More cyclone questions...

[Don Kondra]

Quick recap, I'm retrofitting a 2 Hp King two bagger dust collector.

Using the existing (11") impeller and motor, I'm adding an Oneida Super Dust Deputy with a 35 Gallon bin and a Wynn 300 sq. ft. exhaust filter.

https://forum.canadianwoodworking.com/attachment.php?attachmentid=92625&d=1439190117

I haven't been able to find a reference that speaks to the effect of different lengths of pipe between the bottom of the cyclone and the collection bin.

Usually, the cyclone sits on the lid of the dust bin.

If I mount my cyclone higher I can eliminate two 90's and 4' of straight 5" pipe in my main trunk.

I would simply come straight out of the cyclone and over to my first drop.

But the pipe from the cyclone to the collection bin would have to be 4'.

Seems like a no brainer to me ?

Or have I missed something ?

Cheers, Don

[Bill Adamsen]

As long as the dust/shavings can drop out the bottom of the cyclone, you should be fine. I don't think there is any limit on separation distance. One thing that's not necessarily intuitive is that the cyclone system including collection bin is under "vacuum" and the connections between it and the cyclone need to be air-tight for the dust to drop into the bin efficiently. While a different setup (different cyclone and impellor) I have a short length 6" clear flexible tube mounted on the lid and connected to the cyclone. This allows easily removing containers of dust/shavings - ease is very important.

[Phil Thien]

I believe extending the bottom hose increases resistance about the same as adding straight hose in front of the cyclone. So what I'm saying is, shifting components around as you've suggested is a no-brainer.

[David Kumm]

Michael is the expert but usually a little distance between the cyclone and bin is a good thing. Better than having the extra ells. I'd get rid of them. If you don't want more distance to the bin, put it on a platform. Getting rid of ells is huge in a small system like yours. Dave

[James Gunning]

I agree, more pipe between the cyclone and the bin won't hurt anything. If it allows you to eliminate restrictive fittings, even better.

In most well designed cyclones, the downward airflow around the outer wall reverses to flow upward into the center pipe at just about the bottom of the cone. A longer pipe from the bottom of the cyclone cone to the chip bin won't affect the proper operation of the cyclone at all. No more than putting a larger or smaller chip bin on it, would. Many folks mount the cyclone to the top of the chip bin because they don't have enough overhead room to make that connection longer. You can't really see it in the photos of my DC, but there is a short length of 6" flex hose, connecting the cone and bin lid. I would have made that longer if I wasn't worried about how tall the overall blower+cyclone+chip bin was going to be. As it is, I can just raise the bin lid an inch or so to allow the bin to roll out.

How large a system of ducting are you going to use? One or two drops with 5" pipe if designed with minimum flow restriction would work OK. However, even if you have an honest 2HP blower, your DC will still be small and can't support a really extensive system of ducting. I would urge you to upsize the connections on your machines to 5" as well. Here is a thread showing how I upsized some of mine to 6". http://www.sawmillcreek.org/showthread.php?230820-Yet-another-dust-collection-thread-Adapting-the-machines-to-use-6-quot-pipe

[Don Kondra]

As long as the dust/shavings can drop out the bottom of the cyclone, you should be fine. I don't think there is any limit on separation distance. One thing that's not necessarily intuitive is that the cyclone system including collection bin is under "vacuum" and the connections between it and the cyclone need to be air-tight for the dust to drop into the bin efficiently. While a different setup (different cyclone and impellor) I have a short length 6" clear flexible tube mounted on the lid and connected to the cyclone. This allows easily removing containers of dust/shavings - ease is very important.

Thanks Bill, air tight I can do :)


I believe extending the bottom hose increases resistance about the same as adding straight hose in front of the cyclone. So what I'm saying is, shifting components around as you've suggested is a no-brainer.

Thank you Phil, that is reassuring...


Michael is the expert but usually a little distance between the cyclone and bin is a good thing. Better than having the extra ells. I'd get rid of them. If you don't want more distance to the bin, put it on a platform. Getting rid of ells is huge in a small system like yours. Dave

Thanks David, a platform is under consideration. After all, at some point the bin has to be picked up to dump it and that little bit of floor space will come in handy ! Having it a couple of feet off the floor means I don't have to bend my knees :)


I agree, more pipe between the cyclone and the bin won't hurt anything. If it allows you to eliminate restrictive fittings, even better.

In most well designed cyclones, the downward airflow around the outer wall reverses to flow upward into the center pipe at just about the bottom of the cone. A longer pipe from the bottom of the cyclone cone to the chip bin won't affect the proper operation of the cyclone at all. No more than putting a larger or smaller chip bin on it, would. Many folks mount the cyclone to the top of the chip bin because they don't have enough overhead room to make that connection longer. You can't really see it in the photos of my DC, but there is a short length of 6" flex hose, connecting the cone and bin lid. I would have made that longer if I wasn't worried about how tall the overall blower+cyclone+chip bin was going to be. As it is, I can just raise the bin lid an inch or so to allow the bin to roll out.

How large a system of ducting are you going to use? One or two drops with 5" pipe if designed with minimum flow restriction would work OK. However, even if you have an honest 2HP blower, your DC will still be small and can't support a really extensive system of ducting. I would urge you to upsize the connections on your machines to 5" as well. Here is a thread showing how I upsized some of mine to 6". http://www.sawmillcreek.org/showthread.php?230820-Yet-another-dust-collection-thread-Adapting-the-machines-to-use-6-quot-pipe

Thank you James.

I will have one straight run of 10' and one 4' drop at the end of that. From there I can reach almost everything with less than 10' of flex.

After much consideration, I realized I did not want to run dedicated pipes Everywhere. I have been content (for years) to move the hose to whatever machine I'm currently using.

The majority of my "work" is commissioned, one at a time, pieces in a one man shop :)

Cheers, Don