The final hurdle I needed to overcome was to create an accurate digital copy of the Tyrrell cockpit shrouds.
These come from the 1:12 model of the 6 wheel F1 racing car and are the parts that surround the driver.
As you can see, they are very organic in shape, and there is just no way for me to be able to accurately create them in CAD.
My solution was to use photogrammetry.
This would also be a good test of my original idea to 3D "scan" all the needed donors.
I built myself an inexpensive light tent using PVC reticulation pipe and a roll of tracing paper I had lying around (to diffuse the light).
I grabbed 3 cheap desk lights from Ikea and some 100W LED "daylight" globes.
I used some black cloth as a base and backdrop - this allowed my to have a featureless background so that I could rotate the subject on a turntable rather than have to move around it to take the required photos.
You need lots of photos...
For these two parts (photgraphed in one go) I took 70 shots.
For my equipment, I'm using an old Nikon D300 with a 24-70 2.8 lens.
Photogrammetry has some limitations on what you can capture. Two of the "no-no's" are shiny objects, and those that have no detail.
Shiny, plain plastic model parts are generally not a good candidate!.
To get around this, you need to coat the subject to stop both refelections and add some "features" that the software can match to.
You can buy purpose made sprays for the job, but they are expensive. I went with a homebrew option which I'd read about - talc/baby powder mixed into Isopropyl alcohol.
It worked surprisingly well. The IPA evaporates quickly leaving a thin coat of talc and the IPA doesn't harm the plastic. The talc just washes off in water afterwards.
Here are the parts in my light tent, sitting ready on a turntable after being sprayed with the talc solution:
Here is the result after importing the photos into the software and creating a 3D model.
and cleaned up and converted to a solid body model.
I have to say, I'm really impressed with the results, which are confirmed by how well it matched to the reference photos once I added it to the model.
The Tyrell pieces were then trimmed to match the origianal model with styrene and kit parts also added.
Here is the match to the refeence after it was done
This gives me a lot of confidence going forward for scanning the rest of the donors at a later stage.