This is a small version of the bench press with free weights and barbell, a weight holder for all of the plates, and a bench press which has to be assembled with two pieces. All of these models fit in a 10x10x10cm box and can fit in many places due to its small size. 

Directions 

In order to have the full set, you have to print:

Bench Press Seat

Metal Part of the Bench Press

All of the plates going from 45 to 10 lbs.

The bar

The bench press is easily assembled by putting the seat and its square shaped parts into the slightly bigger holes on the metal part of the bench press. It may take a little force to put them together since I wanted the Bench Press to stay in one strong piece.

The Plates

(I traced off of a real image since it would look better and smoother.)

(Repeat the steps for each without the numbers. I added them in later with pictures from google to trace so they would look good.)

I Boss Extruded the details with different numbers since cut extruding wouldn't work.

I then boss extruded, cut, and then boss extruded again without mixing the mesh so they would have separate colors while being in the same level. The printing process went smoothly after.

I had to print them separately with one color each since the printer wouldn't work efficiently so I made files for each plate, linear patterned them (duplicate), and colored them together. Here are the colored versions for each plate - 

Red / 45 lbs plates

Blue / 25 lbs plates

Yellow / 15 lbs plates

Green / 10 lbs plates

UPDATE  - I had to duplicate them in size while printing since they were too small while printing.

The bar

I cut the bar into two halves since revolved cut only works with one half of the bar.

I picked the color grey for the bar since it matches the real version the best.

Bench Press (Two Parts)

Bench Press Seat

I Filleted all sides to make them smooth.

Square parts so it can connect with the bench press.

Metal Part of Bench Press

Offset and deleted the center

Holes for the seat

Holder for the Bar - I sketched a rectangle onto the placement, extruded it out, made a triangle which left some space on the left side of the holder, and extruded cut. I then sketched another rectangle onto the holders which I extruded so the bar doesn't fall off.

I chose a grayish black color to make it seem like metal.

UPDATE - I deleted the bottom bar holder since it would make the top one print more difficultly and since it wasn't practical.

Weight Holder (Not many pictures for this)

Step 1 - Sketch out a flipped V shape

Step 2 - Offset them out and delete the lines in the center

Step 3 - Fillet the top and bottom part seen on the picture

Step 4 - Boss Extrude out

Step 5 - Sketch circles onto the flat part and extrude until it looks like the picture.

The model should look like this. I chose the color black.