I’m not sure exactly when I started work on this project… Maybe I’d been hoping to get it ready for Tekkoshocon, or maybe for Granitecon last year… But it was already pretty far along when I resumed work on it this summer. In the last update I had the basic paint colors down. Since that point, apart from a few details here and there, it’s just been gloss, decal, gloss, sand, gloss, wash, flat.

For the markings I used two of the dry transfers included with the kit – the “U.N.T. Spacy” mark (very much a 1995-1998 thing… That’s how they marked Federation units in the Master Grade line, up until the Perfect Grade Gundam introduced the “Earth Federation Space Force”/EFSF marking) and the red Pegasus on the front of the left shoulder. That was really about all the kit-supplied markings had to offer, since I wasn’t about to use stickers… The only other thing provided in the dry transfer set were red triangles. I also used markings from a few other decal sheets: Most of the “102″ and “RX-78″ and warning decals and so on came from the Gundam Decal “Real Type Gundam” set made for the Gundam v2.0. Not all of the markings were suitable for this build since my build wasn’t in “Real Type” colors. Others I left out because they seemed too silly… Like the long arrows, those marks never made a lot of sense to me. The Amuro mark on the shield and the “102″ on the backpack came from an old decal sheet I bought from Peter Savin several years ago. The additional red Pegasus marks came from a Gundam Decal set for Earth Federation MS. The intake markings and probably a few other marks came from a Wave “X-Decal” sheet. I think I took a mark or two from an old 1:60 scale Votoms decal sheet as well. Finally, the red stripes on the ankles and skirt armor were from a sheet of red stripe decals. :)

I replaced the hands on this kit with Kotobukiya Pla-unit hands – the “Custom 1:100″ type. For the price (around 500 yen) what you get with these sets is really nice… six static-pose hands, in different poses, that look almost as good as resin hands. There are some challenges when using them with Gundam kits, however: the “Normal Type” hands are best suited for larger machines, which is why I used the “Custom” hands here… But the “Custom” hands are made to hold really small weapon grips… They’re a perfect fit for Kotobukiya weapon sets but MG weapon grips are too big… So I had to modify the hands to hold the beam rifle and shield.

The shield on the stock kit has some fairly ugly features on the back side of the shield – a peg sticking out for connecting to the backpack and three pegs for the hand-grip to plug into… The idea of the hand-grip is that it’s supposed to slide in that track it’s in – I’m perfectly fine with it not actually sliding but those pegs had to go. Additionally, the shield grip itself was originally made of polycap material, so I scratch-build a replacement so I could paint it. The peg for the backpack connection I replaced with a polycap and a minus-mold plug… So I can remove the plug and insert a rod and connect the shield to the backpack… I have to be careful when doing this, however, because if I stick the peg in too far into the shield, it can hit the back side of the yellow “star” emblem and cause it to break…

I lit the eyes with two surface-mount red LEDs. In order to get the light to look right when it shone through the eye parts, I had to cut away the piece of clear plastic behind the eye visor that held it in place… So handling the eye visor during painting it was fairly fragile, and reinstalling it, it was a bit fiddly. It seems I have a minor light leak between the eyes and the face – I’ll have to fix that later… The eyes are painted clear yellow but actually light red… This is how they worked in the show. Because the eyes are clear yellow, they don’t show up so well when the LEDs are off – personally I think that’s actually a pretty good look for the kit. If the eyes stand out too brightly, it can make the head look kind of goofy, I think. The wires for these LEDs are routed down the back of the neck and into the chest cavity. I cut away a chunk of the core block so I could install a battery pack and microcontroller in there… Unfortunately the battery pack has gone missing, so for now, when you see photos of the eyes lit, the wires are in fact trailing out the back of the head and connected to clip leads that are run to a power source. Hopefully the battery pack and microcontroller unit I built will turn up soon – I worked too hard on that feature to have it wrecked by a simple thing like losing a critical part…

A somewhat simpler modification I did was to mount the “detail-up” parts – the little hooks and such that are on various places on the Gundam and its shield. These were an interesting feature of the early Master Grade kits which, sadly, did not last. These were bits of actual, scale detail – that they would include such things at all really reflects the difference in how they approached the subjects back then. Master Grades in 1995 weren’t really about “technology” or “articulation” – they were about delivering the best-looking Gundam model kits to date. That’s the approach that suits me best. I don’t care how well the kit moves if it’s eye-stabbing ugly like the 2.0 versions of the Gundam and Zaku.

This kit did feature some opening panels on the head, forearms, and lower legs – I disabled these and glued them shut so I could get a better fit on the parts and make the seam where the panel meets the rest of the body smaller than it would be if the panel were left operable.

Speaking of panels – another modification I did to this model was to re-scribe panel lines that were irregularly-molded due to draft angle issues… (Basically – a traditional mold for making plastic model kits is a steel mold of two halves. The mold halves come together, plastic is injected in, the top half of the mold is pulled off and the parts are popped out of the bottom half. This means that any detail on the kit must be designed such that the injected part can be removed from the mold. So when a part is in the mold, the sides that face “up” or “down” can get relatively clean detail that’s more-or-less perpendicular to the surface of the part. For parts that face sideways, detail tends to be skewed a bit to accommodate the molding process. In the case of this kit, panel lines on the front of the lower leg, for instance, instead of being a recessed line in a flat part, were molded as kind of a step, a change in the thickness of the part at the panel line.) This includes the sides of the knee armor, the front of the upper and lower legs, the shoulders, the arms, the panels on top of the head, and maybe a couple other places I forgot about.

