doing some rewiring anyway and I'd already decided to replace the Deans plug with a Tamiya plug. [I know, I know... Dean's are the choice of pros and heroes, and Tamiya plugs are the devil's work, shitty and unreliable. I've used Tamiya plugs in all my other tanks and have never had a problem. Besides, it's practical to use the same kind of plug for all your tanks. In my opinion, RC tanks are a laid-back thing and do just fine with obsolete transmitters, brushed motors, and NiMH batteries with Tamiya plugs.]

Sizing Up the Project: So I didn't actually get to drive the new tank until much later. My first tests were with a battery outside the body, just to see that everything worked, and to see how everything worked. RC Tanks aren't really very complicated since there are a limited number of things that hobbyists do, even when they mod them with parts from different manufacturers. Even though the mass of wires and wire bundles are initially overwhelming and intimidating, once you start digging in, it all falls into place.

In this case, the previous owner had done a major job of tidying up the wiring. This made it look very clean, but it also made it very difficult to understand the tank. If you're going to be doing maintenance and mods to your tank, you need to understand it and wire it according to how your brain works. One of the first things I did was snip all of the nylon cable ties, pry the boards up and turn it into a chaotic mess of wires and floating boards. This let me create my own groupings and plan where I was going to relocate things.

Hooben Elefant RC tank

This is the previous owner's final tidied-up version (from its eBay listing), and more-or-less how I received it. Despite the appearance of lots of space in the center, it couldn't be used to house a battery because the traverse mechanism and the barrel elevation need that room.

 

Hooben Elefant RC tank

My "improved" rat's nest style wiring. To quote some guy from an obscure film from the '70s, "She may not look like much but she's got it where it counts." There's a lot of extra wire in there from wires that originally went up to the turret. I didn't have the patience to snip and resolder them to a shorter length, so I just velcro'd them into bundles. There are 5 plugs in the same area to unplug when you want to disconnect and completely remove the turret.

 

Design Philosophy: This was an interesting exercise for me because I never realized that I actually do have a guiding design philosophy that I try to follow when building tanks. It's very simple: Assume that you're going to be taking the sucker apart, and make it so you can separate the sections so you can work on them separately. The only time you don't want to completely separate them is to replace the battery, so make the wires between the sections long enough so you can do that without unplugging anything or stressing wire connections.

From a maintenance and construction perspective, most RC tanks consist of a few main blocks: The lower hull, upper hull, and turret. The Jagdpanzer has only a lower hull and a turret. Put as much stuff as possible in the same section. For example, if you can put the external volume control in the lower hull near the sound card, do it. It's one less thing to unplug when you disassemble it. Same with the power switch. Anything that has to go in another section should have a wire and plug that's long enough to reach the lower section. That way, you can unplug everything in one place and the fewer things to unplug, the better. That's the ideal, but sometimes you have to diverge from it, especially for controls.

Gutting the Innards: Mark or label wires and plugs. I often use different colored Sharpies to make colored dot or line patterns so I can match plugs to sockets for when I don't have to know what I'm connecting... only that this plugs into that socket. Ideally, you do this before you unplug, especially if it's a system you don't understand yet. When you're trying to figure out how it works, it's helpful to label with the function. Thankfully,the previous owner had done this.

In my opinion, don't sweat the wiring hygiene (within reason). It's much more important that you group wires by function to understand what they're doing. Wires welded in place usually make it harder to do maintenance and troubleshoot. Naturally, you don't want stray wires getting caught in gears; Velcro straps are a quick and easy way to group wire into bundles and change them as necessary.

Killing the Battery Compartment: With the tanks' guts shoved into a heap at the back, I went about Dremeling away most of the battery compartment. For one thing, I don't think battery compartments make it easier to change the battery if you can get the top off fairly easily; turning the tank on its side always makes me feel a bit uneasy. In this case though, the main reason was because interior space was scarce. The turret's stuff was intruding deep down into the hull compartment when the cannon was aiming high. The horizontal traverse mechanism was the biggest offender because it was mounted underneath the gun platform, dipping deep into the hull space. The battery compartment consumed a huge amount of interior vertical hull space. Anything you put on top of the battery compartment or in the mid section of the hull had to allow space for the traverse mechanism.

