This is how to easily home construct a versatile and inexpensive vacuum hose adapter for a DeWALT DWS 779 or DWS 780 miter saw for the factory saw dust collection port that is better than the DeWALT accessories. No mods to the factory port itself are needed.
After recently purchasing a DeWALT DWS779, I learned like others that DeWALT decided not to use a standard vacuum hose connection on their dust collection port on the saw, opting instead to offer a proprietary quick connect adapter system that has differing adapters for their various tools.
Step 1: Homemade Vacuum Hose Dust Collection Adapter for DeWALT DW 779/780 Miter Saw
I did not prefer the DeWALT solution and decided to roll my own. Not readily finding a home-made approach I preferred on the web, I did my due diligence & engineering and arrived at this easy alternative that I think has advantage over the DeWALT accessories, can be built in minutes, and is cheaper by almost half!
This homemade vacuum hose dust collection adapter is also more versatile than the DeWALT available dust collection port set of accessories needed to connect a 1-1/4 and/or 2-1/2 inch standard vacuum hose to the proprietary “quick connector” dust port on the saw. It is just as much a quick change approach and even a simple change for differing hose sizes as there is no need to unscrew the extra adapter DeWALT requires and risk losing it.
Step 2: DEWALT APPROACH (for Reference)
Step 3: HOME BUILT APPROACH (parts)
Step 4: HOME BUILT APPROACH (procedure)
Shorten the Item 1 shop vacuum multi-adapter smaller stepped pipe. Cut off the adapter portion to 4-3/16 inches long from the large end. This retains the proper inside diameter step to take a 1-1/4 inch standard vacuum hose inserted from the large opening end. Discard the smaller stepped cutoff piece.
Install the Item 2 rubber coupling with the small 1-1/4 sized end onto the saw dust extraction pipe on the rear of the saw. Lightly tighten the worm drive screw clamp.
Insert the multi-vacuum adapter smaller end into the large end of the flexible coupling until it is well seated but not jammed in. The worm drive screw clamp on this end of the flexible coupling is not installed/used. This allows the vacuum adapter to be easily removed and used for other vacuuming tasks if desired.
Step 5: HOME BUILT APPROACH ( Usage)
Now we have three different “quick change” usage choices available for dust collection:
a) Insert the factory dust collection bag into the large end of the vacuum adapter until it seats
b) Insert a 1-1/4 inch standard vacuum hose through the large end of the vacuum adapter until it seats
c) Insert a 2-1/2 inch standard vacuum hose into the large end of the vacuum adapter until it seats
Note: If there is no intention to ever use a 1-1/4 inch vacuum hose then the "stair step" on the multi-adapter that the 1-1/4 inch hose affixes within can be cut off to further improve suction flow into the 2-1/2 inch hose or the dust bag. This is an irreversible step if the adapter is shortened in this way.
Step 6: Conclusion
The approach provided here is, in my view, an improvement on an already great saw and is both a cheaper and more versatile approach than the proprietary factory method for dust vacuuming attachments. In addition, your investment in the vacuum multi-adapter can always be used for other normal vacuuming purposes between the two hose sizes in the shop or on the job. I hope you find this modification useful in your shop.