For laughs, I pitted the MG Gundam against my 1:100 scale Zaku… Perfect for Gunpla’s 30th anniversary, I’d say… a kit from the beginning of Gundam kits (well, 1981, so their second year) and one from what is now the half-way point… The 1:100 Zaku is pretty goofy-looking, and I built it as a joke – but I think it’s a great old kit. I bought a second one, I want to try a build that’s a little less OOB and see what I can accomplish this time around.

This is, of course, the original Master Grade Gundam, the first Master Grade ever, released in 1995. I have a great appreciation for the early Master Grades. I love how their design focuses on both honoring the original design, and on lending it credible details. I also love their relative simplicity. I do appreciate the kind of poseability that a modern MG offers, but I don’t always need that. Often I’m quite happy to have a kit that looks nice and is affordable. Additionally, I don’t always enjoy building inner frames and such. Sometimes when I work with old kits from the 1980s I find their simplicity refreshing. Old MGs are like that, but they’re also prettier than most 1980s kits. I’m not too fond of the direction the MG Gundams have taken since the v1.0, either… In particular I think the v2.0 is butt-ugly. It’s supposed to capture the “retro look” and win on the basis of nostalgia – but it really doesn’t capture the look of the original Gundam very well at all, so it’s mostly just bland. I think the G30th design is an improvement – it’s kind of a weird mish-mash of design elements from older versions of the Gundam (including the MG v1.0) but it’s a pretty good look, I think. Hopefully they’ll do a MG of that… Though with Real Grade, who knows… They may not.

Anyway, this is mostly a straight build, but with a few minor changes:

First, I used the detail parts included with the kit (and a few borrowed from a MG GM kit) to add a bit of “scale detail” to the thing. I’m not sure exactly what the different pieces are supposed to represent. The triangular ones I figure are stowage hooks: so someone could run a cable through those hooks to attach various necessities to the exterior of the machine. (Of course, not all the hooks I put on there are really in good places for that…) The rectangular bar things I figure are used to lift the Gundam or its parts. (Actually it seems like a little U-shaped hook, like on the Scopedog, would be better for attaching cables for suspension… but whatever. My other guess for these bits was “ladder rungs” but I wasn’t interested in putting a ladder up the side of the Gundam) Since the Gundam separates, there’s hooks on the shoulders, to lift the top half (or the whole Gundam), and hooks on the side skirts to lift the bottom half when the top’s not attached. I also put some on the arms… I have no idea what those would be good for.

Second, I replaced the kit-supplied hands with Kotobukiya “1:100 Custom type” hands. These are nice-looking, very cheap injection-molded hands for robot kits, but there’s one major issue with them if you want to use them with Gundam stuff: the “Custom type” hands are made to fit Kotobukiya weapons, so MG weapons won’t fit. I altered the gun hand to fit the beam rifle, and built the whole set of six hands.

Third, I provided a new grip for the shield, and cut away the other two pegs on the kit part for placing the grip in alternate positions. The kit-supplied grip was relatively undetailed, and it had a big mold-parting line down the side of it… and the grip was made out of vinyl, so removing that seam would have been difficult, and paint wouldn’t have stuck to the part anyway. I made the replacement out of styrene strip and plates, with a hexagonal rod for the grip and two “minus mold” parts for a bit of detail. It was very easy to make.

Fourth, while the stock kit has a gimmick for flipping up the top of the head, and mechanical details inside the head, I mostly got rid of that – primarily because I think the stock kit has some alignment issues with the face… and whether there’s alignment issues there or not, I don’t like the position of the face… And I also wanted to slot out the face for easy painting… And I wanted to eliminate the gaps between the sides of the head and the “scalp”… So at present the flip-top gimmick still works but some of the internal detail was cut away… Ultimately I’ll probably glue the scalp down.

Fifth, the arms originally had an opening panel – a nice feature, but the panels never really closed properly. At best they’d close but there’d be irregular gaps between the panel and the rest of the arm and an irregular surface across that seam… So I altered the panels to fit better, glued them down, and rescribed the lines.

Sixth, various other panel lines were rescribed… For instance, detail on the front of the legs (molded from the side), detail on the sides of the knee guard (molded from the front), things like that…

The paint scheme is obviously pretty standard. My plan for this build was to go with the full-on clown colors, no excuses and no apologies. But there are a few choices I made that I think stand out:

• The vents are yellow, but the housings around the vent slats are blue. Originally the Gundam didn’t have a distinct housing around the vent slats, the vents were just embedded into the front of the chest. But the MG Gundam made the vents a more distinct feature, similar to how they look on Zeta designs like the Mk.II or GM II. Usually this style of vent is painted all-yellow, but I thought it’d be interesting to make the housings blue. This was a bit of a masking challenge, since on the original MG the whole vent is just one yellow part.

• I painted the back of the shield red. This is anime-accurate, in fact, but the real reason I did it was ’cause I thought it’d be an interesting change from the usual. Initially my plan was to leave the back of the shield white and paint some details metallic – but I tried this and didn’t like it, so I decided to take a cue from the anime.
• The beam rifle’s painted in a two-tone scheme of metallic and navy blue… I’m not entirely sure I like it. Actually at first the foregrip was metallic as well, but I decided there was too much metallic so I repainted the part. I thought about painting the whole thing navy blue and being done with it, but decided instead to stick with the two-tone. If nothing else it’s a little different from the usual look.
• Head vulcans are done in the same metallic (Alclad magnesium) as the joints and hands and so on, instead of the more anime-accurate yellow or gold.

