4″ Dust Collection Mod

Let’s make life easy shall we…

Our Shopbot CNC router creates a lot of chips. The current system is a Central Machinery (Harbor Freight) single bag , over and under. Considering it has to pull the chip stream up a few feet, it works great. The lower bag holds about 30 gallons or so and can be quite heavy and awkward to empty. The plan is to put an unused cyclone lid inline on a wheeled 42 gallon barrel. This should make emptying the bag on the collector less frequent and make the whole process less arduous.

Photo of dust collector
Central Machinery 97869 ( Harbor Freight )

The cyclone lid we have is a Veritas brand made for a shop vac. The inlets are 2.5 inch female, our system will require 4 inch male flanges.

Unmodified cyclone lid
Veritas Cyclone lid for 2.5″ connections

Using Fusion360, I modeled a flange with a suitable diameter and exported it as an .stl file. Using Technocopia’s common space printers (Lulzbot Taz6) , I printed out a pair .

two four inch flanges on table
4″ Flanges ready to be installed

The modification to the lid was very straightforward. The lid had space around the 2.5 inch holes to enlarge it to 4 inches. My guess is that they sell a 4 inch version produced from the same lid component. A Dremel tool with a cut off wheel removed the bulk of the material then I switched to a course sanding drum and carefully ground away to the scribe marks.

completed lid on a barrel
Completed lid awaiting installation by the shop steward.

The fit was very good and the hose connections would likely have kept the flanges from moving. Since we had it available, I applied a bead of Permatex gasket maker around the filet between the neck and the flange and seated it firmly into the lid. This should insure an airtight lid for maximum efficiency.

The dust collection closet had some used sections of 4 inch hose and some clamps. Allowing the gasket material to cure over a weekend, the installation was a breeze.

By using a donated lid, some spare hose components and some shop supplies the cost of this upgrade was zero dollars. The design and time to do it was minimal. I liked doing it anyway as it was a fun project that will reward me every time I see someone using it.

Author: Joe