The 3d Printed Invisible Bookshelf

An entirely 3d printed bookshelf capable of holding 15lbs!

In this instructable, you can learn about finding studs behind drywall, 3d printing functional parts, and walk away with a cool shelf to hold ya books!

Tools needed:

• FDM 3d printer
• screw gun
• screwdriver
• bubble level (or phone with level application)
• magnets (or a stud finder)
• pencil

Supplies needed:

• 2x drywall screws 1.5-2.5 inches in length
• PLA +/ Pro Filament

Printed Parts needed:

• 1x shelf
• (optional) 1-2x drywall hangers

Open your choice of slicer that works best for you and your printer. Attached here are the .3mf and .stl files, I recommend using the .3mf if you can, as it has the slice profile ready to go. If you are going to use your own profile I recommend these base settings:

• PLA+/Pro
• 8+ walls
• brim on
• 0.28 layer height
• supports off
• Orientation: Lay the shelf on its long side. For functional prints we almost always want our layer lines to be perpendicular to the strongest force, in our case, gravity. This will keep the part stiffer and more resistant to creep over time.

If you are experiencing difficulty getting a good print or repeated failures, I must guide you to the ones who helped me: https://teachingtechyt.github.io/calibration.html#intro

Step one: Find the Stud

I have found the most reliable way to find studs, is with a medium to strong magnet. The magnet sticks to the screws that line the perimeter of drywall sheets. These screws secure the drywall sheets to the framing studs of the wall. Find the screws in the drywall, you found the studs behind the drywall.

If you are having trouble finding a stud it helps to know where they are supposed* to be. Studs are almost always 16" or 24" inches apart from each other, 1.5 inches wide, and every light switch or wall outlet should* have a stud directly to the side of it on the left or right.

Once you've found a drywall screw you should be able to find a vertical line of them, this should give you a pretty decent idea where your stud is, mark the left and right edge of the stud with a pencil.

If you are not able to find a stud or need your shelf somewhere where none exists, It is highly recommended you use some quality drywall hangers. If you don't have any on hand, I have provided some that you can print.

• drill a pilot hole for your hanger, and make sure your hole is the right size for your hanger. If using the printed ones provided (7mm or 1/4inch drill bit)
• install the drywall hanger by hand, you do not want to strip out the drywall.

Step two: mount the shelf, first screw

Place your shelf on the wall where you think you want it, use a bubble level or your phone's app, and trace a line where level is. Your first screw should now be placed somewhere on the line and in the middle of your stud.

When installing your first screw, do not worry about keeping your shelf level, as this is can be adjusted when installing the second. Instead, focus on the angle of the screw matches the shelf hole angle and be sure not to over-tighten the shelf. If you over-tighten the screw it can crush the 3d printed plastic shelf. It is better to be a quarter turn loose, than a quarter turn too tight in this case.

Step three: second screw

If you want to be extra secure your second screw can use a drywall hanger, but if you found a good stud on the first it is not necessary.

Now that you got the first screw in, your shelf should still be just loose enough to adjust to make it level.

Install your second drywall screw, and like the first be careful not to over-tighten, but in this case we are trying to avoid stripping out the drywall (or drywall hanger)

Once you are all done,

• your shelf should be tight up against your wall
• be level
• and screws facing upwards

Best practice for adding books:

Use your largest hardcover book as the base

Stack books heaviest to lightest, and largest to smallest.

Note, very large books (textbooks) will have a center of gravity beyond the edge of the invisible shelf, and will not stay on the shelf on their own. Adding smaller books on top will keep it in place but these large and heavy books will cause the shelf to sag more than a small heavy book will. be careful and use your best judgment when is too much for the shelf to handle.

Note, that the FDM-printed plastic is semifluid and very susceptible to heat. heavy loads in hot environments will cause the shelf to slowly fail over time.

My recommendation is to use smaller stacks of books and print a bunch of shelves for the best results.

Congrats, thanks for following along, and enjoy!

Attached is the Fusion 360 file, if you need to make it smaller, or bigger, or know how to make it better. Please help yourself!