SF3D Ma.K MANIA 2011
Part 2 - Building the Nitto 1:6 Fireball SG
10/01/11-- S.O.S. = Same Old SAFS. The Fireball SG kit is practically identical to the Super Armored Fighting Suit (SAFS) kit, other than some superficial differences. To be honest, I wanted to build the 1:6 Melusine kit instead since I like novelty. However, it's been a while since I've done this kind of stuff, and the Fireball SG was already unboxed and had sat on a shelf for years, accumulating a deep yellow staining (I mean, really, really stained-- I'm almost too embarrassed to show pics!). Ten years ago, I didn't have any fun new ideas to motivate me to dive in, and regurgitating the construction of my other SAFS suits wasn't an exciting prospect.
This time, there was the novelty (for me) of adding the split-suit feature to the Fireball, as seen in the Medicom/Toys McCoy SAFS. I wasn't interested in doing the fold-out arm panels because that would be a lot of work for something that I don't think looks very good or makes much sense. In my version, the pilot doll would (hypothetically) control the arms inside the cockpit of the suit. Hey, this is supposed to be futuristic sci-fi, so they should have figured out nifty ways to control prosthetic arms by then, right?
Adding the fold-out panels would also weaken the structure of the vinyl kit; the kit would be fiddly enough with the split-suit feature. Articulation would have better range (and be simpler) using doll arms attached to the suit, as I'd done with my other SAFS projects. With armoured figures, articulation range is pretty limited, so every chance to improve it is a good thing.
Basically, the split suit modification would make it easier for a 1:1 scale human to put the doll inside the suit and wrestle it into postion. It would also make it easier to access the interior, and show more of the doll sitting in the suit. Besides, it's a fun mod to do, and gratifying when it works.
As long as I'm doing heresy, the iconic surround padding in the cockpit would have to go as well. It's a neat futuristic concept, but it hides so much. In my opinion, it's not as interesting as being able to see (and make) the interior details, like a traditional cockpit. The padding also makes it more difficult to stick your hand deep in there to jam the @$@!!! doll's legs as far as they'll go. The cast padding positions the head forward, which makes it harder to keep the head low enough so that the top hatch closes. There's so much space in the back, might as well use it to make the cockpit seem less cramped.
Cutting the Pieces The main body was cut into front and back sections based on the Sentinel SAFS, minus the extra cuts to articulate the arm panels. The cut path was pretty obvious, and I left an extra margin up the sides for rigidity. The shoulder armour panel hinges weren't affected by the cut, but the leg armour panel hinge pins were split between the front and back pieces. I'll use flexible straps to attach them.
The front half is really just a cover; the back half is the "guts", or the structural base that supports the arms, legs, cockpit seating and toilet facilities. The huge vinyl plug for the legs was left mostly intact for extra rigidity at the expense of some interior room. (I'd trimmed most of it in my first SAFS project.) It's puttied to the back piece, so it forms an interior cup for the doll to squeeze into. The front lip was beveled to help the front cover pivot on screws at the bottom. Magnets and screws were embedded in putty at the top to seal the two halves. I was surprised and pleased when the the halves lined up perfectly and snapped shut, then pulled apart again with just the right amount of force. (If I'd used 2 magnets instead of the screws, I'd have had a heckuva time separating the halves... those neodymium magnets are strong!)
Limitations of Vinyl The Medicom/Toys McCoy SAFS brought home a very important construction point: Vinyl isn't an ideal material for a large model, especially one that's articulated and meant to be handled. Its flexibility doesn't provide the preferred rigid structure to attach hinges and other moveable parts. Flexing will cause texturing putty to pop off and will mess with the alignment and flush fit of hinged parts. Cutting the one-piece body casting into parts just aggravates this by making the separate pieces easier to flex.
It's not an ideal solution, but you can make the flexible vinyl parts more rigid by applying a layer of epoxy putty or pouring rigid casting resin to cover the backside of the part. The idea is to put down as thick a layer as practical, while covering as much area as possible, forming a rigid interior copy under the vinyl casting skin. I did the puttying before cutting the halves since I didn't want to risk the halves warping after I'd cut them: If they did, I'd probably have had a heckuva time trying to make them align.
Putty and resin do have some flex when applied in a thin layer, and if you flex them too much, they break. Putty doesn't bond very well with the vinyl, so flexing may make the two separate. If it does, superglue to the rescue.
