An engineer mods Porsche 911
 

Here is a mechanical engineer who explains his chassis mods simply, executes them himself, and then measures their effects.

Here he is seam welding and measuring the effect A/B:
https://m.youtube.com/watch?v=RfDPUD-RhMM

Here he is describing other chassis mods:
https://m.youtube.com/watch?v=T0bOIdr1sTA

He should get more attention on the YouTube.

Is it misleading to say you are an engineer if you've never had an engineering job, but have a degree?

No, but it would be if he claimed professional specialty experience or employment he does not have. He said he was never employed in mechanical engineering? I didn't notice.

You find some fault with his measurements of the 911's chassis stiffness?

No. I graduate in December and wanted to know if I could call myself an engineer even though I haven't had a engineering postition yet. :D

When they do give you your degree, take your feet clear off the ground or load up barbell weights. Otherwise is to put your thumb on the scales.

The 1920s Briggs & Stratton Buckboard Flyer had solid axles and all chassis flex.

I was thinking the same thing. Weighting it not using yourself shouldn't have been too hard. Then you could wait out the oscillations and get a more accurate deflection.

To be fair, he apologizes profusely.

How many significant digits is an apology worth? :D

Aww! Everybody so hard on the poor diy guy. He said he took his feet off the floor! C'mon give the dude a break... what ecomodder is suddenly the height of precision?!. :)

Congrats (a little premature) on your degree, M_a_t_t !

I dunno, there's all sorts of hair splitting over in Aerodynamics

I was pleased to see detante breaking out recently.

It runs hot and cold.

Cold War never much better than the hot war for the non-aligned countries.

A licensed engineer, even though may not have actual business experience, is still an engineer.

I was just getting lost in the youtubes and stumbled on this video. Didn't think it was good enough for its own thread and it has relevance here. Haven't watched any of the other videos in this series yet.

https://www.youtube.com/watch?v=G-p4...nicaldesign101

A lesson of the video might be that the Tesla truck might have a lot more rigidity than an F150, assuming its odd look is because it is a true "space frame" rather than a ladder frame.

My reading of the structure is four moncoque boxes at the corners with a Vierendeel truss on each side.

'A lot' could be an order of magnitude.

Frame difference also, the F150 still has some frame rails

IIRC the triangulation gives the most accurate clue about the rigidity of some structures, including vehicle frames. No wonder the Cybertruck has such odd bodystyle.

I've seen a lot of structural modifications done to old Porsche 911's, but never some of the things he is doing. I say BRAVO, good work.

The one issue I didn't see him address is the weak spot in most cars, where the large holes in the side of the car are - called doors. Even more flex is Targa and Convertibles with no top to arch over the doors and complete a box shape.

Normally in so-called full roll cage these issues are addressed.

Falling just short of a full roll cage are rocker panel reinforcements that are often triangular in shape from foot-well zone going upward to middle part of B-pillar.

When a car "folds in half" it is the area around the doors that "give it up" and allow the occupants to be crushed. Stiffing this area stiffens the chassis considerable but comes at the cost of ease of entry and exit.

I can only guess that the author of the videos knows this and is doing modifications that allow a stock look.

Reminds me of the BMW i8 with its quite high door sills. Not so hard to slide inside, a PITA to get out.

Toward the end of the second video, he mentioned he would be adding the back half of the roll cage. That implies that the front half is either in there already, or is at least planned.

The most effective cages serve as space-frames and go to the suspension pickup points, holding them in place relative to the rest of the car. Some rule sets prohibit that, or limit the number of attachment points, so that is not always done. (There may be other, e.g. aesthetic, considerations as well.)



Does the Cybertruck have a space frame? That almost always refers specifically to a structure made of some sort of tubing, consisting of mostly triangles for strength, with lots of space in between them. I would have thought that the Cybertruck had a unibody or possibly monocoque construction.

Yeah... A quick Google search shows Musk talking up the "exoskeleton", which looks more like a monocoque or semi-monocoque than a space frame.

Oops, looks like I may have slipped back toward hair-splitting. Sorry!

-soD

My understanding is that the four wheelwells have the thicker material on the inner wall as well, making four monocoque boxes. The triangular truss has vertical componenets. That's a Vierendeel truss

Here's an ontopic Porsche hybrid moncoque/space frame.

https://ecomodder.com/forum/member-f...11-w07fie3.jpg

A space-frame doesn't need to be always a tube-frame.