Combining Digital Output with Tradtional Methods

So, for a while now I've been thinking about interchangeable parts and casting onto armatures.  Well, it is starting to happen.  For all the time I spent looking into dies for the enamel blanks, it turns out I ended up simply getting the pre-cut shape (30x40mm domed oval copper) from people who specialize in that kind of thing.  I did, however, end up making a ton of custom shapes to be cut from the 430 stainless steel.

I was feeling pretty good about getting to understand Rhino...then I had to use Illustrator and I remembered how INFURIATING computer programs can be when you don't know what you are doing.

I did multiple laser-cut chipboard test runs so that I had something to experiment with.

Above: experimentation.

Each of the eight shapes I've made will be placed into a mold and have pewter cast around the edges, then the assorted tabs and cut-out areas are popped up to make the object function.  I've got a brooch, a pin-on beribboned war medal, a pendant, a game piece, a choker/dual hung necklace, a bolo tie, and the actual pronged piece holding an enamel in place (a magnet under the enamel lets it clip to all of the other pieces, plus hey, a fridge magnet!).  The holes around the edge of each piece allow the pewter to flow in and lock into place once cooled, and the center hole enables the user to pop the enamel out from behind.

The dark green thing with the magnet is the steel; I spray painted it matte green and used the laser cutter to etch the pattern on and then cut it by hand with a jeweler's saw. 

 

Once I get the actual parts made from steel I will sculpt the master pattern for the pewter that will be used to make the mold for casting.  Since I wanted to get a feel for what would happen and the overall effect, I decided to do a test sculpt using the chipboard.

 

Fresh from the laser cutter.  I didn't design them all until after I did the test I'm about to describe, but the recursive nature of testing makes for confusing blog posts when presented chronologically.

Two thirds done with the sculpting; I forgot to take an earlier photo.

The green stuff I'm using for sculpting is a two-part epoxy putty that sets up after a few hours.  This is a pretty standard material for people sculpting toys, miniatures, and figurines, and it stands up to the vulcanization needed for the rubber molds used in spin casting.  If you are familiar with Sculpey or Fimo, it is somewhat similar but requires no baking to cure.  The type I'm using is called Apoxie Sculpt but I've also picked up Fixit, Green Stuff, Brown Stuff, and ProCreate.  All of them are a little different and I need to play around a bit more before I figure out which is best for what.

Scalpels are really way, way better than Xacto knives.

After letting the Apoxie cure overnight, I cut out the center of the chipboard and replaced it with a  test cut of the steel so that I could see if the pin stem was placed appropriately and if the magnet I chose was effective.

Popped-up pin back; after the test I opted to go with more rounded parts. And yes, that is scotch tape holding it together. 

The enamel is in the background with the magnet between it and the pronged plate.  A layer of silicone helps cushion it from shock.  After seeing which magnet worked best I've gone back into the files and shortened the length of the prongs.

Plop.

Ta-dah!  A functioning prototype!

The cost of getting dies made to cut each of the shapes would be exorbitant, and laser cutting complex shapes gets pricey as well (plus the heat messes with the properties of steel and requires additional heat treatment post-cut to restore it), so I went looking for a different process.  Enter photochemical machining, or PCM.  It's an acid etch process requiring an etch-resistant film over areas you don't want to be removed, but rather than submerging the piece in acid or applying an acid paste the sheet of metal is suspended while acid is sprayed at it from both sides.  Now, I have neither the equipment nor the expertise to do such a thing myself, but happily there are multiple on-demand shops which allow you to send them a file and they send you back the part.  I've already put an order in with Great Lakes Engineering; we'll see what the parts look like when they ship later this month, but thus far their customer service has been excellent.  They do some of the machining for the group Nervous System, so I'm definitely optimistic.  Even if I did have to learn to use Illustrator to make the template they needed.

So. Much. Cursing.

Baby's First Rendering

I modeled an object completely from life for the first time, and used Rhino's onboard rendering options to make it purty.  Woo, it's to scale!  Well, not on your monitor, but in the CAD file it is.

This little guy is an iGo 3 e-cigarette.  I've yet to kick nicotine, but at least I've stopped lighting things on fire to get my fix.  Coming up: an entertaining accessory stand so I don't keep knocking it off the table.  As many times as I've dropped it, the thing is shockingly resilient.

New Website

With a great deal of effort, I have finally gotten my project website off the ground.  You should be able to find it at enamelminiatures.com.  If not, I'm going to be sort of pissed off, so please let me know if something goes wrong.

Here's a gif.  I'm going to bed.

(I didn't figure out how to crop gifs until I had done a couple of them, so just pretend it is dancing in celebration of my finishing the site.)

