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1:4 70s/80s Roundels

Started by lespaceplie, Oct 18, 2018, 03:27 pm

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lespaceplie

The ideas have varied wildly over the last few unproductive years, but I'm sticking to making a K-9 minisode, which requires a 1:4 scale TARDIS control room set. Apart from the console, the main challenge here is creating the fiberglass roundels in miniature. For that some thin laser-cut styrene sheets will be combined into a stack from which a few silicone molds will be pulled. The edges will have been rounded a bit by spinning and sanding. The final pieces will be casted in resin. The opaque ones for the door wall will simply be painted, but the translucent ones will be sanded to a frosty finish on the back with some coarse sanding added to look somewhat like the glass fiber. This will be the first resin casting I've done (but not the first casting in other materials) so it's research mode right now to avoid having to experiment too much.

roundel styrene.jpg

lespaceplie

Here are the styrene layers temporarily laid up with some washi tape. Besides being sanded on a lathe the outer convex corners of the profile, the concave corners will be rounded by applying multiple coats of paint or possibly adding epoxy while it's turning.

roundel buck 1.jpg

lespaceplie

Oh well. This approach doesn't work due to the nature of styrene. It melts too easily to withstand sanding on the lathe. This makes the grooves fill with crumbs that fuse.

Scarfwearer

Well even the things that don't work teach us something.
I could give you a list of ways and things not to try to clad dalek shoulders with - from experience! :D

lespaceplie

I'm already on to plan B! Non-bonded acrylic and styrene sheets can be stacked and aligned with a center rod to make a temporary mold to cast a bondo buck - and I know the bondo will take sanding like a champ. I should've thought of this before because I used to cast duplicates of vintage radio knobs.

lespaceplie

Jan 08, 2019, 04:13 pm #5 Last Edit: Jan 08, 2019, 04:16 pm by lespaceplie
It's almost ready to cast the buck. Only one ring needs to be bonded. The wingnut and washer will be removed, but the bolt will be left in place when the bondo goes in. The hole will be needed for when the buck gets a spin and sand after which the hole will be patched. The bondo shouldn't stick, but I will probably use a water-based release (the kind used for polyclay). At worst the layers can be disassembled to get the buck out.

Also, this version is 1:5 instead of 1:4. The change is to both accommodate the 1:5 Kelt console and to simply fit the largest sheets I can laser cut for the walls. It will still be huge!

roundelmoldA.jpg

warmcanofcoke

why doesn't the Guide mention them? - Oh, it's not very accurate.
Oh? - I'm researching the new edition.