This is my Newest Design.
I built the MegaTronXY X! with a 440x440x300 print area, https://www.thingiverse.com/thing:2326560 but it was to slow, Prints were great but it tock to long to print my Comic-Con items.
Then i built a 220x525 Delta, and that printer printed better then my Factory Purchased Kossel from Ebay. https://www.thingiverse.com/thing:2358415
This printer had a full 220 print bed, but it was to small to print my items.

Now i have my Newest Delta.
It is the same parts as my 220x525 Delta https://www.thingiverse.com/thing:2358415 but Larger print area.
405x305, Same height as the 220x525 printer https://www.thingiverse.com/thing:2358415
but with a small print height.It is only 3 feet tall and 2 feet wide.
But this new printer i am able to print my Comic-Con items in one print.
This new printer uses same parts as my Delta 220x525 but with a few extra items to keep the motors cooler since it will be printing a lot longer.
Since it is wider it moves side to side so had to reinforce with cross-members.
This newer printer still uses 3/4 inch square aluminum tubing with 3/4x 4foot aluminum strips to keep printer stable
also uses 3/4 inch self drilling screws to screw it together.
you will also need 24 M3x10 12 M3x16

The idea of this Larger Delta was to be able to print parts faster then my MegaTron XY X1 printer. Don't get me wrong the MegaTronXY X1 printed great parts, but it was longer print time.
i ran a time test, i used my Mega Delta any the MegaTronXY X1 and printed identical parts.
My Mega Delta only tock 6 hours to print one of my Base corners.
The MegaTronXY X1 tock 18 hours,
Same infill same everything. but the MegaTronXY X1 was to slow.
so i decided to see if i can build a Delta with the Same foot print as my MegaTronXY X1.
and this is what i came up with.

I'll be useing the same firmware i used on my Mega Delta https://www.thingiverse.com/thing:2358415 just going to change the dimensions.

Credit goes to the following people for their parts that i used on all my builds.
https://www.thingiverse.com/thing:663101
https://www.thingiverse.com/thing:27177
https://www.thingiverse.com/thing:39662
https://www.thingiverse.com/thing:154832

7-6-2017: I was having some problems with no filament coming out of extruder, so I check gap on bed, check gears, and changed hotends several times before I decided to make or remix a extruder on the Platform. so I tried several variations and came up with a print item that I modified to work with the Rostock/DELTA Platform.
so I made what is called "Experimental Extruder mount Version 2"
so I used https://www.thingiverse.com/thing:755164 and modified his specs to work with the Rostock/Delta Platform.