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dmk0210

MPC R2D2 Build

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Some of the small parts needed some detailing. In an earlier post, I had modified one of the kit holo/light projectors and then made resin copies. Here I am going to do the same thing with some body details.

Here you can see some detail work I did. The parts on the left were modified with bits of plastic and sprue, the ones on the right are the original kit parts.

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To make a two part mold, I build a small box using Legos. Then filled the bottom of the box with clay, making sure that it seals the sides all the way around. Try to make the surface of the clay as smooth and flat as possible.

Now, set your master parts in the clay, carefully pushing them down into it so the liquid mold material can not get underneath. If the mold material gets around the part, it will "lock" it in. You need to be able to lift the finished part straight up and out when done.

Also notice that I used a dowel to press three depressions in the corners. I did this to "key" the mold so the halves will only fit together one way.

A critical step at this point is to cover the inside of the Lego box, the clay and your parts with a mold release agent (non silicone based!).

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The mold material I use is mixed in a 1:1 ratio, so it's easy. Just fill two small cups to the same amount, then mix them together in a third cup. Mix slowly and carefully so as to avoid stirring air into the mix.

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Once fully mixed, slowly pour the mold material into a corner, away from your parts, it will fill the box covering your masters. Once done, tap the box on the table and tap the sides with something like an exacto knife handle(or the large tweezers in my pic) to dislodge any air bubbles and let the rise to the surface. Now set aside to cure. I let mine cure a couple hours.

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When the mold is done curing, flip it over and remove the clay. Be careful not to disturb your parts. It helps to partialy disassemble the Legos temporarily. You can use a stiff paint brush and warm water to get the remnants out.

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Once you have it clean and dry, reassemble the Legos, cover this side with mold release, mix up another batch of your mold material and make the other half of your mold. When it is cured, you can disassemble the Legoes, pull the two mold halves apart and remove your master parts. I like to carefully wash the molds at this point and then spray on some fresh mold release agent.

Some of you may have noticed that I forgot to do something important. I forgot to include pour holes in my mold. :doh:

Luckily, it was easy to get a new sharp exacto blade and cut some large holes into the half of the mold at the back of the part. What I should have done at the beginning was glue a piece of sprue to the back of each part and left them sticking up when I poured the back half of the mold. That would have given me pour holes in the mold.

Another thing to notice is I can probably use just the one half of the mold to cast the flat pieces since onlt the front of the part will be visible on the model. The thin round thing for the legs will require the two mold halves to get a three dimensional part though.

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Put the mold halves together(don't forget to cover each half with mold release!). The resin is mixed exactly like the mold material (Except you have to work a bit quicker, this sets faster). Be especially careful not to mix any air in. Once mixed, pour it into the holes at the back of each part. Tap the mold to release any air bubbles.

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Once the resin cures, you can pull the mold halves apart and remove your new parts. I have a lot of flash because I didn't clamp the mold halves together. I just slapped them together and filled with resin. But it won't be too hard to clean up.

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Edited by dmk0210

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Thanks for posting this process for casting parts. I've haven't seen anyone post a nice step by step how to on making parts like this.

Edited by crowe-t

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I'm glad it was helpful Crowe. Documenting it is helping me too. I'm just starting with casting and need to prefect my techniques.

I really like casting, it allows me to duplicate unique or difficult to find parts I like for other projects (for example wheels for cars, pilot figures for aircraft), and makes it easier to make many copies of scratch built or modified parts that need to look the same.

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Wow Dave, you are doing some great work with this. The note book is out and taking notes ;)

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So did I mention that I really don't like scribing?

Many of the panels on the head were incorrect. I fixed the top earlier, by just cutting and rotating the top 1/3, but the lower panels were more work. My attempt at fixing this was to fill in all the lines with my homemade melted styrene putty, then rescribing new lines. Sounded good in theory, but unfortunately I'm not that good at scribing. There was a *lot* of trial and error, scribing, filing, rescribing, etc. Then there was fixing the slip ups where the line went further or my scriber slipped. I also had a weird problem with tiny air bubbles in the cured styrene putty. I think I must have mixed air in the mixture somewhere along the way. I'll have to be more careful and watch for that next time.

