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Second Pull – Droid Mask

December 16th, 2010 admin No comments

First real pull. Some distortion due to camera, some due to poor casting.

After picking up some white casting resin, I cleaned up the mold from our first disastrous pull (with the wrong type of resin) and tried again.

Success!

Lessons learned:

  1. Use thinner silicone for the first coat of the mold, to avoid bubbles/pits. We have some nasty ones, as you can see around the mouth and chin in the image.
  2. Use different tints for different layers of silicone to avoid thin spots.
  3. Make the master bigger to account for shrinkage. It seems like the plaster probably shrunk a little, the silicone shrunk a little, and so on. It’s not obscenely small, but it is noticeable.
  4. Make the sides of the master higher/deeper to allow trimming of final product to where we need it. Also, create some walls around the sides so we can slush the resin right up to the edges without worrying about pouring it out.
  5. Sculpt the master in super sculpey and harden it before taking a mold.
  6. These are probably all things we could have read in any casting book/tutorial, but doing it yourself is way more fun.

From here, I think our next move is to sculpt a new master, as painful as that might be. Overall, I’m very happy with how this is going, mostly because I don’t have a deadline forcing me to cut corners or live with things I’m not completely satisfied with.

Categories: Doctor Who Tags:

Silicone Casting part 3

November 24th, 2010 admin No comments

We started trying to take a resin cast yesterday. It was probably too cold for this, and I’m pretty sure it will be unusable. Either way, pictures!

Mold pulled from clay mask

Slush Casting test 1

Categories: Doctor Who, General Tags:

Silicone casting part 2

November 23rd, 2010 admin No comments

So we skipped the large scale tests, and moved directly to the real thing, mostly because we’re running out of time (we’re shooting to have this done by Saturday – this molding takes place on Monday). So far, we have applied two layers of the silicone mixture (3:3:1 – silicone:mineral spirits:corn starch), the first layer tinted so it can be cleaned of the white clay more easily. This was all cured after 4 hours (probably less, but we played it safe), and we peeled it off to check how we did. Not bad! We found a couple air pockets that were probably due to not mixing enough goop for the first layer, and thus having to do it in two batches, but I think those will be easily corrected on the casting with a little sanding. Then we put the mold back on the master and applied a few layers of plaster bandages to make a mother mold. More pictures to come.

Mask sculpted by my amazing wife on a plaster cast of her own face.

First batch of tinted silicone goes down - a little short of full coverage!

Two full layers of silicone down

Categories: Doctor Who, General Tags:

Silicone Casting Tests

November 15th, 2010 admin No comments

Three poorly-sculpted clay figures

I’m working on a couple of projects right now where I’d like to be able to mold and cast certain pieces. I found a tutorial for using hardware-store caulking silicone mixed with corn starch to make something called Oogoo in place of more expensive silicone mold-making material.

I decided to test the various methods I found online, to figure out which was best for my purposes. First, I sculpted three very basic objects out of clay, since that’s the material I’d be trying to take a mold of for the real projects.

LtoR: Mixture C, Mixture A, Mixture B

I prepared three mixtures (all measurement by weight):

A) Straight-up silicone from the caulking tube

B) 1:1 Silicone to Corn Starch

C) 3:3:1 Silicone to Mineral Spirits to CornStarch

Results were as follows:

A) Took forever to set-up. When last checked, it has not fully cured (~9 hrs).

B) Very thick and sticky, but set up very quickly (<2hrs). Difficult to get good detail due to thickness and stickiness.

C) WINNER Very pourable, and cured in <4 hrs. Seemed to pick up all details. This is the one I will go with for larger scale tests.

I made resin casts from B and C, but haven’t taken photos of the results yet.

Categories: General Tags:

Holiday ornaments galore

August 3rd, 2009 admin 3 comments

I stopped by Hobby Lobby this weekend, on the hunt for three things. A) Something to use for the main radar eye lens. B) Something to use for the holo-projector lenses. 3) The main orb for one of the holo-projectors, since I don’t want to pay another $25 dollars for the correct doorknob set. It turns out Hobby Lobby now has their Christmas ornaments out, and I found one for each of my needs.

radar_eye_lens01

Radar eye with lens (not glued in)

Radar eye lense and bolts being glued in

Radar eye lens and bolts being glued in

Ornament sanded and cut with small ornament for lens

Ornament sanded and cut with small ornament for lens

Scope cap in place

Scope cap in place

Fece-post cap in place

Fence-post cap in place

The original, from A New Hope

The original, from A New Hope

A later version, from a museum tour

A later version, from a museum tour

Categories: R2D2 Tags: , ,

Panels in place

July 28th, 2009 admin No comments
These will all need to be repainted

These will all need to be repainted

So yeah, I’m going to have to re-paint these panels. Either my clear coat is too old, my new can of anodized blue isn’t playing well with the other coats, or it was too humid or something. Also, I screwed up some of the parts that I had masked-off when I removed the tape – I ran an exacto blade along the edge of the tape before I peeled it off, but it actually looked better when I didn’t do that. There’s also a “dent” in the paint on the radar eye, where I watched a piece of fluff/lint/hair land on the primer, and I tried to gently remove it. Finally, I forgot to paint the blue ring around the collar, so I’d have had to break out the rattle cans again anyway.

