(Morrigan, as a synonym of Morgan of Arthurian legend)

Wednesday, 6 May 2015

Single Curvature bodywork

Some more progress with body work design, still needs some more tweaks to the back end, but it is getting there. I'm pleased with the overall appearance, especially that it is all single curvature with the exception of the wings. This means that all of the major panels can be unrolled and be pre-cut from sheet, then 'simply' draped over the forms and fastened to the rib structure.

I am currently using a single radius on the wings as this is simpler to form using rollers, it remains to be seen if this will survive the next design review.

The current all up weight for the assembly is 700kg, so should manage to build the vehicle under a tonne.
Inner structure view
Body work view

Monday, 4 May 2015

Front end arrangement

I though I would share the front end arrangement that I have ended up with, primarily driven by the suspension point locations.

In order to minimise bump steer the steering rack needs to be in-line with the steering points on the wheels. I have opted to use the ford escort rack, as it is readily available in various options as a new part. This will require a pair of extension stubs to bring the ball joints out to the required position.

Heavy tube is used to provide the mounting location of the rack and allows the rack to pass through the chassis with clearance for the track rods when simultaneously in bump and turning.

The link from spring to lower wishbone needs some further refinement and structural checking, fatigue loads are my main concern for that location, given the reversing loads. Additionally the design needs to be an all bolted arrangement; so clevis & pins.

Front suspension arrangement

Edit; A simpler arrangement that can be easily fabricated using water / laser cutting from plate.

Updated inboard wishbone

Wednesday, 22 April 2015


The design of the bodywork is progressing and updates have been made to the chassis to get the EPAS column to fit and have suitable locations for mounting.

The body design needs finishing before I can start on its internal ribs and stiffeners that will give it rigidity and provide the attachment points for the panel pieces.

Updated chassis and current itteration of the bodywork

Mirrored bodywork

The plan for building the body shell is to use the construction method employed for light aircraft; namely internal lightweight frames with a riveted skin. By using countersunk rivets it should be possible to attain a high finish by using a combination of body filler, sanding and a high build primer.

The body ribs would be held by a framework and the same connection locations would be used to attach the body to the chassis; hence the hoop frames of the chassis.

Below is a picture of a full strength countersunk rivet connection, where the plates have been dimpled prior to the rivet being affixed. A combination of rivets and a flexible epoxy glue will give a lightweight rigid shell.

Dimple countersunk rivet

Some good sources for dimple flush riveting come from the home aircraft builders in the USA the photo above is linked from the sonex1362 blog. Other links are; vansaircraft for military riveting design specs and skysaber.com for flush riveting solid rivets.

Friday, 10 April 2015

Body design

The bodywork is being styled using two 1930's vehicles as a basis. The first the Alfa Romeo 6C 2300B Mille Miglia Spyder for the front end; I need the horizontal parallel single curvature of the Alfa inner wings to cover the wishbone suspension. And secondly the Squire Vanden Plas from aft of the wings which will be swept down to running boards. 

Alfa Romeo 6C 2300B Mille Miglia Spyder 

Squire Vanden Plas

So far the design has used single curvature panels for all of the bodywork with the exception of the radiator / nose. The wings are yet to be designed, and these may need to be either made to order (cant avoid double curvature without significant welding requirements) or made up in carbon / flax / GRP composite.

Body work to date I

The plan for fabrication is to upset / dimple the sheet for counter sunk rivets in combination with epoxy adhesive. The skin will be supported by transverse and longitudinal elements which will also be used to provide attachment points to the chassis. More on this later.

Body work to date II

Wednesday, 4 March 2015

Various parts of the design are slowly being added to and tweaked, to ensure that the smaller components will have a home. I have started roughing out the bodywork; profiles and sections. I'm playing with the options for windscreen, although having a custom curved screen is possible, the cost is likely to be prohibitive. 

So in lieu of having access to measure up production screens, I am looking at using flat glass, but in a split screen arrangement with raked panels and curved interface edges to the scuttle.

I plan to use nickel strip / profile brazed together to make the frame.

Initial bodywork designs

Sunday, 8 February 2015

Initial chassis design

Design of the suspension and chassis under-way, The chassis structure will need refinement for road loads. Design is a cyclic process of making changes and then checking the impact of those changes.

Top view

Underside view

FE analysis of rear hub carrier to check load capacity

1D Initial chassis FE analysis