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So here we are after priming with Tamiya Fine Surface Primer which uncovered surface defects. I covered them with Mr. Surfacer here, but that didn't work so well for me (I don't know why I keep trying it). As it cures, it shrinks back into the recesses that you are trying to fill. What finally did work for me was super glue (CA) and Zap CA accelerator. Apply the CA on the spot you need to fill using a sewing needle with half the eye cut off so you have a two pronged fork. A tiny bit of CA will be held by your little fork allowing a precision application. You can use another needle/fork or a toothpick to apply a small bit of ZAP accelerator to the spot and the CA will immediately set. However, it is still not quite fully cured, so you have a few minutes to sand it smooth. It will not shrink, so you won't see that defect again. However, make sure that you do have it sanded down smooth exactly like you want it now, because once it sets overnight, the CA will be much harder than the plastic around it making it very difficult to work with (which is why I always hesitate to use CA for a filler unless I've exhausted my other options).

2012-09-16123355.jpg

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Looking good!

Something else you might try for filler is Tamiya's Light Curing Putty.

One of the guys in my model club has been raving over it. Basically, it cures when exposed to UV light, and it hardens within about 30 seconds and doesn't shrink. The down side is its expensive and it doesn't seem to be available stateside yet so you have to get it through someplace like HLJ. Sounds like a nice alternative to CA for seam filling, especially for someone like me who is allergic to CA.

-Dave

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With all the surface defects finally smoothed out, it's now time to move on to more fun stuff. Painting. :)

R2 is not going to get a chrome treatment here, but I'm going to use the same paint technique just to illustrate how that's done. The only difference is I'll use Alclad Aluminum instead of Alclad Chrome, I won't polish the plastic before painting and it won't buff to a high shine afterwords.

So first thing is mix up some paint. I'm using Testors Gloss Black enamel (I know the bottle says Boyds, but apparently it's the same thing). I used a plastic pipette (I buy them in bulk on Ebay) to fill my paint cup about half way (but notice the cup is smaller on the bottom, so it's really holding maybe 1/4 to 1/3 of the paint), then top off with mineral spirits. Suck the whole mixture back into the pipette and swirl it around to get it mixed up. You can even add a bit more paint and mineral spirits to the cup and suck that up too, just hold the pipette with the tip up, put a piece of paper towel over the tip and puff off some of the extra air, stick the tip in the paint cup and release the bulb to pull the paint in. Swish it around again in the bulb. Now you are ready fill the cup and start painting. Make sure to stand the pipette tip up so the paint doesn't leak out while you are working.

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Here you see the first coat down. It's very, very thin. Almost like Tamiya Smoke (though it actually looks a little darker than the picture). It's also very, very glossy. Just paint this on lightly, let it set a few minutes, then layer another coat. Do maybe three coats like this, just one pass each time, very light.

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Now add just a couple drops more of black to your mixture in the pipette. You've probably used about half of it already. Here it is after another two coats, again letting it dry a few minutes between each coat. So maybe five or six passes total at this point. It's very glossy. Lots of reflection.

Now at this point, leave it dry for at least a week (7 days). Cover it with something to keep dust off. Put it in a covered plastic bin or something. I'm going to leave it in my paint booth and close the door.

Normally, I would pick out the parts that need Alclad and get them painted with the black enamel early in the build, so I have other things to do while waiting for the enamel to fully cure. But the scribing on the dome was driving me nuts so it got painted much later. Nonetheless, I have quite a few other things to do with this kit in the mean time, so no biggie.

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BTW, if you have any paint left in your pipette, you can put some clear packing tape over the tip and it will keep for at least a week in case you need to do any touch ups. This is really handy for custom paint mixes.

2012-09-30132134.jpg

Edited by dmk0210

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Looking good!

Something else you might try for filler is Tamiya's Light Curing Putty.

