General Woodworking

[Allan Johanson]

Hey gang,

Do you have a 1.5HP or larger DC with a 5" or 6" main duct? Are you reducing your drop size to 4" or sticking with a lame plastic factory 4" hood on the tool because you aren't sure how to change it?

You'll flow more air at the tool with a 5" or 6" drop and a matching 5" or 6" port on it. As long as the tool itself isn't too restrictive and also as long as your particular DC and duct run can support a larger pipe size.

I just want to give you some ideas and best of all these are inexpensive to make and don't take much time.

Here are a couple pics of my tablesaw and jointer. Instead of buying the expensive, small-sized factory port, I made my own by going to a big box store and buying some of their HVAC pieces. A specialty HVAC supplier will have a larger selection. But what I was looking for was an HVAC piece that has a rectangular opening on one end that tapers down to a round inlet to hook up my hose to.

For my tablesaw I'm using an "end boot" with a 4"x10" rectangular opening on one side and a 6" round opening on the other. A scrap piece of plywood and some caulking makes it fit.

For my jointer I found a "side take off" that roughly fit my jointer opening. Once again, a little plywood and caulking as a way to fit the HVAC piece to the tool was all that was required. The hood is attached by screws from the inside of the tool into the plywood.

My Delta 12-1/2" benchtop planer took a little more effort to make, but here's what I did involving copying the Delta design but making the attachment frame from some 1/4" (6mm) Baltic Birch plywood and using an HVAC universal boot that has a 4" x 10" rectangular opening and a 6" round hookup.

Let's get to it!

- Factory hood on left, HVAC piece on right

- Got the plywood cut to size and have moved over the metal lip

- Cut opening in the plywood and glued/screwed it together.  Also rough trimmed the HVAC piece to fit on the plywood.

- Hood complete.  HVAC piece is bolted to the plywood at the metal lip.  I used PL Premium construction adhesive to glue the metal to the wood.  I also sealed any gaps with metal foil tape on the inside and out.  If you only tape the outside then some sticky residue will be on the inside and shavings might stick to it.

- Hood installed.  The best part is the really annoying whistling sound that was there before is gone now!

Doing some airflow testing has only shown a very modest improvement in this case, but that's due to the very restrictive design of the machine.  Not much air can move through it.  An acquaintance of mine gave me a great idea for how to modify this initial hood design and one of these days I'll redo it and test it out.

My bandsaw is a Jet 14" that came with a tiny 1.5" or so port under the table only suitable with a shop vac.  I wanted something better that would work with my cyclone, so once again I did my own thing.  Since I use 6" flex hose to hook up many of my tools, I wanted a 6" fitting on my bandsaw.  The problem is the bandsaw is very restrictive internally and I wanted two hoods, under the table as well as on the door.

I decided to permanently mount an HVAC 6x6x6 wye on the saw and then reduce the two legs to the sizes I wanted.  4" to the door and 5" to under the table.  This whole setup stays on the saw and I simply move my 6" flex hose from tool to tool.  It works well in my crammed shop.

For my SCMS, I decided to go with a large shroud.  Unlike some other models, my particular saw doesn't have through holes in the saw blade relief area in the table. So an under-saw hole in my bench won't work.  No problem, I just cut a large hole behind the saw in my bench.  To get the max airflow I could, I'm running the full diameter pipe from my main duct (7") to the saw.  Then I got the largest 7" round to rectangular HVAC fitting I could find and modified it to make it even larger.  Now I have plenty of airflow behind the saw.  (note: a future mod to this shroud will be to add some simple sliding doors that I can use to help close up the gap between the edge of the shroud and the blade.)

The 3" hose from the port by the blade simply hangs in the large hole in my bench.  It's free to move in/out and left/right as I move the saw.  Rounding over the large hole in my bench with a router helps increase the airflow (by reducing resistance) as well as allows the 3" flex hose to move along the edge of the hole a little easier.

I'm not fond of this crude adapter for my 3" hose, but it'll do for now.  Ideally there wouldn't be such a restriction from the flexible "hood" by the blade and the 3" hose.  This cuts down the airflow a fair amount.  One of these days I'll change it.

With each of these modifications, the total cash outlay was only a few dollars and they don't take very long to make.  Airflow was improved and I'm able to breathe a little easier.

Cheers,

Allan

[Sawdustr]

Hello Allan,

You have a pretty nice set up there but, I am against having to step over anything higher than 1/2" on the floor and the reason is that I have what is known as a dropped foot and it is like walking on a prosthetic leg so I prefer to make collection boxes that I keep promising myself I am going to make but as yet have not done so. However I do clean up after the pile is only about 12" high under my compound miter and or table saw at least before the cats start using them for a litter box.

My kids usually stay out of the way while I am working but, when I am not they start scratching to do their business. I have seven male and one female cat that usually stay out doors unless the weather and chill factor gets so bad that I allow them to stay in the shop and then it is clean up every day except for one location where I allow them to do their business and clean that part up each morning.

Boy, do my boys keep a tight ship as any strange Tom cat that comes in the yard they are on him like stink on crap.

[Fred Hargis]

Allan, I like that bandsaw setup and intend to upgrade mine to a similar connection once I get moved into my new shop. My current setup only has the 4" going to the lower door, so I'll only be adding the side connection. Great stuff! My Delta DS only had a factory 4" port, and it wasn't designed to be changed to 6". So I made my own....not very pretty, but really functional!

[Allan Johanson]

Hello Ralph!

If you are referring to the mess in my shop, it's only mostly that way during racing season.  Thankfully it's only from March to October around here.  Then in the winter/early spring it can get a bit messy too.  That's only from October to March. 

If you are referring to the hose from the bandsaw, that was only laying on the ground on that position for the pic after assembly.  I don't like stepping over hoses either.

Cheers,

[Allan Johanson]

Excellent job, Fred!  I have a Performax 16-32 sander and it needs a new top bit like yours since the single 4" port could be a lot better.  I was thinking of making my lid to hold two 4" hoses, one on each side. I have another idea if I find that could be improved too. 

Cheers,