Use 2.5" or 37mm vac for ROS, saw table. oscilattng sander, miter saw, planer?

[Doug Hobkirk]

I have two shop vacs, both setup outside with a hose passing through a window and inside on/off switch:

• Craftsman shop vac - 2.5" hoses
• Porter Cable shop vac - 37mm hoses (1 7/16")
• And I have a 4" cheap dust collector that I've never used, but it is available. For now, I think I'm not doing enough woodworking to make it worth the hassle.

Inside I have a 30 gallon DIY separator - it has a 2.5" fitting to vac, 2.5" (OR 37mm using adapter) to tools. Obviously I've only run this using the Craftsman shop vac. It works well collecting almost all the debris (but I'm losing suction, but that's for another analysis).

Tools:

1. Track saw - fitted with 37mm fitting
2. Festool ROS - 27mm - I've added a 37mm adapter
3. Ridgid oscillating sander - 2.5"
4. DeWalt 733 planer - 4" with factory 2.5" adapter
5. Miter saw - custom enclosure, has back and shroud curved to enclose everything up to back of cut line - does pretty good trapping the sawdust - no vac fitting (yet)
6. Other tools I am not including: Ryobi hobbyist table saw (used rarely), router table (has its own vac), jointer (never used, yet)

My confusion on 27mm vs 37mm vs 2.5" vs 4" -

• Assuming each vacuum source is proficient for it's size and type of device, some will generate more suction, some more speed, etc.
  Question 1: Is there some rule-of-thumb?
• Since the sizes match, Question 2: use 37mm system with #1 & 2 ?
• Question 3: use 2.5 with #3 & 4? (The planer produced vast amounts - sometimes I just let it spew through the 4" adapter into the driveway and sweep it up.)
• Question 4: Add outlet to floor of miter saw shroud, but Question 5: what size?

Feel free to explain this like I am a simpleton. Feel free to give links.

Thanks

[Matt Day]

Phew, I’m tired reading all that. My simple answer is anything that’s not a stationary tool can have a shop vac attachment, small being preferred for ease of movement. I used a 2.5” craftsman shop vac on my ROS’s for years and recently moved to a small 37mm or whatever it is that fits my Domino. Works just as good and is small and easy to manage.

[Nick Decker]

( Response deleted, misunderstood question )

[Rod Sheridan]

Hi Doug, 4" collection is used with dust collectors for flow rates around 400 CFM, far more than a vacuum would be capable of.

I have a Festool vacuum, it has a 27mm hose that I use for dust collection from tools and for vacuuming. That size hose isn't suitable for a portable planer, I would need to use the 50mm hose for that.

The 27mm hose does work with Festool's mitre saw, however I don't own a mitre saw.

The 50mm hose is better for large debris, such as typical shop vacuum stuff like leaves, big wood shavings. I use the 27mm for general shop cleanup because the only chips I wind up with on the floor are from hand tool use, and I just sweep them into the floor sweep for the cyclone to take care of.

For stationary tools you're normally in the 4, 5 or 6 inch hose sizes, or using multiple hoses. ( my table saw uses a 5" hose for the cabinet, a 2" hose for the overhead collection.).

One item to mention is that most portable tools aren't meant for dust collection, and it won't be great regardless of what vacuum/hose you use. There are exceptions, my Festool tools have great collection and so does my Hilti drill however all those tools were designed from the start to have good dust collection.

regards, Rod.

[Ben Rivel]

Doug I think you should spend some time reading through Bill Pentz's website. And I say that with the caveat that what he has there IS NOT the end all be all, BUT it does provide a good general overview as to how dust collection for tools should be looked at.

[Doug Hobkirk]

Doug I think you should spend some time reading through Bill Pentz's website. And I say that with the caveat that what he has there IS NOT the end all be all, BUT it does provide a good general overview as to how dust collection for tools should be looked at.

Thanks for the suggestion. I just did again, although the last time was years ago.
Bill's big thing is to use a good cyclone with upgraded filters and 6" pipes with short smooth runs and the only relevant charts (dealing with different tools) I found focused on CFM. He only discussed shop vacs to mostly dismiss them.

[Doug Hobkirk]

Hi Doug, 4" collection is used with dust collectors for flow rates around 400 CFM, far more than a vacuum would be capable of.

I have a Festool vacuum, it has a 27mm hose that I use for dust collection from tools and for vacuuming. That size hose isn't suitable for a portable planer, I would need to use the 50mm hose for that.

The 27mm hose does work with Festool's mitre saw, however I don't own a mitre saw.

The 50mm hose is better for large debris, such as typical shop vacuum stuff like leaves, big wood shavings. I use the 27mm for general shop cleanup because the only chips I wind up with on the floor are from hand tool use, and I just sweep them into the floor sweep for the cyclone to take care of.

For stationary tools you're normally in the 4, 5 or 6 inch hose sizes, or using multiple hoses. ( my table saw uses a 5" hose for the cabinet, a 2" hose for the overhead collection.).

One item to mention is that most portable tools aren't meant for dust collection, and it won't be great regardless of what vacuum/hose you use. There are exceptions, my Festool tools have great collection and so does my Hilti drill however all those tools were designed from the start to have good dust collection.

regards, Rod.

Best regards back to you, Rod. Thanks for the effort and info.

[Andrew Pitonyak]

Sorry, late to the game with my response, but....

I expect that a wider hose will have less resistance to air flow in the hole, not that I can point at an equation that backs this. Also, a smooth hose (pipe) has much less resistance than than a corrugated hose; all vacuum hoses I have are corrugated.

I would use the widest hose I could if that is easy to do.

[Jim Dwight]

I think the hose size needs to consider the debris generation rate of the tool. I have two Ryobi table saws and use a 2.5 inch hose on the one of them I use. If I get dust collection on my planner, it will use a 2.5 inch hose. These tools can generate a lot of dust quickly and a small hose will not have a chance. Same for my router table. But the track saw needs the smaller hose, mine is a Bosch 5 meter as does the sanders. My Hitachi CMS could use more suction but I can't figure out a good way to hook the bigger hose up so I use the smaller. Better than nothing.

Basically I use the biggest hose I can fit to the tool. But the 2.5 inch would be a waste for my hand held sanders. Maybe a stationary sander needs the 2.5 inch.