Starting my 4x8 frame build, couple questions

[f_armer]

So I am starting my frame, I've got all my pieces cut. I'm using 3x3x 3/16 wall, probably a bit overkill on wall thickness.
The long bottom braces says maintain 21" between those and the top rails. Is there an advantage to having more room there? Just wondering?
I presume the center legs should be just centered between the outer legs, centered on the 103" tubes, not centered on the 111" ones for any reason?
Do you recommend leveling feet? I have a fairly level floor in the shop, I was thinking of using shims, if needed, to level it. Is that ok?
The water tray says it can be 106" to 109". Is there an advantage to be 106 or 109? I have a 5x10 sheet of 12g, I can go 109" but is there any advantage to be at 106" Or what is the reason for having the 3" variance?
I just don't want to get it all welded up and find out it would have been better if i had changed something.
Thanks
Don

[jeepsr4ever]

Did you get everything answered?

[f_armer]

Yes, I think so. Frame is all welded up and ready for the gantry kit.
I'm making the water tray 54x106 as per your advice.
I guess I should paint the frame while i'm waiting for the stuff. Not sure what color just yet.

[jeepsr4ever]

We use safety blue but primary colors look great! I have seen customers go green, red, yellow, flames and zinc.

[f_armer]

Frame is done. Hope the pic works.

[jeepsr4ever]

Frame looks like we built it here! Great job!

[f_armer]

Frame looks like we built it here! Great job!

Wrong color though! I had a quart of black handy so thats what I used. Most stuff in the shop is black or red, so it goes with my "theme".

[f_armer]

Got my water tray ready to go. just have to weld in a drain pipe. Is one 1-1/2" enough? Or what do you guys usually put in?
The local Hutterite Colony has a cnc press brake, they did a perfect job, and only charged me $30

[jeepsr4ever]

1-1/2 is good and will work well enough. Thats a beautiful pan!

[f_armer]

Well if one 1-1/2" is good then two must be better! I had a 1-1/2" pipe nipple that I cut the end off, but I still had the other end so I used them both.