Spanish burton with a lower block (4 : 1) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/spanish-burton-with-lower-block-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown No. 17 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- Rope 1 runs from the lower (load) block over the fixed block to a runner; rope 2's standing end is on the fixed block's becket, it runs under the lower block, over the runner and down to the hand. Rope 2 carries P, the runner hangs on rope 1 at 2P, and the lower block is held by rope 1 (2P) and both legs of rope 2 (2P): P = W/4.
- Pitch-Ø40 fixed block with a becket, pitch-Ø20 runner and pitch-Ø20 load block; the weight stem is on the line of the resultant pull (x = −10).
- Brown's No. 17 shows a second Spanish barton; this is a Xem Studio arrangement of the same family, all strands vertical in one plane.
- Parts (each has its own page): tackle-beam-240-sockets, tackle-block-20-top-stem-becket, tackle-block-10-top-socket, tackle-block-10-load-hook, rope-sheave-3mm-pitch-40, rope-sheave-3mm-pitch-20, ropes-3mm-spanish-burton-with-lower-block, tackle-weight-d40x40-socket, dowel-pins-metric.
- Brown's movement No. 17 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

parameter  value
fixed block  pitch Ø40, becket
runner  pitch Ø20
load block  pitch Ø20
mechanical advantage  4

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 17: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_017.html

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/spanish-burton-with-lower-block-mechanism/index.json
API: https://xemstudio.com/api/geometry?object=spanish-burton-with-lower-block-mechanism