Rethinking the Traverse Mechanism: Related to this, I noticed that the traverse mechanism was poorly-designed, with resultant poor performance. Basically, it was an elevation mechanism turned on its side with the arm driving another arm connected to the axis of rotation. Most of the gun array-- elevation, recoil and heavy barrel-- was on a platform rotating on top of a metal plate, controlled by a short arm lever screwed to a pin (the rotation axis) through a hole in the plate, maybe less than a centimeter in diameter. The plastic pin had a flat side to which fitted an aluminum arm. The problem was that this concentrated all the arm's force to rotate the gun platform on a very small area of aluminum and plastic, relying totally on the flat side of the arm's opening and plastic pin to move the platform, which was fairly heavy. Plastic's a lot softer than aluminum, so naturally, the system developed massive amounts of slop. Enough slop so that the arm didn't rotate the platform reliably and you could practically traverse the barrel by hand without budging the mechanism's gears. While you could beef up this mechanism by using harder materials or increasing the diameter of the axis drive, a much easier solution was to mount the mechanism on the platform to push/pull the side of the metal plate (like a venetian gondola pilot) with a simple wire linkage from the gun platform, using the original pin simply as an axle. This relocated the mechanism from underneath the plate onto the top side of the gun platform. This gives the mechanism more leverage and restores a lot of useable interior room to the lower hull. It does require a longer arm to push the platform through its full sweep, so in a sense, the force is transferred to that arm-- but there's less force required because of the leverage. Bottom line is that the traverse works better and frees up more useable space in the hull compartment because the mechanism isn't mounted underneath the gun platform.

Hooben Elefant RC tank

Relocating the traverse mechanism (at right) on top of the deck solved some big problems. The unused remnant of a momentary contact switch hints that a different style of recoil mechanism was attempted, but abandoned in favor of the servo system. Judging by the styrene work and its revisions, it looks like this was a real PITA to get working. Been there, done that, and know the feeling.

ElMod ECO or PRO? While I was deep in the horizontal traverse motor problem, I considered replacing the mechanism with a much more compact servo. My original ElMod board had a socket for servo elevation control, but it never worked very well... maybe the newer version had fixed that problem? I consulted the ElMod manual only to find that the ECO model didn't have any servo options, whereas the PRO model did. Bummer. That also explained why the tank had an extra board specifically to control the recoil servo. This added to the wire count on the interior and made it a little more complicated, but it works fine. Personally, I would have spent the extra 50 bucks or so to get the ElMod PRO, but that's just me.

Relocating the Guts: I moved the speaker on top of a square section of the battery compartment that I'd left intact; this put it directly under the center grill, close to the engine deck. The main ElMod board slid in under it, with the receiver floating in the very front section. A side wall was left intact to support/retain the battery.

This let me relocate the power switch from a hatch in the turret section to under the driver's hatch where the speaker had been located (and where the builder had originally put the switch). A brass bar was mounted across the hull interior to support the switch at an easily accessible height through the hatch. Since the switch wasn't mounted in the engine deck, there was one less wire to unplug for disassembly. Bonus: Now a figure could be placed in the open hatch for display. Along those lines, I also relocated the volume pot from the separate engine deck to the hull, attaching it to the other end of the brass bar. This engine deck hatch was molded with a recessed compartment for the pot. I cut it off to give access to the relocated pot; it also allowed a figure with a hollow torso to be placed there, over the pot's shaft. Again, it was one less plug to detach from the board for disassembly.

