3D Engineers - Vehicle re-creation specialists

1924 Bugatti Type 35 Reverse Engineering World 1st

History

The Bugatti Type 35 was Ettore Bugatti's best design and arguably the most successful Grand Prix car ever having won an incredible amount of races.

The design of the car had many innovative features including a hollow front axle to reduce unsprung weight and solid alloy wheels at a time when wire wheels were normally fitted.

This car could achieve 110mph and was designed on lightweight principles, at a time when the commonly accepted belief was that heavier cars held the road better.

Project goals

The principal goals were:

1. For 3D Engineers and The Bugatti Trust to be the first people to digitally recreate an out of production car.

2. Create via 3D models of the parts an accurate set of historical documents that could be cross referenced with original drawings and physical parts to allow accurate performance data and historical research to be carried out on the Type 35.

3. Enable owners of this type of Bugatti to verify that their cars are to an original specification and allow them to obtain parts that are produced more accurately and to the correct or better material specification.

4. Prove that 3D modelling of old designs has a measurable and important role to play in the study and maintenance of older designs.

5. Show to the younger generation that engineering does not have to be boring and that it encompasses many areas of interesting study and work.

6. To create the most accurate historical record of an early Bugatti Type 35.

 

Methodology used

The Bugatti Type 35 changed throughout its life, so early on in the project it was decided to create a version of the vehicle produced between 27th November 1924 and sometime up to the end of December 1924.

The reason for this decision was:

1. Up to chassis number 4421 (produced in December 1924) Bugatti Type 35's had wooden infills to the dumb irons.

2. From 27th November 1924 the helical ramp ignition advance was used.

3. Up to the 17th chassis produced at the end of 1924 (it is a moot point whether 4421 was 17th or 16th but it is the last 1924 car - important to me) lots of changes were made. The vehicle specification became standardised as of this point.

It is understood that there are only four surviving cars that meet a "loose " standard early build criteria and these are chassis numbers 4332, 4392, 4393 and 4421. Chassis number 4421 is the vehicle we are ideally basing our reverse engineering project on, being the last early car and first standard build vehicle.

The Bugatti Trust had the foresight to obtain and scan into a computer the original works drawings for the Bugatti Type 35.

The task 3D Engineers committed to was accurately converting all the drawings into a 3D format and then using pictures and anecdotal evidence design the parts that had no or simply incomplete drawings, research their origin and either obtain the parts plans from the original supplier or get an original part and use a 3D scanner to obtain the data to recreate it in a modern 3D format.

This task was complicated by the fact that some of the drawings being older photocopies scanned into a computer, were poor quality and extremely difficult to obtain accurate data from, other drawings such as those for the bodywork, carburettors were missing altogether and almost all the drawings were annotated in technical French.

In total, there were over 800 unique parts, all inter-related with each other. 3D Engineers approach was to systematically obtain all the drawings. The annotations were translated into English with considerable help from Richard Day the curator of The Bugatti Trust. We then methodically traced all the features of the drawings using a technical drawing pen to bring out the detail before converting the information into a 3D file. The files could then be translated into numerous file formats.

As the project progressed, the project leader Stuart Brown held regular meetings with the curator of the Bugatti Trust Richard Day and also Geoffrey St John, a gentleman who's knowledge of the Bugatti Type 35 is unrivalled. Hugh Conway also contributed to ensuring that the project remained on track and both his and Richard's personalities moved the project forward.

The purpose of these meetings was to ensure that we maintained the design intent of Ettore Bugatti's drawings and incorporated features that were not present in the drawings but none the less were present when the part was manufactured. For confidentiality reasons we cannot disclose the features, but the Bugatti aluminium wheel possesses features that do not appear in the drawings but appear on the finished part.

Methodically creating each individual part paid dividends, in that as the project progressed and parts became assemblies we were able to cross reference dimensions gradually building up a strong design intent and part history. Errors were eliminated and the corrections noted as dimensions open to interpretation.

Our attention to detail even extended to creating templates for the original unusual Bugatti thread types.

Once a part had been created, all relevant design information was added to the parts book.

 

For each part the book has an e drawing, references to factual information used to create the part, the material the part is made from and its original Bugatti part number.

 

Timescale and security

From start to finishing the parts, has taken over 4000 hours.

Now that the parts have been created, the next phase of the project can begin which is analyzing the design. This has proved a difficult aspect of the project, as the Bugatti Trust quite rightly do not want replicas popping up all over the place and for our part. 3D Engineers did not want all our hardwork copied by someone else for financial gain. An important part of our collaboration with the Bugatti Trust was to use our computer knowledge to ensure the design information could only be accessed for genuine reasons.

 

To this end, all pictures and animations placed on the internet have been carefully produced to ensure that key design information is invisible or disguised without ruining the visual experience for the internet user. In addition to this, the files were encrypted and are only available for use on The Bugatti Trust's computer system, thus ensuring that the design information is kept confidential.

 

The future

The ultimate goal of the project, as stated above, was to create the most accurate historical record of the Bugatti Type 35 Grand prix car. This has been achieved.

 

The main future goal is to create the Bugatti Type 35 as a virtual system and simulate in real time how the car as a whole reacts under particular loads and situations. For example, if it is run at a constant speed of 70 MPH, at an ambient temperature of 60 degrees 1000 feet above sea level in fourth gear for 1 hour, what happens? Does the water temperature get too high? Does the gearbox seize? If these things happen will a change of material solve the problem? Will a design amendment correct the problem?

Finding answers to these questions is our goal.

 

I hope this resume of the project has proved useful. Should you have any questions or if you would like us undertake a similar project for you, please contact info@3dengineers.co.uk.

For further pictures, animations and information on the project, please refer to www.bugatti-trust.co.uk.

Better still, visit their premises at Prescott Hill in Cheltenham. admission is free and the museum is superb!