Fine-Pin Dovetails Without A Dovetail Bit, For Origin

Through dovetails for Origin on the Workstation, cut with straight spiral bits only.

1) Start by entering the cutting parameters for the straight bits you want to use.
2) Enter the stock and overall dovetail joint parameters.
3) Enter parameters for the initial layout.

By default, the pins will be kept as fine (skinny) as your bits allow, but you can edit that in the layout section, or on the Pin Layout Display to change them individually.

NOTES:

  • This cutting technique leaves a radius in the tail socket corners. Either use a sharp chisel to clear the radius from the corners, or turn off Chiseled Corners in the Pin Layout Display, to round the pins to fit.
  • Dimensions as whole numbers or decimals without labels are interpreted/displayed as millimeters. Dimensions using fractions without a label are interpreted as inches. You can enter Freedom units by specifying a plain fraction (3/4 or 1-5/8), a quote (") or (in).

Pin Layout

Seen on the end of the front: the boards’ bottom edge is at the left, and the front’s outside face runs along the top.

Drag to turn · scroll or pinch to zoom
Cut Sheets
Cut area Guide Anchor
Cut Cards – also included in the SVG files above, which you can send directly to Origin or print out for reference.
Save and Open
How the Geometry Works
  • The finest bit that reaches through the side becomes the tail finishing bit. The narrowest tail socket is that bit plus the Slot Clearance. Measured from the front’s outside face, the taper keeps narrowing outward by the Slot Clearance before the socket turns into a straight slot, which sets the automatic pin width at the outside face. The overcuts past the side’s end and edges and past the front’s faces are likewise set from the bits that cut them (see Fit and Overcuts).
  • You set the Number of Full Pins, and two edge half-pins are added. With even spacing, the pin centers are equally spaced, with the end spacings measured from the half-pins’ centers, so every tail comes out the same width when the half-pins match the pins. Tails take the width left between pins, and their narrow end follows from the pin angle and the front’s thickness. The most pins shown is the limit where every tail still clears your pin bit.
  • Tail sockets are cut coarse to fine with as many of your bits as help: a Pocket with the largest bit no wider than half the socket; then any middle bits, stepping down in size, each an Inside cut held back 0.2mm; then the finishing bit, an Inside cut on the line with Roughing Passes off, so every depth step runs the full socket, including the narrow slot past the end. With only one or two suitable bits, the steps in between are left out. Pins use the largest bit that fits, as a Pocket followed by an Outside pass with a large negative offset.
  • Pass counts come from simulating each cut on a fine grid. For every bit, the page finds how wide a strip of stock that bit still has to remove after the earlier bits. A full-width cut uses that bit's Depth per Pass. A lighter cut gets proportionally deeper passes, capped at the Max Plunge Depth. The narrow slot at the board end is always a full-width cut for the finishing bit.
  • The anchors sit at the bottom-edge corner. One tails file serves both sides with the left face up. The left and right pins files are mirror images.
Fit and Overcuts
  • Joint Clearance: the gap left at each pin wall. The pins’ final Outside pass runs this far past the drawn line, so each pin is this much narrower on each side; 0 cuts on the line.
  • Pin Protrusion: the pins are cut the side’s thickness plus this deep, so they stand proud of the side’s outside face. Plane them flush after glue-up.
  • Tail Protrusion: the front’s outside face lands this far in from the side’s end, so the tails stand proud of the front. Plane them flush too.
  • Overcut Margin: how far each bit’s center runs past the board’s end, edges and faces, so every cut runs cleanly off the board. Each overcut is half the bit that cuts it plus this.
  • Slot Clearance: the narrowest socket is the finishing bit plus this, since Origin won’t cut a slot exactly as wide as the bit. The socket also keeps narrowing this far past the front’s outside face, which sets the automatic pin width.
One tail socket on the side, with the front’s pin seated in it Pin Front’s outside faceFront’s inside face Overcut Margin(bit center past end) Tail Protrusion Finishing bit+ slot clearance Side’s end Side (tail board), face up
Tails: one socket. Gray is cut away, the circle is the finishing bit at the end of its path. Not to scale.
End of the front, showing the waste between two pins PinPin Cut away Overcut Margin(bit center past the face) Outside faceInside face
Pins, seen on the end of the front: the waste between pins runs past both faces so the pin bit’s center clears each face by the overcut margin. Not to scale.
Outside face of the front near its end, showing the pin depth Cut awayCut away Pin Side’s outside faceSide’s inside face Pin ProtrusionSide thickness Front’s end Front, outside face up
Pins, seen on the front’s outside face: the cut depth is the side’s thickness plus the pin protrusion. Not to scale.