Smoker Switch: I added a double-pole slide switch to turn off/on the smoker. To be honest, I'm not big on smokers since the smoke isn't very apparent if there's any wind. In my Heng Long tanks, they always seemed noisy, unreliable and a maintenance hassle-- In my opinion, not worth the trouble. However, the builder had gone to a lot of work to install a quieter and more reliable fan-driven "Super Smoker". The system has dual brass tubing to channel the exhaust to the front at the tracks-- a wierd place, but correct. It's wired with a heat-sink equipped voltage regulator, and tied to the motor power, presumably for proportional control. I haven't studied how it works, but it does. Which led to a moment of panic while I was sorting things out: Smoke is the last thing you want to see when you've applied power to electronics for testing! Anyway, I wanted to put the switch on the exterior, but couldn't find a convenient place for it without running long wires and more plugs. Putting it on the deck beside the smoker turned out to be almost as convenient once I devised a magnetic closure for the turret: It's like the whole turret is a big hatch.

 

Hooben Elefant RC tank

How it looked when I got it; pic from the auction listing.

Hooben Elefant RC tank
Hooben Elefant RC tank
Hooben Elefant RC tank

The original black barrel (1st pic) looked cool and (as I've read) accurately represents the heat-resistant primer used but the paint was chipping off, leaving high contrast between the shiny aluminum and black. I repainted it with a more boring and conventional look. It's unfinished in these first pics with just a coat of red oxide primer and yellow; camo went on later. (Darn, it looks like I forgot to push the turret all the way down! I'd been leaving it unscrewed since it made it easier to work on. It closes very neatly if you align the rear screw posts with the holes, but the turret isn't quite rigid enough to do that quickly.)

 

Finally...Run Time: Once I'd completed my wires and boards relocation project, I finally got to put a battery in, fire it up and run the sucker. Amazingly, everything worked. Even the LED muzzle flash is quite bright and of appropriate duration. Originally, I considered replacing it with a Heng Long strobe flash, but that won't be necessary.

The Sounds: Naturally, the sounds are great and are a compelling reason for installing an ElMod board. I was happy to regain the sound set that I used to run in my Tiger and don't mind the ridiculously long startup sound (well, not too much... but it's easy to replace). It came configured with most of the great Tiger II (Annanas) sound set with a few different sound. As much as I like that long cold startup sound, you can't drive until it's done, so I eventually had to replace it with a more abbreviated startup sound from another Maybach tank (Sturmtiger?). I replaced a few of the high-pitched chain sounds with some of the haunting dissonant squalks from the Tiger II set. The excessively long dead1.wav sound ("ach lieben!") that you can hear in the battle system video at the end of this article was replaced with a shorter death & destruction sound. It was fun fiddling with this stuff, and the structure of the blaster.ini file is the same as it was 4 years ago when you managed the files and directories manually. The new Blaster board seems to be simpler since you don't have DIP switches to select the active folder on the SD chip-- you're supposed to do it through their MasterBlaster.exe program, which copies your chosen active set to the "111" folder. It's not nearly as convenient since you have to shuttle the chip back and forth to your computer. It's strange that the website doesn't seem to have the .pdf that explained the structure of the .ini file.

After I installed the Clark TK-22 board in my Pzkpfw IV, I realized that while it had great functionality and very respectable sounds, the sounds aren't of the same caliber as an ElMod or Tamiya board (Not really a knock, since the Clark is about a quarter of the price!).

Motive Power: Thanks to the 480 motors, it's definitely not underpowered, and the beefier 20-amp max current rating is a huge improvement over the old board's 10-amp limit. (I suspect that's what crippled my original ElMod board.) The momentum and braking feature built into ElMod works very well and eliminates the unrealistic jackrabbit starts and abrupt stops that you see in many online RC tank videos. It coasts a long, long way from full speed, but the brakes and emergency brake function can avert an unfortunate accident. I wish my Turnigy speed controller-equipped Tamiya tanks had this feature! At full throttle, it runs very fast-- too fast for a tank of its size and heft. Of course, I do have a stick on my transmitter to control that, and many transmitters have channel travel adjustments that can be used to limit top speed.

ElMod's USB "Configurator" dongle would be fun to play with, to fine-tune the tank's performance characteristics-- their program seems to have some very deep parameter editing capabilities. Unfortunately, it's about 50 bucks, so I can live with the stock presets.

