Project: OZ-13MS Gundam Epyon Part 2

Creating the new beam saber. This is really the crux of this entire project. Most of the 1/100 scale GunPla models come with beam weapon effects molded in a tinted plastic, in the case of the Epyon it is molded in green plastic. But I want to be able to light up the plastic. I had previously tried to accomplish this by carving out a space for the LED inside the saber effect and mounting the LED at the base of the saber effect.

I cut out a hole in the beam saber blade for a square LED.

 It does work… sort of. But it also brings up a lot of additional problems, the biggest being how do I solder the wires when the LED connections are practically on top of the plastic handle itself and the handle isn’t actually wide enough to survive being drilled through the length to pass the wires through.  So I decided to cast the beam saber effect, and the saber hilt in tinted resin. This way I can physically imbed the LED inside the part, rather then having to cut up the part to fit the LED. I can also pre-assemble the LED, resistors and lead wires before embedding them into the resin and then just pass the wires through the cable tube that actually comes with the model.

 Now, casting is a surprisingly simple process that can become incredibly demanding over very simple aspects. The Epyon’s beam saber with the saber effect when assembled is a design that emphasizes it’s lateral details while having relatively little vertical details. This is of relevance to the mold making process. The silicone rubber will fill in any space that isn’t sealed off. For instance, where the green plastic beam effect sits in the hilt, the hilt is raised away from the saber effect so if the mold is laid out width wise the rubber would encapsulate the saber hilt and fill that void between the hilt and the saber effect creating a wasted effort of a mold. It would be wasted because I would then have to cut apart the mold in order to remove the original part very likely ruining the mold in the process.

So there are 2 ways to make a mold for the Epyon sword, the first is make the mold with the hilt and saber effect mounted depth wise. This allows the lateral details to be taken very well. The second way is to mount the parts laterally and make a shallow mold. The challenge with this second approach is I have to make sure to filling any spaces that will cause the  rubber to encapsulate the original parts.
I made my first effort to create the mold by mounting the saber in the rubber depth wise.

The first mold setup for the beam saber I made.

Well I ran into another problem with this approach, well 2 problems actually. First, it takes more rubber to make the mold like this. And by more, I mean close to 30% more. You really can’t make a silicon rubber mold that is narrower than 1” and with as long as the Epyon beam saber part actually, it’s close to 6” long with the larger saber effect; the mold really needs to be 4” wide, if not wider, in order to keep the blade straight. So making the mold depth wise simply didn’t work out and with that I needed to create a new mold this time shallower and wider.  I used some clay to fill in the spaces that would otherwise be filled by the rubber.

So 2 days later, I had a working 2 part mold for the Epyon beam saber that I can now cast in green tinted resin and embed an LED in it to create the light up saber for the mold. Things are looking good. So I mixed the resin, picked up a bottle of green dye, mixed in a couple drops of green dye to tint the resin green, poured the green tinted resin into the mold, put the LED in the base and then put the green tinted resin filled mold in the pressure pot, sealed up the pot, pressurized it, and left it sit for 6 days so the resin would cure. Yes, the resin I tried this with has a 6-7 day cure time.

This incredibly long cure time is actually a bit of a good thing in this case. When you mix epoxies like resin you tend to mix in air that create bubbles in the resin. With opaque resins this is a non-issue, but with transparent resin it create some visual headaches. So there’s 2 days to deal with this and in both cases it takes a little time and control of air pressure. The first option is to perform a process called “Vacuum degassing” where you put the resin into an air tight chamber and suck all of the air out of the chamber. This causes the bubbles of air in the resin to be pulled up out of the resin. The second option is literally the exact opposite, that is putting the resin in a reinforced chamber that is air tight and increasing the air pressure to between 50 and 60 PSI. The increased pressure crushes the bubbles out of the resin. So both approaches have the same effect, to force the bubbles out of the resin.

So, a week later I depressurize the pressure chamber, pop the top, pull out the mold, separate the two parts, pull out the part that was cast from green tinted resin and find… that it’s blue.

So... how does it come out blue?

And has you can see it’s not even like a blue-green or a sea-green sort of dark green… no it’s blue. So… yeah. What the heck?

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So, what does 2 quarts of Resin get you?

Well, I finished the molds for various parts. Some of them worked out alright. None of them were a complete success. As you can probably guess, I've been casting up copies of the master parts I've been building the last few weeks. Some of the molds turned out pretty good, some of them not so great. In either case it's been a learning experience and now I'd like to share some of that experience with all of you. What I am saying? Learn from my mistakes. Heed my advice. See where I messed up so you don't make the same mistake if you try this sort of work.

So, first up are the molds I've made.

That is a series of 6 molds I've created over the last few months, using various approaches, materials and ideas. Here's the differences between each:

 This is actually the first 2 part mold I made. As you can see I made it so I could cast up 4 hellfire missiles at a time and one Ork twin linked big shoota. I was intending to use the shoota as the basis for my Chaos Thunderhawk Hunter guns, but alas my first attempt at a two part mold was somewhat flawed and the clay I used in the process turned into a sticky gum when I used the mold release agent on it. This mold was made using Smooth-On's Oomoo-30 Silicone Rubber kit.

This is the second attempt I made for a hell fire cast. This rubber is Smooth On's PMC-121. This rubber has the advantage of being much denser and thus stronger and more rigid and thus better at grabbing details. The down side? 16-20 hour demold time. That means once you pour the rubber, it's a day until you can pull the mold up. Making a 2 part mold? Don't expect to be able to use it with 48 hours of starting to make the mold.

These molds are of the various parts for the thunderbolt. The molds at the top are the engine mounts and the intakes for the engine. To save time I made 2 molds of each so I could cast up the pair of each part I needed in one go. 

