Moulding/casting?

I agree with chopping off the drives, along with their mounts, and doing them seperately.  It could be done in one piece but you would have much less trouble with trapping air in three pieces.  The other two sections should be easy peasy!

if casting with molten metal and not spin casting then you need to make the funnel hole at 1 end of molds and clamp mold halves together and have them either turned on edge like the old Gilbert Kaster or Lee metal molds, or laid flat with funnel end tilted up near 45 degrees so material flows in while letting air bubbles escape. use a coating of mold release like talc powder or soot on mold halves for metal casts. also after testing you may discover thin parts needing weep cracks for air to get out so it pores full. if so then silicone rubber molds are easy to do this. use a razor blade and make a shallow slit from those spots to the funnel hole (if larger areas are in the path then you can stop the slit at that point and air will seek its own escape). just dont damage mold integrity with these slits.

Cheers guys!

Ironman, I'll probably just be using a polyurethane. Something fairly simple like SmoothOn.
So in turn it seems logical to just use a standard silicone moulding material of some form in a two part per piece set up.

N2ri, danke, that's a bucket of info!

I'd actually thought about splitting the main hull thing down the middle and laying it on the flat for moulding. But again, very unsure.

Hmmm indeed!

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons

near impossible to see the slits with camera unless mold is flexed to open them up like a flesh wound. main thing to remember on planet earth, gravity is our friend. air rises and metal falls, making it easy to vent. I also dust talc into slits while flexing mold b4 using mold then as in every prep with talc knock molds upside-down on table to get excess off and out of details. just dont over do vents too deep so metal etc dont seep out, also dont chop pieces out of mold. injection molds and most spin molds wont need vents as air will be forced out mold edges and maybe tiny amounts of casting material. since I was a kid I have been collecting and using all types of toys that make other toys and some even recycle left overs or failed castings. I call them 'molding/maker toys' many I have created new custom molds for using a jig I made to fill bottom half with silicones then coat master object with release like 'Pam' spray or thinned Vaseline and pushing master into silicone then I made a funnel plug that slides through side of jig til touching master, set it aside where it wont be disturbed till cured (some silicones take 5-7 days for this) then I use single edge razor blade to carefully trim around master to proper level for halfway point of mold (mine has a thin lip with guide holes at corners to hold it in toy caster) then apply same release agent posted above over entire top surface of mold and master b4 added plenty more silicone on top then place top of jig over it lining up with the 4 corner guide pins with pre determined depth so I can press them tight together smushing out excess silicone and set aside as b4 to cure, then carefully slice all oozed silicone flush with outside of jig and very carefully pry the 2 halves apart, remove jig parts and clean mold halves while removing master. then see if anything needs repaired like filling in any bubbles in silicone etc. after new mold is all set dust with Talc test a cast to see if vents are needed then re-dust with Talc and use.
  now this is my low temp alloy non-toxic casting stuff (melts at 174f) and the jig is made of smooth wood and impregnated with hot wax (looking for chucks of nylon or teflon to make multiple jigs of. and I use silicone like in calking or tubes mostly clear for seeing defcts better. if using lead or hotter them the vulcanized silicone mix must be used and its not as flexible but same processes but cured faster in oven or chemically.

as for pics I am gathering that for my other topic on 'art form' also listing all forms of manufacturing I do. plus when my son can work me into his videography schedule (side job) I am going to make some youtube info videos also. as these are fast becoming forgotten. nobody gets rich with these so keeping it secret is just nonsense.

Ok, I'd heard about using PLA in that manner, but damn that was cool to watch. Worth it just for the robot dance.

Actually, had a thought.
If I built a clay base that came up to approximately half of the main body with the drives still attached could I not just make the mould like that? The model is exactly (cm) 13.966w x 39.5d x 6.806h so the strength of the poly shouldn't be that much of an issue.

Dunno, at this point I'm still just thinking out loud.

Thanks for the advice, people.

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons

Basically just this.
https://www.youtube.com/watch?v=FQ1A7ZjTsx8

Visualising is indeed an annoying thing to do

This is a crowd funding thing that I'm running: http://www.gofundme.com/bvi140 It's for pretty selfish reasons

Serin, Great video...Thanks!

I would still think you would at least need to split the model at the nicelle struts (on the main body) and use a mortise and tenon + glue arrangement to connect them after molding.

Will be nice to see n2ri's examples...