Making hard to find Ferrari parts
Every now and then, an unusual challenge drops into our inbox. So it was when we were asked if we could help make a clutch pedal for a Ferrari. This was needed for a project to convert a rare right-hand-drive Ferrari from an automatic gearbox to a manual stick-shift.
To be clear, car mechanics are not our strong suit. So this project would require a lot of input from our client. Luckily, in this case, our client seemed to know what he was asking for. His long-term project was to convert a Ferrari “612 Scaglietti” to a manual transmission. He would be the first person, worldwide to complete this. Apparently, only 27 right-hand-drive versions of this car were ever made, and whatever stocks of spare right-hand-drive clutch pedal arms were originally manufactured, none are currently available on the market.
Our first discussion was on whether the clutch pedal was a safety-critical part. If it was, then a whole lot of testing and assurance would be needed that would have likely made the job uneconomic. While a clutch pedal failing during operation would be annoying, it would not affect the safe control of the vehicle or the ability to bring it to a stop. So, we were happy to proceed.
In very general terms, the job split into two phases. First to recreate the CAD (digital) version of the design, then Second, to select the most appropriate way of manufacturing the part and get it made.
As with any job that initially looks fiendishly complex, it’s a case of decomposing it down into small tasks that can be accomplished, and then make a start and work your way through your list of tasks. Our assessment of the job was that, although it looked complicated, we had enough contextual information and known measurements to figure out the design. It was an interesting challenge in reverse engineering. And, who doesn’t want to work on a Ferrari?
Recreating the design in CAD
We did not have access to the Ferrari CAD files for the clutch pedal. The reference available to us was some 2d drawings from a maintenance manual, photos from a car with manual transmission, and the bracket that all the foot pedals fit to.
Using these references, we would need to create our own CAD design. Our design had to meet some key design criteria:
- The location of the pins and pivot points where the part joins to the bracket needed to match the actual bracket.
- The location in space, angle and range of movement of the socket that accepts the connecting rod from the clutch mechanism needed to be correct – as seen in the 2d drawings in the manual.
- The max and min range of travel for the pedal arm needed to match the drawing in the maintenance manual.
- The location in space of the clutch pedal relative to the other pedals needed to match the photos of existing manual transmission examples.
Although we have never actually seen a clutch pedal arm for a RHD Ferrari, and the only drawing we had consisted of a single side-view, as long as we met these criteria, the bearing points and interfaces were at the correct angles, we were confident that the part would work.
We created a new CAD version in Autocad Fusion 360. A big advantage of using Fusion 360, is that we were able to give our client online access to the project so that we could both see progress and comment on the design as it developed. This gave our client some confidence that the part was evolving in the right direction and that progress was being made, but also allowed us to tap into the knowledge and experience of our client to resolve tricky aspects of the design.
Manufacturing the part
To reduce the risk of wasting money on parts that were not quite right, we ran two iterations where a plastic versions of the pedal arm was 3d printed as a test-fit. Final tweaks and adjustments from the test-fit fed back into the CAD design.
Having confirmed the correct size, shape, connection points and angles, we were ready for final manufacture. Three main options were explored to create the final part. Each with its own pros and cons.
Direct 3d printing in metal. Pros: Quick. Underhangs and voids easily done. Cons: The size of the part meant that it would have to be 3d printed in a few pieces which would bolt together to form the full-sized shape. Some machining of bearing surfaces would be needed to finish. Cost: £££
Investment Casting. A sand mould would be made around a 3d printed plastic master, then cast in aluminium. This is how Ferrari made the original parts. However, when trying to find a company to do this, we were not able to find a foundry that could handle the size of the part. We learned that the larger the wax master, then the hotter the furnace needed to successfully melt it out. Pros: Would result in a single piece, Cons: Some machining of bearing surfaces would be needed to finish. Some voids would need to be filled in and cut out later. Unable to find a foundry that could handle the part. Cost: N/A
CNC Machining from metal stock. Pros: Best surface finish. Bearing surfaces would be finished in a single process. Cons: Quite a complex shape – would require advanced tooling. Cost: ££
The final process was to send the CAD files we developed to a CNC machining shop via 3D Hubs. For this project, our client chose to send the files to 3D Hubs himself. For other projects, we can take care of this as an end-to-end service. The key part of the process where Celtic3d can add value is in creating the digital files that can then be sent to manufacturing.
These images show the CNC machined part received from 3D hubs. It was a complicated shape to machine. To be honest, we were prepared for a request to modify the design, perhaps splitting it into a few different parts to make it easier to manufacture. But, the machine shop found via 3D Hubs, had a 5-axis CNC machine and no problems with it.
Making your parts
It is always rewarding to see a digital creation you have worked on, produced in physical form. We are particularly pleased with the way this job turned out. As an example, this job perfectly illustrates what is possible if you combine the ability to create 3d content with flexible on-demand manufacturing capability.