At this point, most of the painting is done… I think there’s still some spot-painting to be done here and there, but for the most part it’s ready for the first clear coats and the markings. I look forward to finishing this one – this kit is a real classic.

Anyway, it was inevitable that there would be a Zaku Kai in this lineup. In 1:144 scale that left me two options: the first is the old kit from 1989, which is somewhat close to the mark but with enough errors to make it look generally bloated and with much of the impact of the original design lost. The second is the HGUC kit released a couple years ago. The HGUC seems to have the opposite problem. Instead of being too chunky, it’s too thin. Instead of everything being flattened out by bloat, it’s just plain flattened out. Typical of Bandai’s cowardly approach to kit design these days. On the other hand, though – what the legs lack in bulk they make up for in style. I decided to see what I could do with the HGUC: whether I could make a few simple tweaks and make the HGUC capture a little more of the spirit of the original design.

So out-of-box, the kit looks kind of like this:

I have my own ideas of how the Zaku kai should look, of course – my efforts were not focused on turning the HGUC into a scaled-down version of my 1:100 version, but rather to try and correct issues that stuck out in the hope that I could end up with something that had the feel of the Zaku Kai – but perhaps its own style. So I tried to focus on the way the shapes flowed. In particular, I wanted to get the skirts a little bit wider, so the slope of the chest block would flow into the skirts. I changed the angle of the backpack and got rid of the weird tapering of the chest block sides, replaced the shoulder armor with one from the 1989 kit, and rearranged the waist cables so they would hook to the backpack instead of the rear skirt and flex when the Zaku pivots at the waist. So I got to about this point:

At this point, I got very frustrated with the project. The skirt mods didn’t have the impact I was after, and vigorous scrubbing has so far failed to wash the ugly away. I’m pretty certain now that I can’t be satisfied with this kit. It’s just too far from what I feel the Zaku Kai should look like. So I’m ditching the HGUC build and building the 1989 one instead.

A few simple mods and Yuji Kitano made this sockmonkey kit look pretty mean. I considered following his formula verbatim – but I decided to use my design plans from the 1:100 build as a guide instead…

I find working with the old kit a lot more enjoyable than dealing with the HGUC. It has its share of problems but at its core I think it’s a lot closer to how I think the Zaku Kai should look. I feel like a lot of Bandai kits are disappointing in the same way the HGUC Zaku Kai is – they start with some beautifully funky design and release a kit version that’s watered-down garbage. I think we should expect better from them.

My previous post about this project was all about the FG Char’s Zaku – I’m trying to wrap up construction on that project now and get it ready for paint. The biggest piece of work left for me at this point is the monoeye. It was important to me to get this model to be more poseable but I didn’t want the modifications to get too complicated… Anyway, I think what I came up with for the hips will work pretty nicely:

Basically, I used a polycap in front of the hips to give the legs a way to swing forward and out of the way of the skirts… Then a Kotobukiya T-polycap for the hip joint itself, and a ball-shape joint on each leg to handle pivot and lateral extension. While I was rejointing things I also replaced the ankle joints I made before – I couldn’t get the old ones out of the feet so I had to steal feet from another FG Zaku kit…. The old joint was just a regular ball joint, it didn’t really do much because there was no clearance for the foot to move around. The new joint is similar to what’s in the MG Zaku F2, or to the various recent HG Zakus (F2, FZ, etc.) – the ankle ball joint is connected to another joint in the middle of the foot – this extra joint allows the ankle joint to swing upward out of the foot, providing more clearance for the foot to move around. Between these two mods, it’s now very easy to get the legs into various useful poses.

Been doing a few other things with the kit lately – I made a better shield for it (from a HG Zaku), I set up leg cables, and I finished mounting the thrusters in the lower legs:

The reason I chose this particular kit is because I wanted to build a Char’s Zaku, and I like the way the Perfect Grade/First Grade design for Char’s Zaku incorporates most of what I like about the Master Grade Zaku v1.0, while representing the “elite” status of Char’s Zaku in a unique and cool-looking way. (Various Char’s Zaku kits include extra thrusters or whatnot to account for the unit’s superior speed – the PG/FG version has rounded thruster housings on the lower legs and backpack… I think it’s a cool design.)

For those who don’t know, the original First Grade kits were released in 1999: the Gundam and two versions of the Zaku. They were released on the occasion of Gundam’s 20th anniversary. They were kind of a nod to the original Gundam and Zaku kits (similar complexity and construction, similar box art) but in terms of their design they were very contemporary. Actually, they’re nearly direct scale-downs of the Perfect Grade Gundam and Zaku… These original First Grade kits were a fabulous offering to Gundam fans – dirt cheap, but very good-looking – so they’re great for use as a source of extra parts, building a large number of Zakus for a diorama, etc.

