Final Stretch of Lights - fine details of everything.

Owned by Jasmine Thind
Last updated: Dec 05, 2023
7 min read

Based on discussions with Hardware, all regulations should be met if we use the reference lights. That is exactly what we did, we bought all reference lights. Hardware does not need any special housing area for lights, this has been discussed with Forest. Below is all the mechanical details of everything (a few design images are missing as of now, will put full lights CAD up into GitHub)

Headlights:

1. Headlight Cover

Right Cover

These are just the design itself

Left Cover

 

 

Integrated into AERO:

  • Integration into Aero:

Cutting of the composite body will be done using a dremel and stencil (look below). However, there needs to be a way to set the cover into the body so that it is flush with the aeroshell. In regular cars there are usually tabs that connect to the cover and then screw on in the inside of the car. In our case it would be difficult to screw the tabs with anything as the aerobody is out of the picture and the chassis is too far away from headlight covers. To seal in the cover with the aeroshell, I will be using automotive grade butyl tape. This tape is less sensitive to varying temperatures and maintains stickiness in upto 300F temperature. We need a flange with the headlight cover so that I can actually apply this tape and seal the cover with aeroshell.

The flange going all around the cover is 2cm (0.78”), which is sufficient as most butyl tape is either a little under this thickness or a little more, which is okay in both situations. It also can be cut (putty-like material).

The depth/thickness of this flange is 4mm. Ideally it should have been like half of this, however given my experience and trials with thermoforming it is very difficult for us to pull exact edges and there is often a small fillet formed which would reduce the thickness. The exact variation is difficult to measure however with 4mm if I pull it exactly perfect then I can add thicker butyl tape which is easy to obtain and if it ends up thinner I can go with something thinner. Increasing the depth just ensures I can actually pull the plastic in that area. The aeroshell (Matt measured is about 1.5mm), this leaves 2.5mm for the tape (if pulled exactly). This is ideal as it is thick enough for the tape to provide sufficient sealing and not too thick that we have giant blobs of tape.

  • Mold Manufacturing:

    • The mold will be made of MDF. When assessing the mold, I realized that I will have a negative draft angle hence I made the change of forcing the flange to be a little offset which gives a positive angle greater then 90, avoiding negative angles, before thermoforming if this seems too large an angle (difficult for installation) it can be sanded down, however, as can be seen in the images the angle is not barely obtuse, almost 90.

    • We will machine one mold at a time and run a thermoforming test over it before making the left.

    • To do: Split up this mold for the MDF cutting

2. Headlight Cutting Stencil + Datum

  • Manufacturing Method: 3D Printing

  • Material/Where to do it: RPC

  • Design:

The stencil design is very simple, as it is simply an outline of the headlight, which hooks on to the shell to the outside surface of the aerobody.

For the datum many designs were considered. The datum feature should help one locate where the stencil goes in terms of the aeroshell, as well as line the two stencils horizontally. The main idea is to have an extension of the 3D printed stencil and an MDF piece connected. The concern I had was ensuring that the MDF is supported from the bottom and top as otherwise it would result is some sheer stress, rip and potentially cause trouble during cutting (if only one side has the 3D support and then screwed on). A design was made so that the MDF sits in between a top and bottom flange.

 

However, due to the slant on the aerobody shell fitting the MDF between the two flaps and then between the two stencils becomes very tricky (we would almost need a MDF sheet on an incline type beat). My proposed solution to this is having the 3D printed flap on one side only and fastening with screw and nut with the MDF (but this needs to be a very thin sheet). Once the stencil is placed on the aeroshell and we have aligned the two, the thin MDF can be unscrewed - this will ensure that no further stress is applied as we cut using the stencil. To make this structure more strong I can use a heat-set insert, instead of just a hole. The 3D printed extrusion from the stencil will allow us to measure from the tail to the stencil (on both ends), the thin MDF (it does not need to be MDF, can be any thin and low weight material) allows for horizontal alignment and more points of measurement from the tail. Additionally, if in any scenario this does not work, my fail safe is a laser level. The laser level will ensure that we can align the stencils horizontally and the 3D printed flaps will allow measurements from the tail end (so just eliminate MDF sheet in this design).

3. Headlight Internal/Support

  • Manufacturing Method: 3D Printing, tapes

  • Material/Where to do it: RPC

  • Design:

    • Small ports will be made for each light

      • So that makes three ports (turn signal, inner DRL, outer DRL)

      • The LED will be taped on with butyl tape in this port

    • The rest of the housing will also be taped on to the cover (around the edges)

    • Since the butyl tape is black this should be a okay for aesthetics

  • Validation:

    • By using just tape I ensure I am not complicating with other parts (ie ribs/chassis)

    • But is this strong enough?

  • Integration:

    • The housing will also be taped on to the cover (around the edges)

    • Since the butyl tape is black this should be a okay for aesthetics

    • This housing will also be further taped to the aeroshell itself using flanges which will ensure structural stability

4. Optics/Coatings

  • What is the purpose and where to get

Side Marker Turn Indicators:

1. Cover

  • Manufacturing Method: Thermoforming, these are essentially going to be simple pieces that I can melt a little and fit into the holes for side markers.

  • Material/Where to get: Extra plastic from headlight covers

  • Design:

  • Mold for it: Not needed

  • Integration into Aero - Cutting and how to do this:

    • For these measurements can be taken from multiple points of the car - ribs will be ideal

    • A cutting stencil can be easily made around the shape using 3D printing

2. Internal

  • How is light inside being supported:

    • The light is enclosed in a 3D printed housing which holds the LED strip

  • Manufacturing: 3D Printing

  • Any Validation:

    • This housing will be taped on to the aerobody and cover (butyl tape)

Rear Lights:

1. Cover:

  • Manufacturing Method: Thermoforming, this is just a thin rectangle

  • Material/Where to get: Extra plastic from headlight covers

  • Design:

  • Mold for it: Not needed

  • Integration into Aero - Cutting and how to do this:

    • We are simply cutting a rectangle for the rear light + turn signal to go in

2. Internal Assembly:

  • Which light goes where, how are they supported:

    • The turn signal and rear brake light can be in any order no regs on this (ask Hardware)

    • This part of the aerobody is already fairly tight and the housing can be designed based on the final manufactured shape

      • It may not even be required and the LED’s may simply be attached using the butyl tape

High Mounted Centre Brake Light/BPS Fault Indicator:

1. Cover:

  • Manufacturing Method: Thermoforming

  • Material/Where to get:

  • Design:

  • Mold for it:

  • Integration into Aero - Cutting and how to do this:

2. Internal Assembly:

  • Which light goes where, how are they supported