One of the guys in my model club has been raving over it. Basically, it cures when exposed to UV light, and it hardens within about 30 seconds and doesn't shrink. The down side is its expensive and it doesn't seem to be available stateside yet so you have to get it through someplace like HLJ. Sounds like a nice alternative to CA for seam filling, especially for someone like me who is allergic to CA.

-Dave

Thanks Dave

I need to try that Light Activated Putty. I saw something about that a while ago and forgot all about it.

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So speaking of Alclad. This Apollo Command Module was painted with Alclad Chrome.

I polished the bare plastic with a three step nail polishing pad (dollar store beauty section find), washed it with dish detergent and cold water, airbrushed Testors Gloss Black enamel as described above, let it cure for a week, then covered with Alclad Chrome. After 24 hours, I polished it with a soft cloth (t-shirt material).

2012-10-05090244.jpg

Edited by dmk0210

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StarWarsIV_047Pyxurz.jpg

This weekend I did some work to make the feet look a little better.

The kit has a rectangular hole at the top of the foot, but if you look at the screenshot from the movie above, you can see that R2 actually has a slot at the top of each foot. So, I cut a notch out of the front and rear of the inside half of each foot and removed the alignment pins and the plastic that supported them.

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With the slots more open now, I had to box in the sides so you can't see inside the foot. I used a magic marker to mark the hole for the leg mounting pins and pressed the plastic against it while it was still wet, so I know where to cut that out.

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The kit had little wheels for R2 to roll on, but that just didn't seem right to me. Though I can't find any mention that he had treads, I had these in the spares box (from the 1/144 Revell Space Shuttle crawler). I sectioned them and they fit right in there. Didn't Robby the Robot have treads sort of like this or was it B-9 from Lost in Space?

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Had to also fill in the space on the legs. This was pretty straight forward.

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I wanted to be able to assemble the feet so I could fix seams and paint them, but the kit's leg pins were captive and there would be no way to insert the legs. So I drilled out a hole on the inside half (which is hidden by the box (power pack?) mounted to the foot. This also removed the pin that held the power pack box, so I drilled right into it as well. I shaved off the existing pins on the leg and drilled a hole there too. I found a nail of the appropriate diameter, and cut it to length with my trusty Dremel. Now I have a pin to hold the whole thing together. I can insert it after painting and it will be hidden by the power pack box which will also be aligned with the same pin.

2012-10-07193117.jpg

Edited by dmk0210

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Seam repair and detailing the legs in this post. The seams all the way around required some putty, gap filling super glue and aggressive sanding. The detail along the outside edge wasn't that great anyway, so I shaved it off and will scratch build some bits to replace it.

After smoothing out the seam, I had to scribe a prominent line around the shoulder area. Luckily the seam was slightly offset to where this line needed to go and there is a ledge on the leg that serves as a guide to start this line. It was actually pretty straight forward to wrap some Dynamo tape around the shoulder, starting at the ledge, wrapping all the way around to the ledge on the other side. I used the back side of the Exacto blade to get it started and then my UMM scriber to finish it off

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You can see the seam I just scribed in this picture. Also had to add some bits that look like actuators of some type just under the shoulder on the front and rear. The kit had some poorly molded detail to indicate this and it was only on the front. Though in fairness to MPC, I have seen pictures where this detail is missing from the rear and others that clearly show it, one of the little differences between the various R2 props used in the movies. I chose to add it to both front and rear. I used some stretched sprue to fabricate these. Some thinner pieces for the rods and some thicker pieces were chopped into little circles and then chopped in half to represent the joints at the top.

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At the bottom of the leg were some plates that didn't look much like the ones in the pictures of R2. I shaved these off which helped me fix the seam there, but left a hole. I filled the holes with bits of sprue. After the solvent holding the sprue set, I filled in the gaps with superglue, used some Zip Kicker acceleration to flash cure it and then sanded smooth.

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Here are the plates I was talking about. I fabricated some new ones with some styrene sheet and strips. There are left side and right side plates which are mirror images of each other.

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I made two masters and casted two copies, so I now have four plates for front and back of each leg.

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That's all for now. Hope you guys are enjoying this.

