Homework - Cyril Wichers
Chris Ellerby
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Homework for live workshop student Cyril Wichers
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Chris Ellerby
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As Craig noted after the class, this could be used as an underskull directly, with the possibility of maybe ordering another one later on, doing a sculpt on top of that and then making the molds for the skin from that.
So I had to decide what to do; leave it at that and wait for the next class, or try to use this as a starting point and go throught the process of making a mold, a core and another mold for the underskull.
As I got the impression that we would be working on mechanics from here on, I'm hoping that I can do those partially without the underskull and started the process of moldmaking anyway.
To start with, I watched the tutorials on "How to make a stone mold" by Gary Yee and "How to make a monster puppet" by David Monzingo
I took the dimensions I would be needing for the next class (distance between the eyes from center to center and the diameter of the eyes I ordered), got / ordered some materials and went to work.
I started with propping up the head on a piece of wood and trying to find the case line (using tips from the tutrial by Rob Freitas)
Then I made some filler blocks on which I can build up my clay wall.
Unfortunately, that's as far as I got. I hope to have some time to at least finish the negative mold (I decided to do a matrix mold out of silicone and glassfibre) before the third class and maybe have some time to work on the eye mechs in between.
I've started brushing on the silicone, but now I'm second guessing my decision to cover the flange also. Could it be problematic having a layer of silicone between the flanges of the fibreglass shell? I could try and cut the silicone away before I start laying fibreglass.
Good point about the silicone falling inwards. My fear is, that I might compress the silicone too much when tightening up the mold and distorting the cast.
What I could do is just cut away the part that goes over the keys, so the fibreglass will be touching there, whilst there will still be a flange of silicone to keep the silicone parts in place.
The extra silicone came off smoothly. Next: fibreglass.
I also started to design my eye mech. It's based on a mech I made earlier. If possible, I'm going to print it. That should save me some time.
Today, after work, I trimmed the back side of the mold and tried to get it off the mannequin head. It took some convincing, but after I got a tiny crack started, I managed to separate both halves by inserting plastic wedges. After the last wedge was in, it just popped off
There are some imperfections, but for a first try, not too shabby!
Well, at least the design of my eye mech is finished. Printing will have to wait until tomorrow.
The eyes will rotate on a ball joint.
Today I hooked up the linkages and programmed my rc transmitter. Unfortunatily, it turned out that one of the outputs on the receiver has a problem, so I couldn't hook up all the servo's. That's why the up/down movement of the left eye isn't working.
In hindsight, I would have been better off using u-joints instead of ball joints, but they would have been too small to print and I could only find suitable ones in China, which would have taken three weeks to arrive.
The eyeballs are 26mm (1.02") in diameter and 39mm (1.54") apart (65mm/2.56" center to center)
The mech has up/down and right/left movement for the eyes, blinks and eyelid tracking.
Your work is always so clean and polished. You'll have to share your secret for the 'no mess' approach.
Or are you hiding pictures of your workshop *Laughs*
Thing is, I don't have a lot of working space, so I have to keep cleaning up, otherwse I lose all my stuff. And I can't stand having to look for stuff all the time, so I tend to keep my workspace organised.
Well, I sorted out the problem with the servo. Turned out to be a setting in the transmitter I changed when I last used it on a quadcopter. Completely forgot about that. Much better this way!
I left some contact points where the eyes were in my "sculpt" and I made a key in the back of the neck. I hope that, if I bolt the core to the negative where the key is, It will locate the core correctly.
I also put clay on the flange and made a couple of divets in it. The idea being, that hopefully, after I pull out the core, I can position it inside the negative using the contact points, and then draw a line so I know where to trim the core.
I sealed the clay with clear acrylic spray paint and put in some mold release for good measure. I put in 3 layers of 160 gram fibreglass cloth.Now we wait until tomorrow and hope for the best...
I've put on the plaster bandadges for the throw-away mold for the underkull. It's taking quite long to dry, but I've read somewhere that these could take up to 48 hours to totally cure. Let's hope I can get both halves separated from the core tomorrow or the day after that.
I made the two fibreglass halves for the underskull and, after trimming, put them together, just like I did for the core.
So now, it's time to try and cast a skin, so I can get the eye mechanism positioned correctly in the underskull.
I was a bit nervous about getting the core centered correctly inside the negative mold, so I tried a trick somebody mentioned here; casting a "skin" out of gelatin.
Even though I put a layer of clay around the mold, some of the gelatin still leaked out. Luckily I had some to spare, so I could keep topping it up, untill it stiffenend up enough.
I was surprised at the end result, it actually came out looking pretty good, even if I say so myself!
Well, that turned out to be a lot of work. But I learned a lot in the process, so that's pretty cool!
Front half removed. I added the pins so I would be sure the core was lined up correctly.
Removed from the core and placed on the underskull.