10 inch Equipment Rack r2 (stackable, sides, handles, adjustable feet)

(Edit: I've added a picture of the 8U version as well, made by stacking the previous 4U with the existing 4U. Pardon the glue.)

This is a complete rework of my previous model which created the skeletal beginnings of a 10 inch equipment rack. Like the original, it maintains the following goals:

1. Supports replaceable hangers so that they're both easy to replace, easy to swap out (if you would like to use another style), and easy to modify if you'd prefer them longer (simply stack the 2u model to your desired length.

2. Allow reuse of existing M6 mounting bolds and cage nuts. This was a personal goal as I had a bunch spare from old rack equipment.

3. Allow printing on 3D printers with small beds. Every piece is easily printable on smaller printers. Mine was printed on my 220mm x 220mm Ender 3 V3.

While it should still be possible to use MakerBeamXLs to some degree, in order to take advantage of the stackability and handles, I would actually recommend using the included corners from here on out.

In addition to the above, the 2nd revision now has a number of new features, including:

1. Infinitely stackable (within reason, of course.) The core skeleton can be stacked to any height, and I have tested up to 16U with little issue. It was so tall that I actually ran out of cage nuts and M3 screws.

2. Vented sides are available for the design, and slot into the space left by the side supports. As such, I would recommend starting with a single 4U segment, and stacking additional 4U segments until you reach your desired height.

3. A vented top is available for the design which attaches to the same attachment points used for stacking, and the handles.

4. Handles are available for the design, and can be attached both with, and without the vented top if you so choose. The handle is split into 2 base parts (the same part, printed twice), and the handle itself so as to make it easier to install.

5. Mounting points for M8 adjustable feet and casters are available for the design. I've personally tested both straight off of Amazon, and have been very happy with the results.

6. In addition to the original 1U stiff blank, I've included a second version split in half so that 3D printers with smaller beds can print 2 at a time. 

I will note at this point that I also tested making the skeleton horizontally joinable, but this actually made things more complicated, made the hanger screws more difficult to install, and lead to small bends in face plates being emphasized throughout the structure. To compensate abandoning horizontal joining, I've made sure that the adjustable feet fall directly under the skeleton, instead of to the side. This should allow you to place multiple racks directly next to each other with little issue.

Requirements (for 4U)

(Note: If you want to increase the height to 8U, 12U, etc, simply multiply the parts you need for the sides by the number of units divided by 4. You can technically go with 2U increases, but the sides are designed for 4U increments.)

Things You Print

1. Print 2 x 4U front left/rear right corners.

2. Print 2 x 4U front right/rear left corners.

3. Print 2 x top side supports.

4. Print 2 x bottom side supports.

5. Print 4 x vented side walls.

6. Print both parts of the vented top.

7. Print 4 x universal feet mounts.

8. Print 4 x handle base parts.

9. Print 2 x handles.

10. Print 4 x 4U square hole hangers (or 8 x 2U hangers. Up to you.)

11. Print 4 x stiff blanks. For the purpose of these directions, you're assembling the rack empty. 4 stiff blanks will ensure that the rack is solid.

Things You Buy

1. 1 or 2 boxes of various M3 nuts/bolts/washer. These are very easy to find on Amazon.

2. A pack of M6 cage nuts/bolts.

3. A pack of M8 adjustable feet (or casters, if you want.)

Printing

As with the original, this build is not picky. PLA and PETG have been tested, and are both fine. You can use any layer height, but in the interest of speed, I used 0.28mm for all parts with the exception of the M8 mounting point (as it's threaded) which I printed at 0.08mm just to be careful. Also as with the original, I used almost entirely default settings, with the exception of disabling brims as using glue on your bed should more than suffice for every single piece of the design.

A note on the 2 part 1U stiff blank design. If your bed does not have even heat across the entire surface (the Ender 3 V3, for example, is hotter in the center), ensure that the thicker joining parts are placed on a part of the bed with consistent heat to avoid warping. Alternatively, you can just print the whole 1U stiff blank, but that will make it difficult to print other parts at the same time.

Assembly

For the sake of your sanity: assemble the sides first. All places a bolt will be tightened include either a partial, or complete cutout so that you don't have to worry about holding the bolt yourself. The top side support, and the adjustable feet mount specifically have a place to insert their M3 bolts ahead of time. I would strongly recommend that you do this, because doing it later will be more trouble than it's worth. Insert 2 in the adjustable feet mounts, and 2 in each of the top side supports. You can either pull them in using a screw, or push them in. I usually recommend pushing them in to avoid damaging the threads.

Assembling the sides themselves is pretty straight forward. Attach the top side support, both side wall halves, and the bottom side support to the 2 corners for that side. The end of the corner facing down should not have a bolt cutout, so that's how you know you have the correct corner. After the pieces are all attached (16 screws/washers/bolts per side), attach the 2 feet mounts for that side to the bottom (4 screws/washers/bolts per side.) After that, you can attach the hangers to the corners as well (8 screws/washers/bolts per side.)

At this point, it should be safe to install your cage nuts, and attach your blanks at the top and bottom of both sides. This will give you a reasonably stable box to work with. Attach your adjustable feet if you have them and place the skeleton on a flat surface. Leave it all reasonably loose because you're now going to assemble the top and handles.

For the top, connect both halves together (4 screws/washers/bolts) and place the top on the rack. Then attach the handle bases. You will need 2 longer screws for each base (25 or 30mm) as it will go through the handle, the slots in the top, and the top of the corners/top side supports. The top side supports will already have the nuts you inserted, so the only new nut you should have to insert is in the tops of the corners. Once the bases are all attached, go ahead and slot in the handles themselves, and insert the screws (2 screws/washers/bolts per handle.)

With that, you should now have the completed rack. Feel free to insert your own devices, rearrange the blanks to fill in spots, etc.

Please let me know if I've mislabeled/mixed up any of the model files. With so many parts it's bound to happen eventually.