Panel Hinges Ya just gotta do the panels, since they're begging to be hinged. Hinges, though simple things, are tough to figure out! A simple door hinge doesn't work very well for an outward opening panel unless you put the hinge on the outside or cut a channel and have the pin part of the hinge showing. To get a flush fit with no outer evidence of a hinge, I made sliding hinges for my old SAFS's top hatches, and it wasn't easy: I guestimated the design of the parts, and eyeballed the fabrication. From the Sentinel SAFS, I saw that a double hinge would do the same thing, be stiffer, and be much simpler to make using a pair of brass dollhouse hinges. These are tightened to remove slop, then glued together with the pins oriented opposite to each other. That said, mine don't work nearly as well as the hinges on the store-bought SAFSs. Actually, it's all just trial and error unless you're an industrial designer.
That damned vinyl thing: The panel, once cut from the body, has a hard time fitting as flush as it did before it was cut from the body-- there always seems to be one or two corners that poke up a tiny bit. It's useful for having something to snag when opening the hatch, but it's a mystery. I even put putty all around the opening and on the panel (since removed) to rigidize it before cutting, and beveled the edges after the panel was cut. Oh well. The interior details were glued to a piece of styrene that is inset by walls of putty; it's tacked into place with contact cement so it could be removed and worked on (still not sure if I want to put an LED in it). A magnet was added to the detail parts (from a Tamiya Marder II kit) to keep the hatch closed: very useful to keep it from banging around while working on the project.
The Top Hatch I decided to commit another major bit of Ma.K heresy by articulating the top hatch at the back, not at the side. This was done for several reasons, mainly driven by intuition: When open, gravity tends to pull the side hinged hatch forward at an angle since it's hinged and balanced along the downward slope of the suit's contour. If the hatch is heavy and you leave it this way for a long time, I believe it tends to distort the vinyl hatch and possibly the hull, so it doesn't fit as well when it's closed. Basically though, it just seemed more intuitive to hinge it at the back. I think it also shows off a partially inserted doll better, since the hatch is behind the doll. From a geekish perspective, one might say that it's better for the armored hatch to open behind a partially dismounted pilot for protection against unseen, rear attacks from the display shelf. Whatever.
Instead of using the brass dollhouse hinges, I cannibalized a more robust plastic ganged hinge from an old toy robot (Zortron of the Zap Power Force!). Like the panel hinges, this was an exercise in trial and error; the hardest part of trial and error is testing the full range of opening and closing from the outside where you can't see or touch anything when the hatch is closed. I tried to visualize how the ganged hinge would work, and kept running up against the problem that it would go into propped open position okay, but would close too far forward. When positioned further back, the hatch would close okay, but wouldn't open wide enough to rest in the open position. After an hour of fiddling with it and attaching the parts with temporary adhesive putty and servo tape, I determined that it wouldn't work. The hinge needed a sliding element, like my other SAFS projects. I didn't want to use that type of hinge though, since the two-rail design has a lot of twist slop and was hard to make.
Luckily, the Zortron hinge had enough clearance under one of the hinges for a brass strip, and this would provide the sliding mount at the hatch-side end of the ganged hinge. The ends were bent downwards to attach to the hatch, and the hinge travels along the length of the brass strip. There's a bit of twist slop, but the hinge provides enough support to keep the brass strip fairly straight.
The Arms Since I've gotten stupider as I've aged, I had to read my original project pages to remember how I did it last time. Following that recipe, I snagged an old Classic Collection GI Joe body to cannibalize its arms. (They're crappy PVC arms, but I'd rather not destroy anything nice.) Screws and nuts were used to tighten the elbow hinges and the arms were cut at the biceps so they could be lengthened to match the location of the joints of the kit's vinyl arms. The elbow hinge pins are quite long, so it's likely you'll run into them when you cut the biceps; you don't want to bind them when lengthening the arm.
The vinyl suit arms were cut into segments to create sleeves for the Joe arms. The upper arm segments were easy, although the right upper arm piece needed to be heated since it was a tight fit. The forearm segments were a bit more trouble since they're large and the doll arms are much thinner. The filler had to be light yet firm. I also wanted a design that wasn't too permanent in case I wanted to add stuff on the inside. I used a dense packaging sponge to pad the interior of the segments so the forearms could be inserted and wouldn't rattle around. (If you do this, always use a long-lasting sponge material: the rubberish foam turns nasty and crumbly over time.)
The shoulder rotation flange of the Joe arms were grinded smaller so they could be jammed into the kit's pins. (For final assembly, the vinyl pin is inserted into body first, then the Joe arm is jammed into the heated pin.) The shoulder hinge has a longish shaft so the business end is a distance from the arm swivel hole; this gives the hinge a bit more range than it would if it were closer to the arm hole.
I used the same pleated scarf fabric that I'd used to make the bellowed hose arm covers for my other SAFS projects (It has that retro dryer hose look). The fabric is saturated with colored silicone caulk which makes it opaque and more substantial. It's sewn up the side, then turned inside out, so it's not quite as attractive as a cast bellowed hose. However, it's very flexible, much more so than any cast plastic ribbed hose that I've found-- an important quality, since you don't want the sleeve to fight the hinge articulation.