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Also had to add some bits that look like actuators of some type just under the shoulder on the front and rear. The kit had some poorly molded detail to indicate this and it was only on the front. Though in fairness to MPC, I have seen pictures where this detail is missing from the rear and others that clearly show it, one of the little differences between the various R2 props used in the movies...

There are also some recessed details on the outer surface of R2's "shoulders" set into a rectangular shape and two square shapes. Apparently, these change position from shot to shot as well; sometimes the rectangular recess is in the front and the squares are in the back, sometimes they're reversed. For us modelers, accurization occasionally means choosing which version we think looks best and running with it. :D

Nice work! I'm taking notes so I'll know what needs to be "fixed" the next time I build one of these. ;)

Al

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There are also some recessed details on the outer surface of R2's "shoulders" set into a rectangular shape and two square shapes. Apparently, these change position from shot to shot as well; sometimes the rectangular recess is in the front and the squares are in the back, sometimes they're reversed. For us modelers, accurization occasionally means choosing which version we think looks best and running with it. :D

I saw that pointed out in one of the Astromech forums. Actually, it's one of the details that MPC got right, depending on what scene you are looking at.

You're right though. There are so many variations in the different scenes, even using just the original movie as a reference. I just went with the clearest detail screen shots I could get to plan the details, so mine probably won't be 100% accurate to any one particular scene, but a composite of the whole movie.

Edited by dmk0210

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Finally, here are all the body parts ready to prep for painting. :)

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I used a bit of paperclip to make pins for the little tubes on the feet. This gives me a holder to clip onto for painting, plus it allows me to drill a locator hole in the leg for proper positioning.

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After washing everything (especially the resin parts) with some simply green and warm water to remove dust, mold release and fingerprint oils, I primed all the parts with Tamiya Gray Fine Surface Primer.

2012-10-18155721.jpg

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After letting the primer dry about 2 hours, I shot some Testors Flat White enamel on the body parts.

I see folks post about having trouble painting white. It's not difficult. You need to have a consistent neutral base color (in this case the light gray of the Tamiya primer) to cover up the color difference of your seam work, putty, resin parts, etc.

It is also important to use flat white, not gloss. I never use gloss white, except sometimes as a final coat over flat white. According to what I've been told, flat white has better pigmentation than gloss white (bigger color pigments, or more pigments or something. I just know it works better, and it also dries quicker). You can use a gloss clear or gloss white top coat if you don't want a flat finish.

When shooting the white, spray it on in many light layers letting it dry a minute or two between. I used four light coats here, and you can still barely see some soft shadows from the gray underneath, which I left intentionally for a dirty look. (If I wanted a clean solid white, I would have added two more light coats and then maybe a gloss white on top.)

I'm going to use Glosscote lacquer on top of the enamel after about a week or so, to act as a barrier for an enamel or oil wash.

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Remember those parts I painted with Testors Gloss Black enamel about two or three weeks ago? That enamel is well cured now, so it is safe to paint lacquer over the enamel now.

Here are the parts I used Alclad Lacquer on. You can see I used a few different flavors to give it slightly different variations of aluminum coloring. Some were painted over the gloss black, and some were painted over the Tamiya gray primer, also giving some variation of shade and texture.

2012-10-19095341.jpg

Edited by dmk0210

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Really enjoying watching this come together. You are doing an excellent job, and can't wait to see it all come together.

Thanks for the posts!

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Really enjoying watching this come together. You are doing an excellent job, and can't wait to see it all come together.

Thanks for the posts!

Thank you!

I'm glad you're enjoying the build. I am too. :)

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More masking and painting.

Last weekend, I masked around all the silver panels with Tamiya tape, and then masked out the larger sections with (cheaper)blue painters tape. Since I had sprayed white enamel on the body just a few days before, there's a chance it wasn't yet fully cured. So I used Testors flat silver enamel to avoid any issues.

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I masked the head with Tamiya tape and yellow Shurtape (which is similar to the Tamiya tape, but wider and cheaper). Then I burnished the tape down with a toothpick so I could see the scribed lines that indicated the sections to be painted blue. To make them even easier to see, I followed along the scribed lines with a pencil. I used a new exacto blade to carefully cut out the sections.

