390 size brushed DC motor: Ø27.6 × 47 mm, Ø2.3 shaft — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/dc-motor-390-size/  (CC BY 4.0)
Basis: Sigmanortec 390 motor listing (no maker's drawing found). Envelope only: the outside of the motor at its published sizes. The windings, magnets, brushes and bearings inside are not drawn.
Catalog version: 2026-10-20

Sizes: see table below
- Envelope only: the outside of the motor at its published sizes. The windings, magnets, brushes and bearings inside are not drawn.
- The can is Ø27.6 × 47 mm, not counting the bearing sleeves at each end.
- The Ø2.3 shaft is 14 mm from the face, 11 of it beyond the 3 mm front sleeve. The sleeves' diameter is not listed, so they are not drawn.
- Two 2.5 mm screw holes 16 mm apart in the face (the same spacing as the 380 family), drawn 2.0 deep only to mark them; the listing gives no thread or depth.
- Terminal tabs and the wire exit are not drawn. Only one listing gave these sizes; check the motor in hand.
- In DIY Stirling builds, brushed DC motors of this kind are turned by the engine and used as a generator (an LED, a resistor or a meter across the leads) or as a load on the flywheel shaft.

feature  mm  from
can  Ø27.6 × 47 (without sleeves)  Sigmanortec
shaft  Ø2.3  Sigmanortec
shaft from the face  14 (11 beyond the sleeve)  Sigmanortec
front sleeve height  3  Sigmanortec (14 − 11)
face holes  2 × Ø2.5 on 16  Sigmanortec

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Sigmanortec: 390 motor listing: Ø27.6, 47 long without the bearing sleeves, shaft Ø2.3 × 14 (11 beyond the sleeve), 2.5 mm screw holes 16 mm apart — web — listing [verify license at link] — https://sigmanortec.ro/en/motor-390-6-24v-13000rpm-shaft-23x14mm

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/dc-motor-390-size/index.json
API: https://xemstudio.com/api/geometry?object=dc-motor-390-size