Could it be, because it's more cost effective to design and build.
The simple thing as the quic loq has taken years before it has made any money due to the high costs involved in the making/designing of it. Could this be why the crane works because its easier to manufacture.
Also why ask if we know any manufacturers to help, it sounds like your making the same mistakes again.
Make your prototype, test it, refine it and when you have a working refined prototype get a patent and then search out your manufacturer.
All the best and I hope this works for you and then you can stop posting the rubbish that you have 👍
