I'm entirely mystified and enthralled by your process, but that will make watching this piece come together all the more enjoyable.
The tail section already looks great. And at 1/10th scale, this should result in a T-Rex that's display worthy, without being terribly overwhelming.
... a cry went up into the shuddering air, and faded to a shrill wailing, passing with the wind, a voice bodiless and thin that died, and was swallowed up, and was never heard again in that age of this world.
Wow, somebody out there was listening: yesterday I was saying how ribs didn't seem to be considered "sexy" enough. Today I find out (through the above-mentioned Dinosaur Mailing List) that there's a paper about tyrannosaur ribs and vertebrae! For those who are interested, the paper is here:
If you've never read a scientific paper before, here's a taste. I haven't read this myself (I just looked at the pretty pictures) so I don't know how much technical language, jargon and anatomical nomenclature there may be, so be warned; you may come away with an expanded (or confused) vocabulary.
Kent Stevens "Dinomorph" pages look at the science of dinosaur movement in three dimensions. Seeing just how these animals were put together and what their possible ranges of motion and postures were helps to ground our view of dinosaurs a bit more in reality.
While we're "morphing", check out Digimorph, the online Digital Morphology library at the University of Texas, Austin. This library has CT scans of hundreds of creatures, including some dinosaur fossils. Some are just the skull or skeleton, some are the whole creature. A useful resource for any figure sculptor and just plain cool.
The Black Hills Institute of Geological Research is a commercial fossil excavation, preparation and reproduction company. Home of the T.rex specimen known as "Stan" and the original excavators and preparators of "Sue", BHI offers for sale both casts of fossils and original specimens.
Hey, Thagomizer! Love your name, first of all. Secondly, this looks like a very challenging and interesting project, and I'll be following along to watch your progress. Thirdly, thanks for the links! That walking T-Rex skeleton in the first post was awesome!
I'm truly inspired my friend.. who'd have thought of that eh? That's some serious undertaking and planning. Wow. I'm very much looking forward to seeing the whole thing through. Many thanks for sharing!
More vertebrae! Dorsals this time. Fairly similar in construction to the tail verts, but the transverse processes are angled upwards and made of thicker cardboard since they will eventually need to support the ribs. You can see the beginnings of the sacrum (fused vertebrae that will be attached to the pelvic girdle), pubis and ischium. The cervical, or neck, vertebrae are going to be a bit more complicated. It will be harder to use the simplified planes that I have used up to now. Still figuring them out.
If you're building something up out of a whole bunch of pieces that look a lot alike (but which are in fact different from each other), be sure to have them clearly labeled with some sort of system to keep them straight. So each of the vertebrae is made up of several parts; each part receives the number (for dorsal) or letter (for tail) of the particular vertebra. This results in a lot of numbers and letters on each vert, helping to ensure that as each one gets worked on ( and I try to work on them in numerical or alphabetical order so I know I haven't missed any) and added to, that at least one of the labels will remain uncovered to enable identification. The same goes for distinguishing left from right for paired, repeated elements like ribs, toes, etc.
A photo of the original fossil mount of Sue confirms that things seem to be going in the right direction. Reality checks like this are important. If you're doing something wrong, you want to find out early. I had just such an experience in the planning stages of this project. I discovered that there were discrepancies in my primary reference between the scale as indicated by the scale bars in the photographic illustrations and as determined from the table of measurements. In some instances the variation was more than 10%. I decided to go by the table of measurements, figuring that there was less chance of figures in a table being incorrectly printed than mistakes being made in the paste-up, layout and compositing of the photos with the scale bar graphic. Fortunately I discovered this before I'd actually started cutting or gluing anything, so all it meant was a bit more work slaving over a hot photocopier. If you have photographic references where a scale bar or some other object of known size is right in the photo, you're laughing. But beware of perspective, as it will change the relative proportions of objects depending on the subject to camera distance. I'll have a bit more to say about perspective when we get to planning out the skull.
One of my next tasks is to start working on hinge mechanisms for the hind limbs. I'll probably use wire for the front limbs, but the rear will need something more robust that will have a more limited range of motion, mostly in the parasagittal (fore and aft) plane.
I was actually able to pull some casts from my plaster limb girdle molds over the weekend. It looks like they came out pretty well, too.