The gearboxes are very quiet, no doubt due to the mix of brass and nylon gears. I don't know if this is a good thing since nylon and brass do wear out more quickly than steel, and I doubt any off-the-shelf gearboxes will fit. Cross that bridge when I get to it I will...

The gearboxes are at the rear, which is unusual for RC tanks. It doesn't seem to make much difference in how it drives though, compared to other tanks. The tracks are very loose, which give them an appropriate saggy look, so there's occasional track bunching. Having sprockets at both ends probably helps keep the tracks in place, although it probably makes a little more noise than a standard smooth-wheeled idler system.

Trouble in Paradise: I did have one mechanical problem that's a little bit worrying: The allen/grub screw that affixes the sprocket to the drive mechanism loosened, resulting in a functionally pillboxed tank, doing a death spiral. The troubling part of this goes back to the design: The allen screw is fairly small and it's expected to hold tight against the flattened area of the drive shaft. The design is unconventional: The gearboxes are very close to each other near the center of the hull, so an extension shaft (with the allen screws) takes it out to the sprocket, which is attached the way everyone else does, by a bolt through the center of the shaft. It seems like they could have mounted the gearboxes farther apart and avoided using the extension shaft. There may be a good reason for doing it this way that I'm ignorant of. I've considered drilling into the flat part of the drive shaft so that the allen screw could effect a more secure lock, but this would be a challenging mod. I'll wait to see if it's a recurring problem before working on a solution.

[Sorry, It's Really An Indoors Tank: 08/04/13- I came to this conclusion after running it with both baggy and tight tracks, trying to figure out what was causing various problems. The bottom line (for me) is that this isn't as reliable an outdoors runner as any of my other RC tanks. The tracks jam far too easily from pebbles, twigs, or even from its own tracks. I thought that by running them baggy, it could deal with pebbles and twigs easier, but then the tracks can bunch up at the drive sprocket and jam against the sponson. Yes, it can be run outdoors but works reliably only in a relatively "clean" environment like packed dirt, sandy dirt, concrete, carpet, tile, wood, etc.-- environments without hard, loose debris that can get easily trapped in the tracks and jam them. You can drive in dirty environments, but you need to watch the ground and know when not to turn sharply. As far as I'm concerned, there's no solution: It's inherent in having minimal suspension travel and wheels in pairs (not interleaved) with enough space between them for the track horns to trap and feed whatever happens to enter into the next pair of wheels. I don't think a spring-loaded idler could fix this. I've left my initial assessments of the problem as they were originally written (more or less), to give you an idea of what I went through to come to the conclusion that it's really an indoors runner.}

Idler Adjustment: I learned of an important point from another build thread: The front panel should be made removeable so that you can access the idlers for adjustment. The instructions indicate this, but this is one of those "builder's intuition" things that comes up at the time of assembly. The builder has to ask, "If I glue this together, how the hell am I going to get in there to tighten that thingamajig when it comes loose?" I'm not sure if that's the case here, and it's one of those things that you find out if/when you ever have to deal with it.

[08/01/13- I got around to dealing with it, mainly because the tracks seemed exceptionally baggy, wrapping nearly 3/4 of the way around the sprocket at times. They made a clacking sound, which sounded to me like the sprocket teeth weren't digging into the track holes properly. After breaking some paint bonds, I was able to remove the front panel and adjust the idlers. It's a very simple system: 1 bolt aligns with the wheel axis (but doesn't bind the wheel when you tighten it), and the other sets the position of the idler along its adjustment track. Simple enough. Moving them forward removed most of the slack in the tracks. I went out and tested it.

It turns out, there's a very good reason for leaving lots of slack in the track. As I note in my videos below, the Elefant is a leaf and twig magnet ("Zweigjäger"). Even worse: Pebbles and gravel. With the slack gone, there's nowhere for pebbles to go except to jam between wheels. Attempt to force the issue and you will blow a fuse or worse. Fortunately, I realized this before doing either. It's unlike any of my other tanks, none of which have a problem turning on gravel. The spacing of the wheels probably allows more track-jamming stuff in than other tanks. Or maybe it's the suspension? Regardless, the fixed idler system is what blows fuses. It needs an active spring-tensioned idler system (best installed when you're putting the tank together), or live with really baggy tracks, or resolve to run only on clean dirt or concrete surfaces. If you don't, watch it like a hawk lest you suffer the Curse of Kursk!

