Hi there,
This is Bogdan from Romania.
I'm a mechanical engineer - specialized in the industrial robotic field, 3D designer and modeler (from time to time and some projects I could make the functional prototype too).
I'm doing product design, industrial design, reverse engineering, ideation, etc.
I have over 15 years experience working on various systems/devices across multiple industries, from concept to launch.
1 - the foldable rack for weight lifting could be made simpler than the model shown - that one looks complex most probably due to the profiles used (maybe some existing profiles detoured for this purpose)
2 - even with the minimum welding design, you will still need the laser/waterjet cutting, bending and electrostatic painting... (in order to make an astonishing rack :) )
3 - my advice - the poles to have a wheel/caster - after a while of using the equipment, it will get deformed and the bottom end of the poles will be scratching the floor
4 - also there should be a system/device for locking the poles into the position
Regards
Bogdan