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NeilBlanchard · 08-04-2010, 08:00 PM

Okay, if you can clarify/correct me on the construction process, here's what I am thinking of doing:

Cut plywood former sections about every foot -- I can plot full size templates/patterns from DataCAD, and then use spray adhesive to stick 'em to the plywood. I will lay them out in DataCAD to try and fit as many as possible on each sheet. I'd like to be able to test the physical size and layout of the entry method and seat layout etc., before committing to build this car.

Now, I want to have a composite foam sandwich monocoque, both for strength and for thermal insulation, so do I need to form the inner walls on the inside of the formers first, and then do the outer surface, and then foam in between?

How do I best form the surface using the formers?
Do I need to use Styrofoam and carve it, or can I use wires and/or screening as a substrate for the composite?
It is okay to leave the plywood in place and have it as part of the structure, or is is better to pull it out and then rejoin the surfaces with spacers/foam?
Is fiberglass significantly less expensive than carbon fiber, and what are the advantages/issues with each?

I can cut the plywood so that the windows are slightly recessed, to form the lip/flange -- should the windows just be left open and trim the edges, or does it help to cover them over completely and then cut out the openings?
For the main hatch door, and the rear doors, should they be formed as part of the whole outer skin, and then cut out? Or, should the opening be left out of the main piece and then make the doors themselves separately?

I want to form a surrounding "beam" around the front and sides of the passenger compartment (which will double as the main air duct into the passenger compartment) -- I hope to have it flush on the inside, and let it into the formers. If the beam was metal, it could be hollow -- can it be made from composite and be hollow?

I'm trying to figure out how to best do the crumple zone in the front: a tubular subframe or a composite structure? Have you seen "crush cones" used between a structural bumper and the firewall/structural passenger cell?

How does the suspension get attached to the monocoque -- do reinforcing plates need to be embedded, or...?

I'm hoping to hear from FVT about the size of their battery pack, so I can try and lay out how it will fit inside the floor. I would ideally try and at least have the space for a really big battery pack (50-60kWh!!) so I can get 300-400 mile range. This would be incredible if it could be made to fit!

I would love to hear whatever your thoughts are! Thanks in advance.

Some more slightly revised images of the SketchUp model:

Link to my blog: http://neilblanchard.blogspot.com/20...e-project.html

08-04-2010, 08:00 PM	#86 (permalink)
NeilBlanchard Master EcoModder Join Date: May 2008 Location: Maynard, MA Eaarth Posts: 7,908 Mica Blue - '05 Scion xA RS 2.0 Team Toyota 90 day: 42.48 mpg (US) Forest - '15 Nissan Leaf S Team Nissan 90 day: 156.46 mpg (US) Number 7 - '15 VW e-Golf SEL TEAM VW AUDI Group 90 day: 155.81 mpg (US) Thanks: 3,475 Thanked 2,952 Times in 1,845 Posts	Okay, if you can clarify/correct me on the construction process, here's what I am thinking of doing: Cut plywood former sections about every foot -- I can plot full size templates/patterns from DataCAD, and then use spray adhesive to stick 'em to the plywood. I will lay them out in DataCAD to try and fit as many as possible on each sheet. I'd like to be able to test the physical size and layout of the entry method and seat layout etc., before committing to build this car. Now, I want to have a composite foam sandwich monocoque, both for strength and for thermal insulation, so do I need to form the inner walls on the inside of the formers first, and then do the outer surface, and then foam in between? How do I best form the surface using the formers? Do I need to use Styrofoam and carve it, or can I use wires and/or screening as a substrate for the composite? It is okay to leave the plywood in place and have it as part of the structure, or is is better to pull it out and then rejoin the surfaces with spacers/foam? Is fiberglass significantly less expensive than carbon fiber, and what are the advantages/issues with each? I can cut the plywood so that the windows are slightly recessed, to form the lip/flange -- should the windows just be left open and trim the edges, or does it help to cover them over completely and then cut out the openings? For the main hatch door, and the rear doors, should they be formed as part of the whole outer skin, and then cut out? Or, should the opening be left out of the main piece and then make the doors themselves separately? I want to form a surrounding "beam" around the front and sides of the passenger compartment (which will double as the main air duct into the passenger compartment) -- I hope to have it flush on the inside, and let it into the formers. If the beam was metal, it could be hollow -- can it be made from composite and be hollow? I'm trying to figure out how to best do the crumple zone in the front: a tubular subframe or a composite structure? Have you seen "crush cones" used between a structural bumper and the firewall/structural passenger cell? How does the suspension get attached to the monocoque -- do reinforcing plates need to be embedded, or...? I'm hoping to hear from FVT about the size of their battery pack, so I can try and lay out how it will fit inside the floor. I would ideally try and at least have the space for a really big battery pack (50-60kWh!!) so I can get 300-400 mile range. This would be incredible if it could be made to fit! I would love to hear whatever your thoughts are! Thanks in advance. Some more slightly revised images of the SketchUp model: Link to my blog: http://neilblanchard.blogspot.com/20...e-project.html __________________ Sincerely, Neil http://neilblanchard.blogspot.com/ Last edited by NeilBlanchard; 09-12-2010 at 04:36 PM..