Anyway, the build – So far I’ve been focusing on replacing the plastic-on-plastic joints of the original kit with polycaps and ball joints. I also cut away the original eye visor so I can installed a lit and detailed version later, and I cut out some of the thruster panels to add missing thruster bells or detail things up a bit…

So far, the main things I’ve done with the arms have been to polycap the shoulder joint on the left arm, and to cut away the shoulder pauldron from the shoulder block it was molded into… But gutting the shoulder joint parts out of the inside of the shoulder pauldron meant that I effectively destroyed one of my kit’s shoulders. Rather than reconstruct the shoulder block, I just swiped one from one of my green FG Zakus. Actually, since this isn’t the first time I’ve worked on polycapping a FG Zaku, I just swiped the whole left arm. I’m going to use it with the forearm from a 08th MS Team HG Zaku kit, because I think they look better than the PG/FG forearm design…

I rejointed both knees using a Kotobukiya T-Joint polycap (one of the most useful aftermarket polycaps you can buy!) and slotting it into the knee area of the lower leg frame. I cut away the original ankle joint and replaced it with a Yellow Submarine ball joint. The ball joint is nice but I think I may need to switch it to some kind of double-joint system if I want to improve the flexibility of the ankle.

The thrusters on the lower legs were bugging me a bit – the kit includes the cool-looking thruster pods on the lower legs that were present on the PG Char’s Zaku, but there’s no actual thruster bells there – the area’s just blanked out. So I cut out the thruster panels on the right leg and I’ve been working out what thruster part I want to use there. Similarly, on the backpack, I cut away the whole thruster panel so I could hack together a simple-looking “engine” to go with that thruster bell, and sink that into the backpack.

It’s been a fun project so far. I’m trying to keep the whole course of this project fun and simple, looking to get the best yield without too much effort. I’d say the results are good so far.

If I kept working on that first sculpt I could probably improve it quite a bit – but there were some problems with how I addressed that sculpt that I think would have made it needlessly difficult. First, the whole lower leg was built up out of just five cross-section pieces: a center line, two offset 5mm from the center, and two incomplete profiles that I did for my initial plan of sculpting just the common parts of the leg… But sculpting the whole leg instead of just half of it meant it would have been a lot harder to take a contour gauge to the thing, or to compare halves in different ways to check symmetry…

So the first alternate approach was to use more cross-sections. Instead of profile cross-sections, I used horizontal cross-sections, spaced at 5mm intervals.

However, what struck me about this approach was that, as with the shoulder armor I did a while back, sometimes it’s not the exact curvature that counts, but rather the exact placement of edges… In this case, the ridges near the knee and the boundary of the pod are probably the most important for now, and the boundaries of the thruster openings and so on will be important later. Working with just horizontal cross-sections meant that the diagonal and horizontal pod edges were almost completely ill-defined by the cross-sections, and the vertical leading edges were poorly defined and very sensitive to errors in placement of the templates… Continuing with this approach, I’d ultimately wind up in a situation like what I got with the shoulder armor – having to refine the sculpt to try and correct those edges.

So I tried again: this time, I started with the edges I was interested in. I drew out the path the edges followed, I picked out elevation data along that path using the Blender model, and created strips that could be bent along that path. Then, when filling in between the templates with epoxy putty, I’d be able to know (almost) exactly where the pod boundary should be… So long as the strip was placed correctly, and so long as it remained more-or-less perpendicular to the center plane, I’d have a good indicator of where the boundary should be.

So after I got my plans together for this method, I started putting together one half of one leg (the inboard side of the right lower leg) – it took a while and it was difficult to get the strips to follow the paths… When that was done I used the horizontal cross-section patterns I’d made for the previous attempt to flesh out the shape of the pod, and then started filling in with epoxy putty.

I think this approach has worked out very well! Easily the best-looking of the three attempts so far, and this is before doing any refinement work on it. I think the method of making elevation strips to follow the paths of prominent edges is a lot easier to deal with than using cross-sections to flesh out the volume of the part. Though the real test will be to see how the other three turn out – will the matching parts match? Things like that. Like I said, Mitsuaki Misaki I ain’t. In the Scratch Build Manual he built these lower leg parts at least three different ways, and they all matched… I don’t know how much time he spends on something like that, but damn, man…

As a side note – my last update to the site was four months ago. I spent some of that time trying to complete projects for Tekko (I failed) – but then there was a huge flood. Our garage filled with water and some of it seeped into the basement, too. My workspace carpet was ruined and I had to spend a ton of time tearing the place apart and I’m still picking up the pieces. It feels good to be getting some model work done again.

There’s not much to show of the VF-0 at this point, as so far I’ve just been doing the basic assembly. This has been a very interesting build for me personally: the Hasegawa VF-1 battroid has long been one of my favorite anime model kits. Hasegawa’s done several Macross fighters now, but only a couple of them in their humanoid battroid form. The battroid kits are nice because they’ve got great detail, but are fairly low-cost and they don’t go overboard with features like inner frames and such like Bandai kits tend to. The result is a great-looking kit with relatively little excess to it. It’s a pleasure to be working on a Hasegawa battroid again, and it’s very interesting to see how they refined their approach for the VF-0 kit. I haven’t figured out yet what variant I’m building. I initially planned on the Focker version, but that VF-0A head is rather temping as well.

The other kit I’ve decided to take a shot at finishing for Tekko is this Bandai Scopedog. This kit has always looked a bit odd to my eye – something weird about the proportions in the chest – though I think that may just be because I’m used to the look of the old Takara and Wave kits. I’m not quite sure. If you look at the manual for this kit they have an excellent side-by-side comparison of the Bandai kit’s CAD design and the original lineart: it makes a compelling argument for Bandai’s design.

