Mini 3D Assembly Square

A smaller, smarter version of our Original Midi 3D Square — designed for projects where space is tight but accuracy still matters.

At less than half the height of the Original Midi version, the Mini 3D Square is ideal for drawer boxes, narrow carcasses, frame units, and door linings, where the full-size jig is too tall. It’s also perfect for precise alignment of studwork frames or compact shelving, and can even be used upside down on the bench for small-section timber joints.

Hold parts tight and square in three dimensions with no fuss, and screw directly through from the outside — knowing your joints will stay perfectly aligned.

See Gaz from GNJoinery building door linings with them in a video in the gallery.

*For limited periods only we may have stock of ultra-rigid and pre-assembled Compacmel mini squares. We no longer offer this material for the Midi and XL squares due to it's weight, but for the mini square it is well balanced and ideal for site-fitters - put it in your toolbag or tool caddy where you can grab it easily, you'll always want it within reach.

IMPORTANT: After initial push-fit assembly, all screw holes must be piloted to the full depth of the screw using a 2.5mm or 3mm diameter drill bit (not included).

Why it works

• Holds parts perfectly square in 3 dimensions for precise screw-fastening.
• Eliminates marking out, dominos, biscuits, or complicated joint prep.
• No fiddly 2D clamping squares, just fast, accurate, strong joints — every time

Smart, Practical Design

• Unique overhanging lip for perfect visibility and alignment from a single face mark.
• Corner details act as a guide for marking and squaring screw positions.
• Side guide holes (optional to drill) allow fixing to rough timber for studwork or framing.
• Compatible with Festool, Makita, and DeWalt rail clamps, plus most Irwin types (except mini variants).  Clamps are not included.

Perfect for DIY & Trade

DIY: Makes tricky assembly jobs simple with minimal tools.

Trade: Speeds up production and boosts efficiency on site or in the workshop.

Workshop-Tested

At Freebird Interiors, we've used this jig concept for many years before refining and improving it for CNC production and sale to you. 

We still regularly use this jig in our 2600 sq ft Sheffield workshop, alongside CNC, Lamello, Festool and Mafell tool systems - because sometimes, this simple tool is still the most efficient solution.