Downdraft box modification.....

[Terry Hatfield]

I used my new downdraft box Sunday while I was routing some mdf. It worked great but when I put the fairly large mdf pieces on the box the air moving through the remaining open holes was very loud.

I laid out a grid in-between the pegboard holes and drilled 165 1/2" holes with a forstner bit. It is much better now. I tried drilling the peg holes larger on a piece of scrap but could never get the holes drilled cleanly. This method worked out much better.

Terry

[Von Bickley]

Terry,
I have been checking out your downdraft box and really like the way everything looks. If you were building the box as a stationary unit with legs, would it be better to have the dust port located on the bottom/center of the box, or would you installed it on the end in order to pull air across the box?

[Terry Hatfield]

Von,

Seems to me it would probably be better if it were in the middle of the bottom but I really am not for sure. There is more suction closer to the outlet when nothing is on the box, but as soon as you put a good sized piece on in and start sanding or routing the air flow pretty much evens out over the entire surface. If I were to build one free standing I would probably try the bottom center outlet using a bigger register boot.

I am quite pleased with the performance. I hate routing MDF because of the shop full of dust and the DC attachments for the PC routers always seem to be in the way. I just can't run a router with a hose hanging off of it. The box didn't get every bit of dust but it sure got most of it. Made the experience much nicer. I don't know why I didn't build one sooner.


Terry

[Jim Becker]

Originally posted by Terry Hatfield
I used my new downdraft box Sunday while I was routing some mdf. It worked great but when I put the fairly large mdf pieces on the box the air moving through the remaining open holes was very loud.

I have this kind of problem...sort of...with my router table. The Rout-R-Lift has a little hex-shaped hole for the height adjustment tool to fit into. If I don't keep a little wad of paper towel stuffed in that hole while the DC is running...it's a whistle louder than one of our birds doing "Yankee Doodle" when he gets in the mood. This started when I built the new table and equipped it with a 4" port, rather than the smaller 2.5" one that the previous router station had.

[Gary Bindel]

I have the same problem with mine, only I don't need to cover any of it to have the noise problem. Did the forstner bit give you a good clean hole? I drilled a couple of 3/4" holes to make it easy to remove the panels, but peg board mushroomed out around the edges.:mad: I have wanted to drill more holes to allow for more air movement, but needed a way to make a cleaner hole.:confused:

[Jim Becker]

Originally posted by Gary Bindel
I drilled a couple of 3/4" holes to make it easy to remove the panels, but peg board mushroomed out around the edges.

A "sharp" forstner will leave a clean hole in this material as long as you use a backer-board to remove any chance of tearout on the back. It should not "mushoom" if it's being cut cleanly. This is one of the reasons that I've purchased "good" bits for the sizes I use the most. The inexpensive set is fine for occasional use, but they don't cut clean holes like the good ones do, even after repeated honing of the cutting edges.

[Terry Hatfield]

Gary,

Jim is correct. A good forstner bit will leave a nice clean hole as long as you use a backer board. None of the holes mushroomed, but I did do a little bit of sanding just to smooth everything out.

Terry

[Gary Bindel]

Thank you to both JIm Terry for the response.