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

Quote:

---

Originally Posted by Jack E

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.

---

Jack,

Most of the dust from a table saw reports to the cabinet, but the material that spins forward off the saw blade is directed at the operator, meaning we are breathing in plenty of it.

I'm sure a well designed overhead guard/hood will work well on your system. Making the guard from polycarbonate turned out to be a pretty simple affair, even though I had never worked with the material before. One change I would make to mine is to make the entire front section from one piece of polycarbonate. The seam in mine creates a blind spot ... one day when I have nothing better to do I might rebuild it.

A well designed sled/mitre improves overhead dust collection even more.

Quote:

---

Originally Posted by John Samuel

One change I would make to mine is to make the entire front section from one piece of polycarbonate. The seam in mine creates a blind spot ... one day when I have nothing better to do I might rebuild it.

---

Like this ...

Attachment 270276

Quote:

---

Originally Posted by Jack E

Do you mean this Chris?

Attachment 270275

---

As I thought. There is no way the DC is able to operate properly at maximum flow as the design does not allow for enough air to be drawn into the foot and thus remove the debris the cutter produces. The problem is the lack of a port to allow air to flow in and so the lack of make up air means that all the debris are not being picked up by the air stream. Ideally you want to have an inlet matching the extraction dust port size. It can be any shape as long as the total area equals exhaust size at the minimum. I recall seeing a dust foot which did have an air inlet but cannot find it now when I went searching.

When designing the air inlet you need to make it so the cutter does not mechanically throw the debris into the port and they escape so it most probably needs to be tall rather than wide. If I( were designing from scratch I would make the inlet a full perimeter port that would be very narrow but the total length would make the area subject to a bit of maths to come up with the dimension needed. Some plexi and Sikaflex should raise the port enough to stop debris escaping. I looked at Google images and could not find any that satisfy the criteria for all the above. I hope this helps and if you want to have a chat give me a ring.

Thanks John, that's what I have in mind.

Chris, the dust collection on the cnc is actually pretty good.
The dust shroud is what came with the machine but the way it mounts isn't the best so it will be improved at some stage.
I will take that opportunity to improve the airflow as well.

Cheers :)