63mm / 2½" Truncated Ball Valve Type Non-Clog Blast Gate for Workshop Dust Extraction Network

Update 30 Sep 25
Michael Bohrer (MichaelBohre_2970532) commented that he had broken this design because parts of it were too thin. On investigation, I agree that the outer edge of the connecting tube is thinner than I intended. I've therefore made a miniscule change to the design that has yielded a connector tube that is twice as thick as the original, and much closer to what I intended, without changing the connecting tube diameter significantly. To date, I haven't printed this change since I haven't experienced the same problem as Michael and the blast gates that I'm using are all working fine and I don't need to replace them. The modified part is labelled “Case (Thickened).step”.
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This latest design is based on my 63mm/2½" ball valve but truncated to slim it down. This truncated design fits better against a wall than the full size version. I've printed this and, as for the my other ball valve blast gate designs, had it working successfully without clogging. I've also designed a bracket to fasten this to a wall or other support, and incorporated some end stops for the lever, on one side of the case, to positively indicate that the blast gate is in either the fully open position or the fully closed position . This blast gate is intended to sleeve into the UK standard 63mm extraction network tubing and/or 63mm flexible polyurethane tubing (with the helical wire support). I have, however, also included an adapter that sleeves onto this blast gate and intended to fit to 50mm tubing (I don't have any 50mm tubing so this aspect of the design is untested - helpful comments will be gratefully received). The adapter is not included in the 3mf file

In addition to printing filament you'll need 4 short M4 bolts to fasten the two halves of the tube together (I used 2 M4 x 10mm socket head set screws and 2 M4 x20mm to also hold the bracket to the valve),  and an M4 x12mm bolt to hold the lever onto the rotator ball. The holes in the tube / ball housing may need to be eased with a suitable drill bit - 4mm on one side and 3.3mm (for tapping to M4) on the other, or you could drill straight through and use slightly longer screws with nuts (or use heat-set threaded inserts!)

For one blast gate you need to print:

2x case, 0.2mm layer, 4 perimeters, 20% infill, needs support & a brim
1x rotator, 0.2mm layer, 3 perimeters, 10% triangle infill, needs a brim
1x lever, 0.2mm layer, 5 perimeters, 20% triangle infill, needs a brim
1x lever drive, 0.2mm layer, 7 perimeters, 20% triangle infill
1x bearing, 0.2mm layer, 6 perimeters, 30% triangle infill
2x flange seals (Flange seals 1 and 2 are identical), 0.2mm layer, 4 perimeters, needs a brim
1x bracket, 0.2mm layer, 4 perimeters, 20% triangle infill

It's useful to use different colours for the lever and for the tube so that the position of the ball (open or closed) can be seen easily. I mount the lever parallel to the direction of air flow, but it could be mounted 90 degrees around from that should you wish.

I've included step files in addition to stl files. The Bambu Studio 3mf file can be opened by PrusaSlicer  versions from 2.7.4, and includes all the above settings.

Update 11Oct24
Case.step & Case.stl files (and the same on the 3mf) have improved wall thickness at the point where the connector joins the case. With thanks to JB510 who notified me of this problem.