Thread: My DC set up, Jet 3HP Cyclone and 6" duct.

Did a bit more today, I added a y junction near the tablesaw to enable above the blade extraction, and I am waiting on a sheet metal worker to make me two 6" extraction points, one for the tablesaw and one for the jointer.

Also added flexi duct for the CNC, it turns out I didn't need as much track as I thought.
Not perfect but it works well.

Just the band saws to go.

Looking good Jack!

Above the CNC I would add a WYE and then an open 6" duct that will be able to scavenge the invisible dust that will fill that corner of the room with prolonged CNC use.

Something like this. I have perhaps show it too long as you'd want it to not interfere with the 4" flexy.
IMG_1341p.jpg

I also notice you don't have blast gates are located near trunk line junctions.
This means rarely unused verticals may fill up with with dust as the air rushing past open ducts creates low pressure zones.
Like this, WIth Machine A the air rushing along the horizontal trunk past the open vertical arm connecting junction will fill up that arm with dust.
Locating the BG up near the trunk line reduces that problem

Hi Bob, a 6" opening above the CNC would't be hard to add.
It may not be effective though, I did some test cuts on the machine today and the dust collection seemed pretty good, but not brilliant, possibly because of the flex.
I think an additional 6" opening would mean too little air flow from the router.

The tablesaw blast gate is a compromise between being close to the main line and close enough to easily reach without reaching over the saw.

The blast gates at the jointer and thicknesser are as close as they can be to the Y joint, but there may need to be another one above the Y closer to the main line, especially when that line continues around to the band saws.

There are blast gates near the cyclone where the two main lines split.

I'll have to get onto Chris and see if he can get more blast gates.

Edit: I just noticed you said "rarely used verticals", there aren't any oh those

Originally Posted by Jack E

Hi Bob, a 6" opening above the CNC would't be hard to add.
It may not be effective though, I did some test cuts on the machine today and the dust collection seemed pretty good, but not brilliant, possibly because of the flex.
I think an additional 6" opening would mean too little air flow from the router.

I was not suggesting you run them simultaneously. When any machine makes dust some dust escapes into the shed, it might look like you are picking up all the dust but believe me it is impossible to pick it all up, especially through a 4" duct. This means when you finish using a machine it really is worth running your DC for 10 -20 minutes afterwards to scrub the shed. The trouble is doing this through a 4" duct is 3 times slower than doing it through a 6" duct. SO when you finish using your CNC I'd leave the 4" CNC line open and also be opening the 6" duct to vent the shed.

The tablesaw blast gate is a compromise between being close to the main line and close enough to easily reach without reaching over the saw.

If you can't reach a gate then pulleys and levers may be worth considering.

Edit: I just noticed you said "rarely used verticals", there aren't any oh those

Rarely is also in relation to the the amount of sawdust drawn. A duct carrying a lot of sawdust say from a thicknesser can fill an open vertical in minutes whereas one from a sander doing light work may take months.

Thanks Bob, your point about running a 6" opening after using the CNC makes sense, I'm also considering a room filter.

I can reach the blast gate over the tablesaw, given that I am 190cm and my shed is only 2.4m tall I can nearly reach everything
If I moved that blast gate it would only be about 300mm higher.

As for the open verticals I must have just been lucky as the thicknesser and jointer both use the same vertical and from there they go straight to the cyclone.
The CNC dust will travel past the tablesaw vertical dropper but that is only about 400mm down to the blast gate.
The only other drop in that line is the drum sander, which is closest to the cyclone, but that only gets connected when being used, otherwise it is capped at the Y joint where it joins the main line.
The drum sander has to be moved to be used, hence not being permanently connected.

The dust from the band saws will travel past the thicknesser and jointer vertical drop and as I said earlier I may but a blast gate at the top of that drop.

Originally Posted by Jack E

Thanks Bob, your point about running a 6" opening after using the CNC makes sense, I'm also considering a room filter.

