Design your own joint
Where two members cross, the app cuts a half lap for you, and where a member ends on another it cuts the end flush against it. You can cut either with a joint you design instead, and use the same joint wherever it fits, square or at an angle.
Open the designer
Section titled “Open the designer”- In Fitting, select one of the two members. Under Half lap (or Pass-through), click Design a joint…. You can also select both members together: the panel then shows Crossing with the same button.
- The designer opens with a half lap to start from, and a 3D view of the two parts cut as the joint cuts them. Part A is white, part B light blue and on top.
- Change the cuts on the right. Every change shows at once, in the preview and in the model behind it.
- Click Done. Undo and Redo at the bottom take changes back one at a time.
To start from another shape, open Joint and pick one under New joint: half lap, housing, pinned half lap, pegged housing, sliding dovetail, knife-plate slit or blank.
Click Add cut and choose:
| Cut | What it makes |
|---|---|
| Outline | Any outline, cut to a depth or right through. Click Draw on its card to draw it on the face. |
| Housing | A box sunk into a face, its walls square or leaning, or left open. |
| 3D housing | A housing whose floor tilts along and across. |
| Drilling | A bore, square to the face or leaning. |
| Peg through both | One bore through both parts on one axis, for a pin or a peg. The two holes always line up. |
| Rebate | A channel along the part, open onto a side. |
| Groove | A channel along the part between two walls. |
| Saw cut | One saw pass, or a kerf of a set width for a steel plate. |
| Sliding dovetail | A dovetail housing across one part and the ridge left on the other, slid in from the side. One cut makes both halves, so they always fit. Only where the two parts cross square. |
Each cut has a card. Pick the part, and click the face on the small drawing. Positions are measured from the middle of the joint: along the part and across the face. Click a card to show its cut in blue in the preview. Make the mate puts the same cut on the other part.
Sizes that follow the timber
Section titled “Sizes that follow the timber”Every size is either mm or Tied. A tied size is a share of the timber, such as 0.5 × the other part’s width, and the field shows what that is here: = 50 mm here. Tied sizes are what let one joint fit crossings of other sections.
An angle is degrees, or Tied as a rise over a length, so a sloping floor keeps its slope wherever the joint is used.
Check the fit
Section titled “Check the fit”Under the preview the designer says whether every cut is made and the two parts fit. A cut that cannot be made shows its reason on its card. If the parts still share timber, it says how much.
With Machining compatibility set to BVN or BVX, a joint is cut whole or not at all: if one of its cuts cannot be written in that format, none of it is cut, and the part says why.
Special machines
Section titled “Special machines”A 3D housing, a leaning housing wall, a bore leaning across its face or a sloped rebate wall needs a five-axis head. Such a cut carries the Specialised machine badge on its card, and the joint carries it too. See Which machine can cut it.
The joint library
Section titled “The joint library”The outliner lists your joints under Joints, each with a drawing, how often it is used and the badge it needs. Click one to open it, double-click the name to rename it. The icons select the parts that use it, open, duplicate or delete it. A deleted joint gives its crossings back to the half lap and its ends back to flush.
In the designer, Apply to all matching crossings cuts every crossing of the same two sections that still has the automatic half lap, and where the joint fits.
A joint at a member’s end
Section titled “A joint at a member’s end”A joist on a beam or a post under a plate is cut flush against the member it meets, the host. To cut it with a joint instead, select the member: under Ends on a beam each such end offers Choose a joint (so does each end in a point’s panel, and the member selected with its host). Every starting shape is drawn on this end’s own sections: Let in, T housing, Stepped housing, Partial housing, Housed tenon, Round tenon, Dovetail, Knife plate with dowels or Blank end. Pick one and the designer opens on this end.
Dovetail runs the end 28 mm into the host and puts a dovetail tail on it, with its socket in the host: the usual 60/45 cutter, with a 15° flank and a 46 mm round end. The tail stands as far out of its shoulder as the end runs in. Under Runs, Down points the tail down the host’s face, so a joist drops in from above whichever side it arrives from; At an angle turns it. Where the host is split under the end, the socket is cut into both halves. A tail owns its end, so the joint takes no tenon or end work beside it. Make the mate works at an end for a dovetail only: on a tail’s card it adds the socket, on a socket’s card the tail, with the same numbers.
The End cut says how far the end runs into the host: drag the arrow at the end in the preview or in its card, or pick flush, 20 mm, a quarter or half of the host. A housing tied to it follows. An end also takes a Tenon, and a bore, mortise, recess or slit in its end face. Apply to all matching ends cuts every flush end of the same two sections where it fits.
Stepped housing lets half the end in a quarter of the host deep and steps the other half shallower, the way a jack rafter sits on a hip; Partial housing lets in only half the end. A Stepped end card in any end joint sets which long face the step opens onto, how deep it goes and where it stops, its shoulder always parallel to the host’s face. Round tenon is a housed tenon with round ends in a mortise as a router cuts it; any tenon and any housing can take round or radius corners on its card.
Two ends may meet a post at one height from two sides, as ring beams and knee braces do in a timber frame. Both are cut as long as their mortises and peg holes miss each other and leave timber across the post. On the Tenon card, Off the middle, across its thickness moves a tenon toward one face; give its mortise’s centre the same number on the mortise’s card, so two tenons from neighbouring sides pass each other. Where they still meet, both ends go back flush and each says which part it met.
Joints at an angle
Section titled “Joints at an angle”A joint you design square also cuts members that meet at an angle. You do not redraw it: the designer shows the angle as a badge beside the machine badge, says in a line what the joint does about it, and each cut says what it follows.
- Crossing at an angle. Lengths along a part are still measured along it, but lines across a face run along the other part’s side. So the other part’s footprint is its real print, a parallelogram, and × other’s width is its length along this part. Outlines, housings, saw cuts and bores follow; a square bore or saw cut stays square, so one knife plate still stands in both kerfs.
- Member rolled. Where the faces do not lie flat on each other, a recess in the contact face becomes the housing that takes the other part: its ends follow that part’s faces and its floor lies square to where the two meet. A half lap gives each part such a housing.
- End at an angle. The end is cut to lie on the host’s face, and cuts in that face follow the end: a housing sized from the end is its print, its walls leaning with it. At a point where the host is split, the housing is cut into both halves.
A tenon or a dovetail tail on an end at an angle stands square to the host’s face, in a mortise or socket square to that face too. A housing that tilts or leans needs a five-axis head, and carries the Specialised machine badge. Work in an end that is not square, such as a bore or a slit, is not made yet: the starting shape says Does not fit here, and the part says why. An end square to the host but turned about its own axis takes every starting shape. Members closer than 15° to parallel, or an end nearly along the host’s face, take no designed joint.
Where two members cross at any angle, a script, an assistant or a building system can also let one into the other, as a carpenter lets a post in for a block across its corner or scribes a hip round a post. The member let in loses, as one pocket, whatever of the other it runs into; the other stays whole. Where the timber they share is no pocket a cutter can take in one go, nothing is cut and the part says so.
A rafter crossing a plate gets a birdsmouth where its mouth is square and shallow. At an angle in plan, or deeper, it is let in the same way, as one pocket; a seat deeper than a third of the rafter is cut and named, so you can check it.
A rafter that ends on a plate sits on it: its end gets a seat on the plate’s top and a plumb cut flush with the outside, so it bears on the plate instead of hanging off its side. Drawn from the plate’s centre line, that seat is deep, and the part says so; a hip foot is not seated.
A copied selection brings its joints along, also into another project, and so do components.