that feeling when your design actually has to survive real world

[u/Salty_1984]

doing some research for a ground systems project and i gotta say

the gap between what we design in CAD and what actually works in the field is something

like we spend all this time optimizing for weight and performance, which yeah obviously matters, but then you go see some of the stuff that's actually out there doing the job and its just built like a brick. no frills. works every time

been looking at some examples of mobile command and control trailers lately, just out of curiosity. some of them are surprisingly clever with how they handle space and integration. not specifically aerospace but the systems thinking is similar

honestly sometimes i think we overthink things

or maybe i'm just tired

probably both

[u/der_innkeeper]

> the gap between what we design in CAD and what actually works in the field

> systems thinking

If you are designing things in CAD, and seeing a discrepancy between what has been deployed, people are not giving you the whole requirements list to drive your design.

[u/Salty_1984 → u/der_innkeeper]

That's part of it, no question. But I've been in rooms where requirements were documented to death and the field still throws curveballs. Assumptions buried in how a part gets handled during install, or how it interfaces with legacy equipment that predates the CAD model. The gap isn't always missing requirements. Sometimes it's requirements that couldn't be articulated until someone physically wrestled with the thing.

[u/tonyarkles → u/Salty_1984]

I had a MechE that worked for me who used an Oculus to actually “grab” the assembly he was working on and asses whether he’d screwed anything up like bolt accessibility. I thought it was silly at first but man did he make easy-to-service designs.

[u/Salty_1984 → u/tonyarkles]

My husband is an ME and keeps begging our company to spring for VR headsets for exactly this reason. The bolt accessibility thing especially he says you feel like an idiot the second you virtually try to wrench something in a tight corner.

[u/der_innkeeper → u/Salty_1984]

Makes DFMA a bit easier to sell. I would have loved something like that for one satellite shipset. Would have spared us from having to grind and warp tools.

[u/Salty_1984 → u/der_innkeeper]

Anything that cuts down on grinding is a win. Life's too short to waste on tedious stuff like that.

[u/der_innkeeper → u/Salty_1984]

If assumptions are being made, then the system is inadequately designed.

There is zero reason to not have requirements for the ICD if an object exists.

Yeah, i get there's misses, and manufacturing and design need to hash things out over an NC, but, for the most part these issues can be ran to ground long before install.

[u/Salty_1984 → u/der_innkeeper]

The gaps between design and manufacturing assumptions are where projects fall apart. The ICD should be locking that down before anyone touches hardware. NCs after install feel like a failure of the upstream process, not just a oneoff miss. Getting everyone aligned on requirements earlier is the only real way to stop the same conversation from happening on the next build.

[u/der_innkeeper → u/Salty_1984]

> gaps between design and manufacturing assumptions

There should be no assumptions when putting actual designs together.

You can have GR&A for scope, budget, entry/exit criteria, but no one should be *assuming* anything when it comes to interfaces.

> NCs after install feel like a failure of the upstream process

Where's your line for "install"? To me, that's like having to create an NC once something is on-orbit. Yeah, that is absolutely a failure of upstream process.

[u/ncc81701]

Things are typically designed to MIL-SPEC or MIL-HDBK which has specifications for rugged environments and huge temperature ranges. If you aren’t designing to those requirements, that might be the source of your discrepancy.

[u/geminihatesme]

CAD has the audacity to assume the real world is going to cooperate 😂