I successfully cast the chest plates this fall (see two posts ago), but after many casting attempts on hip bones this winter, I finally ran out of slurry. I can't order more because it would arrive frozen, resulting in permanent chemical damage.
Issues included areas that cooled too fast, porous surface, and pieces of the mold breaking off prematurely:
So, I am switching back to box casting. Here's the breakdown of the parts I have left to cast:
Shell casting with SuspendaSlurry
Hip Left
Hip Right
Chest Base
Shin Snockplate Left
Shin Shockplate Right
Box casting with UltraVest
Hip Bottom Connector
Spine Top
Spine Bottom
Spine Middle Left
Spine Middle Right
Foot Upper Shock Plate (2)
Foot Shock Plate (2)
I also started working on polished sheet metal bracelets to attach arm bones without using elastic belts or gauze (like in the movie).
Last week I finished two more molds for shin shockplates. The only other "required" part left is the chest plate, one of the biggest and coolest-looking parts of the exoskeleton. There are a bunch of optional parts I would like to cast as a stretch goal, notably the tiny details placed on the hands, the vacuum tube holders with light-up tubes, and some tech gribble for the face to complete the cyber ninja look.
Fig 1: Preparing to pour the second part of both two-part molds
Fig. 2: Finished making the first part of a two-part mold with 3D-printed model suspended in clay
Fig 3: Resulting two-part molds I will use for casting wax positives
Fig. 4: Resulting wax positives that will be shell-cast by adding 10 layers of ceramic shell and melting the wax out before pouring metal
In the past 3 weeks I cast the remaining parts for the spine as well as shock plates/armor that will be attached to boots:
Just before that I cast two extra parts I was missing before, a shoulder connector with some extreme detail and an unsightly hip connector. One of the parts here is repeated above.
My sheet metal order of bent spine connectors and arm bracelets came in:
I decided I might as well make those in 2mm stainless steel after prototyping with paper and cardboard, since the cost of getting them done in a sheet metal shop was going to be high either way:
The past three weeks have been a living hell of trying to cast two large plastic parts with complex geometry and thin edges out of rubber. Today it ends!
Thank you! Today I poured the last mold required to complete the project. There are some optional parts left to make molds for that I might do if I have time left before the Wasteland Weekend.
I finished casting all the required parts mid-July and moved onto re-drilling & threading holes, filling imperfections with metal filler & modeling primer, polishing, and using a rotary tool to clean up small details. Can't believe how much work that really is - after a full day of drilling & filing I feel like I've been kicked around by bunch of people. There is no real clean up effort on the machined parts so it should go faster from here. I hope painting doesn't take months or I will miss the wasteland weekend deadline!
Lastly, I did a work-in-progress presentation on this project to a group of high school students at Pacific Northwest College of Arts:
Thank you! I don't know the full weight yet, because it has to be assembled first. All the bolts that hold it together actually weigh more than the suit by themselves.
This is the last week of painting before assembly and tuning.
Assembly this week, hoping to be done by EOD Thursday. It feels real, with pleasant weight, the coolness of metal, and the musical dings the pieces make when they touch each other, instead of dry clanking of plastic. The paint isn't perfect, but generally this is coming out as exactly as I envisioned.