Hey,

I had a disassembled drawer lying around and thought, why not use it for a quick project? 
I wasn't happy with the footrest I bought previously, so with a plank from the drawer and about 10 minutes of CAD work, I came up with this.

With just four legs, you can transform any scrap wood  into a mini footrest (or even a small table if you're extraordinary small).
 

I recommend designing your own legs to perfectly match the height you need!
I’ve provided a tutorial below for those new to CAD. It’s also a very simple project if you want to get started with CAD.
 

Feel free to like, comment and/or add a make if you want to support my projects :)

Printing:

I printed the legs with these settings:

• 0.4 mm nozzle
• PETG (less brittle and therefore more durable than PLA)
• Supports: Disabled
• 0.28 mm layer height
• 20% infill

It's a very simple print, and your default PETG or PLA profile should work just fine. If you want to make the legs stronger, consider increasing the infill or wall count.
 

Parts List:

• One scrap piece of wood
• 4 printed legs
• 12 wood screws (M4)
• (Optional) Some piece of felt or dampener to prevent scratches on the floor

Assembly:

It's pretty self-explanatory.

1. Mark the places where you want to attach the legs, Try to make the arrangement  as symmetrical as possible.
2. Screw on the legs. The legs should be angled outward from the center of the plank (refer to the pictures).

Design your own  Legs:
 

Here’s a quick tutorial on how to design your own legs if you're new to CAD modeling. 

1. Determine the Height:

First, decide on the height you want your footrest to be. Sit on your chair and use some books or other spacers to find a height that feels comfortable for you. With my previous footrest, my office chair couldn't get close enough because the rollers would interfere with the footrest. Make sure to take this into consideration when choosing the height.

2. Model the base:

This is the base sketch for creating the leg shape. It consists of one rectangle and a trapezoid. All horizontal lines are 30mm.

Simply adjust the height (125mm) to match your preferred height from step 1. It may also make sense to adjust the angle if you change the height significantly. A wider angle will make the footrest more stable, but it will also put more stress on the parts under load. I chose an arbitrary angle of 16 degrees.

It’s important that the bottom of the rectangle is centered on the origin (15mm to the left and right). Later, a polar pattern will be used to create the flanges for the screws. having the bottom face centered will make things much easier.
 

You can modify any dimensions as you wish. Making the legs thicker will create a more stable footrest, while making them thinner will reduce print time and the amount of material used.

3. Pad the Base Sketch:

Pad this sketch by 30mm (or whatever width you chose in step 2). It’s important to pad symmetrically relative to the plane to keep the origin at the center of the bottom face, which will be useful for the polar pattern.

4. Add the flange

Select the bottom face and create a new sketch. Draw a rectangle that extends 15mm outward (green rectangle).

Pad this sketch by 5mm.

To add more strength, create a chamfer as shown in the picture. I made it as large as possible (9.99mm).

Select the bottom face and create a new sketch. Add a circle at the center with a diameter of 4mm. This will serve as the bore for the screw. If you're using a different screw, be sure to adjust the diameter accordingly, for example, an M5 screw requires a diameter of 5mm.

Use the pocket tool to create the through hole  from the sketch. Make the hole deep enough to remove all material, but avoid making it go through all, as this could cause problems later (hole will be present in the leg after the polar pattern due to the angle of the leg).
 

Select the face highlighted in the picture and create another sketch. Draw a circle at the same position as the through hole, making it slightly wider in diameter than your screw head (I used 8mm for my screws 7mm screws).

Since wood screws are often chamfered, you can add a chamfer as well (as shown in the picture).

5 Add a polar pattern

First, check if your origin is centered on the bottom face. If it isn't, you will need to modify your initial sketch (step 2) or the pad (Step3).

Now you can create a polar pattern (it may be called something different in your CAD software, just google for "polar pattern" along with your software name).

Choose 360° for the polar pattern and set the number of occurrences to 4. Select all the features of the flanges. The result should resemble the picture on the left.

6 Make it printable on the side

Technically, the leg is finished now, but there are two issues to consider:

I wouldn’t recommend printing the leg upright, as the print is weakest along the layer lines. Printing the legs standing vertically increases the likelihood of them snapping off.

You won’t be able to access one screw hole because are tilted in an angle 

To address both issues, we will remove one flange to enable the footrest to be printed on its side. Select the face that is tilted inward and create a rectangle that spans the entire flange. Then, use the pocket tool to remove that flange. You will now have a flat surface on which to print the leg.

7 Add some side covers.

Not really necessary but I added some side covers to make the plank look better.

It's very simple. Just measure your plank and create a sketch with those dimension.
Pad the sketch with a few mm and hit print.

I put mine on with some double sided tape.