A router's greatest strength, and among its largest liabilities, is its ability to quickly turn waste stock into dust. There are better solutions when the router is table mounted, but your options are limited when you work freehand.The vac adapter mounts on top of the router base with two knurled thumbscrews. Thumb and forefinger are all the tools I need to install or remove the adapter. The symmetrical mounting allows you to install it pointing away from you, or toward you, displacing the clear guard temporarily. Like all vacuum ports in or above the base, dust collection is effective only for face cuts; you'll still need a side cup to collect the chips on edge cuts.
The port is a non-standard size, or at least it didn't fit anything I had in the shop. I epoxied a universal adapter to the end so I could connect my shop vac hose.
Its location above the base plate means you have to remove the bit before installing or removing the adapter. It would be an unusally short bit that would clear the small space remaining. No matter which way you point the outlet, front or back, I found it difficult to change bits with the adapter installed. Pointed out the back, it set the router on its wobbly, round part of the base. Sticking out the front, it took minor contortions to get at the collet lock. Removing the adapter to simplify bit changing is not an option; it goes on before the bit, and comes off after the bit. The best solution I found was to set the router (a 1613) upside down on a short length of 2x4. This fits nicely on the flat spot between the power cable and the micro-adjuster.
The smallish throat further limits the size of bit you can mount, and also your visibility. Even so, it's a minor improvement over leaving the view obscured by chips and dust.
One last surprise came while cutting a dovetail slot. First, the vacuum was effective at removing the chips so the bit wouldn't burn. The surprise was the shriek made by air rushing through the small gap left between the adapter throat and the collet. The dovetail bit is rather short, so the plunge was almost at the router's limit, putting the collet right at the top of the adapter. This reduced the throat size to where the air rushing in shrieked loud enough to obscure the shop vac's whine.
Overall, the vac adapter does what it was made to do: pull chips from face cuts. It won't help appreciably on edge cuts, and you'd be tempted to remove it if you didn't have to pull the bit first. It's effective enough on face cuts to tempt you into installing it. So, sometimes it's mounted; and other times I don't bother. I wish for a better solution.
