Down-draft router table dust extraction?

[cgallery]

I've been working on my router table extension for my BT3K. I am using a Rockler FX router lift. I've thought about adding an under-table box for down-draft dust collection for dados and other instances when the fence-based dust collection isn't effective. However, I've read a few articles elsewhere from people that say it doesn't work that great. Any opinions?

Thanks,
Phil

[JimD]

Phil,

I have a router table and a router table capability in the extension table of my BT3100. On the BT3100, I hung a box with a door around the router under the extension table and then put a 4 inch dust port on the bottom. Then I hooked my 1 hp Delta DC to the port. I sucked everything out the bottom. This worked pretty well but I think the router got hotter than normal. I might have just been that it was working hard but I got a little worried that the DC was moving air the opposite direction of the cooling fan of the router.

On my router table, the motor is on a lift which fills almost all of the router area. I have the DC hose routed to the top of the lift plate so it sucks with the router instead of against it. I also have suction off the fence.

There are situations where the fence port doesn't pick up much of anything. Suction from inside the cabinet will help in those situations. If you can, moving the suction port up where it can work with the router instead of against it is a good idea, I think.

Jim

[cgallery]

Phil,

I have a router table and a router table capability in the extension table of my BT3100. On the BT3100, I hung a box with a door around the router under the extension table and then put a 4 inch dust port on the bottom. Then I hooked my 1 hp Delta DC to the port. I sucked everything out the bottom. This worked pretty well but I think the router got hotter than normal. I might have just been that it was working hard but I got a little worried that the DC was moving air the opposite direction of the cooling fan of the router.

On my router table, the motor is on a lift which fills almost all of the router area. I have the DC hose routed to the top of the lift plate so it sucks with the router instead of against it. I also have suction off the fence.

There are situations where the fence port doesn't pick up much of anything. Suction from inside the cabinet will help in those situations. If you can, moving the suction port up where it can work with the router instead of against it is a good idea, I think.

Jim

I sure wish I could see a photo of your current configuration (dust collecter routed to top of lift). I'm not sure if I'm getting it.

From your description is sounds like you have an under-table cabinet/box, but that the extraction happens at the top of the box rather than the bottom. Am I correct?

So I assume that you have to occasionally clear the bottom of the box of whatever debris makes it down there?

Thanks!
Phil

[MilDoc]

One thing I have read about this arrangement - with suction applied from the top of the router (as it would be with a box around the router in a table) air flow is going against the air cooling of the router itself, which directs flow from the top to the bit. I don't know how important this is.

Comments from those with more experienced?

[just4funsies]

I think I'd try to get as much as you can from above the table. Pulling any more dust below the table than what would occur naturally might tend to gum up the works in the lift, especially if you lube the fittings. Use an insert ring that fits neatly around the bit.

[Tom Miller]

I built a box around my table-mounted (not accessory table) router. Out of convenience, I use the underside DC (through the box) almost exclusively. There are times when only the underside DC will be effective (dados), but I can't think of such times for the fence DC. There are lots of times when either would work.

Even though I can't remember the last time I used the fence DC, I think the dust port on the fence is the key to good dust extraction through the throat plate.

Regards,
Tom