# Spanish burton with a lower block (4 : 1)

> How does adding a lower block change a Spanish burton?

- Category: Mechanisms › Pulleys and tackle
- Kind: Hardware
- Basis: Xem Studio design following Brown No. 17 (1868)
- Page: https://xemstudio.com/objects/spanish-burton-with-lower-block-mechanism/ · JSON: https://xemstudio.com/api/geometry?object=spanish-burton-with-lower-block-mechanism · Plain text: https://xemstudio.com/objects/spanish-burton-with-lower-block-mechanism/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- 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.

## Sizes

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

## Where the files are

- Henry T. Brown (1868, public domain): [Five Hundred and Seven Mechanical Movements — scan on archive.org](https://archive.org/details/fivehundredseven00browiala) — web — Publisher's page; dimensions are facts
- 507movements.com: [Brown's movement No. 17: figure, his text and an animation](https://507movements.com/mm_017.html) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/spanish-burton-with-lower-block-mechanism/index.json · license: https://xemstudio.com/files/hardware/spanish-burton-with-lower-block-mechanism/LICENSE.md

- spanish-burton-with-lower-block-mechanism-assembly: [STEP](https://xemstudio.com/files/hardware/spanish-burton-with-lower-block-mechanism/spanish-burton-with-lower-block-mechanism-assembly.step) · [STL](https://xemstudio.com/files/hardware/spanish-burton-with-lower-block-mechanism/spanish-burton-with-lower-block-mechanism-assembly.stl) — Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)

## Questions

**How does adding a lower block change a Spanish burton?**

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.

## Fits with

- [Tackle beam 240 × 20 × 12 with Ø3 sockets every 5 mm](https://xemstudio.com/objects/tackle-beam-240-sockets/)
- [Single block for a pitch-Ø40 sheave with stem up and a becket socket](https://xemstudio.com/objects/tackle-block-20-top-stem-becket/)
- [Single runner block for a pitch-Ø20 sheave, rope socket on top](https://xemstudio.com/objects/tackle-block-10-top-socket/)
- [Load block for a pitch-Ø20 sheave with a side rope socket and a weight stem](https://xemstudio.com/objects/tackle-block-10-load-hook/)
- [Rope sheave for Ø3 rope, pitch Ø40 (rope centre), Ø44.4 rim, Ø4 bore](https://xemstudio.com/objects/rope-sheave-3mm-pitch-40/)
- [Rope sheave for Ø3 rope, pitch Ø20 (rope centre), Ø24.4 rim, Ø4 bore](https://xemstudio.com/objects/rope-sheave-3mm-pitch-20/)
- [Ø3 ropes for the spanish burton with a lower block (drawn in place)](https://xemstudio.com/objects/ropes-3mm-spanish-burton-with-lower-block/)
- [Weight Ø40 × 40 with a Ø3 top socket (394.58 g in steel)](https://xemstudio.com/objects/tackle-weight-d40x40-socket/)
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/)