Anyway, apart from questions of the kit’s design, one other thing always bothered me about this version of the kit: it is very short on weapons. It packs only the Scopedog rifle. Normally this is all a Scopedog would carry, but it really doesn’t seem like much, and I do wish they’d included a more complete weapons set… the flamethrower, for instance, or the pentatrooper? Or even the “solid shooter” bazooka… Still, I’ve been giving some thought to the question of what sort of Scopedog I really want to build: heavily armed variants like the Red Shoulder Custom are cool, but most soldiers would’ve gotten much more ordinary equipment for their Scopedog… This is what led me to the same conclusion I reached last time: I want my Scopedog to carry the Parachute Pack.

The thing about the Parachute Pack is that it carries more than just a parachute. It carries additional fuel and ammunition, some kind of large tarp-thing, and, I’m guessing, a small amount of cargo. In other words, it’s not just something you mount to a Scopedog when you’re gonna drop it out of a plane, it’s something you mount to a Scopedog when you’re gonna send it somewhere and don’t know exactly when you’ll pick it up again. In other words, it’s a Scopedog upgrade for soldiers who are being expected to continue to do their job with minimal outside support. Perfect for “VOTOMS”.

Since Bandai hasn’t released a parachute pack for their Scopedog, and the current price for the 1:24 scale Takara/Wave one is completely unreasonable, I’m scratch-building it. My design is based on some measurements from the 1:35 scale Takara version from my earlier Scopedog build, and some observations from the lineart and other sources.

On the design sheet, there’s actually two versions of the design there. The one on top is the earlier one. For the second version below, I made the pack a little bit narrower and angled the ammo rack as on the Pailsen Files mission pack. With the design roughed out I created the second and third pages to design the shapes I’d cut out of styrene plate and assembled to make the pack. After a few hours of cutting parts with a straight-edge and blade and gluing them together, this is what I came up with:

Unlike some of the early construction I did for the Zaku Kai chest block where I had to mitre-cut all the plate edges to join them together at weird angles, here I just used box joins. This means, for instance, I cut two 1mm plates for the left and right faces of the parachute pack, and then the top and rear plates would be 2mm narrower than the full pack width, so that the plates can be simply glued together. The parts will require some more refinement later on, of course. If you look inside the pack, you can see how I mounted it to the backpack: basically I just cut a couple holes in the place where I’d measured the mounting hooks to be (and then cut them again, because I’d measured wrong) and mounted a rod in there. The holes are just big enough that the pack can be lifted off the Scopedog. Also note that once the ammo magazines are mounted on there, the Scopedog won’t be able to go to “down-form” any more. This is actually pretty common on Scopedog equipment. Several mission packs, including the Parachute pack, handle this problem by hinging upward to get out of the way for “down-form”. I won’t be reproducing that feature in this build, though it’s something I’d like to address in the future, perhaps.

One problem with the Bandai Scopedog and mission packs is that they made the ammo magazines very small: only 8mm wide. The magazines on the Takara 1:35 scopedog are nearly 8mm thick. However, it all comes down to an issue with the lineart. Bandai’s ammo magazines are very accurate to how the magazines are shown when mounted on the rifle, or on the Scopedog’s side skirts. But the lineart for mission packs like the parachute pack shows two or three ammo magazines mounted side-by-side on the bottom of the pack taking up almost the entire width of the pack. It was common in older kits for this discrepancy to result in different-size ammo magazines on a single model. On the other hand, Bandai’s magazines just don’t fill enough space for backpack ammo racks, as seen on their “Pailsen Files” version. The Bandai Scopedog’s chest is about 54mm wide, and my parachute pack is 46mm wide. Three 8mm ammo magazines would take up 24mm, barely more than half that space. Even adding 4mm spacing between the packs they would only fill 28mm of width. To solve the problem I’ve decided to bulk up the magazine to 10mm thick and cast copies. This way, with 3mm spacing between magazines, they’ll fill 34mm of width, roughly 3/4 of the width of the pack. A 2mm increase in thickness is a noticeable change but not a drastic one: I think it’s a good compromise.

In the last update I showed the shoulder mechanisms and the upper arm part: since then I’ve refined the upper arm part quite a lot, and gotten a good start on a forearm and a leg.

One thing I was really going for in my Zaku design plans was to capture the curvy, bulky look of the lineart. To my eye, Bandai kit designs are always a bit timid in this regard. Whether it’s for broader appeal or better posability or whatever I couldn’t say. The leg is probably the part of the design I worked on the longest, going through five or six big revisions on paper before making the Blender model and then tweaking it further. So for me, finally having the leg in physical form (even in kind of a rough state) is very exciting.

As with the shoulder joint, I’m building my own hinge joints for the knee joint, to be cast in resin around a polycap. The barrel part of the joint was made by turning poly putty around an axis, and then chucking it on the drill press and block-sanding it to get the sides right. The cap at the end I made out of Aves – I was able to sculpt the rough shape pretty well by hand before refining it with sandpaper on the Dremel.

As for the forearm – I actually built those parts not long after my last post about the Zaku, but never got around to posting them. Both parts were turned poly putty, but I recently added more detail to the “elbow hubcap” part by carving out the middle and resculpting it with Aves.

