Thread: Twin vs Single dust ports

Originally Posted by royflatmate

I am looking at buying a drum sander and have a few questions regarding choosing between a single or double 100mm dust ports.
If the dust extractor is 1200cfm on a dual port machine does this mean there is 600 cfm at each port.Will there be better suction if
a Y connector is placed closer to the machine than running to single hoses from the extractor.Would a single port drum sander get better
extraction ? I have previously owned a drum sander and the dust port size and location was next to useless so I am hoping for a better
result this time.

To fully answer your question it is necessary to know the specs of the DC including HP and port size.
The size and type of ducting used
The number of ports and size of the dust ports on the sander.

From the info. you've provided I'm assuming you've got a 1.5 or 2 HP DE? You can only get so much air flow through a 100mm dust port. Putting a 'Y', which has a 100mm hose/duct, at the single flow point in the Y will result in negligible improvement of dust collection at the sander. If you want better dust collection from a drum sander you need twin 100mm dust collection points on the sander hood and to join them into a 150mm hose/duct OR continue with twin 100mm hose/duct all the way to the DE inlet. I agree that dust extraction through a single 100mm port on even one of the smaller 16"/400mm drum sanders is pretty underwhelming. If the port size on the sander is smaller, as it is on many of these sanders, a 100mm connection is not quite a waste of time but pretty close.

Originally Posted by BobL

To fully answer your question it is necessary to know the specs of the DC including HP and port size.
The size and type of ducting used
The number of ports and size of the dust ports on the sander.

Bob the DC I am looking at is 2hp and has dual 100mm ports. I would be using 100mm flexible hosing.It's a LPVH With a cyclone.
The system is on wheels so I can move it around.

The sander is the Sherwood 20 inch with dual 100mm ports placed on top of the machine.

Hope this provides enough information.

cheers.......Roy

Originally Posted by royflatmate

Bob the DC I am looking at is 2hp and has dual 100mm ports. I would be using 100mm flexible hosing.It's a LPVH With a cyclone.
The system is on wheels so I can move it around.
The sander is the Sherwood 20 inch with dual 100mm ports placed on top of the machine.
Hope this provides enough information.

Thanks for the info.

The bad news is
- that DC in stock form with no machinery attached to it will only deliver about 580 CFM through those two 4" ducts ie about 290 CFM each
- those sanders with the 2 x 4" ports are also significantly restrictive so each 4" would then be down to around 250CFM.
- using flex makes this worse again
- the good news is that, because by now the flow is low, that adding a cyclone won't drop the flow by much more.

The reality is that those 2HP DCs are not really up to dealing with a 20" sander.

To get maximum air flow hence max fine (invisible) dust removal, you need to do all of the following.
- Read the sticky at the top of the Dust forum on how to modify the 2HP DC to get around 850 CFM out of it.
- Don't use a cyclone
- run a 6" hard pipe direct from the top of the to the top of the sander and add a 6" Y with 4" of take and then add a 4" adapter to the other leg of the Y.
- If you can open up the front of the sander like this.

IMG_1916.jpg

Even so there will be visible sawdust on the outfield side of the wide belt that is not collected (especially on wide pieces) so catch tray (e use a cardboard box) under the end of the wide belt will reduce the mess.

I realise you probably won't want to go with all these recommendations so do what you can and as an alternative beef up your forced ventilation.

Cheers Bob appreciate your reply.