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At the very top of the head is a donut shaped circle of silver. To mask that out, I used two different size hole punches.

To do this, I stuck a piece of clear packing tape to a piece of paper. Then I put a piece of Shurtape on it. (I did this to make it stiffer. The Shurtape alone was too flexible and the punch did not cut a nice clean round piece.) I first punched the smaller hole, then I punched the larger hole, careful to center it on the smaller hole. That gave me a nice donut shaped mask which easily peeled off the clear tape.

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The aluminum silver on the head and the other small bits shown were painted with Alclad lacquer, so there would be no problem spraying Testor's Deja Blue lacquer over it the next day. This is the first time I've ever used Testor's One Coat Lacquer. I sprayed it right from the can and it came out fast and heavy. I had to keep the can moving quickly and kept it far away (maybe 8 inches or so) from the surface. I had no runs and once it dried it looks good though. Next time however, I'm decanting it and using the airbrush.

2012-10-24183129.jpg

Edited by dmk0210

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Finally, have all the paint on.

I really like the Testor's One Coat Lacquer. This morning I decanted some into a bottle and after letting it gas off for about an hour, I sprayed it through my airbrush to do section of the body and legs. It airbrushed very nicely at about 8-10 psi. I used it right as it came out of the can, no thinner at all.

This afternoon, I usd it to brush paint some details (over the Alclad lacquer applied previously ) and it actually went on nicely from a detail brush, only two coats were required. Brush painting lacquer can be problematic sometimes. I wouldn't brush it over enamel though, unless I had a Dullcote or Glosscote barrier on first.

Tomorrow, we'll start on weathering. :)

2012-10-27163525.jpg

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WOW, this all looks so accurate! :thumbsup: The Testors De Ja Blue Lacquer is perfect for the blue on R2. Great choice.

This is the most accurate build of R2-D2 I've seen yet.

Mike.

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I just stumbled upon this thread ... and am I ever glad I did!

The manner in which you describe your techniques is really valuable for us 'beginner' builders.

Tips like: Sprue putty and how to make it; Using the BACK of a blade to cut and how to cut the top off of a dome; Your paint booth; How you mask a circle; Painting, using Lacquers (and Pipettes) and how you use multiple light coats and the brief wait times in between.

You're being very generous with the details you're offering and the excellent solutions you're demonstrating ( ... not to mention your use of complete sentences and almost flawless spelling, a pet peeve of mine :thumbsup: ) are rare on this site. I can't wait to try some of these out!

Oh, and your build is a real treat too! I absolutely love the scratchbuilding and accurizing you're using and the finish of R2 looks terrific. It's builds like these that I don't want to see come to an end! :crying2:

Thanx alot!

Pete

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Hey thanks guys!

Crowe-t, I like that blue too. I saw in mentioned on one of the full Droid builders forums. It really is a nice match and much easier to use than some of the other concoctions those guys came up with.

As far as accuracy, I've tried to fix some of the glaring issues, but there are some other inaccuracies I left alone.

K2Pete, I'm glad you are enjoying the build. I've learned a lot from other folks posting their builds on the various forums, so it makes me feel good that I can give something back to the community and help others out.

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I agree with K2Pete on your 'how to' descriptions and your techniques. They are valuable tips and tools for any model builder, no matter what the subject is.

There are always inaccuracies that get left alone either due to scale issues or other considerations. You did make the more noticeable 'fixes' needed to make this build of R2-D2 a thing of beauty. I really can't wait to see this project finished and hope you submit it to the gallery section.

Mike.

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Thanks for the nice words. :)

Some of the details in the kit really bugged me so those were the ones I mainly focused on. Other things looked like it would be a lot of trouble though(like the front 'arms') and from past experience I've realized I can get so bogged down in details that I'll never finish the kit. I'm a slow enough builder as it is! :rolleyes:

We're on the home stretch now. Hopefully I'll have this wrapped up in a week or so, and I'll definitely post it in the gallery.

Edited by dmk0210

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