The recent work has relied heavily on Aves, as opposed to a lot of the earlier work that used more Bondo – I think Aves has given me a lot of trouble when working on the shoulder armor, so I was wary about building more parts with it, but I decided to give it another try. A big change from most of the other parts is that the leg parts are built from solid Aves, rather than being built as a hollow shell. As a result, I will need to hollow out some of these parts myself later on – even so, I think this may prove a lot easier than trying to rough out the shape of the hollow with clay, then layer on Aves and try to get a uniform thickness and a good exterior surface. Working solid also makes it easier to change the contour of the surface if I need to.

One feature of my leg design that isn’t present in the parts I’ve built is the asymmetry around each leg’s center line. The upper legs have to have hip joints and cable points on opposing sides for left and right, of course – but the lower legs are, in my plans, actually longer and bulkier on the side that faces outward. I did this because I felt it made the design look more natural in a wider stance. But the part I built is like the smaller half of one lower leg, mirrored and stuck together. There are a few reasons I did this. First, left and right sides each need a version of that face of the leg, and it’s a bit simpler to make them consistent if I build them together. Beyond that, however, I am thinking of recasting this symmetrical lower leg and then modifying it to produce the left and right lower leg parts per the original design plans. I think that modifying a copy of the inboard side of the leg to produce the outboard side of the leg will probably be easier than rebuilding that whole half of the lower leg.

I didn’t take photos of it, but I’ve also been working on a rear skirt part. I am somewhat eager to make more progress on the skirts, because they’re one of my favorite features of the Zaku Kai. I’ll probably continue with the legs and feet for a while, though…

Version 1

Initially, when thinking about this design, I was trying to minimize the pin count of the microcontroller to get the smallest footprint possible. This led me to look at the SOIC version of the PIC 12F683, an 8 pin device. Using that chip as a starting point, I developed the first version of the board with a size of 11mm x 10mm:

This design was fairly compact, and provided four extra ground connections to make it super-easy to hook up multiple LEDs. Unfortunately, there were also some problems with this design:

• The 12F683 has only 6 I/O pins. One of these is input-only, and another two are being used up in this design as communication lines. That leaves only three I/O lines capable of driving LEDs.

• Instead of using series resistors and driving the LEDs directly from the I/O pins, I used the resistors as pull-ups, so that the PIC could turn off an LED by driving the pin low, or turn on an LED by setting the pin as an input. Unfortunately this means that while an LED is off, there’s more power going through that resistor than would be going through it while the LED is on – and all the PIC would have to sink all that current. This severely limits how much current I can feed to the LEDs without sinking too much current to the PIC in the “off” state.

Ultimately it was just the shortage of I/O lines that made me rethink this design. 3 lines could have been enough for the Hakuheisen, except that driving four LEDs at once on a single output line would limit how bright those LEDs could be, due to current-capacity limits on individual PIC I/O pins. That and the fact that the 16F688 was available in a SSOP package: a 14-pin SSOP is roughly the same size as an 8-pin SOIC, because the pins on the SSOP are smaller and closer together…

Version 2

Version 2 was the first version I designed using the 16F688 as the basis. It’s also an 11mm x 10mm board, and it provides access to four of the PIC’s twelve I/O lines. An interesting feature of this version of the board is that the top and bottom I/O connections can also be used as connections to the 5V source or ground, by leaving out the series resistor for the I/O pin and shorting out the pads on the other side of the board. The I/O pins provide connections to port pins C0, C1, C2, A2, and A5 (not in that order) – and there’s a small connection at the bottom of the board for access (without a built-in series resistor) for A4. The ICSP clock and data lines are tied to port pins C4 and C5 (which are used by the PIC’s built-in serial port hardware). I/O pin C3 has no connection – it was hopelessly boxed-in by this design. Later on as I learned more details about the BatchPCB service I discovered that the drill size on the vias is smaller than BatchPCB allows – so I would have had to fix this design before I could attempt to have it made…

One of the funny things about this design in retrospect is that the PIC is basically backwards of how it really ought to be… most of the connections start on the right side of the board and have to cross to the left, or vice versa. Experimenting with the orientation of the PIC and the ICSP connector has been one of the main things I’ve changed between versions of the design…

This design provided more I/O pins than v1, but access to voltage and ground was a bit of a compromise. There was no way to provide an entire strip of ground connections as in V1 because I couldn’t route a trace for ground around the five I/O pin holes which took up the entire width of the board. This design got me thinking about ways to make the board more versatile.

Version 3

Version 3 is the version I sent off to BatchPCB. Unfortunately, as I mentioned in my earlier post, the design had some mistakes…

Version 3 introduced the idea of an area of the board which could be cut off to make the board smaller. The overall board was 12mm x 12mm but it could be cut down to 12mm x 10mm with the loss of four I/O pins and a ground connection. I used Version 2 as a reference when creating this design, which led to the first major mistake in the design: I connected the SSP clock and data lines to the ICSP header, instead of the ICSP clock and data lines… I also somehow managed to get the power connection backwards…

Apart from these mistakes I think version 3 had a lot going for it. All the I/O lines apart from those of the ICSP header were available as full-size through-hole solder points with series resistors. Also, there were pads for a pull-up resistor for the reset line (useful if you want to use the reset line, I guess – personally I’d just disable the reset line in software). Apart from the functional mistakes in the design, one thing I don’t like about this version in retrospect is that the order in which the I/O pins are arranged on the board is completely arbitrary. If you cut off the “optional” section you wind up with three PORT C pins and two PORT A pins… And the pins aren’t labeled, either. I didn’t think this would be important (the idea was that after everything was hooked up, software loaded onto the PIC would be used to configure and report on what pin held what function) but in retrospect I think it would have been useful. After I got the defective boards back, I did a quick fix to the board:

