Thread: 2hp dust extractor mod - build

re the flex and 4"pipe I seem to recall I shrunk the 4"down a little to get the flex over the outside of the 4"




Pete

Originally Posted by mannum3

Thanks Bob, Just checking.......the blue lines and figures? flow in feet per minute?

Yep

Thanks, I'll aim for 6". It seemed too good to be true that I had the perfect length of 5" flexy and a decent shaped 5" machine mount! Now I'll need to find some more 6" flex in Canberra.

In terms of the 4", yes it was substantially smaller than the dwv pipe. But everyone else seems to find this a close fit so maybe I was testing with an odd piece. I'll check again when I get back in a few days.

Thanks

Trav


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Made a bit of progress in the last few days. The first photo is of the bandsaw, now connected. I will add a third line in soon, but I ran out of Wye junctions. I was planning on mounting it at the back of the table somehow to collect the dust that is not drawn down into the machine. I'll have a hunt around to look at the approach others have taken. I'll add a blast gate in just before the 6"-4" reducers.

I've cut out the useless crosses that were inside the machine ports, but from what I've read, I'll possibly need to add a few more vent holes in the bottom of the machine door to allow enough air to get in. Let me know if this is not correct.

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I've been researching and building blast gates for the last few days on and off. They all look easy, but I've found them harder to make in practice. The next few photos show my progress. I'm using 9mm mdf for the walls, but fixing the 150mm PVC has proved tricky. I cut the holes with an adjustable hole saw on the drill press until I got the hole just right. For some I have sized the hole to fit snugly inside standard 150mm pipe, and for others it is standard diameter. This way I can cut the holes just one size, mounting the pipe inside the hole for the smaller diameter and on the face for the larger size. Hopefully the bond will be strong enough, but I guess time will tell. I'll assemble them tomorrow.

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Once the blast gates are in place, my next job will be all the machine connections. Bandsaw is largely done, the jointer should be easy enough, but it's the table saw I am thinking about now. It has a less than 4" port at the bottom, just below the door to the back of the cabinet. There's no room to expand the port - it is already at the bottom of the dust chamber in the saw. I don't want the ducting to come straight out the back of the cabinet as there is only a small space between the saw and the jointer. My tentative plan is to bring it out on an angle, almost like the dust port on a big thicknesser. I'll try to sketch up a plan at some stage.

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Trav

The first few pics in this thread Dust extraction upgrade at Roy Schack's workshop shows what I did to Roy's TS, might be a few ideas there for you Trav.




Pete

Here's a pic of my small saw. It is a remarkably clean bandsaw. Essentially, it is three 90 mm lines feeding into a 150 mm main line.

IMAG0036.jpg

This pic shows the original port ... soon opened up with an angle grinder.
IMAG0032.jpg

I followed Chris Park's lead and held the door to the lower cabinet open by about 20 mm with a wedge. Works perfectly well.

Originally Posted by Trav

Made a bit of progress in the last few days. The first photo is of the bandsaw, now connected. I will add a third line in soon, but I ran out of Wye junctions

Instead of using lots of Y junctions to reduce from a 6" duct down to 3 (or more) 4" ducts for a BS, given that most BS are constricted one possibility is to just cut diagonal 4" holes into some 6" ducting and poke some 4" ducting thru these holes and glue oR seal them up with silicon.

I've cut out the useless crosses that were inside the machine ports, but from what I've read, I'll possibly need to add a few more vent holes in the bottom of the machine door to allow enough air to get in. Let me know if this is not correct.

yep

. . . I cut the holes with an adjustable hole saw on the drill press until I got the hole just right. For some I have sized the hole to fit snugly inside

I assume you mean outside?

It has a less than 4" port at the bottom, just below the door to the back of the cabinet. There's no room to expand the port - it is already at the bottom of the dust chamber in the saw. I don't want the ducting to come straight out the back of the cabinet as there is only a small space between the saw and the jointer. My tentative plan is to bring it out on an angle, almost like the dust port on a big thicknesser. I'll try to sketch up a plan at some stage.

