vac head???

[Lucid]

Looking for advice ....... will this work provided I have enough vac power?

3.5 hp dust collection 4 inch hose to Y 2 inch dual

[groswald]

I would think probably not. You simply aren't going to get enough air flow through the 2" inlets (probably smaller due to the heads) to suck in the massive amounts of air needed with the open design. With the open design you'll get all kinds of nifty interference patterns, but not the smooth, consistent flow you need to effectively collect chips and dust. Remember, you are trying to move massive (relatively speaking), high-velocity chips using air molecules. You need all the air molecules working together.

Assuming that everything was absolutely symmetrical you would likely have a dead zone centered on the tool bit. In the real world a low velocity, low pressure eddy right where you want maximum suckage seems more likely.

Add a hood and things should get much better. A hood with a single 4" port would probably be the best.

Of course, I could be dead wrong.

Regards,

Randy

[Phife]

Nice Machine!,

As for your "Vac Head"

Nope, wont work too well. You will be surprised at the speed that chips can come flying out at. You need to surround the bit from all sides to capture all the dust and chips. Those vac heads will only catch dust and chips sent directly at them, and will miss most of the fine dust (if routering wood) and chips that come from different angles.

Make a dust shoe, or an enclosure for your machine.

[ger21]

A single 4" port has twice the area of two 2" ports. As they already said, you need to surround the tool with brushes (or something else, but brushes work best imo), to keep the chips from flying. On larger machines, I've seen streams of chips shooting over 5 ft from the tool. With the setup you have there, you'd get about 1% of the dust in that situation.

[Lucid]

What is the best curtain material to use? I milled a piece of foam and it worked great but...... thats foam... wood and metal I think will be a different story. Still very new to cnc and this was the first time building one but every thing has worked so far........except every thing is milled 90 degrees from what the mach3 screen shows.

[Lucid]

A single 4" port has twice the area of two 2" ports. As they already said, you need to surround the tool with brushes (or something else, but brushes work best imo), to keep the chips from flying. On larger machines, I've seen streams of chips shooting over 5 ft from the tool. With the setup you have there, you'd get about 1% of the dust in that situation.

point taken I will redesign my thought...... but the blue hoses looked great

[Lucid]

I have changes my plans as you suggested and build a brush head today....give me your thoughts

[Phife]

Better, do the brushes come off easily for tool changes? Can the brushes get into the cutter? they seem long.

One of the things I dont like about my home CNCs dust shoe is that the curtain gets cut up sometimes, next time I will make sure they are far enough away so they dont interfere.

[Lucid]

I have 2 hole in the dust shoes of which I put a quick release toggles on. Should be ok to change cutter..... the length of the brushes are 4.5 inch... I thought it was always easier to make shorter then longer. The brushes can just barley touch the cutter....

[Lucid]

Progress..... do you loose vac power over length? My machine is 14 feet tall to the top of the gantry. I need to put an over head hose arm off the ceiling... So I am going up the wall 16 feet over 8 feet and down 9 feet....

[Phife]

Yes you do loose suction with longer length runs, especially with that flex hose since the inside is not smooth.

That being said, I have about 14ft of 4" flex hose that connects to about 12ft of 4"PVC before it reaches my dust collector, some suction loss, but it still works well. Use only as much flex hose as you need, and try to keep the rest of the run made from solid tube.