I am intrigued Sadie. Did you do the designing from scratch or draw up other's ideas?
Well done you if the latter.
I have an HNC Mechanical Engineering and have physically worked in most aspects of Mechanical Engineering including hours spent filing a block of metal to one inch in each dimension so that it fitted a hole in a plate that I had also very accurately filed. I had to file each face to within one thou (one thousand of an inch). As a joke they gave me (the only girl, amonst over 250 male apprentices) the task of filing a french curve.

I also experienced time in most departments that led to my design job, so that I understood it all at base level and upwards. For instance I had to learn what a good weld looked like; the necessary currents and electrodes needed ... and strengths etc. It was very difficult welding. I eventually managed a decent weld horizontally, but above my head welding proved impossible for me. Welders are VERY skilled and not to be looked down upon. I also worked in a chemi lab, the metallury Lab, the main Research Dept.; the garage as a Grease Monkey/mechanic etc.
Perhaps my greatest challenge was working in a foundry. Here I learned all about making the molds, heating the steel and pouring the red hot moulton steel into the casts. Red hot sparks evetwhere! I learned the techniques by doing everything myself, including the pattern shop. Wow are some of the pattern makers ever skilled !! Also the testing labs, and at the same time, the capabilities and weaknesses of castings in design. Obviously I also learned about getting on with others of all backgrounds
This ability to appreciate and get along with all types from Labourer to Managing Director was the best lesson that I ever learned. I really appreciated the characters at the foundry, generally rough and ready but really nice guys.
Upon completion of my apprenticeship I was lucky and was placed in one of the two senior design drawing offices, and I loved it.
I generally worked as part of a design team.
Only on one project was I leader and I had no-one working specifically for me, except a stronger Mathematian than I, who helped with calculations and also had some drawing up of details by others, along with a tracer who transfered my pencil drawings in to permanent ink drawings (on waxed linen, I think). In the next department was our development team who actually made prototypes full size to our designs. Because of my knowledge and training they never questioned me. They knew that I knew as much, in some cases more, than they did.
I am no Bell or Edison or Leonardo. They were geniuses. But I was a young keen Design Engineer, still learning, who worked with greater precision and integrity than some.
Few design engineers do much "pure design" of the Edison, Leonardo type, but develop and extend others ideas. The history of the motorcar is a fine example. It didn't start off as an air condioned, air tight, comfy vehicle with pneumatic tyres, top speed of 100mph etc. but stage by stage it was developed by design engineers
Because of pregnancy I left this much loved job, which I was still not a senior in .. and then with children the hours were impossile .. and the engineering business was folding. We worked 40 hour+ weeks in those days with two or three weeks holiday per year, including bank holidays. I was not a modern mother; I wanted to be with my children as youngsters, rather than farm them out
I am very proud because I was not only the first pioneer woman engineer trained via a Nationally approved apprenticeship, BUT also three guys in the office had tried to do my sole single, hydraulically based, engineering design and had failed.
And more important to me, my design was very successful and probably is still being used 50 years on. Also my very good Design Office boss bought the plans/ rights (not sure what you call them) and they provided a lucrative income for him for the next 30-40 years. Am so pleased about that.
Crikey, have I gone on. Apologies.
MODS: May I suggest that this post is left up for a few days and then along with Sunnys post that prompted it, taken down. TY. If you leave Sunnys post or any others of a similar ilk, on here, then please leave this post in response.