Release agent is Vaseline smeared into the mold with a finger then wiped down with a facial tissue to even out the coat. I use three kinds of paper to make the cast; wrapping tissue (white-onto white plaster- hard to see, harder to photograph) brown craft paper and newsprint, all of which were recovered packing materials from work. FREEE! YIPPEEE! The adhesive used to bind it all together is Weldbond (which, because it is waterproof, should not soften with the later application of any water based primers or paints).
The first layer into the mold, the "gel coat", as it were, consists of the wrapping tissue. Being thin and flexible, it should do best at picking up details from the mold. It's torn (not cut; torn edges blend in more smoothly) into smallish strips (size varies according to the complexity of the shape it is being laid into; flatter areas have larger strips applied to them), dampened and then laid in the mold with some overlap between adjacent strips. Weldbond is brushed in behind; it ends up soaking into the paper. While still wet, a second layer of tissue is applied, with any luck, it will cover spots I missed in the first layer. Press the paper firmly into the mold to ensure good bonding of the layers and good conformation with the interior surface of the mold. (The edge of one of my molds was a bit on the thin side and actually broke, but I was able to mend it and continue with my work.) Paper layers continue out over the mold, beyond the edge of the part boundary.(Make sure that you've applied your mold release to this area as well). This will provide a lip or flange around the part which will make it easier to pry the part out of the mold without damaging the cast.
The next layers are the brown craft paper and the lighter newsprint. These thicker papers will provide most of the bulk of the cast parts, adding strength and body to the tissue layers. Having each layer a different colour lets you gauge your progress and ensures even coverage of the mold. Being a bit on the impatient side, I actually started to layer these papers in while the tissue was still damp, once I was sure that doing so would not mar the tissue beneath. About eight layers altogether are used in this case. Each layer went on while the previous layer was still wet; not all at once, though.
The hardest part is waiting for the lot to dry. If you come back in a little while, they should be ready to pop out.
We've got parts! Yahhoooo! The flange around the part gives you a section you can test for dryness and strength without risking the part itself. If it doesn't seem to be strong enough to come out, add more layers and let them dry.
Once the parts seem ready to pop, find a flange edge and gently pry it up, away from the plaster mold. Try to pry up along the longer side of an oblong shaped part; going along the short side might risk the part folding on you if it's (unbeknownst to you) still not quite ready. In my case, no problems.
The parts look pretty good. I'll get a better idea of the quality of the detail once I get a coat of primer on them, but from what I can see at this stage, they're going to be fine. I'll probably put the scapulocoracods back into the mold and add more layers (including some card) for added strength. They are pretty narrow and more flexible than I would like. I want to be sure they'll retain their shape throughout the construction process. At their current thickness, that might not happen.
Not sure how well it would work for your larger scale sculpt here - but in the past, finding myself in a pinch and also using Vaseline as a sep-agent, I found you can additionally soften or "thin" it to an even softer *brushable* oil-base with a simple blow dryer aimed at the jar somewhere out of your way (blow-dryers can get a bit noisy).
You may not require fine detail on your base casts, but thinning the Vas' a bit allows you to brush it and keeps your hands free, although less moisturized, from petro-based fingerprints. Could be worth a test.
Thanks for the tip, Lilalex! I'm not sure that it would make a lot of difference to what I'm doing and how I'm doing it, but thanks for sharing that with our viewing audience. It sounds like it would help in making castings with very fine detailing
Alas, my household has no blow driers, partly because I don't have a lot to blow dry!
I hope to have more photos up soon. I've got the initial structures for the cervical (neck) vertebrae and the fused verts of the sacrum done. I've also trimmed the scapulocoracoids and ilia that I cast in papier mache. They look quite good if I do say so myself. I still have to apply some paper strips along the cut edges to help seal them and round out the rather too sharp look of those edges. Next up will be arms and legs. For the legs I'm planning on making a hinge joint mechanism using dowels and tongue depressors. I think I'm just going to use wire for the arms and hands; we'll see. If the wooden hinge stuff works well for the legs, I may use the same technique for the front limbs.
What the heck, I'll post some pictures now.
Here's a preview of how I'll start the skull. This is constructed from layers of corrugated cardboard, planned out like a contour map using side and top views mosly. This is an earlier version I did a while ago before I set myself the task of building a whole skeleton. So I'm actually going to do it over again including the internal structure of the skull. Over the cardboard I'll then lay plasticine and sculpt a master that I'll make plaster molds from, in which I shall cast papier mache parts as I did for the limb girdle bits. I'll take more detailed images during the planning and drawing phases so you can get a better idea of how it works.