Table 1.
Bill of materials, with all values in USD. Complete bill of materials with sources and more specific costing et cetera available at https://doi.org/10.17605/osf.io/ktxuh.
| Part | Qty | Total Cost | Pro rata | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|
| 3D-printed parts: | $24.99 | 1 kg spool | |||||||
| Rendered colour: | Mass (g): | ||||||||
| outer | 1 | Pink | 58.66 | ||||||
| inner | 1 | Blue | 52.05 | ||||||
| sleeve | 1 | Brown | 3.21 | ||||||
| shaft | 1 | Red | 1.11 | ||||||
| pie | 1 | Green | 10.45 | ||||||
| nut | 1 | Orange | 1.61 | ||||||
| barServo | 1 | Yellow | 4.91 | ||||||
| barLink | 1 | Cyan | 1.65 | ||||||
| barShaft | 1 | Dark blue | 1.78 | ||||||
| Total Mass: | |||||||||
| All printed parts: | $3.37 | 135.43 | |||||||
| HX12K servo | 1 | $10.21 | $10.21 | torque | |||||
| range | |||||||||
| speed | |||||||||
| Servo arm | 1 | Supplied with above | |||||||
| O-Rings: | |||||||||
| 22 × 2 | 2 | $0.68 | $0.14 | Pressed into wedges in inner | |||||
| 18 × 2 | 1 | $0.60 | $0.60 | Sleeve | |||||
| 6 × 2 | 1 | $1.68 | $0.04 | On shaft | |||||
| 41 × 2 | 1 | $1.06 | $0.11 | Between inner and outer | |||||
| Hardware: | |||||||||
| M3 × 40 mm | 2 | $1.47 | $0.30 | Joining inner and outer | |||||
| M3 × 16 mm | 5 | $2.03 | $0.21 | Attaching servo (4) | |||||
| Joining barServo & barLink (1) | |||||||||
| M3 × 10 mm | 2 | $0.82 | $0.18 | Joining barShaft & barLink(1) | |||||
| Servo shaft connection (1) | |||||||||
| Standard M3 nuts | 6 | $0.47 | $0.12 | ||||||
| Standard M3 washer | 20 | $0.55 | $0.22 | ||||||
| M3 lock washer | 7 | $0.90 | $0.63 | All non-rotating connections | |||||
| M3 nylock nut | 2 | $0.87 | $0.07 | For bolts which connect bars | |||||
| Total: | $46.33 | $16.27 | |||||||