Drop-in GPU Bracket Assembly
Remove all of the brackets and drive cages from the front of the Rosewill L4500 case.
Replace or re-install the case fans so they are oriented to exhaust/push air out of the front of the case.
Insert M3x35mm bolts, two washers and hex nuts through the fan mounting brackets.
Attach the fan posts to the fan beams using a M3x25mm bolt and washer (at the top hole) and a M3x14mm bolt in the bottom hole.
Repeat for left-side post and beams.
Insert the hex nuts of the fan cage bolts into the slots of the fan beams.
Attach small angle brackets to the fan posts using a M3x6mm bolt and hex nut.
Attach a large angle to the bottoms of the fan posts using a M3x10mm bolt, washer and hex nut.
Join a side beam and side post via a small angle bracket, M3x6mm bolts, washers and hex nuts.
Note how the milled-out area in the center of the side beam is facing upward.
Fasten two large angles to the front beam using M3x10mm bolts, washers and hex nuts.
Attach the post and beam sub-assemblies to the front beam with m3x10mm bolts, washers and hex nuts.
Insert the bracket into the case and slide the post and beam sub-assemblies to the sides of the case. Re-tighten all bolts.
Note: the front beam should be pressed against the protrusions that poke up from the bottom of the case.
Fasten the side posts to the sides of the case using flat head M3x20mm bolts, washers and hex nuts.
Insert the fan support sub-assembly into the case and expand the beams and posts toward the sides of the case, all the while aligning the fan brackets with the front opening. Tighten all bolts.
Fasten the fan sub-assembly to the base by inserting a hex nut into the top slot of the side beams (via the milled-out area), pushing the nut underneath the large angle bracket and attaching it using a M3x10mm bolt and washer.
Insert 7 M4 hex nuts into the slot of the milled GPU support beam. Fasten the beam (the milled side should face toward the inside of the case) to the small angle brackets using M3x12mm bolts (the support beam has a 3mm threaded hole).
Insert seven t-slot nuts into each riser support beam.
Loosely attach the riser supports beams to the base using M3x6 bolts and hex nuts (inserted via the milled-out areas)..
Attaching the risers to the beams using two M3x10mm bolts at opposite corners of the board. For a seven card rig, the boards should be space 15mm apart.
Adjust the placement of the riser beams (front-to-back) by test fitting with a GPU. Tighten the riser support beams to the base!
The GPUs are bolted to the bracket via M4x5mm bolts (Phillips head).