Two layouts for sixteen
Sixteen pockets divide two ways. Two rows of eight give a long, low block, 79.8 mm by 24.2 mm, where every bit has an open side: the front row is reached from the front and the back row from behind, so nothing is buried. Four rows of four give a block of about 41.4 by 45.5 mm, nearly square, which takes less shelf length but leaves four bits in the middle that can only be lifted straight up. This page uses two rows of eight. For the square block, open the generator from the link and set the bits per row to 4 and the rows to 4.
What to measure
Check a bit across its flats: 6.35 mm is standard, and most bits read 6.30 to 6.35. Then measure the space. In a drawer, the block needs its 79.8 mm length plus room for fingers at one end. In a case lid, measure the clear width and the height available when the lid shuts: with 13 mm pockets a 25 mm bit stands 12 mm above a 15 mm block, a total of 27 mm. If the lid is lower than that, cut the block height to 12 mm and accept shallower pockets.
Clearance, walls and material
The pocket clearance is 0.25 mm, for a pocket 6.6 mm across flats. Walls of 3 mm separate the pockets and surround them, and the rows are about 10.6 mm apart from centre to centre. The block is 15 mm high over a 2 mm floor, which makes the pockets 13 mm deep, enough to hold a bit upright when the back row is brushed while reaching for the front one. PLA is the right material: the block does not flex, and PLA prints the sharpest hexagons. PETG works with the clearance raised to 0.3 mm.
Printing
Print flat, pockets up, with no supports. Sixteen hexagons mean many short perimeter loops, and that is where a printer shows its habits: if the pockets come out tight on one side, the seam is piling up there, so set it to the rear or to random. Use 0.2 mm layers and three perimeters. Before printing all sixteen pockets, you can print a strip of two with the same clearance as a fit test; it takes a few minutes and settles the number.
Outline drawing
Top view, to scale. Pocket centres are 9.6 mm apart along a row and about 10.6 mm apart between the rows.
Parameters the generator will use
| Setting | Link parameter | Value |
|---|---|---|
| Model | model | bit_holder |
| Bits per row | count | 8 |
| Rows | rows | 2 |
| Bit size across flats | across_flats | 6.35 |
| Pocket clearance | clearance | 0.25 |
| Wall between pockets | gap | 3 |
| Wall around the pockets | margin | 3 |
| Strip height | height | 15 |
| Floor under the pockets | floor | 2 |
All lengths are in millimetres. Outer size from these values: about 79.8 x 24.24 x 15 mm.
Open the generator with these values
This model needs the $7 licence key: one payment, one key, and it opens all five paid models. Get a licence key on Gumroad ($7)
The hex bit holder strip needs a licence key: without one the generator shows the model locked, lists the values from this link and fills them in as soon as you unlock. The fitted drawer organiser bin is the free model and downloads with no key.