After further running tests with tightened tracks, I believe that the soft suspension and the sponsons are responsible for some track binding. The suspension springs are very soft so the tracks ride high and occasionally rub against the underside of the sponsons, hitting the edges of some rounded guides sculpted onto the underside. These keep the tracks further from the sponsons at the front and back but despite being rounded, have abrupt edges that may catch tracks. With the tracks taut, I believe that it happens more readily and can occasionally jam a track, causing a sudden, unexpected turn. This usually happens when driving from a stop, when the tracks are pulled taut. Reversing direction seems to clear the jam. Of course, all this is just conjecture. If I were braver, I'd delve into the formidable task of stiffening the suspension, but for now I'm content with running the tracks baggier and living with the clacking sound. (Until I realized that bunching loose tracks can cause a jam just as easily. Solution? Run the tracks tighter and don't run it in places where there are things that can jam the tracks.)]

Minor Quibbles:

Hooben Elefant RC tank The rear hatch was glued shut, only the small hatch in the center opened. It was designed to open, and the auction pic shows it with interior hinges, so it's likely they broke after the pic was taken (Hooben's hatch hinges are really flimsy and iffy in operation). I can imagine that it worked poorly because of the slop in their hinges-- especially this one, a side-mounted hinge. But heck, it's a hatch and I have a compulsion to fix things like this, no matter how pointless they are. The glued-on hatch was carefully pried off and the bent hinge arms were made of soft brass. Piano wire was used as a hinge pin in the hatch's hinge stay. Brass tubing was used for the turret side, secured with epoxy putty. It's ugly, but at least it works... poorly, like it's supposed to.

I think it's interesting from a construction/design perspective: When studying the instructions, I thought that the lock tab at the bottom, properly glued into place, would prevent the hatch from opening. That would be true if the hinge mechanism were constructed without any slop. However, the design relies on slop so that the hatch can be twisted enough for the lock tab to slip over the lip of the opening. An accurate rendition would probably have the lock tab on a pivot so it could be turned to unlock the hatch. However, since tiny humans aren't inside to do that, this design and the slop makes a lot of sense. My Tamiya Panther has a high-quality aftermarket hatch that illustrates this perfectly: It's authentic as can be, but you'd never know because it stays locked-- I'd have to open the turret to unlock it!

IR Emitter LED: The builder had come up with a very cool and ingenious solution to the problem that there's no natural place on the Elefant to put the battle system's IR emitter... so both the muzzle flash and the emitter are in the muzzle, with the flash behind the clear IR emitter. It's an elegant solution and a bit of a construction challenge since fitting two sets of wires is a tight squeeze in the narrow barrel. This means the LEDs had to be soldered on after the wires were threaded and fit into the muzzle. The flash LED is especially challenging since it has to fit in the short space that's available in the back section, and squeezed into the side opening. The IR emitter is soldered on outside the muzzle, then pulled back through and an aluminum tube with styrene interior tube insert is slid over the LED from the front. Everything has to fit tightly and exactly. It's definitely a more difficult maintenance job than most simple flash or IR emitter installations, but how often does that come up?

Unfortunately for me, the IR emitter didn't work. I checked the plugs and tested an unmounted IR emitter at the board-- it worked, so I assumed that the emitter LED had fried somehow. So I had to figure out how to replace it, which led to the disassembly. I tested the unmounted IR LED at the bare leads of the suspect IR LED and it worked, so I fired up the soldering iron and was about to do the replacement. Then I thought to check the polarity... an unlikely possibility since the builder would have tested it, and not made the mistake. How could the polarity have changed? My guess is that the previous owner accidently changed it during the course of cleaning up the wiring. The solution was as simple as swapping pins at the plug, so all the disassembly was unnecessary. But I was glad that the original emitter wasn't fried because I didn't have a clear replacement. Moral of the story: Expect the unexpected when dealing with stuff that has a history!

