CarBEN EV5 Full Sized Prototype Construction - 5 Seat Electric Car From Scratch

[sgtlethargic]

I would like the Sketchup model. I recently started using Sketchup.

[gone-ot]

Pardon my ignorance, but what's "Sketchup"? I assume it's a commercially available CAD program, running most likely on a PC under Windows, correct?

[basjoos]

Originally Posted by NeilBlanchard

Hi Jim,



It is a design experiment, and it may or may not be practical; but I have designed the seating etc. so that you get in and out the back doors. On this first prototype, the side windows will be fixed; though I may have a small sliding section on the window to the left of the driver. The side windows are two layers with an air space for thermal insulation, by the way.

I'm intending to have robust air flow through the inside (as needed), and if that is done well, then the drag of open windows can be avoided.

A cheap and easy way to have openable side windows is to use the system found on the Citroen 2cv, which used a 2 piece glass with the upper piece hinging inward and down to open the top half of the side window. The Renault 4 used a simple opening system where the glass slid horizontally.

[freebeard]

Old Tele man -- Sketchup is available for XP and Vista and Mac OSX 10.5+. Recently sold by Google to Trimble, the Pro version is paid and the basic version is a free download.

Sketchup Warehouse, is a repository of free to download models. For instance there is a model of R.B.Fuller's Dymaxion car.

[cRiPpLe_rOoStEr]

Originally Posted by basjoos

A cheap and easy way to have openable side windows is to use the system found on the Citroen 2cv, which used a 2 piece glass with the upper piece hinging inward and down to open the top half of the side window. The Renault 4 used a simple opening system where the glass slid horizontally.

The sliding window setup has only one problem, since it slightly increases the drag. And in the Citroën 2CV the lower piece is hinged out and up, opening the lower half.

[NeilBlanchard]

The SketchUp model is in the Google 3D Warehouse (2 versions of it actually), or PM me your email and I'll invite you to join my Dropbox folder.

Today's progress photos:



I started to glue up the hatch door, today as well. It was a bit over 50F, and it will be warm until Monday, at least.

[freebeard]

I took liberties with your posted pix:



Have you considered spraying a guide coat to follow as you sand down to the final contour? Do you have a sanding block that is ~2' long?

[NeilBlanchard]

This is still the rough shaping - painting it would be a good idea, and I'd do the final pass by hand, though some of the surfaces are concave making a really long sanding block impractical for all bits. The chines need work, too; and the widows will be cut out eventually.

The small bit of progress to report for today was I started to glue up the rear wheel skirts. It is still about 50F, and tomorrow and Monday will be even warmer. I hope to glue the hatch door together.

[freebeard]

I don't want to come across as an expert on this (but that never stopped me before ), but...

a body long-board has a turnbuckle on the back so you can warp it from [slightly] concave to [slightly] convex.

It might be worth it to make custom sanding blocks for the edges, to keep them uniform.

With paint you can feel irregularities with your fingers that you can't see with you eye. Probably not on soft foam, but you don't want to hold the sandpaper without a block.

If you haven't used guide coats before, they don't have to be more than a mist of paint. If you knock down the highs without hollowing out the lows less filler is needed.

Is this form male or female? Or was it that you haven't decided?

[NeilBlanchard]

This form is going to be the core of the working prototype, ideally. I need to test it and then make adjustments before doing a second one. Or, if it all works great, then I could make molds from this and go from there.

I'll try to find a flexible rubber block, I think; and the paint method sounds like a good one. I'm only going to be able to do peel ply fiberglass, so perfection is not likely. Some of the inside of both the passenger compartment and the motor bay will likely have to be sprayed in and then use peel ply as possible.