My Home Made Shop Vac Adapter for DeWALT DWS779/ DWS780 Miter Saw




Introduction: My Home Made Shop Vac Adapter for DeWALT DWS779/ DWS780 Miter Saw

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)

For reference, the DeWALT accessories (approximately $36) are:

For a 1-1/4 inch vacuum hose use adapter DVW9000

Additional Adapter to add for 2-1/2 in vacuum hose add adapter DWV9190

OR ---just build your own...


PARTS NEEDED (approximately $18)

Item 1: Shop Vacuum Multi-Adapter

Lowe's (preferred) is what I used

or a similar item from

Home Depot Item

Item 2: Flexible PVC Pipe Coupling 1-1/2 in to 1-1/4 inch size

Home Depot (preferred) is what I used

or a similar item from


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.


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.


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4 weeks ago

Hi Dewalt referred me to this link, I made this same adapter from Lowes work for my DWS779 when I couldn’t find one for it. My question to Dewalt was the way the inlet rubber on the other end of the tube sucks up to block the tube making it worthless when the vacuum is on. I sent them a video of it closing and that they implied it wasn’t designed for a vacuum to be used and to use the bag. The instructions says you can use the bag or with adapter you can connect a vacuum to it. The rubber I believe is to flimsy for the application. Has anyone else have this problem?. The vacuum is nothing special a 30 year old Craftsman 5HP shop vav


1 year ago

Hey there two questions for you -

If my vacuum hose is 2.5 inches then is the step connector necessary at all? Can’t I just use the 1.5 inch to 2.5 inch flexible coupler alone?

Second, I noticed that bizarrely the vacuum port on the DWS 779 is two halves screwed together as opposed to a single formed piece. Did you have any issues with air leavkage?


2 years ago

Had to log in and post you a big THANK YOU. So much easier when somebody posts what they figured out so that we don't have to do it. Found this while searching google for a compatible dust collection adapter for my Dewalt DHS716AT2 Flexvolt Miter Saw. Thanks so much for saving us all some stupid money!


2 years ago

Thank you for posting this solution! Worked perfectly on my DeWalt DW715 miter saw as well.

DIY Hacks and How Tos

Clever solution. I have a lot of shop tools that I would love to hook up to a shop vac.