The relationship of a mechanical engineer with electricity

[rfranceschetti]

Hi all,

I have in mind that an engineering project tends to be quite "integrated", as in, it envolves different engineers. So, for instance, in order to build an aircraft, you need not only a mechanical engineer, but also an EE, Materials, managers, etc etc. So lots of teamwork.

However, I'd like to know how much of "electricity" a mechanical engineer handles in their job routine, i.e., if they have to know about electronics, circuits and whatnot, or they basically just project the mechanical part of the system and then leave for the EE to do the electronics. I assume these different engineers are always in touch with each other, but I was wondering how much of electronics a mechanical engineer actually knows (if any).

Thank you.

 

[bishop27]

If you are talking about airplane mechanic I guess there should be not much. I think they only have to see if there are disconnected or worn out wires. They are more concerned with the gears, hydraulics, some other visible and moving parts staff. Aeronautics Engineer on the other hand should be able to handle all. But there could be specializations in the electronics, electrical, mechanical, etc...

 

[Tom.G]

As a retired Electronics Eng. I would say that a rudimentary knowledge of the fields that touch your project is very helpful. An example is one electronic device where the customer insisted on some plastic mechanical parts guaranteed to last 100 years. We went around and around on that until It was pointed out that the very first plastic (Bakelite) was invented only 88 years earlier; therefore there was no solid proof for a 100 year life of any plastic! Another instance was the somewhat complex packaging/assembly design for some military equipment. The mechanical draftsman that was assigned was unable to manage a tolerance stack-up situation of nine items required to hold the thing together. Here I was, a 23 year old Electronic technician spending an afternoon in the mechanical drafting department doing his job of a worst case analysis (admittedly a simple part of it though.)

Overall, a passing knowledge of adjacent fields leads to a more varied work life and to being a more valued employee. Be curious and enjoy!

 

[rfranceschetti]

Hey, thank you guys for the answers.

I wonder because I see mechanical engineers specialising in mechatronics, but wouldn't that require a reasonable knowledge of electronics?

 

[S.G. Janssens]

This is an interesting topic.

As a non-engineer I cannot comment on job practice, but perhaps you find the subject of analogies between mechanical and electrical systems interesting. In addition to the references there, you may also find Olson's 1943 "Dynamical Analogies" worthwhile looking into.

 

[xxChrisxx]

Depends what state the project is in. About 100,000 volts usually.

 

[Bandit127]

A mechanical engineer with an appreciation of electrical and electronics engineering will be able to find the electrical or electronics engineer who knows what the mechanical engineer doesn't know. The mechanical engineer will also be able to accurately communicate the job in hand. The job then gets done...

A mechanical engineer who is constrained to his mechanical discipline will be less flexible and, in my experience, less likely to be able to lead the team that gets the job done.

A mechanical engineer who lives in a vacuum of pure mechanical engineering is outside my experience.

 

[Dr.D]

I have spent a lot of my working life learning more about electrical and magnetic systems, far more than I learned in college. If I were starting again (thank goodness, I'm not!), I'd definitely learn more of it in college. Almost every mechanical system you will ever see is driven either by electric, diesel, steam, or air power. You need to know something about what makes things move.

 

[rfranceschetti]

@Dr.D If you could, would you go back and switch your major to EE? (I'm assuming you're an ME).

 

[Dr.D]

I am definitely an ME, and no, I would not switch to EE. I would, however take a lot more EE courses than I did. I only had one circuits course (really, just an ODE course), and a course that combined fields and vacuum tubes (it was that far back in time!). In particular, I would have taken more fields and a machines course. Those are the topics I've had to learn on the side, and they have not come easy.

 

[rfranceschetti]

I am definitely an ME, and no, I would not switch to EE. I would, however take a lot more EE courses than I did. I only had one circuits course (really, just an ODE course), and a course that combined fields and vacuum tubes (it was that far back in time!). In particular, I would have taken more fields and a machines course. Those are the topics I've had to learn on the side, and they have not come easy.

I see. I would like to seize the moment to clarify some doubts, if that's okay?
I'm starting engineering next year, but I haven't quite made up my mind on what branch. I'm much more inclined in taste to study Mechanical, but I feel that technological progress is really happening in electronics and computers (I'm putting aside more scientific areas like quantum computing, etc.). Surely mechanical engineering has a lot to offer, but isn't it a bit "behind" in terms of innovation compared to EE? Could you give me your thoughts on this subject, and potentially tell me about your career experience (if that's ok)?

Thanks.

 

[rfranceschetti]

By the way, I might be saying really rubbish things here. It's a complete lame person point of view.

 

[Dr.D]

Well, the basic rule is "To each his own." Do what ever it is that excites you, and do not worry about being "on the cutting edge," or any other such foolishness.

In my own case, I have always been fascinated with things that move, and with describing motion. When I took my first freshman physics class in Mechanics, I said, "wow! This is it! This is what I want to do, and I still feel that way today." I could hardly care less if someone considers me "backward" or "behind the times." It is motion that I enjoy, and quantum computing leaves me utterly cold.

As I suggested in a previous response, I had to learn more about electrical machines because so many systems are actually electromechanical. Electric motors drive a vast array of machinery, and if you want to fully describe the motion of those machines, you need to know not only the mechanical dynamics but also the electrical side. I have found very few people who were good at both. I've talked to a lot of EEs who thought that they knew mechanical systems, but most of them were really pretty poor at it. The most common thinking flaw comes from much work in circuits where all that really matters is the relative voltage between two points. When they shift over to mechanical systems, they want to define the position of a mass as relative to some "ground level." That is a recipe for disaster in many, many mechanical systems.

On the other hand, there are very few MEs that know much about electrical matters. At one point in my career, I worked for a large company that build engine driven generator sets in all sizes. One of the products we were building at the time were standby power sets for nuclear power plants. The idea is that if an earthquake or similar even causes the nuke plant to loose power, the standby sets must power up, start generating, and provide power for the core cooling pumps. This all has to happen typically in about 15 seconds from the initial alarm.

One Thanksgiving holiday, while I and my family were eating turkey and dressing, one of our nuke standby sets was failing an acceptance test. It started, but when the load was applied, the engine faltered and died. Not good. Monday morning, I had the assignment to develop a comprehensive simulation for the engine-generator, along with the distribution and pump motor and pump. I had to learn about motors and generators in a big way very fast, but it was really intriguing, and I would do it all again today.

To my mind, that is where the real value of engineering lies, in doing things that enable others to do what they need to do, in this case, build and bring on line that nuke plant. I can see that, I can readily imagine what that accomplishes. Maybe I'm just old, but the new stuff is just to ethereal for me; I've never even seen an electron! When the lights of a city go on, I know what we have done. When a bunch of quantum jump, I don't see a thing. But, as I said in the beginning, To Each His Own. Run with it!

 

[rfranceschetti]

Thanks for the thoughtful answer, Dr.D. It's really helpful. Mechanics is my favourite subject in high school physics, while electrodynamics is not. So that's a big warning already, I believe.

 

[Dr.D]

I should add one other item. If you want to discuss this further, please send me a private message through the PF message system and we can discuss whatever you want.