A Project came to me that required re-engineering of parts from a 1930's Sears Bike. There are not many of these bikes left, from what I learned the need for metal during WW2 lead to premature destruction of these awesome looking bikes. This is the bike specifically:
Note the 4 points I was asked to rengineer:
A) The Emblem (awesome)
B) The light lens
C) The chrome crown
D) The crowns side piece
There were some issues with doing this project I had to overcome.
A) Manufacturing was much different
B) All pieces were Chrome, or Clear - Scanning those is not good
C) Some pieces were modified geometry over time (~90 years)
D) The emblem had broken pegs
E) I dont have resin or metal printing in-house
The Crown, I coated it with scanning spray, scanned it. The walls were very thin, and it is beng a little too far too one side. There was no current process able to manufacture a 2mm thick part consistently with the same fidelity.
So what I Came up with: taking the side in spec, covering it with painters tape to make a pattern. I then used that pattern to make a flat. I additionally made a forming tool out of ASA(had ASA loaded).
The Lens was then sprayed and scanned; this took multiple scans to be perfect. I had to also build up some of a broken piece in blender. I instructed the person I was working with to get this printed in a clear resin. I could easily re-engineer this, but I would lose the texture of the lens as it was made in the 30's and did not want it too perfect.
The logo was scanned, and the posts were fixed as one was supposed to be threaded. Then after getting quotes from facfox for metal printing, they suggested to take off the thread and they will add one. The scanned part was in .1mm accuracy of the physical part. I printed one in ASA just because - it won't be used.
This customer did not know about 3d printing nor 3d scanning. They have the digital files, and the guidance to get a 3D Printed lens in resin printing. a 3D Printed logo in 316L (SLM) that is polished and threaded, and 3 sheet metal parts with a forming die already made for them so it can look handmade. I worked to preserve the integrity of the original design, and the customer will now be offering the parts to the few people who own these awesome looking bikes.
Reach out if you have a project that needs this type of reverse engineering and guidance, I sent the customer to three 3d printing companies from which I make 0 commissions from and prepared everything and worked with the companies on spec.