1/20 FSB: RMX-000X Raptor X Part 6

Power to the Pistons

I'm currently working on the fuselage and cockpit designs, letting them run in my head for a while mainly to incorporate how the hip will connect to the fuselage. With it was an incessant itch (that I have had since the initial build) to add a dual opposing piston that will run and connect the back of the thigh to the front of the knee in between the knee intermediary. This serves both as void filler, as well as functional mobility to the leg, which theoretically speaking, gives the leg more hydraulic power and support.

Instead of the usual exposed piston barrels like what I have done previously, I decided to encapsulate these in a plaplate "box." On very rare occasions, I do use superglue for quick bonding work, as well as the fact that these tubes are unaffected by cement. I glued the pistons on a slab of 1mm HIPS, cut it to size, and glued the other side. I then cemented a small piece of HIPS on each end, boring holes aligned to the tubes. I then cemented 0.5mm HIPS on the sides.


I drilled holes 1mm + 0.5mm deep on the wider side of the box, rounded the tips of 3mm round beams, and cemented them into place. I made the usual T-shaped beams for the shafts.


This box piston will be held in place by the side pegs, which in turn will move freely along the length of the knee intermediaries. I ran this scenario over my head quite a few times as I was doing the foot and the shin armor when I realized that that section will look rather empty.


I modified the thigh and shin frames to fit the box piston by cutting away a bit of material from each that come into contact when the leg is folded. I also added a few strips on the calf section of the leg, both to reinforce the part and as detail prep. The thigh and shin "cheek" frame intermediaries were also "slightly" modified to hold the T-shafts of the pistons. Though the modifications were simple enough, I made a few mistakes aligning the holes, so I had to plug and re-drill a few times, which took a lot of time just waiting for the cemented plugs to cure.


Without actual measurements and just basing it on visual estimates, the box piston fits perfectly inside the void of the legs (which I had to modify) when the assembly is folded.


In order for this to work, the intermediaries had to be modified as well. I drilled 1mm holes 2cm apart and drew a straight line between them, drilled a few more holes, and progressively enlarged the holes to 3mm to fit the box piston pegs. I shaved of the excess plastic with a knife, then filed the surface smooth.


Test fit. I wasn't sure if this will work, or will lock the entire knee assembly, ruining hours upon hours of work and imagination, but sometimes, I do amaze myself when something this random actually works the first time I do it.



Up next:


Trivia: This is one of the rare posts wherein I didn't need to include a thumbnail...

1/20 FSB: RMX-000X Raptor X Part 5

The Shin Saga

I've had a few sketches as well as a few more bad dreams and nightmares as to how the shin armor would eventually look like, but not of them quite made the cut. I had about 4 or 5 cardboard prototypes of the shin armor, and posted the last two in my previous post.

Even in my initial fittings, I deliberately made the armor over-sized since it's easier to remove than it is to add later on. Using the cardboard prototype, I cut whole sections of 1.0mm HIPS for the side and mid sections of the armor.





To fold the HIPS (or plaplate, as the case may be), I scored the underside of the slab twice, 0.5mm apart, and at most 0.5mm deep. I then carefully ran my knife along one of the score lines at an angle to create a V-shaped groove. This can also be achieved with a V-shaped scriber, but it'll take a lot more control as opposed to a knife. I also used a very blunt knife for a more controlled cut, and as you may well see, even a blunt knife can cut deep.

Using a ruler placed along the groove, I carefully folded the slab into the groove to the angle I needed. This is the same method I used to fold the shin armor's main sections.





At this point, I've double-layered all the parts (making them 2.0mm thick), including the intermediaries that will hold the three main sections. Like in previous updates, pegs, along with tension between parts, will hold the entire assembly together.





With that done, the shin armor connects to the leg frame via slots. This was a bit of a challenge since the sides are angled, so I had to cut identical angled slabs 3mm thick, attached two of them to either side of the prepped leg frame and aligned them with each other with slight difficulty. This locks the leg parts that hold the calf pistons, and the opposing action also partially locks the shin assembly as well. Regardless, The peg assembly is employed in consideration of part casting (and painting, for that matter). The shin armor, ultimately, will be glued together as one part.





Test fit. Further detailing will be made, and I might trim the shin armor. I've been itching to make the front of the foot larger, and this just made the itch a rash.

1/20 FSB: RMX-000X Raptor X Part 4

This one took more time than usual with me deciding on what joint to use (aside from having a class early this week and the previous week). It would have been simple with a ball and socket joint, but since this is going to be a resin kit, I anticipated a few problems on my part with the lack of available add-ons I have in my stash. Also, I prefer hinge/swivel joints anytime.

With that in mind, I needed intermediary parts that would bring the leg, the ankle and the foot together.

Say Ankle!

The ankle intermediary is a simple "catch" that joins the leg to the ankle. I sawed slits to the lower leg joints' "cheeks." This is where the ankle intermediary will slide onto, locking the leg joints in turn.