The wing mold... oi vey as this thing ever been a pain in the butt. See here's the thing. In the final wing I want to have magnets in the bottom of the wing Pylon so I can attach hell fire missiles or fuel pods to the model. So I want to be able to put the magnets IN the wing pylons when I cast the wing. Well there's no way I can cast the pylons, and the wing at the same time. So I have to spray down the mold with release agent first, then cast the pylons and let those set till at least stiff and not runny. Then I have to close us the mold, and cast the rest of the wing. And what happens if any part of the process has a problem or isn't done correctly?

This!

So what do I do? I have to be VERY patient and do each step correctly each time. Roughly it will take me about an hour and half to cast the wing properly.

Like this one:

The rest of the casting results depend largely on my patience when I cast the part in the question. The exception to this are the engine intakes and the engine mounts.

 The intakes turn out fairly well with little effort. Just a little clean up to even out the backs and they'll be good to use.

The engine mounts likewise turn out well easily enough. To reduce the weight, and the amount of resin I need for each I submerged sealed styrene tubes in to the resin as it's setting. You can see one of the tubes in the above picture. This effectively makes the part hollow with needing to make it a multi-part construct. Again, just need a little clean up to make the piece workable.

The Engine itself as been a trying expirament:

Oh yeah, the engine has proven to be the most difficult large piece to cast. Because of the small details on it, the resin tends to "bubble" over the details and then dry, leaving a void in the finished piece. You can this in the first couple attempts. So how have I solved this? Simple. Patiance. Namely instead of trying to cast the entire engine in one single go I try to cast in three steps using less resin and poring the resin very slowly at each step.

In this lastest effort I did it in three passes, pouring about 1/2 ounce of resin each time, pouring it along the shaft of a stir stick and trying to keep it the pour rate to a very shallow thin stream in order to give the resin time to spread out and fill in the details on the inside of the mold. Still need some clean up on the finished piece but a substantial improvement over the earlier attempts.

The small tiny details on the weapons have been an absolute nightmare to overcome and honestly I haven't quit gotten them beat yet. Much like the small detail on the engine, the resin as a tendency to bubble up and fill the mold of the smaller pieces creating these large gaping voids ruining the part.

This is the most notable example of this particular problem. Where is the rest of the Lascannon? And why is the body of the hellstrike Missile hollow? Yep, that bubbling problem at work again.

This casting was notably better but still has a hallow body to the lascannon. I MIGHT be able to use this one. Have to look into it more closely.

This is actually the best casting of those parts yet. YES it has a metric crap ton of clean up on it but guess what? All the of parts and pieces are there! So that's a win.

Now, here's a piece of advice for you if you get into casting: Spend the $10 bucks and get one of these:

Why? So that if you have an extra 1/2 ounce of resin you don't waste it. Spray this rock mold with some mold release and pour the extra resin into the mold. Just save the extra rocks in a box. You can use the rocks for basing or other terrain projects. You'll look into the box at some point and go "Holy crap! That would look great for my [insert model name here] as a base!" or something of that nature. And you'll wind up with plenty of them in a hurry too.

Same thing works if you're using green stuff and have some extra. Press the extra into the rock mold. Viola! You've got a rock you can use for basing or detailing.

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288 lego bricks.... 3 quarts of silocone rubber... 2 pounds of synthetic silicone clay... a couple ounces of silicone ethal spray... 3 ceramic tiles...

So, what does all of that add up? Well right now it adds up to 3 Lego boxes filled with silicone on top of the dryer. My orders came in and now i can continue work on the Thunderbolt, the body of which you can see on the flight stand on the left side of the image.

The first box (on the left) is the first half of a 2 part mold which will have the back section of the engine, the Ammo Hopper I built a while back, a lascannon, and the Autocannon with the angled mount for the thunderbolt. The second box is a single piece mold and contains the intake for the engine and the engine mount itself. The third box in the first half of the mold for the right wing.

Something I'm going to try to do is adding magnets to the design of this model. Particularly for the missiles. So what I'm going to do is cast the wings up with magnets at the base of the weapon pylons, and then cast up the hellstrike missiles with magnets in the bodies of those. So that way the missiles can be attached to the pylons, and removed once they are fired in a game.

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still alive

Okay, it's been a helluva couple weeks but I haven't been totally inactive.

First and foremost, my father built a case for some of my tools. This case had originally been intended for my computer tools for work. However, it turns out that I'm prohibited from bringing my own tools to work. So I had this great case, and no immediate use for it. What do I do? Convert it for use with my hobby materials of course!

my new tool case.

The case has three foam inserts that I cut out spaces for the respective tools.

The top tray houses my 'most used' tools, and these include my hobby knife, extra blades for it, my razor saw, the files, tweezers, and sculpting tools.

the middle tier of the case.

The middle tear houses my green stuff, milliput, ticky-tack, glues, magnetic probe, and accelerent.



 Finally the bottom teir of the case:

the bottom tier of the case

 

 

 

The bottom tier houses an assortment of clamps, hole punches, my utility knife and my caliper.
So now rather then having the majority of my tool shoved hap-hazardly into a drawer I have a nice case with individualized slots for many of my tools.

I've also been experimenting with resin casting and mold making. Remember that Thunderhawk I'm working on? Yeah... rather then build 4 weapon mounts, 2 separate engines, 2 pilots seats, and an assorted over pieces multiple times... I'm looking into the process of making one master version of each type of part, making molds of the master and then casting the multiples of those parts I need.

I haven't gone into the mold making yet but I've been experimenting with pre-made molds, I have acquired over the years. I've made several groups of rocks that appear to be useful as base material.

It's a rock, Jim.

 One thing I am considering is modifying a future casting to include space for a AA battery pack and thus use it as the base for a model that will use LEDs to light up in some form.
If I space it properly, I think I can make it work:

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