Future Mods: There are some mods that I may do so later... it's what you do when the project is finished but you don't want it to be done.

Lights: There isn't a single light in this model, other than what's inside on the electronics. A convoy light would be nice. The instructions showed LEDs behind the front vision ports (that they called "headlights"). Hey, they could be reading lights, right? I've seen pictures of a real Elefant or Ferdinand with a Bosch light, so maybe? (Done, 07/19/13: See article)

Machine Gun Laser I originally got the idea from my Tiger's Creeping Death turret 4 years ago (and long since scrapped), and I liked it so much that I've put one in all of my RC tanks. It replaces the LED and is usually brighter, plus it's fun. Hopefully, I can get the beam aligned with the tiny bore of the narrow machine gun barrel and still have a sufficiently bright dot projected. (Done, 07/12/13) The machine gun sound and LED/Laser flashing are often poorly synchronized, and the laser makes it more apparent. It's probably a consequence of being able to change the sound files. It may explain why Clark Models doesn't want to bother with customizable sounds: Why would you want the customer to f'up your carefully-programmed synchronization and make your product look lame?

Limit Switches: I was thinking of adding lever switches with diodes to shut off the traverse and elevation motors at the ends of their travel. The elevation gearbox allows the arm to rotate 360 degrees so gears aren't in danger, but it does look funky when it switches direction. The traverse system doesn't, so gears could be stripped if left dwelling against the edge for too long. However, it's not likely since the horizontal stick is self-centering, and it's pretty obvious when you reach the limit. This may be one of those mods that are tempermental and difficult to keep aligned so it may not be worth the effort. (Done, 07/11/13: See article)

Beefing it Up Reinforcement and bracing are usually a good idea, either by brass tubing or strips or epoxy putty. As I mentioned, the Hooben plastic is fairly thin in areas. When you remove the turret, it's a little alarming that you can feel the sides flex. This would probably help keep the resin zimmerit panels from separating should the superglue bond shear loose. On the other hand, that would add weight to an already overburdened suspension system.

TURNIGY 9X TRANSMITTER
07/16/13- Immortal Hobby's version comes with a fully self-centering left stick, a backlit panel, and is flashed with a special tank version of the er9x firmware. The firmware is the key to figuring out how to set it up so you'll want to include "er9x" in your search for the manual. Hopefully you'll find the very enlightening .pdf that shows you how it works and how to modify the settings. For instance, the channel reverse setup is in the model's "LIMITS" screen (set up the channel as "INV" to invert its output). If you've got an ElMod, the mode 2 receiver connections (4-channel mode) are Ch1= green, Ch2=brown (INV), Ch3=yellow, Ch4=orange, Ch9=power. This sets the right stick as the drive stick and the left stick to control turret functions; reverse Ch3 for cannon fire at top. I've only begun exploring it, but it seems like it has huge potential for doing really cool things. It's a vast improvement over the original transmitter. Read my full-blown article here.

A New Radio I'm expecting an 8-channel Turnigy 9x transmitter configured for RC tanks from Immortal Hobbies (finally addressing the obsolete DX6 problem), so that should open new modding options for all my tanks. The Aero Sport 5 transmitter that was included works fine but lacks a self-centering left stick vertical, which leads to the barrel elevation inadvertently running when it should be stopped. It's very annoying.

 

Hooben Elefant RC tank

Hooben Elefant RC tank

Hooben Elefant RC tank

It's a big tank (16.75" hull length) and its size is more apparent when it's placed next to the runt tank, the Pzkpfw IV. With battery, it weighs 11.4 pounds.