The power lines were switched back, and I did a simple fix to get the ICSP lines onto the ICSP header. This resulted in them being opposite the way they’re arranged on other versions of the design: “Ground, 5V, Data, Clock” instead of “Ground, 5V, Clock, Data”… By convention I try to keep my connections in the latter order (ground comes first, then power, and then the serial lines – you can’t even attempt to read the data line without the clock line, so the clock line comes first… It’s arbitrary, really, but it makes sense to me, and it’s very useful to establish a consistent pattern for these things…) I also arranged the left side of the board to provide connections to PortC 0-4 in order. 3b would have been workable, but I wanted to see what else I could improve, as well…

Version 4

Version 4a was another 12mm x 12mm board with a 2mm optional section, like Version 3… The main difference was that I set out from the start to arrange the available I/O pins in order. If you look at the back side of the board, you’ll see the pins on the left edge are labeled, simply, “PORTC 0-4″. If you’re reading that right-side up, then C0 is on the left and C4 is on the right…

The back side of the board seemed very spacious, so I did another version in which I made the board 1mm narrower:

One new feature of this board is it includes not only a pull-up for the reset line, but a capacitor to ground, as well. Still, like I said before, I never use the reset line, so this could just be a waste of board space… I don’t know. It might come in handy someday, I guess! :)

In version 4 I rotated the PIC to make it “tall” instead of “wide” – this allowed me to put the resistors for Port C on the same side of the board as the PIC. But when I was experimenting with the V3 boards I got back from BatchPCB, it seemed to me that these boards still might be a tight fit inside the Hakuheisen belly space… It seemed as though if I put those resistors back onto the back side of the board again, I should be able to significantly cut down the board’s width. And looking at the back-side of the board, it seemed like I had all kinds of space there just going to waste. I mean, I formed five vias into the triangular-grid pattern from the Ingram’s head in Patlabor, and all the back-side traces are curvy and silly – and there are only a few components on the back side of the board. So while I think v4 is great and I actually enjoy those silly features visible on the back of the board, I was sure I could do better.

Version 5

In version 5 I made two attempts to redesign the board into a narrower, longer format, about 9mm x 13mm. To do this I moved almost all the components other than the PIC to the back side of the board, made the holes for the I/O pins smaller, and started over.

In v5a I made the connection holes about 0.6mm in diameter, down from the original 1.0mm. The board is 9mm x 13.5mm with two optional sections: one at the top (including pin C5 and the extra power connections), and one at the bottom, containing the three remaining pins of Port A.

Version 5b is half a millimeter shorter, at 9mm x 13mm. The optional section at the bottom contains only power connections (two ground, one 5V), while the optional section at the top contains I/O pins. The design is a lot more cramped than earlier versions: the back side is littered with resistor pads and vias, while the front is dominated by the PIC. There was very little space remaining to put markings on. I feel like 5a is a little bit cleaner, which is nice: 5b has resistors alternating orientation on neighboring I/O pins and markings not quite exactly where I’d want them to be, and so many vias all over that there’s no room for any text… 5b is smaller but 5a seems like a cleaner design. In any case, to go with either design I’m going to have to be careful to make sure those pin holes are really large enough. The 1mm holes on the v3 boards are more than large enough for any of the pins or connectors I’d use there now, but I wouldn’t want to have the boards made and discover later that I should have made the holes larger…

The trick is, the one place on this kit where it’s really easy to install a circuit board in this kit and be able to access it later is the belly – and there’s not much space there. If you cut out some of the excess material you can get a space about 10mm wide and maybe 13mm long in the belly. It would be possible to get more space up in the torso, but it would mean gutting the area in question, and then possibly rebuilding the area to give it structure again… And while the torso seems quite large, the problem there is it’s very very flat. Short of cutting up the torso (for instance, something similar to all the cockpit mods you can see on AC Armory) it would be very difficult, in my opinion, to install a circuit board in the AC’s chest, especially if you need to be able to get at it…

So my solution to this problem was to design a circuit board for projects like these – a board just about as small as I could manage, but incorporating as many features useful to controlling and lighting a model as I could manage. Today, after a couple weeks of waiting, I finally got the boards back from BatchPCB, the fabrication service I used… There is good news and there is bad news…

Are you wondering why I would need a special circuit board to be able to fit this circuit in my model? Basically despite this being a fairly good-sized model (around 15cm tall, humanoid, reasonably bulky) the kit is generally rather dense – and for maintenance reasons I needed a central location. Really the only options were the chest or the belly, and I went with the belly. Using regular pin-through-hole parts wouldn’t have been totally impractical, but it would have been very tough. As it is, I think it’ll be rather challenging to make the connections to this thing and put everything together nicely…

First, the good news. I ordered four 1″ x 1″ boards (each of which includes four 12mm x 12mm “Raven” boards) – and I got eight. This happens sometimes, I understand, because BatchPCB works by bundling a whole bunch of orders together into one big panel, then cutting up the big panel to get the individual boards people ordered… If something goes wrong with a part of that panel, they’ll re-do the panel… But when they cut up the panels into the individual boards, they’ll actually ship out both copies of your order… So it seems likely that part of someone else’s order was defective, and I lucked out and got an extra set of boards as a free bonus as a result.