Thats one port that really needs to be a6" port. What's in the way?

Originally Posted by pjt

The first few pics in this thread Dust extraction upgrade at Roy Schack's workshop shows what I did to Roy's TS, might be a few ideas there for you Trav.




Pete

Pete

Great thread, can't believe I haven't seen it until now. Your sheet metal skills make me very jealous!

The TS port you made up for Roy looks exactly like what I have in mind. Mine will be from mdf, but a similar concept. Instead of cutting out the existing port, I was planning on putting in a false floor inside the TS cabinet and replacing the existing door to accommodate the new ducting and port.

Love the pic of the jointer. The chamber of my jointer (a little 6" jet jobbie) is a fraction of that size and fills up quickly if I don't use dust extraction.

Thanks for the ideas.

Trav

Originally Posted by John Samuel

Here's a pic of my small saw. It is a remarkably clean bandsaw.

IMAG0036.jpg

This pic shows the original port ... soon opened up with an angle grinder.
IMAG0032.jpg

I followed Chris Park's lead and held the door to the lower cabinet open by about 20 mm with a wedge. Works perfectly well.

Thanks John. I've read your threads about machine ports and you've come up with some great options for improving your extraction. I've got a 17" carbatec/generic bs, so I'll see how the 3x4" pipes go. I'll try the wedge idea first to see how it goes, but my longer term plan is to put in a suitable vent on the lower door opposite the port.

Trav

That little bandsaw is as clean as one could imagine, but the bigger re-saw band saw is not as good.

aaaBack (Finished).jpg

aaaFront (Finished).jpg

There are two reasons for the poorer performance ... I think.

First, dust gets trapped in the kerf of wide timbers (typically 250 mm to 350 mm deep). This dust falls onto the table and is pushed over the back edge of the table. Second, the port to the lower cabinet is under the rising blade rather than the decending blade. I think this reduces performance a bit.

It is still OK, but is a disappointment after the little saw turned out to be so clean.

Originally Posted by John Samuel

There are two reasons for the poorer performance ... I think.

First, dust gets trapped in the kerf of wide timbers (typically 250 mm to 350 mm deep). This dust falls onto the table and is pushed over the back edge of the table. Second, the port to the lower cabinet is under the rising blade rather than the decending blade. I think this reduces performance a bit.

i agree. The port in the cabinet on my BS is under the descending blade and this cabinet is generally very clean. The port in the top of the lower cabinet just under the table is rubbish and I collect more flow and dust by jamming a flexy immediately under the table in front of the blade. I also agree about the sawdust getting trapped in the kerf.

Originally Posted by BobL

i agree. The port in the cabinet on my BS is under the descending blade and this cabinet is generally very clean. The port in the top of the lower cabinet just under the table is rubbish and I collect more flow and dust by jamming a flexy immediately under the table in front of the blade. I also agree about the sawdust getting trapped in the kerf.

Mine is the same. The port just under the table allows dust to spill out between the table and the lower cabinet, so I blocked it off and followed your lead with a piece of flexy jammed between the table and the lower cabinet to draw dust off the blade. This works better.

Considering relocating the port in the lower cabinet ... maybe ... one day ... when I am bored and have nothing better to do.

Bob

Thanks. I like the idea of removing some of the wyes and connecting straight to the pipe. It's getting pretty busy in that corner. I'm also short one Wye over near my router table, so I could do the same there, or use the extra Wye saved from the BS. I've been fiddling with thermoforming in the last few days to get the flex to fit the fixed ducting so I could bend a few 4" floor flanges around the 6" pipe to strengthen the joint. I'll have a play in the next few days. I want to get this all done this week.

For the table saw, there's only a small space behind it where I would stand to use the jointer. See below to give an idea. Excuse the mess. There's also a folding outfeed table to come into that space. I want to vent from the TS out to the pipe you can see in the RHS of the phoTo.

Trav

image.jpg

Can you cut an opening under what I assume is the motor cover to the right of the pipe opening in the picture?