This is a mechanical cake stand I made for a friend’s birthday. As you turn the crank, the entire cake rotates and one of the slices lifts up and out. The cake can rotate a full 360 degrees.
 

You will want a 10” cake base (cake pad? cake board? cardboard circle thing?) under your cake to protect the screw heads from coming in contact with any frosting. Your guests will appreciate it. You will need to cut a slice out of the cake base as well. Secure the base down with double stick tape or vhb or similar – especially on the cake lift – to help prevent a tumble. Particularly tall cakes may have stability issues.

There’s an included slice marker to help cut the correct-sized slice from the cake. I suggest including a tiny amount of draft angle in your cut to help operation.

I printed this in PETG, using copper, gray, and white filament. All parts were printed with three perimeters and 20% infill. Many parts will need support material - All are oriented how I printed them out. Parts that print flat without support should be obvious.

This project is something of a moderate to advanced build. I’ve included a full assembly for reference - you should not print the completed model, only the individual parts. Files that need to be printed in multiples are prefixed with a number, e.g. 6xLeg.stl

In addition to the printed parts, you’ll need quite a bit of hardware. The project uses a wide assortment of M3 screws in various head profiles, both regular hex and nyloc nuts, and a total of nine skateboard bearings. Most of the holes in the legs and handle support will need to be tapped prior to assembly. Don’t over tighten screws that are threaded into plastic, and avoid repeated installation/removal.

Here is a complete hardware list, presented roughly in order of assembly:

For the Turntable:

19x M3x12mm countersunk screws to assemble deck and large gear

2x M3x20mm countersunk screws to hold center of slider rail

16x M3 nyloc nuts for most screws

16x M3 washers under each nyloc

5x M3 hex nuts for screws in the slider rail

For the Input Handle:

1x 608 skateboard bearing

1x M3x8 countersunk screw to attach bearing retainer

2x M3x12mm socket caps to attach the upper support to the upper frame ring

3x M3x8mm button head screws to attach the lower support to the upper support

2x M3x6 socket caps (or button heads) to attach to the lower support to the lower frame ring

1x M3x12 button head to attach crank handle

1x M3x10mm button head to attach handle arm

1x M318 button head to attach crank gear

The various printed axles for the handle should be pressed together using a vise or a clamp.

For the Frame:

Legs and Frame Rings:

6x 608 skateboard bearings

6x M3x10 countersunk screws to reinforce bearing posts (these don’t retain anything, just add a bit of strength)

24x M3x8 countersunk screws to attach upper frame ring

12x M3x16 socket cap screws to attach lower frame ring and feet

Installing the turntable should be done just before attaching the final upper frame ring part. You should be able to squeeze the last screw between two of the teeth.

Offset Ring:

1x 608 skateboard bearing

12x M3x10 button head screws to attach offset ring

12x M3 nut

The bearing in the lower frame ring is positioned opposite the crank handle. The cake lift is lowered when it is nearest the handle and fully raised when furthest away.

For the Slider Crank:

1x 608 skateboard bearing

2x M3x10mm countersunk to attach bearing retainer

2x M3x20mm countersunk screws to attach crank connectors to crank arm

2x M3 hex nuts in arm

Add a small bit of grease to the slider and rail. I applied vaseline using a cotton swab.

For the Slice Lift:

2x M3x18 button head to attach long links to slider and lift subframe

2x M3x10 button head to attach center link to lift subframe and lift cradle

1x M3x35 button head to attach outer links to lift subframe

2x M3x12 button head to attach outer links to lift cradle

3x M3x16 countersunk to attach center of lift deck to lift subframe

14x M3 nyloc nuts

4x M3 washers - under nyocs for the outer links at the lift cradle, and also under rear nylocs attaching lift deck

Button head screws are important for clearance on the linkage screws. If you use socket caps, they may collide with the deck during operation. Space is tight. Don’t use washers between the links.

All links need to be able to rotate, so tighten screws snugly then loosen a quarter turn or so.