Reducing router dust
The main problem with reducing dust from your router is that the router bit is spinning at around 20,000 rpm, causing any shavings to be flung at extremely high velocity from the bit.
In this article we look at routers being used free hand, and devise a method for maximizing the collection of its dust/shavings.
Make new base for router
Metal hood with exhaust pipe
Use thin plastic sheeting for template
Fold extra material to form flange and bolt in place
Welded hood with baffle
Add shield to control saving direction and air flow
With the router being hand held, the only way to pick-up the shavings, is to use a pick-up hood mounted directly on the router. This hood is then hooked up with a hose to your dust collector (or vacuum cleaner). Bear in mind that the length and weight of hose present challenges to the safe operation of the router, and that the hood has to be positioned in such a way that it will not interfere with the changing of router bits.
The safest and most efficient way to fashion and attach a hood to your router is to make a new base and attach a dust hood to it.
The material I chose was some polyethylene sheeting that I had sitting around the shop. This material is easy to machine.
Lay out the base of the router on the material. As you lay out the base, make sure that you leave room for the hood to be attached. Countersink all holes that you drill through the sheet, so that the heads of all bolts are sunk below the surface. You will also want to round over all corners and edges, including the opening for the bit.
My hood is made from 20 gauge metal with an outlet of 3 inches. Look closely at the photo of the metal hood and notice that the outlet is more oval than round. It started off as a 3” diameter exhaust pipe, but I decided to form it so that it would take up less room. The photo of the metal hood also shows the main part of the hood after its preliminary shaping (with the outlet sitting in place).
With the base attached, place the router in its furthest down position, and proceed to design the sides of the hood. Keep in mind that the regular mechanisms must still be accessible, in order for the router to work properly. I used thin plastic sheeting as a template. Determine the height and profile of the sides. Mark out the angle where the sides will meet at the back of the hood.
You will need to leave an extra 3/8” of material along the bottom of the side panels when you cut them out. This extra material will be folded out to form the flange that will allow you to fasten the hood to the base. As with the router base plate bolts, the heads of the hood bolts also must be countersunk into the base plate.
Spot weld the hood, and bolt into position. Look closely near the rear of the router and you will see that I placed a short baffle inside the hood. That will help to direct the airflow from the area around the router bit.
The object of this exercise is to control shaving direction and air flow, therefore, it is also necessary to add a shield on the front of the router. The challenge here is to add the shield without hindering mandrel access. That means that the shield must be easily removable.
Apply a little silicone to the seams for sealing and you’re done.
To reach my work area I installed an arm and suspended the hose from it. I found that my new set-up worked great for cuts made directly over the work piece. However, when I did edge cuts, the hood only retrieved about 80% of the dust. The limitation was because of the size of the bit opening in the base plate. To improve that performance, be sure to do the edge cuts in conjunction with a downdraft table.