Thanks for your new and revised logo designs!
Please see my "brief update" comments, that I just posted on the site.
#50 is cool-looking, and an improvement on #7. I like your idea to have the $ signs interacting with the gears... but is there a way to make it look more animated? Can you make it look like the $ signs are getting bigger, and/or are being created by the gears? Or, can you use something other than gears to produce or create the $ signs?
#51 is really great! It's the favorite design, out of all of the other logos, from the feedback my friends are giving me. I really like it too! There are so many things that it makes in its statement... like how the engineering is the foundation, and the $ (and the rest) is built on top of it. And, the little crane is in there, as a finishing touch, building the big $ sign - just in case people don't catch the other subtle references to engineering. I love the gradient (if that's the right word) used in the blue section, which looks a bit like a city skyline, and also like a stock chart too. Very good!
I'd love to see some revised versions of this design. One comment I have is to try to make the $ sign pop out a bit more, to the eye. Not sure how you might do this, but see what you can do. Also, can you make the blue blocks higher on the right side? If it's going to remind people of a stock chart, then I'd like it to be in an "uptrend". It doesn't have to go straight up, of course, but for it to be highest on the right side might help. And, although I agree with the scale you've used for the crane on top, can you make it a bit bigger? It's just because it might be hard to see, when the logo is shrunk down onto a business card. (And, some people don't have very good eyes.)
A few other thoughts are to consider using gold and /or silver in there. But, you don't have to. Just some options. And, maybe you could make it a bit 3D-ish... just so it pops out a bit... (although that might change the effect it has... and the detail could get lost when it's shrunk onto a business card...). Well, there's a lot you can play with here, and it has a lot of potential!
I'm really excited to see your revisions! (I might have to try to extend the contest, to give you more time!)
Any other, different, unique concepts?