Build guide

Roulette Wheel

21×42 @ 2.54mm pitch · 20 components · 40 wires

1. Prepare

Verify component pinouts against each manufacturer’s datasheet before wiring. Label cut wires with their wire numbers; the same numbers follow them through every stage. Wire colors are written out for black-and-white printing. Custom colors can be named in the wire library.

Progress is saved on this browser for this board revision. Changes to the board or measurements start a new checklist. Printed diagrams are references, not life-size templates.

40 wires to prepare; 1406mm total wire, including end allowances.

Parts List

11 unique parts

Ref DesPartValueManufacturerPart NumberQtyLink
C1Ceramic Cap220nF——1Amazon
C2Electrolytic Cap47uF——1Amazon
J1Power Input (2-pin)——1—
LED1LEDGreen——1Amazon
LED2, LED3, LED4, LED5, LED6, LED7, LED8, LED9, LED10LEDRed——9Amazon
R1Resistor (axial)1k——1Amazon
R2, R3Resistor (axial)100k——2Amazon
R4Resistor (axial)220——1Amazon
U1DIP-16——1—
U2DIP-8——1—
U3Tactile Button 6mm——1—

Links may include affiliate referrals.

2. Cut wires

Cutting quantities by color and length

40 wires · +5mm per end for lead-through

Cut#NetColorRouteCut LengthBends
6TIMINGBlackN38 → N3615mm—
24CATHODESBlackJ20 → H2015mm—
36GNDBlackR23 → R3438mm—
12Q8BlackL19 → P3042mm19mm (45°)
18Q3BlackL7 → N2763mm51mm (45°)
309VBlackC5 → G3084mm69mm (90°)
23CATHODESBlueN20 → L2015mm—
29CATHODESBlueE16 → E1220mm—
5SPINBlueP33 → K3323mm—
35GNDBlueP29 → K3128mm10mm (90°)
11BUTTONBlueP40 → R3235mm25mm (90°)
17Q2BlueI8 → K2760mm48mm (45°)
4SPINGreenR36 → R3318mm—
28CATHODESGreenG19 → G1618mm—
22CATHODESGreenS18 → O1923mm8mm (90°)
10DISCHGreenL38 → M3325mm18mm (90°)
34GNDGreenQ22 → P2828mm20mm (90°)
16Q9GreenG18 → M3158mm38mm (90°)
40GNDGreenS22 → D591mm48mm (90°)
319VRedH31 → H3418mm—
37GNDRedP34 → P3718mm—
25CATHODESRedP13 → N1023mm10mm (90°)
7TIMINGRedM39 → G3828mm20mm (90°)
1Q7RedM18 → M2733mm—
13Q0RedG15 → J2748mm35mm (90°)
19Q5RedQ11 → H2774mm46mm (90°)
27CATHODESWhiteJ8 → I914mm—
9DISCHWhiteJ38 → F3820mm—
21CATHODESWhiteO16 → O1220mm—
3CLOCKWhiteG34 → J3121mm—
39GNDWhiteN37 → E3440mm18mm (90°), 25mm (90°)
339VWhiteD37 → O3943mm10mm (90°)
15Q1WhiteG11 → I2756mm10mm (90°)
20CATHODESYellowQ18 → Q1615mm—
26CATHODESYellowM9 → K915mm—
329VYellowI35 → E3828mm13mm (90°)
8TIMINGYellowM37 → F3431mm16mm (45°)
38GNDYellowQ35 → I3135mm15mm (45°)
14Q6YellowO15 → L2748mm35mm (90°)
2Q4YellowO8 → N3181mm10mm (90°), 69mm (90°)

Total wire: 1406mm (55.3in)

3. Bend wires

Use the straight-line ruler to mark bend points on the wire before bending. Use the bent shape as a visual reference while bending.

Bend ruler and shape for wire 1
Cut 33mm.
Bend ruler and shape for wire 2
Cut 81mm. Bend 90° down at 10mm. Bend 90° left at 69mm.
Bend ruler and shape for wire 3
Cut 21mm.
Bend ruler and shape for wire 4
Cut 18mm.
Bend ruler and shape for wire 5
Cut 23mm.
Bend ruler and shape for wire 6
Cut 15mm.
Bend ruler and shape for wire 7
Cut 28mm. Bend 90° up at 20mm.
Bend ruler and shape for wire 8
Cut 31mm. Bend 45° left at 16mm.
Bend ruler and shape for wire 9
Cut 20mm.
Bend ruler and shape for wire 10
Cut 25mm. Bend 90° right at 18mm.
Bend ruler and shape for wire 11
Cut 35mm. Bend 90° right at 25mm.
Bend ruler and shape for wire 12
Cut 42mm. Bend 45° down at 19mm.
Bend ruler and shape for wire 13
Cut 48mm. Bend 90° right at 35mm.
Bend ruler and shape for wire 14
Cut 48mm. Bend 90° left at 35mm.
Bend ruler and shape for wire 15
Cut 56mm. Bend 90° down at 10mm.
Bend ruler and shape for wire 16
Cut 58mm. Bend 90° right at 38mm.
Bend ruler and shape for wire 17
Cut 60mm. Bend 45° down-right at 48mm.
Bend ruler and shape for wire 18
Cut 63mm. Bend 45° down-right at 51mm.
Bend ruler and shape for wire 19
Cut 74mm. Bend 90° left at 46mm.
Bend ruler and shape for wire 20
Cut 15mm.
Bend ruler and shape for wire 21
Cut 20mm.
Bend ruler and shape for wire 22
Cut 23mm. Bend 90° left at 8mm.
Bend ruler and shape for wire 23
Cut 15mm.
Bend ruler and shape for wire 24
Cut 15mm.
Bend ruler and shape for wire 25
Cut 23mm. Bend 90° up at 10mm.
Bend ruler and shape for wire 26
Cut 15mm.
Bend ruler and shape for wire 27
Cut 14mm.
Bend ruler and shape for wire 28
Cut 18mm.
Bend ruler and shape for wire 29
Cut 20mm.
Bend ruler and shape for wire 30
Cut 84mm. Bend 90° right at 69mm.
Bend ruler and shape for wire 31
Cut 18mm.
Bend ruler and shape for wire 32
Cut 28mm. Bend 90° left at 13mm.
Bend ruler and shape for wire 33
Cut 43mm. Bend 90° right at 10mm.
Bend ruler and shape for wire 34
Cut 28mm. Bend 90° left at 20mm.
Bend ruler and shape for wire 35
Cut 28mm. Bend 90° left at 10mm.
Bend ruler and shape for wire 36
Cut 38mm.
Bend ruler and shape for wire 37
Cut 18mm.
Bend ruler and shape for wire 38
Cut 35mm. Bend 45° up-left at 15mm.
Bend ruler and shape for wire 39
Cut 40mm. Bend 90° up at 18mm. Bend 90° left at 25mm.
Bend ruler and shape for wire 40
Cut 91mm. Bend 90° left at 48mm.

