Stone walls and resin printing

1Choose a stone face

Stone is chosen where the brick bond is. Open Brick Settings at the top of the left-hand column and pick from the Bond Pattern list 1. Below the brick bonds it offers:

• Ashlar (scored stone blocks) - squared blocks in level courses;
• Random rubble, medium stones and Random rubble, small stones;
• Coursed rubble (long stones, level courses);
• Random ashlar (broken courses);
• Plain (render, no joints).

Choose any rubble or random ashlar face and the card describes it - "Random rubble, medium stones (100-400 mm)" - and adds two things:

2

New stones lays the wall again with a different set of stones (section 4).

3

Ashlar quoins at the corners, with a reminder that the window and door dressings are under Windows & Doors (sections 5 and 6).

The face belongs to the panel, so each wall of a building can have its own: a stone front with brick sides, say. Stone sizes follow from the course: one brick course is 75 mm full size, so the stones come out the right size for your scale.

For this chapter we drew a 90 × 60 mm wall with a square-headed window (with a cill, a lintel and stone quoins down its sides) and a door under a segmental arch with Stone voussoirs, and tried each face on it.

2Ashlar blocks

Ashlar (scored stone blocks) draws squared stone blocks in level courses, each course broken half a block from the one below, like a stretcher bond in stone. Two boxes appear under the list:

• Block course height (mm) - three brick courses to start with (3 mm in OO);
• Block length (mm) - one and a half bricks to start with (4.5 mm in OO).

Ashlar is laid like brickwork, so it has no New stones button and no stone-quoin box: use Corner Quoins in the right-hand column for its corners.

3Rubble and random ashlar

The other stone faces are laid stone by stone for each wall. Each joint is one engraved line, and the stones are laid round the openings, quoins and dressings, so nothing is cut through.

4New stones

Every wall gets its own stones, so two walls of the same building never repeat. If you don't like how the stones have fallen - an awkward small stone by a window, a joint running up the wall - click New stones. The wall is laid again in the same style and sizes; click again until you like it. The stones are saved with the project, so they come back the same next time and in every export.

5Ashlar quoins at the corners

Rubble walls were usually built with dressed ashlar blocks at the corners, long and short in turn. Tick Ashlar quoins at the corners in the amber box. If the quoins still have their brick sizes, BrickIT! changes them to stone sizes - 450 and 300 mm long and 300 mm high, full size - and says so in the box.

The quoins are the same ones as in the Corner Quoins card in the right-hand column, where you can change their sizes and choose the Left and Right corners. If you change the sizes there, the amber box offers a button to go back: Use stone sizes (450 / 300 mm, 300 mm high) 1.

6Dressed openings

The windows and doors of a stone wall are dressed the same way as on brick, from the Windows & Doors card. Pick an opening in its list and scroll down:

• Stone Quoins: tick Add quoins to sides for long and short blocks up both jambs. Their Long and Short lengths in mm and Height (courses) start at 4.5, 3 and 2.
• Stone Cill: Add cill below opening.
• A lintel over a square-headed opening: Add stone/concrete lintol above opening.
• An arched head in stone: choose Stone under Voussoirs, at the top of the card.

The tracery, mullions and stone frames of church and chapel windows are covered in chapter 3; they work on stone walls just as on brick.

7Plain render

For a rendered, stuccoed or cement-faced wall, choose Plain (render, no joints). The card says what it does: no joints are engraved, so the panel cuts plain, for render or a smooth face.

The quoins, cills, lintels and arches are still engraved, as on a rendered house with stone dressings. Turn them off on the wall and its openings if you want a completely plain face.

8The resin print

As well as cutting a wall on a laser, BrickIT! can make it as a 3D model for a resin printer. Its face is modelled the way the laser panel is drawn - every engraved joint becomes a groove - but with depth the laser can't give:

• Mortar joints are sunk into the face: 0.35 mm deep between rubble and random ashlar stones; 0.2 mm wide and 0.25 mm deep for brick, ashlar blocks and dressings. Rubble and random ashlar stones have rough, pitched faces, and brick is very slightly out of true, as real walling is.
• Stone dressings stand proud, as built: cills 0.3 mm, string courses 0.25 mm, lintels 0.2 mm, quoins 0.15 mm and arch heads 0.1 mm.
• Tracery and stone window frames fill their opening, set 0.4 mm back from the face; a hood mould stands 0.3 mm proud.
• It all stands on a 1.5 mm back, the cut lines of your panel giving its outline and its openings.

The button is in the Output/Export column, under Export SVG:

1

Printer plate: the size of your printer's build plate (section 9).

2

Whether this wall fits it, checked a moment after every change you make.

3

Stone dressings stand proud, shown when the wall has quoins, cills, lintels, string courses or arch heads. Untick it to print them flush, as the laser cuts them.

Export STL (resin print) makes the model of the wall you are working on and saves it as an .stl file named after the panel.

Making the model takes a few seconds for a small wall; the button shows how it is getting on. When it is done, an amber note gives the size and thickness and how to print it.

9Your printer's plate

Choose your printer's build plate in the Printer plate list. It offers five common sizes - 153 × 77, 165 × 72, 196 × 122, 218 × 123 (the starting choice) and 298 × 164 mm - and Your own size…, which shows two boxes for the plate's width and depth in millimetres.

BrickIT! remembers your plate on this computer, for every project. The note under it tells you straight away whether the wall you are on fits.

10A wall too big for the plate

A long wall won't fit the plate in one piece. Rather than leave that to you, BrickIT! works out where to cut it - only along mortar joints, so the pieces key into each other like real walling, never through a window or door, and with the pieces as even as it can make them. Buttercrambe church's north side is 301.5 mm long:

1

A plain-English summary: how many pieces, side by side or one above another, cut along the mortar joints.

2

A picture of the wall with the cut in red, stepping along the joints, and each piece numbered.

3

The button now reads Export STL in 2 pieces. Each piece is its own file, named "… - piece 1 of 2.stl" and so on; the desktop app asks once for a folder to put them all in.

Sometimes the only way to cut a wall goes through an opening - a long arcade, say. Then the note says so in amber, and a box appears: Allow a cut through an opening. Tick it and the cut may run through a window or door, to be glued back together along the cut. If a wall can't be split at all for your plate, the note explains why and the button stays greyed out.

11Print and glue

The note after an export says how to print: flat on the plate, back down, with no supports. The joint depths are chosen for 50 µm layers.

1. Load the .stl file (or the pieces) into your printer's slicer and lay it flat, back down, without supports.
2. Print at 50 µm layers.
3. For a wall in pieces, glue them together face down on a flat sheet, in order, each keyed into the next along its joints.

Where next

• For tracery, mullions and stone window frames: Windows and doors.
• To see the stone walls standing as a building, with copings and buttresses: 3D, roofs and pictures.
• To keep a stone wall to use again: Projects and the library.