NYT Frozen · sets · due Sat 07-Nov

Frozen Rolling Bases

Four 2' × 3' rolling bases. A 2x4 box on edge, a 1/2" plywood top, a flat 2x4 block across each corner, and a 3" caster on each block.

4bases, identical
72x4x8 boards
14x8 sheet, 1/2" ply
163" plate casters
~2"frame off the floor
~6"deck height

What it looks like upside down, illustration

One base upside down: 2x4 frame on edge, plywood underneath, a block across each corner with a swivel caster on it

For the look only. The real blocks are a flat 2x4, 1-1/2" thick, so they sit lower in the box than drawn here, about 2" below the frame edge. Measure from the drawings below.

Bottom view one base, flipped over, to scale

36" 24" 21" 5-1/2" Dashed circle = the space a 3" caster sweeps when it swivels. It stays clear of the frame.

Each block's short edge faces the corner and meets each frame side 5-1/2" from the inside corner. The two blocks on a 21" side end about 1/8" apart, so they don't touch.

Corner block 16 needed, 2x4 laid flat, to scale

caster plate 7-3/4" short point (toward the corner) 14-3/4" long point 3-1/2" 45° 45° The two 45° cuts lean in toward each other. The caster goes dead center.
A 3" plate is about 3-1/8" × 4-1/8", so it fits on the 3-1/2" face with about 3/16" to spare on each side. That's why the blocks lie flat.

Side view heights, with a 3" caster

floor block (behind frame) ~6" ~2" 3-1/2" 1-1/2" 1/2" plywood

The caster mounts 1-1/2" below the plywood. A typical 3" plate caster is 4" to 4-1/8" tall, so the frame clears the floor by about 2" and the deck sits about 6" up. A 4" caster (about 5-1/8" tall) would give about 3".

Cut list

PartSizePer baseTotal
Long side, 2x4 on edge36"28
Short side, 2x4 on edge21"28
Corner block, 2x4 flat, 45° both ends14-3/4" long point416
Top, 1/2" plywood24" × 36"14
3" swivel plate caster 416

Board layout how the cuts come out of the stock, to scale

Boards 1–4 (each) 36" 36" 21" ~2-1/2" left over Board 5 21" 21" 21" 21" ~11-1/2" left over Boards 6 & 7 (each): 8 blocks, flip every other one Uses about 95" of the 96". Start from a clean square end. Plywood sheet, 48" × 96" (scale halved) 24×36 24×36 24×36 24×36 2 × 24×24 left over Rip the sheet at 24" first, then crosscut each half at 36" and 72".
Boards 6 and 7 have only about an inch to spare. Cut one block, check it against the corner of a finished frame, then cut the other fifteen.

Build order

  1. Cut everything. Boards 1–5 for the frames, boards 6–7 for the blocks, then the plywood.
  2. Frame. Stand the 2x4s on edge. Put the 21" pieces between the 36" pieces and drive two 3" screws through each long side into the end of each short side. Check the corners are square (the diagonals should match).
  3. Blocks. With the frame top-side down on a flat surface, drop a block flat into each corner, short edge toward the corner, so it sits flush with the top. Drive 3" screws through the frame sides into each block end.
  4. Top. Lay the plywood on and screw it down with 1-1/4" screws about every 8" around the frame, plus a few into each block.
  5. Casters. Flip it over. Center a caster on each block and screw the plate down with 1-1/4" screws (they won't poke through the 1-1/2" block). The casters may go on at the sets build area instead.
  6. Roll test. On its wheels, every caster should swivel all the way around without touching the frame.