4. Place wires

Component side. Select a wire to emphasize its route in its own color and highlight its endpoints. Wires follow number order, matching the bend guide and solder checklist.

W1 · M18M27
W2 · O8N31
W3 · G34J31
W4 · R36R33
W5 · P33K33
W6 · N38N36
W7 · M39G38
W8 · M37F34
W9 · J38F38
W10 · L38M33
W11 · P40R32
W12 · L19P30
W13 · G15J27
W14 · O15L27
W15 · G11I27
W16 · G18M31
W17 · I8K27
W18 · L7N27
W19 · Q11H27
W20 · Q18Q16
W21 · O16O12
W22 · S18O19
W23 · N20L20
W24 · J20H20
W25 · P13N10
W26 · M9K9
W27 · J8I9
W28 · G19G16
W29 · E16E12
W30 · C5G30
W31 · H31H34
W32 · I35E38
W33 · D37O39
W34 · Q22P28
W35 · P29K31
W36 · R23R34
W37 · P34P37
W38 · Q35I31
W39 · N37E34
W40 · S22D5
W1 · M18M27W2 · O8N31W3 · G34J31W4 · R36R33W5 · P33K33W6 · N38N36W7 · M39G38W8 · M37F34W9 · J38F38W10 · L38M33W11 · P40R32W12 · L19P30W13 · G15J27W14 · O15L27W15 · G11I27W16 · G18M31W17 · I8K27W18 · L7N27W19 · Q11H27W20 · Q18Q16W21 · O16O12W22 · S18O19W23 · N20L20W24 · J20H20W25 · P13N10W26 · M9K9W27 · J8I9W28 · G19G16W29 · E16E12W30 · C5G30W31 · H31H34W32 · I35E38W33 · D37O39W34 · Q22P28W35 · P29K31W36 · R23R34W37 · P34P37W38 · Q35I31W39 · N37E34W40 · S22D5

5. Solder connections

Bottom view: horizontally mirrored. Coordinate names still identify the same physical holes. Highlights mark wire endpoints; wire routes belong on the component side. Check each connection and the listed solder bridges.

Board is horizontally mirrored. Column A is on the right.

W1 · M18M27
W2 · O8N31
W3 · G34J31
W4 · R36R33
W5 · P33K33
W6 · N38N36
W7 · M39G38
W8 · M37F34
W9 · J38F38
W10 · L38M33
W11 · P40R32
W12 · L19P30
W13 · G15J27
W14 · O15L27
W15 · G11I27
W16 · G18M31
W17 · I8K27
W18 · L7N27
W19 · Q11H27
W20 · Q18Q16
W21 · O16O12
W22 · S18O19
W23 · N20L20
W24 · J20H20
W25 · P13N10
W26 · M9K9
W27 · J8I9
W28 · G19G16
W29 · E16E12
W30 · C5G30
W31 · H31H34
W32 · I35E38
W33 · D37O39
W34 · Q22P28
W35 · P29K31
W36 · R23R34
W37 · P34P37
W38 · Q35I31
W39 · N37E34
W40 · S22D5
W1 · M18M27W2 · O8N31W3 · G34J31W4 · R36R33W5 · P33K33W6 · N38N36W7 · M39G38W8 · M37F34W9 · J38F38W10 · L38M33W11 · P40R32W12 · L19P30W13 · G15J27W14 · O15L27W15 · G11I27W16 · G18M31W17 · I8K27W18 · L7N27W19 · Q11H27W20 · Q18Q16W21 · O16O12W22 · S18O19W23 · N20L20W24 · J20H20W25 · P13N10W26 · M9K9W27 · J8I9W28 · G19G16W29 · E16E12W30 · C5G30W31 · H31H34W32 · I35E38W33 · D37O39W34 · Q22P28W35 · P29K31W36 · R23R34W37 · P34P37W38 · Q35I31W39 · N37E34W40 · S22D5