SWNZ Forums

oota goota wrote:...
well ok I was think maybe vac forming into a negative shape rather than a positive. I've done a little bit of this you would be able to get some good detail lines which would reduce the amount of cutting.....

Please explain

Bazzack wrote:

oota goota wrote:...
well ok I was think maybe vac forming into a negative shape rather than a positive. I've done a little bit of this you would be able to get some good detail lines which would reduce the amount of cutting.....

Please explain

ummmm....instead of vac forming over a dome I would vac form into a dish to basically get the same shape but the detail lines would be on the outside of the dome and not the inside. If I could get the detail lines right it would mean less cutting or no cutting really. The only tricky part of this approach is any dust that lands on the forms during vac forming will read in the plastic. If you have a look at the inside of any stormtrooper armour you'll get the idea.

Nice one OG. That's what I assumed you meant. My wee brain just couldn't understand how it was actually possible to vac pull into a dome rather than over one.

I don't see an issue with dust spots in the pulls. A little bit of surface clean up prior to paint is no biggy in the scheme of things

Sounds like a huge amount of work to produce the negative form though right? All those tiny lines...

On another subject, am I mistaken or has Cambrian plastics all of a sudden wacked up the price of their domes?
$96.44+ GST for a 500mm polycarbonate half sphere? Thought they were around $60 when this thread was started..??

Bazzack wrote:...On another subject, am I mistaken or has Cambrian plastics all of a sudden wacked up the price of their domes?
$96.44+ GST for a 500mm polycarbonate half sphere? Thought they were around $60 when this thread was started..??

Polycarbonate is 96+Gst, Acrylic is 60+Gst.

MattG wrote: Polycarbonate is 96+Gst, Acrylic is 60+Gst.

Ahhh! My bad. Glad to be mistaken

Bazzack wrote:

MattG wrote: Polycarbonate is 96+Gst, Acrylic is 60+Gst.

Ahhh! My bad. Glad to be mistaken

That's a nice mistake to make though Bazzack! Well I reckon a proof of concept is the way to go. Make a thing see if the idea works. There's two ways to make the negative I guess: Make a positive shape then make a hard mould of it giving you the negative. Or cast onto the acrylic dome and fabricate the details in the positive. Mmmm even just writing this makes me think the first option will be best.

Just to clarify, we're mostly talking about the Dome detailing/ possible vac forming at this stage right? Which will be based on a 300mm half sphere. They're only $38+GST in acrylic. Or $59+ in PC.

Or are we talking about a detailed vac formed body wrap as well?

For the 500mm body shell the general consensus is that acrylic will be too brittle, so polycarbonate is likely the body shell option that I'll be looking at.

Bazzack wrote:Just to clarify, we're mostly talking about the Dome detailing/ possible vac forming at this stage right? Which will be based on a 300mm half sphere. They're only $38+GST in acrylic. Or $59+ in PC.

Or are we talking about a detailed vac formed body wrap as well?

For the 500mm body shell the general consensus is that acrylic will be too brittle, so polycarbonate is likely the body shell option that I'll be looking at.

Yeah I see the vac formed pieces as cladding attached to two half spheres a lot like the xrobots guy did I think. That way you don't get any join lines like if we were gluing together two detailed half shells.

What do you reckon MG and Bazzack? It might be the wrong tack to take

oota goota wrote:...Yeah I see the vac formed pieces as cladding attached to two half spheres a lot like the xrobots guy did I think. That way you don't get any join lines like if we were gluing together two detailed half shells.

What do you reckon MG and Bazzack? It might be the wrong tack to take

That sounds like the double-skin method used to get "panel lines" on most astromechs...should be as perfectly a good way to go on a full sphere as on a cylinder or R2 dome.

Sounds ideal for the body cladding. Are you thinking the same for the dome? Or more towards a full one piece cast or vac formed dome?