A Room air filter will be quieter but slower because filters inside the room air filters are not as efficient as the one on your DC.
The main remaining weak link in your system is that your DC is inside your works space. More than half of all DCs I have looked at have VISIBLE leaks which blow fine dust back into the work are and most have an invisible leaks that can only be detected with a particle detector. I would be looking on a regular basis very carefully all over your unit (especially the seals) for leaks

I can reach the blast gate over the tablesaw, given that I am 190cm and my shed is only 2.4m tall I can nearly reach everything
If I moved that blast gate it would only be about 300mm higher.
As for the open verticals I must have just been lucky as the thicknesser and jointer both use the same vertical and from there they go straight to the cyclone.
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.
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All good.

Mine is 4" and I am very happy with it.

Hang on ummm... I mean...ummm

I have now run the 6" flex straight to the jointer and am happy with the duct collection on that machine now.

IMG_1372.jpg

The table saw still needs work.
There is now 6" direct to the cabinet.
I have also fitted an arm to attach above blade extraction, the arm was saved from a skip bin.
Unfortunately the hood was missing so I will have to come up with something.

I did try above the blade collection with a 2.5" and a 4" hose but it wasn't very good.
Perhaps it will be better with a hood fitted.
Or perhaps I am asking too much of the system to run 6" to the cabinet as well as some sort of above the blade collection.

IMG_1370.jpg

IMG_1371.jpg

For blade guards look at something like this


Or look in John Samuel's thread on large dust ports.

John has the right idea that the flexy should be attached to the very front of the top of the guard/hood.

Jack, have you got a pic of the CNC dust pick up?

Originally Posted by Jack E

I have also fitted an arm to attach above blade extraction, the arm was saved from a skip bin.
Unfortunately the hood was missing so I will have to come up with something.

I did try above the blade collection with a 2.5" and a 4" hose but it wasn't very good.
Perhaps it will be better with a hood fitted.
Or perhaps I am asking too much of the system to run 6" to the cabinet as well as some sort of above the blade collection.

Jack,

I don't know your Jet machine. I use a 4 HP cyclone with 6" flexy to the cabinet and 4" flexy to the blade guard and it works a treat; but the riser in my guard is equivalent to a 3.5" pipe, so that is the restriction. Guard/hood design is important. Have a look at this 30 second video. Table Saw Overhead Dust Collection.wmv - YouTube It seems likely you could get similar results with a good guard/hood design. If you like, you could choke the inlet of the 6" flexy to the cabinet down to 5" to draw more air through the 4" flexy to the overhead guard/hood. (Bill Pentz recommends 5" to the cabinet and 3.5" to the overhead guard/hood.)

Do you mean this Chris?

image.jpg

Originally Posted by Jack E

Thanks Bob, your point about running a 6" opening after using the CNC makes sense, I'm also considering a room filter.

Jack,

I also considered a room filter, but figured out that if my cyclone does a good job (good ports/hoods etc) and if my vac did not push invisible dust into the shop, it would be superfluous.

I guess the approach chosen was one where the air in my shop did not get dirty in the first place. Everything I have read indicated that capture at source was the best solution, so I have focussed on doing that. Getting there ... step by step ...

Originally Posted by John Samuel

I don't know your Jet machine. I use a 4 HP cyclone with 6" flexy to the cabinet and 4" flexy to the blade guard and it works a treat; but the riser in my guard is equivalent to a 3.5" pipe, so that is the restriction. Guard/hood design is important. Have a look at this 30 second video. Table Saw Overhead Dust Collection.wmv - YouTube It seems likely you could get similar results with a good guard/hood design. If you like, you could choke the inlet of the 6" flexy to the cabinet down to 5" to draw more air through the 4" flexy to the overhead guard/hood. (Bill Pentz recommends 5" to the cabinet and 3.5" to the overhead guard/hood.)

Thanks John, it has a pretty straight 6" run to the saw, maybe when I get around to making a hood it will work okay.

that job is on the back burner though.