63mm / 2½" Sliding Blade Non-Clog Blast Gate for Workshop Dust Extraction Network

Update 24Aug20:

I've posted a new design for a blast gate based on a ball valve: Print 137795

After having unclogged the groove, in the commercially available blast gates in my workshop dust and chip extraction network, for the umpteenth time so that the gate closed fully, I decided that there had to be a better design. Naturally, I looked on Thingiverse but didn't find anything that seemed quite right. I set to in Onshape with an idea, which, as I drew it, developed into two ideas, and then into two finished 3d printed objects. They both seem to work without clogging, and each has its own advantages and disadvantages.

This is the first idea, where the blade of the blast gate passes through the centre of the airway and dislodges any dust in the groove - a self-cleaning arrangement rather than the anti-clog action of the butterfly/throttle valve of the second design. The disadvantage of this design is that sufficient space is needed for the blade to slide out of the frame at both sides. (the second design is Print 137801).

Both designs are nominally for a 63mm (2½" ) rigid tube system, as shown in the photographs, but flexible hose of the same nominal size also fits.

In addition to printing filament you'll need 4 short M4 bolts of some kind. I used M4 x 10mm socket head set screws (because I had them!). These self-tap their own threads into the holes printed into the frame, or you could use an M4 tap (or any other thread size that fits the hole). The holes may need to be eased with a suitable drill bit.

The spacers between the two frames have elongated holes so that their positions can be adjusted to change their grip on the sliding blade. If the blade won't stay where you've put it, just loosen the screws, squeeze the spacers more tightly against it, and re-tighten the screws. If the blade won't move easily...

You need to print 2 frames, 2 spacers (the stl has two) and 1 blade for each gate.

Print Settings

Printer Brand:

Anycubic

Printer: 

Kossel

Rafts:

No

Supports: 

No

Resolution:

0.25

Infill: 

10% to 15% (doesn't matter)

Filament: Steadytech & Enotepad PETG Red and Blue

Notes:

I use a 0.5mm nozzle, but I doubt that's important (except it's never clogged {so far!}, unlike the 0.4mm nozzles I started with!)

Post-Printing =============

Assembly

The two frames are fastened together back to back with the slider inserted between them and a spacer inserted at each side of the slider. The M4 bolts hold this together.

Start by inserting and loosely bolting in a spacer at one side.

Slide in the slider from the unfixed side and then insert and bolt in the second spacer.

Tighten the bolts with sufficient squeeze inwards on the spacers to give a reasonably stiff action for the slider.

To help in holding the slider closed, there are a couple of small wedges incorporated into the slider adjacent to its handle.

Category: Machine Tools