The Mark 1 enclosure was OK – ish at keeping the dust under control but was pretty useless at reducing noise levels and so I decided to start fresh and this is the story of this CNC Enclosure Build.
Maybe a bit of background first. I’m using a 1000 x 1000 Ooznest Workbee predominantly as a hobby and for developing projects that I sell on Etsy etc. I’ve been machining predominantly Oak and Beech to depths of around 35mm as well as working with ply. The dust extraction is courtesy of a Clarke CBE3; a 1HP unit that will draw 450 cu ft / min and unlike shop vacs can be run continuously; it lives in a separate sound proofed space.
The Mark 1 had an old dining table as a base and walls of MDF sandwiching some 50mm polystyrene and and the doors were made of twin wall polycarbonate sheet.
Concept for the new design was to have a torsion box to mount the CNC machine on to for a mix of rigidity, flatness and for sound proofing. The walls and doors were to be formed with outer skins of MDF, an inner skin on the machine side of plasterboard, with a 50mm thickness of sound proofing quilt in the middle.
The Base
The top surface is 18mm Ply and the bottom surface is 12mm MDF with the ribs for the frame being made from 18mm ply cross lapped at intersections for rigidity. The gaps between the ribs were filled with sound proofing quilt and the top and bottom sheets were glued and screwed to the ribs. The whole thing measured 1500mm deep and 1600mm wide.
You’ll see some holes in a board at the top of the image, These link in to 4No. 68mm diameter pipe to feed to the outside to give me fresh air from the given the suction of the dust extractor and, hopefully, a good seal on the whole enclosure. They are purposely off centre in order to get air flow closer to the Duet controller.
The Walls
I only needed to build one wall, to the left of the frame shown above, The back wall is an external, and the one to the right is the dividing wall to the extractor.
Photos above show the general build of the wall. The window gives me a view of the machine from my desk next to the enclosure – its 450mm square and double glazed. The sound insulation is 50mm thick Rockwood Sound insulation slab and the plasterboard is 12mm Knauf Sound Panel – it’s much denser and heavier than conventional plasterboard.
The dividing wall to the extractor was treated to an extra layer of quilt and board that I had left over – this and the other wall were treated to a layer of carpet to reduce the harshness of and sound.
The Doors
The door to the front is made of two centre hinges panels all hung from the right hand side. This was primarily because I didn’t have the space to open a full width door and mechanically the lever arm effect at the hinges will be reduced slightly.
Door construction is similar to the walls – inner and outer skin of MDF and an infill of sound proofing quilt.
The seal around the door, frame and openings is a closed cell self adhesive tape.
Did it work?
As far as dust control – it has been a success which is not surprising given the Workbee now sits and a sealed box. Significantly, the Duest controller would have been covered in a fine dust but now, with the door closed and the extractor running this no loner happens.
Noise levels are down loads as well.
OK not a truly scientific sound measurement but recording around 78dB via my trusty mobile phone app with the door open. But then once the doors are closed there is a useful reduction.
Sound levels are down to around 41 dB and noticeably more comfortable to work beside.
The router is a trusty Makita and it’s running at full speed in the tests – I generally have it running much slower when working so there’s a further reduction in noise levels. Since finishing the original work, I’ve added some secondary seal to the door and bonded 100mm Celotex to the underside of the base – it was destined for the skip!
Hope this has been useful.
The Knauf Sound Board and Rockwool Sound Panels came from the local DIY / builders merchants. Ply came from Stoke Ferry Timber and the double glazing came from N & C Glass