The Fine Art of Weathering: Finally, this falls into the category of one of life's lessons. I'd seen close-up pictures of the amazing weathering job in this tank's build thread. I recently bought Michael Rinaldi's book, "Tankart" and marveled over his close-up photos of rust, chips, streaks and dust. I've long felt that I was just too frickin' lazy and complacent to learn how to do this artisan-class stuff, and that my stone-age weathering techniques could benefit from updating with the latest MIG and AK Interactive materials and techniques. Well... My expectations of learning from this tank were tempered when I realized that most of us don't look at these tanks with a closeup lens or loupe, and that a lot of the fine weathering details that are so evident in closeup photos, aren't really noticeable to the naked eye. At least not to my nearsighted, nearly monocular-visioned eyeballs. To me, without Optivisors, painted on chips look pretty much like the stuff done with a primer coat sprayed with hairspray and a top paint coat chipped with the application of water. I need magnification to see that it's actually the result of layers, and to appreciate the hyper realistic approach. It's also probably more appropriate for static models that aren't handled much and kept under glass to keep those boulder-sized specks of dust from ruining the illusion. I'm more concerned about getting the paint to stay on my tanks because repeated handling tends to wear the paint down to the bare clean plastic. Now that definitely doesn't look realistic. Moral of the story: Photos don't actually lie, but most of us don't walk around wearing closeup lenses.

Hooben Elefant RC tank

Hooben Elefant RC tank

Heng Long Pzkw 4 RC tank

Hah! Last one is my Pzkpfw IV, just to show that even my crummy weathering efforts can look almost respectable when shot close up.

 


VIDEOS

Hooben Elefant RC tank

Even though it was fun doing these videos, I've learned a few things from them, mainly about aggravation.

  • If you start the camera, a cat will appear.
  • Transmitters without self-centering sticks were put on Earth to torture you. A major portion of my attention went to watching and trying to stop the barrel elevation following almost any left-stick movement.
  • You forget how to drive if you're distracted by watching the barrel elevation.
  • If you want to videotape the smoker in action, it will run out of smoke juice and stop working the moment you turn on the camera.
  • If you're looking for your bottles of smoke juice, you won't find them even if you've seen them a zillion times before.
  • The Elefant is a twig and leaf magnet. If there's a big twig around, it'll find a way to lodge itself in the tracks. Leaves will spear themselves on the sprockets just so they can go round and round, over and over.
  • There's always a first time to blow a fuse and it'll happen during what you think could be a "keeper" video and you won't have any 10-amp mini ATM blade fuses in your collection.

 

Hey, it's another video from Stray Cat Alley! The barrel was painted and it wasn't too hard to match the look of the rest of the camo job since I had the same paints used in the original build.

The previous take of the video ran into trouble-- that @#$%!!! sprocket loosened again, so I drilled through the allen screw hole (careful not to ruin the screw threads) into the shaft and stuck a narrower short metal pin inside (cut from an allen wrench), long enough to protrude back into the allen screw hole. The allen screw was tightened against it with lock-tite. Done on both sides. If that doesn't hold, I don't know what will.

That video was kind of funny: Halfway through, the tank began to flounder around doing spirals. Yeah, I meant to do that!

This video (above) shows the tough environment that causes allen screws to loosen, twigs to jam tracks, tracks to jump sprockets, and fuses to blow. I think it has something to do with the tracks since they snag carpet like a cat, and none of my other tanks seem to have so much trouble operating in this environment (except the Tiger, which is supposed to have crappy track retention at the idler wheels). I feel lucky to have gotten through this video take.

The Battle System: If I did IR battling, I wouldn't pick the ElMod system for its breathtaking multimedia representation of battle damage. While the CSI system has an extended mode that allows turret damage, right/left side track damage and a random one-shot kill, its basic mode is pretty... uh...basic! You could almost call it crude and DOS-like. As the video shows, there's no recoil to indicate that it's taken a hit, just the LEDs flashing 3 times. As it progresses through levels of battle damage, the drive speed slows until it's destroyed, indicated by more LED blinking, then none. In this sound set it's accompanied by a long sound file representing carnage, death, and destruction, followed by the miraculous sound of resurrection. Then she's ready to go again. Note that the engine sound doesn't change at all through any of this. It doesn't even shut off when the tank's been destroyed. Lame. What have these guys been doing for the last 4 years? Sheesh! Clark Model's IR battle system puts this to shame.

PART 2     PART 3


 

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