Hybrid Rescue Tank Cockpit Redesign

I have finished the first attempt at redesigning the cockpit of the tank vehicle of the LEGO Exo-Force 8118 Hybrid Rescue Tank. As I mentioned the other day, the existing cockpit design seemed pretty badly done and so I went ahead and tried to improve it. I’m still not entirely happy with the results yet, but I think it’s a fairly big improvement. There is now a rear wall behind the pilot, the canopy is more conventionally situated and provides actual protection for the pilot, there are actual control surfaces instead of a blank tile, and I think it just looks a bit better.

The mechanical linkage between the left upper track hub and the gatling gun is unfortunately still visible in the new design, but not nearly as much as it was in the original.

Here is the original design from the instructions:
Somewhat unfortunately designed cockpit

Here is my design:
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Close-up view:
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Front view:
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With the canopy opened:
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The thing I am least happy with currently is that the movement opening the canopy is fairly stiff and can only really be done by using the small clip to the right. Originally I had used two 1×2 free-spinning axle blocks but moved to fixed axle blocks when the canopy would flop open simply by looking at it. The fixed axle blocks mean that the rotation is happening in the pins used at the ends of the axles and aren’t really designed to turn easily. Ideally I want to put a control on the body opposite the turret spin control that will open and close the canopy. I’m going to have to rework the motion on that front axle before that will be really possible though.

Next step is to fill the gaping cavity behind the cockpit. The initial idea is to use the V6 motor parts from the LEGO Technic 8421 Mobile Crane that I got a few years ago but I will have to see how well it fits the space.

A tale of two LEGO models

This past weekend I splurged and got two new LEGO model kits.

LEGO Technic 8272 Snow MobileThe first kit is the Technic 8272 Snow Mobile and is a really fantastic little model. There are only a few really interesting pieces, two spring shocks and a really cool 28 piece track, but the thing I like most about Technic models really shines here and that is the engineering. The independently sprung front skis with the operational steering system along with a more simple but no less effective rear suspension for the track are simply top notch implementation of sound engineering principles. It looks also looks pretty cool. I suppose if I had to find some fault, it would probably be with the bulky fasteners used on the skis that somewhat ruin the line of the ski, but given the scale of the model I think I’d take the current solution over a likely more fragile joint. I haven’t built the secondary model yet, which is a small bulldozer, but it’s pretty obvious that while it is not as nice as the primary model it has it’s own fun touches.

The second kit is the Exo-Force 8118 Hybrid Rescue Tank. I had been thinking it would be fun to get some of the dual faced mini-figs along with some fun spiky anime hair and the model looked like fun one of my most favorite juvenile fantasy: The-fighter-space-ship-docked-with-a-tank-unstoppable-killing-force! Wait, it says “Rescue Tank” so this must be slightly different version of that fantasy: The-fighter-space-ship-docked-with-a-tank-bent-on-crushing-missions-of-mercy. Or something. It splits up into not one, not two, but three different self contained weapons of mass destru, er, mercy. I’m sure one of those 15 lasers (six in the front mounted gatling gun by itself) and two (non-firing) missiles is some sort of healing ray. Moving on, one of the first things that you notice about the model is that it has dual-front tracks along with a huge rear wheel (a 94.8×44 Balloon Tire and hub) on the tank part that really gives a nice 1970’s era Buck Rogers meets Mad Max coolness. There are a couple of neat features in this model, both built from the 80% Technic part design of the tank. The first is that the gatling gun rotates when the right front track is in motion. The second is that the top turret/fighter dock can be pivoted using a fairly subtly placed gear on the right side of the vehicle. Similarly, the use of Bionicle ball and socket joints for missile mounts on the fighter and lasers on the tank are a nice touch.

Unfortunately after those neat touches you start to notice some of the rather glaring flaws in the model. The first, and probably most minor, is that the “head” of the little flying droid comes off when looked at funny. I don’t know if it’s the parts that I got, or the implementation, or both but while the overall design of the droid is quite neat it’s far too fragile. The second, and probably easiest to fix, is the canopy for the fighter. For the most part the fighter has very clean lines and honestly, for LEGO, flowing curves. But the canopy, while clearly designed to fit tightly over the chin and curved slopping bricks, has huge gaping holes. I managed to get an okay shot of the model before my camera suddenly died. Close-up shot of the massive holes in the front of this \"space\" ship model. I think I finally figured out why they did it this way when I was taking the pictures: There is no canopy hinge so if it was flush with the chin and sides it would be really difficult to remove to get at the minifig. Still, it seems pretty sloppy.

Unfortunately the tank has the worst design issues. The most minor is that when playing with the vehicle it can almost not be turned. Really. It’s like it’s on a rail. I loosened up the nuts on the wheel hubs and it did not help at all. The second and most glaring of the issues becomes pretty clear as you build the model. When I think of a “tank” I think of a solid vehicle. Something that has mass and heft from armor and machinery. All of the box art for the model shows the tank from a single oblique angle from the upper left, and the reason for that is that if you look at it from any other angle you quickly realize that there is nothing else to this “tank” past what you can see right there. From the front, sides, rear, and especially the bottom the model is a vast and empty shell. I can somewhat look past the mostly exposed mechanical linkage between the gatling gun and track, but what really baffles me is the “cab” of the vehicle which consists of an oddly hinged canopy that drops straight onto an unmarked 1×2 flat tile intended to be the controls that unlike just about any other smooth surface on the model does not have a sticker intended for it. The minifig sits under this slightly odd canopy just fine and that’s when you notice that there is nothing else behind it, just empty space. I think it could be easy to blame this total lack of internal features on the use of Technic parts for most of the tank model since Technic models at best sketch the outline of a vehicle but compared even to the relatively simple Snow Mobile model assembled earlier that is a well fleshed toy the tank looks barely like a skeleton from any angle other than it’s single photogenic one. The design isn’t “spare”, it’s lazy.

All that said it is a fairly fun model and I have a few ideas about how to improve it, though I’m not sure I have all the right parts currently to do so. Comparing the two models directly though does really illustrate why I generally only skim the shelves until I get to the Technic section.

UPDATED: Adding more images after I got a new camera today.

LEGO Exo-Force 8118 Hybrid Rescue Tank

Somewhat unfortunately designed cockpit

Another view of the tank cockpit