Footloose!

The foot is made of several parts that interlock. The heel is a simple two-part slide assembly, that will connect to the "core" of the foot via pegs on either side.





The core sandwiches the heel, and the main foot locks the core with a three-piece assembly, and finally by the fool intermediary. As planned, the foot is similar to a raptor's foot in walker mode, and folds onto itself in flight mode.



I wasn't able to take step-by-step pictures of the main ankle joint, but it's also a three-piece assembly that is interlocked by the ankle intermediary via pegs.




I've also made a video of the Ankle and Foot assembly.

Next up, the shin armor. This also took a bit of time thinking about how to execute it, so I use cardboard to make trial and error templates.

1/20 FSB: RMX-000X Raptor X Part 3

Pondering Pegs Provide Plentiful Positioning Possibilities

Though I said I would be working on the Shin Armor as per my last update, I realized couldn't really start on it until I've done the rest of the leg and foot, since armor placement would be largely dependent on the internal frame's final shape. I also had a 3-day class, and that didn't give me much time to work on the leg until last Friday, being that I am actually designing this as I go. Regardless, I've prepped the secondary frame (that holds the rear part of the intermediary joint and the ankle and shin pistons to the leg frame) by adding pegs to it so it can mount easily to the main frame with corresponding holes, similar to what I've done with the thigh. Though I've made the peg connections for these two very snug, the external armor will still serve as their interlock.



I didn't have enough time to do a full step-by-step WIP for these next bits, but these are basically similar to how I did the first pistons. The ankle and shin pistons are about the same size, with the shin piston slightly longer.





Like I mentioned previously, I've referred to the OYW RX-78-2's leg in designing the Raptor's leg mechanism, mainly how the ankle pistons are oriented, but not how it looks, changing and adding a few things as needed. I'm basically just using a single width cut now, cutting and shaping it as needed. I simply cut then build up if I needed a larger shape, as I have done with the thigh cheek frames and just a while ago, the calf. With the ankle, I've cemented a couple of 1.0mm slabs to make 2.0mm slabs and shaped it as such.



This will lock the ankle pistons into position and allows for maximum mobility, articulation and ankle bend when transformed into flight mode.



With the secondary frame of the calf finally done, that, along with the ankle locks, the leg mechanism is complete.


Test fit.



Next up, the foot.

1/20 FSB: RMX-000X Raptor X Part 2

The Poetry of Symmetry

Since I've decided not to enter this to HLJ's Sci-Fi competition (though I might enter another kit if the itch doesn't go away), I'm no longer pressured to do a pair of everything that needs it. The parts I am making are for both the left and right leg, so I can basically skip making another set for the other side. Regardless, I take note of every part I make that has symmetry involved, just in case I have enough time left to make a complete set.

One way for me to keep a running total of parts is to make a basic template, and use that to make duplicates by double-taping the template to a piece of HIPS, cutting it, taping that, cutting it, and so on, until I have enough. These will be the sides of the thigh armor.



Cut Clean.  Build Clean.

I'm exclusively using 1.0mm HIPS now since it's softer and easier to work with than the 2.0mm, for the armor at least.  My shaped plates/slabs are 2.0mm thick, so I had to make eight 1.0mm to make four 2.0mm slabs, so on, so forth.  I made sure I applied enough cement from edge to edge for an even bond, using extra thin along the seam lines to close gaps, and clamping them for at least 30 minutes.  This is essential, especially with parts that will have holes later on.  Any gap without cement will distort the plastic when holes are drilled and/or enlarged.  When this happens I simply apply more extra thin cement and re-clamp the area concerned, but nothing beats doing it right the first time.

I saved a pair of shaped plates just in case, already prepped for the internal frame of the second leg (which is also basically done, sans a few details). I made a 2.0mm slit halfway through the wider section of the slab, and used that slit to make an alignment guide on the "cheek" of the thigh frame.



I then cemented a 2.0mm beam on the cheek along the alignment guide, and this will serve as the "rail" for the thigh armor to slide on.



I initially planned this to be a one-part solid slide on armor which locks the intermediary joints, but being that that would be cast, I decided to make it a three-part slide interlock. The two side armors will have slide rails;



Which will be interlocked by the front armor via the slide rails. The armor will slide from the midsection up, and I made sure the parts fit snugly together when interlocked. I did something similar before with the K'triya backpack modifications (a tale to be told later).





The interlock armor, after a few improvements, like adding bulk (using the same template), beveling and (ugh) koto minus molds. I'm not too fond of koto parts, but I've used these nifty little buggers quite a few times when necessary. I'll be adding armor detail later on.



Like I mentioned before, this will have exposed frame parts, so I guess the interlock is a good option for the armor. Regardless, I might do a simpler, solid version, depending on how Alex would want to tackle this later on.  The back of the thigh kinda reminds me of the Turn A and Turn X.



Size comparison with the PG 00's thigh.



Here's a vid of the modular leg assembly.

Next, the shin armor.