Casting OOP bodies

[firefoxussr]

I just wanted to share some photos from earlier this year.   I think that some of the greatest Tamiya bodyshells won't ever see a re-release, which is a shame because they are simply a wear item if you run your car.  I started with the CLK GTR TGX body (because it already has lots of body post holes and it's cut out, more challenging).   It looks like a simple 3 part mold allows for undercuts and elaborate front and rear clips.  I tried the same thing with the 911 GT1 a few years back, but tried to do it from a single mold, it didn't work.

And FWIW, if you have an uncut CLK GTR body, I'd like one.  Filling the wheel arches proves problematic.

*note: i have no intention of making anything but a runner copy.

Inserts to fill volume, make the mold not so wasteful.

Also note the body shape tries to expand, another reason to seek out an uncut body.

 

[yogi-bear]

thats an awesome attempt there. I've done similar and used wet river sand to support the body, it packs in to hold the entire body and holds firm very well. That likes look plaster you are using, which I initially used, but I might switch to hydrostone for bodies I want to last longer. I've found the plaster is very prone to getting damaged easily.

Also I am curious to see how you vac form it, have you made a vac former yet?

[firefoxussr]

10 minutes ago, yogi-bear said:

Also I am curious to see how you vac form it, have you made a vac former yet?

Not yet, too busy adulting.  I've watched dozens of videos about it.   I've seen it done with success, this guy gets it:

 

[yogi-bear]

yeah, they are good videos, I too copied some of his ideas for mine 1st attempt at a vac former. -> see here

I had no issues form 1 mm ABS, Polystyrene or PETG, but polycarbonate I had many issues, although I was trying 1 mm and in hindsight I doubt I was heating it long enough. I was getting bubbling in the polycarbonate which I took as a sign of overheating. I've since learned that its a sign of moisture being driven away and you need to heat it until it disappears. I've now got some .3 mm to play around with now, but it'll be too thin for a basher body. Ideally I'd be using 0.75mm thickness, but I can't get any in Australia.

I found 2mm ABS is do-able, but I didn't get very good suction around the base of the mold.

In hindsight too I don't think all the holes in the base are needed, and that is one thing I will try on my next update to the vac former. From watching some home made and industrial vac forming videos a centre hole can be enough, and if not, just raise the mold a little. Some even just used thinner MDF with no holes at all, its porous enough to allow suction.