The MINI Box Makers Kit

The Mini Box Makers Kit transforms our Mini Picture Frame Clamps into a full box-making system for mitred joints.

Using precision magnetic spacers, you can now stack clamps vertically to build mitred boxes of any width, length, or height. Each stack easily detaches for standalone framing projects, giving you maximum flexibility from a single setup.

Every kit includes a detailed instruction manual and our Spinnymajig accessory. Designed specifically to save you time when spinning those thumb screws!

Short Kit (Square/Rectangle)

Kit Dimensions:

• Max Clamping Width: 183mm or 7.25"
• Max Clamping Length: 183mm or 7.25"
• Max Clamping Height: 39mm or 1.5"

Kit Includes:

• 2x Frame Clamp Sets
• 8x Magnetic Stacker Blocks (to be inserted onto the rods)
• 4x Magnetic Spacers
• 8x Rods (if selected)
• 1x Spinnymajig

Standard Kit (Square/Rectangle)

Kit Dimensions:

• Max Clamping Width: 183mm or 7.25"
• Max Clamping Length: 183mm or 7.25"
• Max Clamping Height: 65mm or 2.5"

Kit Includes:

• 3x Frame Clamp Sets
• 12x Magnetic Stacker Blocks (to be inserted onto the rods)
• 8x Magnetic Spacers
• 12x Rods (if selected)
• 1x  Spinnymajig

Tall Kit (Square/Rectangle)

Kit Dimensions:

• Max Clamping Width: 183mm or 7.25"
• Max Clamping Length: 183mm or 7.25"
• Max Clamping Height: 91mm or 3.5"

Kit Includes:

• 4x Frame Clamp Sets
• 16x Magnetic Stacker Blocks (to be inserted onto the rods)
• 12x Magnetic Spacers
• 16x Rods (if selected)
• 1x  Spinnymajig

This clamp set makes building mitred boxes quick, accurate, and repeatable. Other sets get close, but we wanted to offer improved reliability at a more affordable price.

We also wanted it to last. So we chose materials that stand up to repeated use time and time again.

The corner brackets are 3D printed in carbon fibre reinforced composite plastic with precisely aligned brass threaded inserts. Set at 89°, the corners naturally pull tight to give you perfect, clean joints, with as little fiddling as possible.

Each set is supplied in a custom laser-cut, foam-lined box to keep the components secure, whether in use or stored between projects.

All rods and thumb wheels are individually checked and deburred after machining to ensure a smooth, precise fit. 

Please note the rods are not stored inside the box, as this would significantly increase its length. Most users store the rods vertically using the supplied hook-and-loop cable tie.

Tips for Consistent Results

• Apply low-tack masking tape to the internal faces of the clamp blocks to reduce glue build-up and simplify cleaning.
• Always clamp on a flat, rigid surface with both the profiles and the clamps bearing firmly against it to maintain accurate mitres.
• Dry-assemble the frame and test fit the clamps before applying glue.
• Wipe away squeeze-out immediately while the glue is still wet.
• Avoid over-tightening. Apply firm, even pressure only.
• Ensure mitres are accurately cut and square before clamping; clamps cannot correct poor cuts.
• Keep clamp faces clean and free from hardened adhesive between uses.
• Use even pressure on all corners to prevent racking.
• Allow sufficient curing time before removing clamps.