The bad news: I screwed up. I’ve found at least three mistakes in my design. I can work around the mistakes, but it’s still kind of a shame because the whole point of making a board like this is to minimize the amount of work I have to do to stick a microcontroller into a model – but since I screwed up, some of that work gets added back in. The first mistake was that I got the power connections backwards! My second mistake was I was careless about how I organized the different I/O pins – The five I/O pins on the left side of the board are (from bottom to top) C3, C2, C1, A4, and A5… The four I/O pins at the top include C0, C4, A1, and A2… This could be awkward when I write the code that will run on the PIC itself…

The last mistake was that I’d meant for the header at the right of the board (the one marked with “0V, 5V, CLK, DAT, VPP” on the back side of the board) to double as an ICSP header for when I had to program the PIC… Unfortunately, I screwed up here – I tied these instead to the clock and data lines for the PIC’s “synchronous serial port” feature… This was a mistake I kind of derived from an earlier version of the design, in which the two pairs of clock and data lines were simply tied together so I could use one port both for programming and for runtime control… Using the SSP pins for the runtime control actually has some advantages, because the PIC includes real hardware support for the kind of interfacing I’ll be doing… To use the same clock/data lines as ICSP means that I’ve got to do all that in software. It’s workable but not ideal. On the other hand, it does mean that the SSP pins are left free in case the controller itself needs to use them to drive other circuits…

What this all means is I’m going to have to connect power to this thing opposite of how the writing on the board says I should… I have to omit the pull-up resistor for the reset line (despite having included a place for it on the back side of the board), and I either need to write firmware for these boards that will communicate using the SSP feature, or else I need to hook up to the ICSP I/O lines located on the removable section of the board… The problems surrounding the location of the individual data lines isn’t a huge problem, except that in projects where space is particularly limited (such as this AC project) I’ll be removing the optional section of the board to save space – that means I’ll mainly have access to three I/O pins from Port-C and two from Port-A… Writing to the pins on Port-A is going to require special care if I write the serial communication code myself (using the same pins as for ICSP), lest I accidentally overwrite some attempt at communication…

I’ve already worked out a “version 4″ of the design that corrects all these problems – and it’s 1mm narrower, too – but getting the new design fabricated will require more money and another couple weeks… I feel like I’d best think about what I can do to make the new design even better – perhaps I could make the new version 10mm wide but longer… So it could still be cut down if it had to be smaller, but it could maybe fit in the Armored Core’s belly without cutting down the board first…

This is the old Sevans 1:5 scale Dalek kit, released in 1984. It’s about a foot tall when assembled. It’s a vac-form kit, which means that all the parts are hollow, made of 1mm thick styrene, and generally have some excess plastic to them that must be trimmed off. Also, any place where the kit is supposed to have a hole, you have to cut it yourself…

One of the interesting little features of this kit is that in the various places where there might otherwise be a large, blank area of plastic that would otherwise be unseen, there is instead a little panel filled with mechanical detail. These panels are apparently meant to be cut out and used elsewhere: I guess for people who want to create a “set” for their Dalek, these would work as control panels and wall decorations, to recreate that low-budget sci-fi look. I think it’s kind of neat that they threw that in there.

The kit includes a handful of injection-molded parts for the plunger, gun, and eye stalk, as well as a couple vacuum-formed clear parts for the lightbulbs mounted on top of the head. I seem to have lost one of these clear parts, so I’m replacing them with leftover parts from my Polar Lights Enterprise kit… I don’t really care about accuracy here, I just want the thing to look cool and take advantage of parts I have on-hand…

Everything I’ve done with the upper body so far has just been for the purpose of seeing how the finished kit will look. The lower body is where I’ve spent most of the time so far: cutting excess plastic from the edges of parts and assembling the Dalek’s skirt. Each panel must be cut out, chamfered on the edges to create a good join with its neighbor, and then glued down. The size and shape of each panel isn’t precisely correct, so I had to tweak a few of ‘em to get them to sit at the correct angle.

One of the things I’m concerned about here is making the assembly very solid. I take pride in my seam work, and good seam work demands a high degree of stability between neighboring parts. Without that, a little bit of flexion can introduce cracks in your carefully-sanded putty. So for starters I’ve reinforced each panel with styrene strips, and I’m using Aves to reinforce the joints on the inside. I haven’t yet worked out whether I’ll be doing anything more extensive in the way of reinforcing the panels. Actually, it seems quite solid so far.

You may have noticed that the edges between panels had some gaps in ‘em – particularly in the rearward-facing panels, the ones I did first… This was sloppy work on my part, but I’ll deal with it later with putty. I think all the panels will require this kind of attention – even on the ones where there’s no gaps, there’s still uneven joins and so on… I find it easier to correct minor issues like that after assembly than to get the initial assembly of hollow, boxy structures made of styrene plate right the first time.

There appears to be a problem with the four panels that sit right at the front of the skirt: basically, the top contour of the frame for these panels doesn’t match the bottom contour, so to install the panels you need to bend ‘em. I installed the first one (L3) by gluing down the bottom and aft edges, and then when that was dry, bending the panel to glue down the top edge and holding it down with rubber bands until the glue dried. I think on the other three “problem” panels I’ll just bend the panel before gluing it down. Perhaps, in the following photos, you might be able to tell that the L3 panel is no longer planar…