Sorry to barge in an Hijack the thread, but when you say "Drawings" or "Paint" (as in MSPaint) I just can't resist...
(Something comes after the pic, and it's not another pic).
This is Mine, see if it resembles anything you know of...

Ok, Akrin, those are not bad, proportions could use some work, and try to stay away from wooden pencils when drawing (EXCEPT for when you are shading, the wider point makes shading look better, and just that much easier).
Look at some round objects with some details on them, and see how the details "morph" when moving to the rear of of a curved plain, this will help with making the cockpit windshield look better on the RAVEN (You are on the right track with it).
With it's angle, run the lowest curve of the windshield, closest to the nose, parallel to the circles edge on the nose, and you have the depth change. With that said, adjust the top curve to do the same thing. Once that is done, you've got it made for that part.
Experiment with details. I find that making my own details for mechs makes drawing them that much more enjoyable.
If you want to make your drawings have the "nice" look that my Warhammer does, draw front views and then side-veiws, and you'll eventually be able to lay down the law with angled views.
This is how I started, and with what I see in those drawings, you have a very HIGH potential to become a really really good artist. If you make a portfolio, those are good to put in to show anyone and everyone how you started drawing, and how now that you're drawings are better than even Microsofts concept artists.
Just because you saw mine, does NOT give you the right to GIVE UP, got that. Print it up if you want to. There's a few more in the MekTek art gallery (Drawings section) that you can print up if you want some other "poses" for mechs to use.
I do not want this to discourage you, too many people that I show my art to end up giving up on even stick figures, ticks me off.
And to be honest, I like how you've done those, I can't draw a Raven worth a damn, lol.