Looking for direction: making a detailed 3D form/shell? 1

[Radivs]

A thousand pardons, as I am not an engineer, but am seeking information regarding plastic manufacturing and the processes available. I have looked elsewhere, but have been unable to find any definitive information, or even those whom might have such information. Tried plastics.com, to no response.

I am trying to discern the best method and material to achieve the following (in rough, general terms):

Ultimately, I am trying to create something akin to a mask- a "shell" of an object, say a planet, with the planet surface being outermost (highest), and with other detail (space debris, satellites, etc.) at lower levels, in order to achieve a 3D effect, without the mass and volume of a solid. I want to understand what processes are available to allow the outer surface of such a display, etc., to have detail, color, etc., in an attempt to avoid painting, etc., after casting. I think of plastic Halloween masks being along the lines of what I hope to achieve, but the resulting display need be considerably more resilient/durable. This will probably be around 30" x 30", and will have a backing structure apart from the shell.

Eventually, should all hurdles be navigated successfully, I would be looking to produce several hundred, perhaps low thousands.

I have read some of the overwhelming amount of information I've found, but realized I really need to have a starting point, to focus my learning efforts; this is why I've come here, to ask for your assistance, advice, ideas, about what my options are, how to proceed, levels of detail available, etc., as my molding & casting experience is considerably more rudimentary than what needs be achieved.

I do appreciate your consideration & time; thank you.

Ray~

 

[MikeHalloran]

I'm still confused about whether you want the surface detail and color on the outside surface or the inside surface of the hemisphere you propose.

Or are you talking about a transparent sphere with stuff floating inside?

For ideas about what's possible, visit a big toy store.



Mike Halloran
Pembroke Pines, FL, USA

 

[Radivs]

Mike,

Appreciate the response.

As I say, like a Halloween mask, opaque surface, with a range of relief, high to low. The outer surface, like a mask, is all that will be seen, so is what requires the detail.

I can see what is possible, yes, but I am trying to evaluate processes, to understand what I can get from A versus B, versus C, the strengths & limitations, etc.. I can get excellent physical detail using A, but no coloring beyond the base plastic; whereas with B you have a range of color detail/placement, but the physical detail will be limited, etc..

I am trying to form a useable, beneficial, bridge between the technical specs & processes, and what I am hoping to create. I know little of the language and particulars, which impedes my ability to know where to look, and what I need look at, what questions I need address, etc..

Ray~

 

[MikeHalloran]

The usual processes for making objects that large don't do color directly. You might be able to silkscreen an image on a thin sheet and apply it to a hemisphere by heat and stretching and some adhesive. ... or maybe inflate a sphere into a cavity, but then you'll have problems with the surface texture you seem to want. Take a look at manufacture of largish globes. Maybe you can contract with a globe manufacturer; I don't think they're doing great business these days.

There is at least one 3D printer system that can do color. The ones I have seen couldn't do a globe or a hemisphere of your size directly, but they could make it in pieces, i.e. 10 or so convex hexagonal-ish pieces that you glue together. You can get pretty good surface detail, and color. You may have to work at hiding the glue lines, but the details and techniques for making large parts in sections on 3D printers have been worked out already.




Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

Well I'm still really quite lost on what is really required.

Are you trying to make a domed round shape like a Viking shield or a hemisphere or are you trying to make a full sphere.

Different colours on a curved surface without paint of some type is hard to imagine. OK I include printing as paint as both apply a liquid colour coating that dries in place.

One no paint two colour system is to buy a special plastic sheet laminated in two colours so say there is a skin in one colour and a matrix or core in another colour. You use a mill or router to cut a patern through the skin layer exposing the underlaying colour. This is typically used for engraved plastic nameplates.

For a domed surface, thermoforming plastic sheet can work. The most simple method is to make a plug out of wood, heat the sheet in an oven, then whilst wearing soft leather gloves, hand form the hot rubbery plastic to the wooden plug and allow to cool until rigid again. PVC sheet could work as might Acrylic or Polycarbonate.

If you want a sphere then rotational or blow moulding are more appropriate for a one piece part, but tooling costs might create some sticker shock.

Mikes suggestion is valid for smaller volumes. Look at leather vs cheap plastic Soccer balls for the various techniques. Leather being made of segments sewn together and cheap plastic being blow moulded or rotationally moulded.

Regards
Pat
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[Radivs]

I thank you both, Mike & Pat, for the ideas and information.

The globe, or another form of relief map, process sounds very much like what I am looking for. A topographical map, in 3D, 3' square, that one could hang on a wall, albeit with some varient to the typical hills and valleys. The actual texture is not critical, but what it looks like is of key importance, so the texture, as such, will need be created by adjustment of the art, only requiring accurate placement on the underlying form.

Have started looking into companies that do relief maps, globes, etc..

Thanks again,

Ray~