Onboard electronics are great fun the first time you play with them... and after that you rarely mess with them again. Years later, you regret not having removed the leaky batteries when they weren't leaky. Oh well, what can I say? Gimmicks are fun to squeeze into projects, and let you linger after you've done all the major construction stuff.
The Medicom/Toys McCoy SAFS's main cockpit blue lighting is very cool. I finally got watch batteries for its laser and control panel, but they were sort of a let down. The laser LED is barely visible unless the nozzle is pointed directly at you (which it normally doesn't because its weight naturally poses it pointed at the ground). It's a prime candidate for unintended battery drain because you didn't notice that you left it on. The control panel's green lighting is better, but it's just a green LED behind a transparent piece of plastic with a circle on it. I don't know what more I expected of it-- it's a cool bit of additional cockpit lighting, but maybe not worth the cost of two LR41 batteries. Given all the fancy electronics gizmos that are out there nowadays, I just felt that they could have done more. On the other hand, I don't think they have a cutting edge electronics division, so designing custom circuits for such a small production run may not have been feasible.
If there's a silver lining in that, it means that a home-brewed effort is on a more even footing. Besides a basic LED circuit, there are some fun building blocks are out there for the tinkerer and model builder: Fiber optics, mini-fluorescent lighting, LED timer circuits, and low wattage lasers. You can also install audio circuits, little motors, radio-controlled servos, etc. Of course, you have to squeeze it in the model and deal with the power requirements, so there are limitations and challenges. But it's fun to try.
I first thought I'd go with a few simple LEDs-- a red one for the exterior right side, and a green control panel LED. Maybe a pointer laser in the laser arm. In a more ambitious mood, I thought about building a chasing LED circuit inside the cockpit, but changed my mind because I didn't want to get too sidetracked. What I really wanted was ready-made stuff that didn't require too much work or brainpower.
At Radio Shack, I shopped for ideas: I found a couple of ready-made circuits that held promise. A blinking LED module was considered because it was mainly a compact battery box for 2 AA batteries-- after all, you've got to have something to put batteries in. The blinking LED was desirable as a kinetic feature. Ideally, I'd be able to tap off the batteries to have solid glowing LEDs in the cockpit as well.
Radio Shack also had a Digital Recording Module circuit that lets you record and playback 20 seconds of audio. Additionally, it fires a blinking LED during playback, and uses a 9-volt battery. This offered more features and it would be easier to fit the smaller 9-volt battery than the AA batteries since it didn't require a case.
The 9-volt Battery At least half the fun of working on this stuff is figuring out ways to install it, hopefully more slick than just stuffing the parts in whereever there's space. It was especially gratifying to come up with the 9-volt battery access design. It uses one of the kit's few parts to hide the battery compartment, allows easy external access to the battery and keeps the battery and part firmly in place with friction. I fitted the body with an internal c-formed box (seen in pic above) that holds the battery tight, and the 9-volt terminal clip is screwed to the part so that when it's removed from the SAFS, the clip and the battery come with it. I think it's pretty cool!
The Audio Circuit Yeah, the digital audio circuit is a cheesy thing. I installed it mainly because I could and because it was different. The single 20-second, no-repeat recording imposed some major limitations; obviously, it wasn't appropriate for an engine idling sound, and a laser cannon discharge sound wouldn't make sense unless it was synchronized with a visual effect. I recorded a snippet of Django Reinhardt's 1939 torch song, "Don't Worry 'Bout Me" to personalize the suit with a retro flavor. It's more of an evocative thing, since regulation SAFSs probably wouldn't have loudspeakers blaring out songs. (It takes a cue from Oddball's Sherman from the old movie, "Kelly's Heroes".)
The two thin pipes on the backside looked like good places for pushbutton switches. I bought a couple at Radio Shack: A latching on/off switch for the 9-volt battery and a normally-open momentary contact switch for triggering the audio playback. With the large buttons pulled off the switches, they look similar to the kit's vinyl pipes, and the diameter of the mounting is almost identical to the pipes'.
The cheapo mylar speaker is barely audible from the naked circuit, but much louder when it's mounted in an enclosure-- like the body. I didn't want to cut a 1" hole in the front or backside for the speaker, so I mounted it at the rear right hatch. Although the opening is trapezoidal, it's a fairly close match for the speaker's diameter. As you'd expect, with the hatch closed, it's muffled; cracking it just a bit makes a big difference.
