RC servo sizes: 9 g micro (SG90, MG90S), standard (Futaba S3003, Hitec HS-311), 1/4 scale (HS-805BB) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/rc-servos/  (CC BY 4.0)
Basis: Servo datasheets and maker / retailer spec pages
Catalog version: 2026-10-20

Sizes: see table below
- Micro 9 g: SG90 about 22.2 × 11.8 × 31; MG90S 22.8 × 12.2 × 28.5 (13.4 g).
- Standard: Futaba S3003 40–41 × 20 × 36 (37 g); Hitec HS-311 39.9 × 19.8 × 36.3 (42.8 g), 24-tooth spline. Quarter scale: Hitec HS-805BB 66 × 30 × 57.6 (152 g).
- Mounting-tab hole spacing, tab hole size and most spline tooth counts are not published as text for these servos: measure the tabs, or design the cut-out around the body envelope and fix with the supplied screws.
- Body envelopes (free STEP/STL) are for pockets and cut-outs; add 0.3 mm a side.

servo  class  length_mm  width_mm  height_mm  weight_g  spline
SG90  micro 9 g  22.2  11.8  31.0  9  None
TowerPro MG90S  micro  22.8  12.2  28.5  13.4  None
Futaba S3003  standard  40–41  20  36  37  None
Hitec HS-311  standard  39.9  19.8  36.3  42.8  24T
Hitec HS-805BB  1/4 scale  66  30  57.6  152  heavy-duty

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- SG90 datasheet (TowerPro): SG90 micro servo — web — Publisher's page; dimensions are facts — https://tams.informatik.uni-hamburg.de/lehre/2023ss/vorlesung/es/doc/sg90.pdf
- GetFPV (TowerPro spec): MG90S — web — Publisher's page; dimensions are facts — https://www.getfpv.com/towerpro-mg90s-digital-servo.html
- Futaba S3003 datasheet: S3003 standard servo — web — Publisher's page; dimensions are facts — https://content.instructables.com/F1V/HY29/IR9E9N75/F1VHY29IR9E9N75.pdf
- ServoDatabase: Hitec HS-311 — web — Publisher's page; dimensions are facts — https://servodatabase.com/servo/hitec/hs-311
- SparkFun (Hitec spec): HS-805BB giant scale — web — Publisher's page; dimensions are facts — https://www.sparkfun.com/servo-hitec-hs-805bb-giant-scale.html

Free files (CC BY 4.0, Xem Studio; STEP + STL, 5 parts): https://xemstudio.com/files/hardware/rc-servos/index.json
API: https://xemstudio.com/api/geometry?object=rc-servos