hose diameter for lathe cart dust collection

[Dan Gaylin]

Hi all.

I have a 1.5 HP Jet dust collector. I am thinking of running a short (10 foot) run of 4" hose to the lathe cart, and then using a y-splitter with two 2.5" ports and running about five foot lengths of 2.5" hose to two points on the lathe cart: one underneath the lathe (drill a hole through the table top) to collect shavings and help with clean-up, and a second one that will be hung by a bracket with a dust hood directly over the piece on the lathe to catch fine dust as it comes off the piece. The smaller diameter hose will be easier to work with since it more flexible and takes up less space. But will it reduce the airflow to the point where I'm not getting good enough dust collection?

thanks for your help.

--Dan

[Jim Becker]

My opinion...mounting a movable hood behind the workpiece for collecting during sanding is quite effective. Anything else...not so much. Chips coming off while cutting tend to go in multiple directions and every direction sometimes. So I use my DC when I'm sanding at the lathe, but otherwise just clean up manually afterward. (because I have a cyclone, I can use a floor sweep to help with that)

Specific to your question, yes a dust collector gets pretty inefficient when you stop it down to 2.5", including when there are two off of a 4" hose. Why? Dust collectors, um...collect...by using air movement and you cannot fit a whole lot of air at a given velocity at low pressure in a 2.5" hose. Shop vacs are better suited toward the smaller hoses because they are designed to work at higher pressure ("suction") and therefore do a better job for small tool collection through small ports.

[Dan Gaylin]

Hi Jim,

Thanks for the info. I had seen this in other posts here, but I was hoping with those shorter runs it might be okay. I know what you are saying about shavings going everywhere. I have a small midi lathe and mostly do small bowls (less than 11") and I overbuilt the cart, so the lathe rests about 6" from the outer edge (facing me) of the table. The result is that MOST of my shavings end up on the table. So having a port there, provided it has enough suction, should suck up a lot of them. I'm actually copying this idea from a guy who posted that he had the lathe on a raised platform with a hole in it, and a dust hose going into the bottom of the platform and he would kick the shavings into the hole!

-dan

[Jim Becker]

It might work to have a port "down there" if your experience is that most of your shavings end up in a particular place and it will reduce your cleanup. It's just important to "set expectations" around this because of the nature of the tool. Every time you move the tool orientation even slightly, what comes off the workpiece goes in a different direction, or as noted, multiple direction. :) :D

[Mick Simon]

Compounding things is when you start turning green wood. If the DC has enough pull to redirect the shavings it will clog a 2 1/2" port in no time. Flexible port behind the point where you're turning is the way to go.