Friday, March 30, 2012

The VB commodore

The VB Commodore is Marcus' car and he spends 90% of the film in or near it. Because of this, I need it to be pretty special. It's like a character in itself. As such, I'm spending a lot (possibly too much) time on it. It needs to be fully animatable, with a metal chassis and animatable front and independent rear suspension. The door on driver's side will open, and the roof will lift off for animation access. I'm planning on setting the magnet locators in the body as it's thicker and putting some bearings in the easy cast struts of the roof stays to help it find the same spot every time.
Because most of the film is in rain, I'm making replacement resin windows and wiper blades with rain in the appropriate points. There will be 24 in all, plus 2 for the non raining sequences.
The car design and animatable chassis design have been complete for a while now. I've been sculpting away on the body and have just begun to add details.
Just need to get my head around the best way to cast the sucker!
I hope to post photos of the entire build sequence and give reasons for my decisions. I'll be keeping the idea of low cost in mind at every turn!

Stage 1a. design the chassis armature for animation. Rear wheels are independently animatable and the front raises off a pivot point, which will change based on the rear wheels. (That way I don't need to correct all 4 wheels every frame. Not sure whether I'll link the front wheels yet. Just a thought for now.) I'm going to sculpt the car first and retro-fit the chassis onto the fastcast body.

Stage 1b. Body design: I bought a 1:43 scale model of a vc commodore which is the most expensive purchase of the film to date. At A$60 I think it was a good investment as I'm still referring to it on a daily sculpt basis.
These ones are for reference when storyboarding.

Stage 2. Building the MDF armature. I chose MDF because it's cheap and reasonably easy to work with using everyday tools. (Just a jigsaw and hot glue in this case.) I traced it off of the original pic above, but found I needed to lengthen the cabin once I put my armature inside as reference. Go the hot glue!

Stage 3. Block out the general shape using Klean Klay. (Lots of Klean Klay! - About 1.3kg so far.)

Refine the shape. I've pilled the dash assembly out and rebuilt and case it now, as I realised I need a few multiples for cutaways of the speedo and tacho rising.

I've just sculpted the dashboard and have molded that.
I used Klean Klay again and molded using pinky-sil (quick cure silicone (20 mins!) and made the border out of LEGO, and a base out of an old cereal box.
Also, to save on pinky, as it's expensive, I cut up some old molds and mixed it into the wet stuff. (My son was actually kind enough to cut up the old molds!)

Ensure the workspace is level and square so your mold has a flat (square) bottom for casting later.

Yes the original gets destroyed if it's plasticine. That's why this step is important to get right and not bubbly, crooked or warped.

To save on wasting extra easy cast, I had a spare truck wheel mold and filled it with the left overs. I think I'll do this as I make more molds. The easycast sets in about 15-20 mins, depending on how much you use, but only had a 7 min pot life, so you need to work fast. Above is it 'going off'. (The larger the volume, the quicker and hotter (temperature) it sets. Don't use it to cast your skin, as you'll get 2nd-3rd degree burns! (Plus it's poly urethane and wont break off at all.)
Make sure your work space is square before you start, as you don't have much time once you mix it!

More car details...
I added the centre console, external details (rust and dents to come) and smoothed off the wonky finish with a scraper tool.
It's looking like a car! (I ran out of Klean Klay, so need to wait until I've cast this bit so I can reuse the KLAY. It's better molding a second piece onto easycast anyhow, as it doesn't wreck when you push on it, and you know it's going to fit after casting... well, with a little finishing anyway!

Space for T-Bar auto, cup holder and Handbrake. (Not much back seat space, but no one goes back there. It's more as a realism thing. - I also had to make it a 2 door too. Commodore enthusiasts will either love the 2 door, or think of it as a Monaro-ised commodore! I'm not really a car nut, but I grew up in the land of the white commodore, so I know a bit by osmosis!)

Back end without lights or number plate

Front end without lights, number plate or grille.
I might need to make a large scale grille for XCUs. (Perhaps a car wrecker will have a real one and I can heat gun it!)

Weirdly, I posted about 4 months worth of good stuff here, but it looks like it vanished! what's up with that?
Here's the abridged version in pictures...

Ready for Molding!!!

The big mold: approx $500 of silicone.
Silicone mold filled with Easy Cast. Bolts are there for rigging points (See below)

Rigging point built in

Remove carefully. Breath steadily

Yay, it worked. (However, it's quite heavy!)

Center console detail

Fixing some air bubbles with 2-pak 'Knead it'

Some bits that need cleaning

Sculpt of bonnet in place on master

Boot / trunk sculpt

Casting the easycast urethane using a different compound urethane was much cheaper than using silicone. The only problem was it was far less viscous and leaked out of the mold box. It took about 18hrs to cure.

Registration of bonnet and boot using dowelling jigs, knead-it and screws.
Magnets were later added to hold parts firmly in place.
I did this so I can remove the bonnet and boot to adjust the suspension (see later) and the parts will land in the same spot when they are replaced. 

So I've now finished sculpting the grill, head and tail lights, number plates and seats. I've cast all and am very happy. My clear resin went bad in storage so ill need to get new stuff, but the grille looks great and fits beautifully.

New seats cast and fitted
With Bonnet and grille in place. (You can see the resin lights in place too. - I went back to silicone for the light molds.)

More views of the lights.
I tried casting in coloured resin, but they became totally opaque. I opted for clear and will paint the back of them. It is suprisingly clear.

Here's a timelapse of the mold making process for making the lights.

Since then, I've started on the roof. It needs to be a little higher than anticipated, due to the size of the puppet I wanted to use. Here's a lesson... Make the puppets first! I had a pupped to base scale on, but he's 1:6 and even though I built my car to 1:10, I'd forgotten, as it's been so long. I'll have to restart sculpting the characters to fit!

I also think that for the F100 camper, I can use the original mold for the commodore, making a new grill and cutting back the sides to accommodate the tray back. I'll still need to make the back of the camper separately, but I think I'll use wood. We did that for the ice-cream truce on Mary and Max, and that worked nicely.
More pics as I make them!

I've been frantically working away on the metal parts. The animatable suspension and some of the armature joints. I think one of the things I love about stop motion is that if you get bored with one part of the process, or you run out of supplies, there are a million other parts you can go on with. 
Here are some pics of the suspension. The plans are at the top of the blog and I'll post some cleaner cad drawings soon. 
Pics here are of the  independent rear suspension and the front suspension, which goes up and down and adjusts according to the rear heights. The tie rods mean the wheels stay aligned to each other. 
Front assembly

Front in place

Rear suspension

Rear in place leaving space for lighting electronics

Close up of rear

All in place

And again!
Here's the 'Blue prints - Not to scale' of the build of this fine piece of animation machinery.
Feel free to use, but not modify my details or take credit.  A lot of thought and work went into this.
I just need to bore out the wheel arches a bit. I was originally going to make the wheels and tyres but found some tamiya racing wheels the right size. I just need to modify the rims a bit  to make the tyres look work, I slipped them onto the chuck of my drill and went top speed. I then held a file against the tyre. They look more authentic. I just need to talc them up a bit before use. 
Finally getting there. 

A bit more work on the body of the car and some painting. 
Unfortunately most of the blog 'vanished' so here is the abridged version and some pics:
Using actual auto paint and dry brushing. Still needs some air brushing. 

Rear panel rust detail

With roof. A bit tall but fits the puppets 

Front detail

Rear rust and mud detail

For the lights I'm using tamiya Tx lights and am soldering switches in line so I can control the indicators. 

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