I didn't find a cool place to disguise the microphone or record button, so the mic and blinking LED are mounted in the periscope and the switch is just stuffed inside the body. Although there were several places where the record switch might have been placed, I didn't want it located where it might be inadvertently tripped and overwrite the stored recording. At this time, I'm happy with the Reinhardt song, so the recording ability isn't a high priority.
The LEDs I spent some time thinking about other electronic gimmicks that would work with the 9-volt battery. Most LEDs require about 3 volts, and I happened to have a Ninco slot car lighting circuitboard to handle this. This greatly simplified things since I could locate the audio circuitboard in the back section and the LED circuitboard in the front, where most ofthe lights would be. The only wire running between the sections is the 9-volt power, with a Molex connector for separating the sections. The circuitboard has a gold cap that stores and releases the charge slowly after the power is cut-- the lights build up to their full glow when first powered up and slowly dim when power's cut. The board also powers the blinking LED circuit without pulsing the other LEDs; I used the blinking LED for the suit right front exterior and installed the steady glowing LEDs in the cockpit area. LEDs are fun, but I didn't want the suit to look like a Christmas tree.
The Laser I really wanted to install a laser, even though it wouldn't be nearly as functional as it is in an RC tank, where it can be aimed and triggered remotely. Installed in the suit, it would be more like a huge, unwieldly laser pointer. Nevertheless, I got a 5 mW green laser that operated off of 3 volts; I've never had a green laser before, and prices have come down considerably in recent years.
I couldn't get it to operate off of the Ninco circuit-- probably not enough current to drive it-- but it did work off of the 2 x AA cell battery box that came with the blinking LED. Wow. That sucker is bright! It's easy to see the dot outdoors in daylight, and in a darkened, dusty room, the beam itself is easy to see. Bouncing it off a couple mirrors reminded me of a high tech security system seen in movies. (If you're a gun owner, get rid of your red dot laser sight-- you want green!)
I was concerned about the weight: The laser-equipped forearm would be much heavier than the hollow vinyl forearm, which is already big and relatively heavy for a vinyl piece. The elbow hinge wasn't a problem since I'd reinforced it with a screw and nut; the shoulder rotation was a different story. There's no easy way to tighten it, and the weight of the stock arm put it near its load limit. However, I wasn't about to let that stop me (as it turned out, it can be posed level with the horizon by bending the elbow, which draws the weight closer to the rotation axis).
Installation was easy, although I didn't come up with an elegant mounting solution for the battery box. It's stuffed in the back of the suit, jammed up against the underside of the 9-volt battery enclosure with a sponge foam block. The only access to it is from inside the suit, which means the doll would have to be removed, as well as the back wall padding that I have yet to make.
To install the laser unit, I cut off the tip of the forearm, then glued and puttied the laser unit in it once it was aligned with the bore. Since I wanted to be able to disassemble it, a sleeve was glued to the inside lip of tip so it could be reinserted in the forearm sleeve and held in place by friction. The leads were soldered to a plug. In the suit, a normally open, momentary contact button switch (a latching switch might tempt you to leave it on too long-- the laser unit does heat up!) was mounted in the left side conduit panel. The wires go out the suit through the spring conduit, into the upper arm, down the elbow hinge and into the forearm sleeve where the female receptacle was installed.
I'd avoided using the spring conduits on my SAFS projects because they seemed an impractical design conceit (why expose vital linkage to damage when it could be routed under the armored skin?). I'm not really sold on the look, and at 1:6 scale, they don't seem to have the proper scale weight: The should droop. However, in this case, I decided to give it a go because the conduit was used to house the wire: Wow, neato! Design-wise, it would have been almost as easy to run the wire concealed under the bellows and covers, all the way to the laser.
Yup, like I said, it's a huge, unwieldly laser pointer... but it's fun!
The Cockpit This was actually fun to work on, but I was running out of steam so it dragged on and on. For the front half, because it could be cocked open and I'd removed the sculpted padding, it need lotsa stuff to make the empty shell not look so much like an empty shell. What stuff was totally open-ended, but I had an inclination to include some retro controls like bezeled gauges and buttons.
I made a mold & castings of sections of the BBI F-15 cockpit and attached them to the interior. I would have liked to backlight the gauges, but there wasn't very much working room behind them, and I didn't want to mount them further forward and lose even more cabin space. I wasn't sure how I'd do it anyway, since there are a slew of gauges and each would probably need its own LED. I ended up putting a single white LED facing them from the side, and put a green LED behind the screen directly in front of the pilot. I also made a cockpit jack for plugging in a small SMT LED attached to the pilot's helmet.
The LED/electronics thing is indeed fun, but I'm very aware of how short-lived the entertainment value is once the novelty wears off. I think the most fun comes from figuring out how to put it in. Other than that, it's mainly good for photos-- photos save on batteries, too.