Tel +44 01524 841500
High-quality fire doors require top-quality finish…. Especially when it comes to the vision panel cassettes. When producing Vision Panel cassettes, the need for an accurate mitre joint cannot be overstated. Accurate mitre cuts reduce the need for further finishing work prior to joining. Creating an accurate, tight joint is also key in maintaining the frame’s integrity as well as reducing the need for filling once joining is complete.
With the correct equipment, a skilled Joiner can produce accurate mitre cut profiles. Using the HOFFMANN Dovetail Router to complete the joint is a cost-effective way of completing the process of producing accurate, high-quality, vision panel cassettes.
Once all the pieces have been mitred (this can be done with a mitre saw or a guillotine, as long as all the 45° angles and the lengths of the workpieces are 100% accurate), the workpieces are transferred to the Hoffmann MU3 for processing the dovetail slots. The Hoffmann Keys are then inserted in the mitre joints to complete the vision panel cassette.
MU-3 Entry Level version for the quick and precise routing of dovetail slots.
MU-3 D Digital version, with electronic two-axis display for the adjustable routing depth as well as the positioning of the centre fence for the routed slot location. It is ideal for high precision work.
MU-3 P Pneumatic version for series production and high throughput. Pneumatic workpiece clamping and controlled router feed. The MU-3 P is operated by foot-pedal control.
MU-3 PD Pneumatic and Digital version – the top machine with the highest operating comfort for a wide range of requirements. Functional features are similar to MU-3 D with a digital two-axis display for the adjustable routing depth as well as the positioning of the centre fence for the routed slot location.
The MU-3 and the MU-3 D have a workpiece thickness capacity of up to 140mm – in the versions MU-3 P and MU-3 PD this increases to 170mm. Infinitely adjustable routing depths up to 95mm and protection against break-out of the finished surface. The dual-function hand lever ensures quick machine cycles when routing smaller workpieces. The scale tapes in the table and the rear fences assist the quick and precise positioning of the workpieces. All versions of the new MU-3 routing machine are equipped with a motor carriage which has vernier adjustment for the precise setting of the router cutter and hence the adjustable tension of the joint.
MU3 / D – The Fence plate is secured in the required position (digital positioning with the “D” version) and the workpiece is laid against it. The router depth gauge is selected (Digitally with the “D” version). By drawing down the hand lever, the work piece is clamped, and the router motor starts. Continued pressure on the lever brings the router up into the workpiece, to the pre-set routing depth. Returning the hand lever to its starting position automatically returns the carriage to its home position, switches off the router motor and releases the workpiece.
MU3P / PD – – The Fence plate is secured in the required position (digital positioning with the “D” version) and the workpiece is laid against it. The router depth gauge is selected (Digitally with the “D” version). Pressing the foot pedal clamps the work piece in place pneumatically and the router motor starts. The router then rises up into the workpiece, when the pre-set routing depth is reached the router carriage returns to the start position, switches off, and the work piece is released.
Once the dovetail slots have been cut into all the mitre faces, the mitres can be locked together by inserting the Hoffmann Dovetail Key all the way into the slot. Optionally, a thin layer of glue can be applied to the surfaces before bringing them together. Once the Hoffmann key is inserted, the joint is secure. NO DRYING TIME IS REQUIRED. So long as the mitres are accurate, work can instantly continue. Frames can be sprayed or lacquered before fitting into the door.
When producing fire doors, all the component parts are essential in ensuring the door maintains its integrity. Hoffmann Dovetail Keys are an integral part of many fire doors. They have been accredited with FD30 / FD60 fire safety ratings for securing the joints in vision panel cassettes. Hoffmann keys have also been successfully tested in composite fire door blanks and solid wood door frames.
For further information contact us or call on 01524 841500
