Miter Saw Dust Collection ( Including Chop Saws and Radial Arm Saws)
Arranging an efficient miter saw dust collection system is complicated by the ability of a miter saw to cut angles which are both vertical and compound, and slide the blade forwards and backwards. The dust can fly in almost any direction.
The same applies to radial arm saw dust collection. If you have a chop saw, dust collection is easy if it only cuts at 90 degrees, simply build a hood at the back (see below).
The dust collection systems that manufacturers provide built in to the saws are generally completely inadequate - more like a token gesture towards health and safety than an effective solution.
The reason for this is that miter saws are mostly intended as portable site saws, not to be installed in permanent positions in a workshop.
Typically, a one inch duct is supposed to direct the sawdust into a collection bag. Almost none of it ends up there. Having said that, some designs are better than others. The best are miter saws with a dust collection flange that takes the dust from the air stream at the bottom of the blade (Bosch).
This type of flange can be widened and extended
to make it more able to catch the dust. If yours is a saw with the one inch outlet at the top of the saw guard, or if you need a homemade dust collection system, read on.
Miter Saw Dust Collection Strategies - Fixed Dust Hood
A dust hood can be built behind the saw. This should be wide enough to accommodate the whole swing of the saw, and as high as the top of the saw, so that the saw dust will be directed into it.
To test how big it should be, make a few trial cuts at your largest angles and watch where the dust goes. It should be about twelve inches deep.
The base of this is where you will collect your dust. A slot is at the centre of the base running from side to side. This slot should be approximately a quarter of an inch wide.
There are two reasons for the narrow slot - firstly to make sure nothing large enough to damage the impellers on the dust collector can get down it, and secondly to maintain a high speed air flow.
The floor in front of and behind the slot should drop towards it, making the slot the lowest part of the floor. A suitable connection must be made underneath this to connect your dust collector.
Miter Saw Dust Collection Strategies - Mobile Dust Hood
Simpler and more portable is the mobile dust hood. Simply, this is a catcher attached to the end of your dust collection hose which can be clamped in the most appropriate place for the job you're doing.
You can either make your own catcher - 12 inches by 10 inches by 10 deep is a good size, or buy a pre-formed plastic one such as the "Big Gulp"
Miter Saw Dust Collection Strategies - Underneath the Saw Table
Another technique for a saw in a fixed position is to mark where the feet of the saw sit on the bench and within the footprint, cut either a round hole if you intend to buy round tube with reducers to fit the dust collector. Cut a square hole if you intend to make the funnel yourself out of ply.
Dust from the saw goes down through the slot in the table and is collected by the funnel underneath and the to the dust collector.
This can be used together with a fixed dust hood behind the saw, and the two connected with a 'Y' connector.
Radial Arm Saw Dust Collection
Generally, radial arm saws have an outlet connection for a dust collector on the part of the blade shroud nearest you when operating it. If this is not adequate, the best thing to do is build a fixed dust hood as detailed above. Related Pages Table Saw Dust Collection Drill Press Dust Collection Router Dust Collection