Design Report Dos and Donts, Seeking Advice

[Andrew07]

Hello all,

I have what written what I feel is a competent design report (not the whole report, just my section). However, I never really make reference to say, actual (numerical) braking torques, pressures, product names, dimensions, etc. I feel like many of these items are taken care of in the Design Spec Sheet. In some instances, though, like anticipated brake torques or brake balances, this isn't the case. However, these things are referenced in the design report and explained how they were accounted for/calculated and why they are important/how they affected design of the system. But reiterating, no actual numbers. There is only so much space in the design report for one part of the car's design. Essentially, what I have written is merely a thought process. Also no mention of FEM/SIM to verify system strength is as needed, because I feel this is an obvious step and I don't want to waste precious space. Nor do I list smaller less consequential componentry.

Am I going about this the right way or is leaving out the numbers going to hurt? Obviously this is my first time writing one of these guys.

Its pretty late so some grammatical mistakes might exist, apologies in advance.

[Andrew07]

Hello all,

I have what written what I feel is a competent design report (not the whole report, just my section). However, I never really make reference to say, actual (numerical) braking torques, pressures, product names, dimensions, etc. I feel like many of these items are taken care of in the Design Spec Sheet. In some instances, though, like anticipated brake torques or brake balances, this isn't the case. However, these things are referenced in the design report and explained how they were accounted for/calculated and why they are important/how they affected design of the system. But reiterating, no actual numbers. There is only so much space in the design report for one part of the car's design. Essentially, what I have written is merely a thought process. Also no mention of FEM/SIM to verify system strength is as needed, because I feel this is an obvious step and I don't want to waste precious space. Nor do I list smaller less consequential componentry.

Am I going about this the right way or is leaving out the numbers going to hurt? Obviously this is my first time writing one of these guys.

Its pretty late so some grammatical mistakes might exist, apologies in advance.

[Charlie]

I'm glad you asked this, Design reports without numbers tend to be pretty awful. I hate to see a page of words; that is not engineering.

As far as product names, I don't think these are necessary. the process is important, what brand software you used, is not. It is sometimes helpful to have a list of software used in the report, but I would have that as a low priority. Pet peeve: 'The intake was designed with Ricardo WAVE.' That says nothing and is a waste of space.

The Design Report is a technical report, so it should should absolutely contain numbers. However, this does not mean it is a place to simply list specifications of the vehicle. The specification sheet is meant to ensure that judges have access to certain parameters, but it does not make the design report any less technical. It still needs numbers.

If the vehicle was indeed designed in a technical way, there should be heaps of numbers that are not included in the specification sheet that help explain the design process.

A sentence explaining good design process can be lifted nearly directly from many texts. The numbers help show that the team actually followed the design process, and didn't just write down what it should be.

Bad: 'Previous vehicle data was analyzed and the engine power curve was developed to match those engine speeds'. This doesn't sufficiently explain the design process.

Better but still not good: 'Previous vehicle data was analyzed, and the full throttle engine speed range was used to develop the engine's peak and average power levels' Without numbers, it is difficult for the reader to fully understand the process and many times, those numbers are an important parameter that helps judges decide if the process makes sense.

Best: 'Previous vehicle data showed a full throttle engine speed range of 8500 - 10200 RPM for the circuit. The design goal for the engine was to maintain an average power of 70 HP over that range' This shows process and identifies the parameters developed in the process. Neither of these numbers are in the specification sheet, but they add a lot of information and credibility to the report.

This is just a very generic example and I am sure lots of holes can be shot through it, but hopefully it gets the point across. Lots of more complex design processes are even more helpful with numbers and units, and it can sometimes be more concise to explain engineering design with numbers instead of sentences.

[Andrew07]

Thanks, I thought the numbers would be asked of us at competition to see if we knew what we were talking about in the design report or not. Glad I didnt trust my intuition on this one. Looks like I have some re-writing to do. Thank you for the response.