Dovetail

A dovetail gives the end of a beam a tapered tail that drops into the crossing beam from above.

Dovetail. Drawn by the editor's own geometry code.

When to use it

Use a dovetail for log building corners. The angled flanks pull the joint tight: the heavier the wall, the stronger the corner. For a joint mid-beam, switch Cut off off.

Fields

Field	Unit	Range or options	Default	What it changes
End		Start, End	End
Position X	mm	from 0	3000	End face where the tail starts. A dovetail may also sit mid-beam (cut off switched off).
Length	mm	from 1	80	Length of the tail itself, inward from the end face.
Rebate	mm	from 0	0	Extra rebate beyond the tail: the lap floor runs on that much further.
Taper	°	0 to 45	15	Taper angle of both flanks. 0° gives a straight lap with no clamping action.
Height reference side	mm	from 1	60	Sets where the flank kinks on the reference side.
Height opposite side	mm	from 1	30	Counterpart on the other side; together with the reference height, the full depth.
StartY (machine)	mm	from 0	20	Raw machine dimension: the lap floor. Everything on one side of it comes away.
StartDepth (machine)	mm	from 0	60	Raw machine dimension: how deep the cut reaches in from the face.
Cut off			on	Whether the timber beyond the joint is cut off.
Face		Top, Bottom, Front, Back	Back	The side of the part the processing is on.

Default: what Add fills in on a 3000 mm part of 120 x 120 mm.

Add a dovetail

1. Select the part in the Parts list.
2. Under Extra processings, click Add.
3. Type dovetail in the search field and pick Dovetail.
4. Set Face, End and Position X.
5. Set Length, Taper and the two heights. Change the machine values only when you copy them from a machine file.
6. Check that the part shows a green check. If not, open the Issues tab.

Tip

The drawing is calibrated against the default values in the official machine files (taper 15°, heights 60 and 30 mm). With other values the drawn angle is an estimate. The exported dimensions are always the ones you set.

Machine export

Format	Status	Details
BTLx	Supported	Dovetail.
BVN (Hundegger)	Not written	Refused: the parameter mapping is not calibrated.
BVX2 (Hundegger)	Not written	Kept when imported, not written.

A file that the app writes is not a check by your machine. See Export for what each format is for.

Related pages

• Tyrolean: The flat Tyrolean dovetail for log building corners: one angled plane per side. Fields, drawing limits and machine export.
• Housed joint: The crossing joint of a log cabin: each beam bites into the other. Eight dimensions, a dashed drawing and machine export.
• Dovetail socket: Cut a dovetail socket into a long face, with a flank angle and a square or round closed end. Fields, limits and machine export.
• Arch: Machine a true circular arc into a face over part of the length: concave or convex. Centre, chord, camber and machine export.
• Scarf joint: Lengthen a beam with a bevelled scarf joint that hooks into its counterpart and takes tension. Fields, limits and machine export.
• Straight lap: The simplest lengthening joint: two ends cut away so they overlap, held by dowels. Fields, defaults and machine export.