14. Double-sided and tiled jobs#

Two ways to cut more than one face, or more than one machine's worth, from a single board. Both lean on the same trick: dowel pins in the spoilboard, and holes in the board that drop onto them, so the board goes back exactly where the program expects it.

• Double-sided — cut side A, turn the board over onto the pins, cut side B.
• Tiled — a board longer than the machine. Cut it in tiles, sliding it along onto the pins between them.

Both are in the machine panel under CAM Operations: Double-Sided and Tiling. A job is one or the other, and neither works alongside nesting onto more sheets — each is one board.

Double-sided jobs#

Side A on the stock, side B on the sheet to its right. Side A's parts show faintly on side B, mirrored as they will lie after the flip; the dashed line is the flip axis and the two circles on it are the pins.

Starting one#

Open Double-Sided and pick the flip under Pick the Flip to Start:

That is all there is to it: the side B sheet appears, the dowel holes are placed on the flip axis, and their drilling is added to the program. The job needs the stock to be its only sheet; if parts are on other sheets, move them onto the stock first.

Drawing side B#

Side B's sheet shows the board as you will see it after the flip. Draw side B's parts there as you want them cut — the coordinates on that sheet are the machine's coordinates after the flip, so its toolpaths are generated like any other and cut exactly as drawn. They are never made by mirroring side A's toolpaths: a mirrored toolpath turns a climb cut into a conventional one.

What helps you line the two faces up:

• The guide. Each side's parts are drawn faintly on the other, mirrored as the flip puts them.
• Snapping. A part dragged on one side snaps to the edges and centres of the other side's parts, as the guide draws them, as well as to its own sheet's edges.
• Send to Other Side in the form mirrors the selected paths across the flip axis onto the other sheet — for a feature cut from both faces, such as a chamfer on both edges of a hole. Sent over and back, a path comes back exactly where it was.

Changing the flip later takes side B's parts with it to the new sheet, turned to suit, and moves the dowel holes onto the new axis — one step, and one undo.

The dowel pins#

Two pins on the flip axis, one bigger than the other. A point on the axis stays put when the board turns over about it, so the holes are still over the pins after the flip. Every wrong way to put the board back — the other flip, or a half turn face up — swaps the two holes end for end, so the big pin meets the small hole and the board won't go on. Pins of the same size would let it go on wrong, slid along the axis; the form refuses sizes less than 1 mm apart.

The holes are a path of two circles, Dowel Holes, kept on the pins whatever you change. They are bored helically with an end mill — a peck would make both holes the size of the bit and the pins the same size again. The form picks the largest end mill that fits the small hole; choose another under Tool. The drilling is always the first cut on side A, so the board is pinned before anything is cut loose.

Running it#

1. Run side A. The dowel holes are drilled first, through the stock and into the spoilboard.
2. Put the pins in, turn the board over the way you chose, and drop it onto them.
3. Pick Sheet 2 · Side B in the toolbar's sheet picker and run side B.

Keep the XY zero between the sides — the pins hold the board to the machine, not to its edges, which are rarely square. Z depends on your Stock setting: set from the top of the stock, re-zero Z on the new top face; set from the spoilboard, leave it.

Simulating it#

The 3D view shows both faces. Simulating side B, side A's cuts are there underneath, and where the two meet you see the hole. Simulating side A, the finished part opens with side B cut too; run or scrub it from the start and side B goes back to bare board, since side B is cut after side A.

Ending it#

Make Single-Sided in the form, or the × on the Double-Sided chip at the start of the Objects strip, ends the job. The dowel holes and their drilling go; side B's parts stay where they are, as an ordinary second sheet.

Tiled jobs#

A board twice as long as the machine's travel, in four tiles. The picked tile is shaded; each tile starts with its pair of pin holes, one small and one big.

Starting one#

Set the stock to the board's real size first, and design and generate as if your machine were that big. Then open Tiling and pick Along X or Along Y under Pick the Slide Axis to Start — the way the board will slide between tiles.

The board is split into the fewest equal tiles your machine can reach. Machine Travel starts at the Table Width or Height you set in Machine Limits; change it in the form. A tile can be a little shorter than the travel: every tile but the last also has to reach the next pair of pin holes.

Nothing about the drawing or the toolpaths changes. A tile is only a window of the finished program.

Placing the seams#

The seams are the dashed lines across the board. Each tile is labelled with its number and length.

• Drag a seam to move it. It snaps to whole millimetres (whole inches in inch mode) of tile length, and — where the cursor is over a stretch the toolpaths cut — out to the nearest clean break, where it crosses no cut and leaves no seam mark. While dragging, the label says clean break or, in red, cuts through a toolpath. Hold Alt to drag without snapping.
• A seam can go into any gap, however short that makes the tile before it. If that leaves the tile after it too long for the machine, the form says so: add a seam.
• − and + take a tile away or add one, re-spacing evenly. Even re-spaces the tiles you have. Each seam's position can also be typed in.

The pins#

Two pins sit in the spoilboard, a fixed distance into the machine's travel. Each tile drills the board's next pair of holes before the board slides on, and the board slides until those holes drop onto the pins, so the next tile lines up with the last. The first tile also drills the first pair right through into the spoilboard — those holes are where the pins go.

The pin holes are Tile Pins paths, one pair per tile, kept in step with the seams. They are drilled automatically, helically, and first in every tile — choose the end mill under Tool. Only the first pair goes into the spoilboard, where the pins live; every later pair goes just through the board (0.5 mm past it), so the spoilboard isn't left full of holes that hold nothing. Every station lands on the board, so keep the pins in the waste.

Running it#

Pick a tile with the toolbar's ◀ Tile 1 of 4 ▶ picker; Simulate and the Machine tab follow it. Export G-code writes one file per tile: job_tile1, job_tile2, and so on.

1. Run tile 1. It drills the first pair of holes into the spoilboard, and the second pair.
2. Put the pins in the first holes.
3. Lift the board, slide it along the slide axis until the next holes drop onto the pins, and run the next tile. Repeat.

Keep the XY and Z zero for every tile. Each tile's program is moved so its window starts at the same machine spot; the pins put the board there.

Where a cut crosses a seam, the tile lifts to safe height, moves over and plunges back in — no more than one step-down, since the passes above it were cut first in the same tile.

Ending it#

Make Single Board in the form, or the × on the Tiling chip, ends the job: the pin holes and their drilling go, and the board is one program again.

The G-code review#

Export G-code checks a double-sided or tiled job too:

• No dowel holes / pin holes drilled — no end mill fits the small hole. Pick one in the form, or make the pins bigger.
• The dowel holes go deeper than allowed into the spoilboard.
• A tile too long for the machine.
• A note with the steps: when to put the pins in, which way to turn or slide the board, and what to do about zero.

A tiled job is checked tile by tile, each at its own origin, as it will be cut.

Next#

• 10. Simulating and exporting — the review before you cut
• 12. Running the machine — sending each side or tile to the machine