But damn – it looks nice all put together, doesn’t it?

Categories: R2D2 Tags: , ,

Did some cutting and painting this weekend

July 27th, 2009 admin No comments

I spent the better part of two days getting back to work on R2, prepping and painting the dome panels mostly, but also figuring out and cutting the holoprojector surrounds. I was unhappy with the way I had cut the first set of fence-post caps to use for surrounds, and since they cost about $2.00-a-piece I bought some more. This time, I spent a while planning out the shape I would cut, then carefully cutting out exactly the shape I wanted (i only cut one so far, so I’ll document the process with the next one and add photos).

After filling in some dremel mistakes with Bondo, I painted all the dome panels and the radar eye. This involved double-checking reference photos to make sure I was painting the correct panels, and masking-off certain panels that needed only a frame of blue or the opposite. I used what I thought was the same formula I used when I painted the pie-panels years ago, but it didn’t turn out as well as it did last time. The pie-panels have much more depth to the finish. Maybe I need to add a few more layers of clear coat. Either way it’s a subtle difference, and not too terrible, so I’m not freaking out.

Categories: R2D2 Tags: , ,

Cutting radar eye

June 30th, 2009 admin No comments

Cutting the data slot in the eye

Cutting the slot was made simple by using the dremel cutting guide. On the right, the side boxes were constructed from my old trash can.

Categories: R2D2 Tags: , ,

Building the radar eye

June 1st, 2009 admin No comments
Paper template test fit on dome

Paper template test fit on dome for sizing

Template glued to aluminum flashing and cut out

Template glued to aluminum flashing and cut out

Aluminum bent and held with tape

Aluminum bent and held with tape on dome


JB Weld brand epoxy applied to the seams

JB Weld brand epoxy applied to the seams

The hole for the radar lense is cut

The hole for the radar lense is cut

Rough aluminum radar eye taped to the dome for fun

Rough aluminum radar eye taped to the dome for fun


Bondo applied to even  out the surface and sharpen the corners

Bondo applied to even out the surface and sharpen the corners

Primer applied to see where more filler is needed

Primer applied to see where more filler is needed

Categories: R2D2 Tags: , ,

Cutting the dome panels

June 1st, 2009 admin No comments

Much time passed since the last time I cut the dome, during which I primed and painted the pie panels using a variation of the “Krider blue” rattle can formula, which can be found on astromech.net. My blue may not be exactly like the real R2, but it uses colors I know I can find consistently.

First holoprojector test fit

First holoprojector test fit

Now that I had gotten two dremel accessory kits for Christmas, it was time to start cutting again. I used the same dome blueprints I used for the pie panels. This time I printed one of them out at full scale so it took up several sheets of 8.5×11 paper, then tacked them all down on a piece of plywood and set the dome on top. I used the measurements from the other dome drawing to get a figure for the heights of the panels (this particular drawing measured in fractions of the circumference of your dome). Once everything was drawn in, I compared it to images of R2 to make sure I wasn’t making any stupid mistakes.

I started by cutting out the circles for the holoprojectors. I started by using a circle-cutter drill bit, but I found it to be unreliable and prone to sticking. I’m sure it works great if you’re using a drill press and/or cutting a flat surface. I ended up rough-cutting the circles with the dremel+cutoff wheels, and cleaning it up with the dremel+sanding attachment and files.

Panels cut. Also, I'm a dork.

Panels cut. Also, I'm a dork.

I finished off a Guinness to steady my hands, and cut out the rest of the panels with the dremel. I know some of the panels should have cutouts within them, and I missed one small additional panel, but I feel like I’m done cutting. I may end up just painting those in.

I should also mention I’m using the “fence-post cap” method for creating my holoprojectors (developed originally by Craig Smith, the god of scratch-builders). This involves cutting a hole into the top of a cap for a chain-link fence, putting a door-knob into it, and capping it off with the top from a bottle of Scope mouthwash. Funny story, these were actually the first things I built for R2 since they’re so cheap to make, and I promptly lost them. Someday years from now I’ll find that first set somewhere safe where they wouldn’t be damaged.

Panels cut, pie panels and inner dome fit

Panels cut, pie panels and inner dome fit

All panels cleaned up, back in place

All panels cleaned up, back in place

Categories: R2D2 Tags: , ,