Gravity roller conveyor on 15-series side frames: 1.9 in rollers, 7/16 hex axles, 3 in pitch — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/t-slot-gravity-roller-conveyor/  (CC BY 4.0)
Basis: Xem Studio design: Ø1.9 in rollers on 7/16 in hex axles (the common gravity-conveyor sizes) between two 1515 side frames, holes at a 3 in pitch on the rail centre line; legs from 1515 set the roller-top height
Catalog version: 2026-10-20

Sizes: see table below
- Roller top = side-frame centre line + 0.95 in. Set leg length so that sits at your bench height.

between_frames_in  roller_in  axle_hex_in  pitch_in
18  1.9  0.4375  3
24  1.9  0.4375  3
30  1.9  0.4375  3

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 80/20: 15 series T-slot profiles and fasteners (1.5 in rail, 5/16-18 hardware) — web — maker's catalogue; numbers cited — https://8020.net/1515.html

Free files (CC BY 4.0, Xem Studio; STEP + STL, 10 parts): https://xemstudio.com/files/hardware/t-slot-gravity-roller-conveyor/index.json
API: https://xemstudio.com/api/geometry?object=t-slot-gravity-roller-conveyor