Dies and Interchangeable Parts

So, I'm looking to make some jewelry pieces which use individually painted enamels in mass-produced settings.  For that to work, the enamels need to be uniformly shaped (I'm working with a slightly domed oval). I have been using an acrylic die in a hydraulic press to shape to copper I'm enameling, then cutting and grinding them down.  It has worked, just not amazingly.  My die is a little on the wonky side, resulting in slightly eccentric shapes (exacerbated by the fact the edges aren't crisp enough to follow easily when I take them to the sander).  Here's a (kind of crappy) photo of the finished enamels.

For reference, the graph paper squares are 1 inch by 1 inch.  I'm pretty happy with the painting, but the circumference difference between the smallest and largest pieces is about 5mm.  In terms of jewelry sizing, that is really big, and limits the options for setting types.

So, I'm trying to come up with something better. Jewelry supplier Rio Grande's commercially available oval cutter is a. really expensive and b. too small.  I've just found Potter USA's dies, which are much cheaper but mostly made for circular press setups (which may or may not be an issue).  I'm going to keep searching, but it may be my best bet is to have something custom made, at least for forming.  I'm still not sure about better cutting options for the formed copper, though this looks interesting.

In any case, if I opt to have a simple steel silhouette die made, there are a number of water jet cutting services available, so if need be I'll have a plate cut rather than resulting to an expensive custom die manufacturer for industrial use.

The Old and the New

It has been very interesting to compare the advantages and disadvantages of Rhino and 3D printing with the work I did over the summer: spin cast pewter.  The vulcanized rubber molds and low viscosity of the pewter can make for extremely high-fidelity, high detail castings for a pretty low cost, though they naturally lack the strength of bronze or silver (or even copper).  However, you can actually cast mountings/pinbacks in place, which is neat, though not magnets given their susceptibility to heat.

I worked for Perth Pewter in Chester, NY, which specializes in larger, more complex pieces for the gift market rather than hobby models.  To give you a sense of the attainable detail, here is a piece slightly more than about four inches high. If anything, the image doesn't do it justice.

Buy me!

Though this is not where I worked, and there are some substantial differences in the details of production
(like the molds' levels of complexity and finishing procedures), this video gives you a taste of the process:

I'm particularly interested in using CAD processes to create armatures for physical sculpting and to make uniform, embeddable objects for casting.

Research

So, I've been thinking magnets.  I'm planning on making interchangeable settings with magnetic-backed "jewels."  For a variety of reasons, I need to minimize hand work and processes like soldering, so I'm looking for cold connections and stuff that can be done via outsourcing.  I found a place that sells neodymium magnets, and can even make them to your specs. 

Beyond that, I've been trying to come up with a magnet-compatible material for jewelry.  Magnets are heat-sensitive (particularly anything close to soldering temperatures), so mounting additional magnets onto jewelry becomes a bit of a logistical issue. Steel is quite strongly attracted to magnets but is inclined to rust unless plated or sealed (and that is no guarantee).  Stainless steel? That starts to get interesting.   

If you've ever dealt with a fancy stainless steel fridge, you are probably aware that magnets don't usually stick to stainless.  This does make me a bit sad, as the stainless 3D printing is all currently non-magnetic.  However, there are multiple types of stainless.  We most commonly see austenitic stainless (the 200 and 300 series); due to its atomic structure, magnets won't adhere to it (much).  What I need is ferretic stainless (400 series).  It doesn't hold up as well as austenitic against things like high heat and certain chemicals, but it also doesn't require heat treatment/hardening to set its magnetic properties the way martensitic steel does.  There are other, specialty alloys of stainless; I'm only touching on ones relevant to my concerns.

However, there is another concern: skin/metal contact and the potential for reactions.  Though I know some folks consider the term "stainless steel" to be synonymous with "surgical steel," that is not the case.  Happily, the British Stainless Steel Association has kindly come up with a list of "safe" stainless with sufficiently low nickel for those with sensitivities.  They were even kind enough to denote the type!

So, for a magnet-compatible stainless steel that doesn't require elaborate hardening treatment, has workability, and is safe for the skin,  I need ...drumroll... AISI 430 / 1.4016 ferritic stainless steel!

Aliens, Cyborgs, and CGI

(This is an older post which apparently wasn't displaying correctly, so I've tried to fix it.)

So. This is not rendered in Rhino.  Still, all of these are heavily CG, and sometimes I have a hard time accepting the fact that we live IN THE FUTURE and these moving pictures come out of magic boxes that live in our houses.

First off, the amazing teaser for Cyberpunk 2077.  Ahhhh, cyberpsychosis.  I've actually not played Cyberpunk (just Shadowrun), but I'm digging what they've got going here.  The figures are a mix of scanned and rendered, with the actress primarily scanned.  (See behind the scenes here.)  CD Projekt Red is doing the game while Platige Image was mostly responsible for the trailer.

Character designer Aaron Sims is responsible for the next little gem, which may be on its way to feature filmdom.  Behold Archetype:

And since what would robots be without aliens, here's Kaleb Lechowski's R'HA, which appears to be  entirely his doing except for sound design and a voice actor:

Thanks to io9 for finding the latter two!