Exhaust fan for BMS250S CBN sharpening machine
Sawmill

Exhaust fan for CBN sharpening machine

The amount of air borne oily mist that is created from the Wood-mizer BMS250S is significant. The design of the machine’s case does less than a desirable job of keeping the mist enclosed. The only way to truly tame it is to create some negative pressure within its environment.

For a while now I had a cloth “skirt” around the lower half of the machine to help lessen the amount of oily mist escaping from the machine. The machine’s lid does keep a lot of it within its space, but even opening the lid results in the residual mist being right in the face of the operator (me).

So we needed a way to to draw that oily mist away and somehow also recover the mist that is airborne. Thanks to the Internet, someone had already thought of what is needed. I simply did a search online to find similar parts and made our own. Links are below. Our Youtube video below shows the results. In the video I said it was a 4 inch diameter fan, it’s actually a 3 inch fan.

The link to Youtube shows what the end result is after installing the parts. I attached a piece of 3/4 inch thick plywood to the back of the cover. The fan was still not close enough to attach directly to that plywood piece, so I made a smaller piece of 3/8 inch thick board to close that gap. The fan can be disassembled into a couple parts with two screws. You have to do that to mount the fan base to the board. Then re-install the fan. Easy.

The fan is sufficient CFM’s to do the job and easily draws in air and pushes it through the filter. After about an hour of use I could start to see oil dripping from inside the fan housing back into the oil reservoir on the sharpening machine. It was expected and welcomed. It means the spinning fan is colliding with the air born mist and “slinging” the mist to the inside wall of the fan, eventually gravity takes over and it drips back down.

Here are the links to the items I bought. This is not a sponsored post, the links are not an affiliate type, so I make no money from mentioning them.

Hon&Guan 3 Inch Extractor Fan High Efficiency Mixed Flow Ventilation System Exhaust Air for Bathroom Kitchen Inline Duct Fan (S Series)
Hon&Guan 3 Inch Extractor Fan High Efficiency Mixed Flow Ventilation System Exhaust Air for Bathroom Kitchen Inline Duct Fan (S Series)
Spectre Universal Clamp-On Air Filter: High Performance, Washable Filter: Round Tapered; 3 in (76 mm) Flange ID; 6.5 in (165 mm) Height; 6 in (152 mm) Base; 4.75 in (121 mm) Top, SPE-9132
Spectre Universal Clamp-On Air Filter: High Performance, Washable Filter: Round Tapered; 3 in (76 mm) Flange ID; 6.5 in (165 mm) Height; 6 in (152 mm) Base; 4.75 in (121 mm) Top

A Newfoundland born Canadian with a life long interest in woodworking, baking and anything else that peaks my curiosity.

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