Enlarging Edge Sander DC Port to 6"

[Chestnut]

On 11/3/2022 at 11:43 AM, wtnhighlander said:

Is it safe to assume that a 6" duct provides substantially less benefit if the blower inlet is only 4"? Or not?  Having no education in fluid dynamics at all ( other that the typical comparisons to current in electrical circuits), I find the calculations for compressible fluid flow totally "baffling".  (  see what I did there? )

It's complicated.... it really depends on the blower, the power of the motor, and the losses in the system between the inlet to the blower and the outlet, be it through a filter back into the space or externally vented. Keep in mind that if it's externally vented makeup air will be necessary or the whole shop will turn into a pressure vessel and the blower will stop functioning. To keep losses down the makeup air port should be significantly larger than the inlet to the blower.

Long answer short a 2hp DC with a 13" impeller could more than likely run 6" ducting even if the port is 4". Even a 1.5hp collector may work better with 6" ducting. A long taper reduction fitting would essentially compress the air into the smaller inlet.

On 11/3/2022 at 12:25 PM, BillyJack said:

I’m not questioning work done here, just the gain…

The gains are significant. These aren't commercial machines designed for commercial collectors. These are hobby machines designed to be the most user friendly. A 6" dust port is a significant hurdle for the average woodworker. I'd venture to say the average wood worker is goign to collect with a shop vac using a 2.5" hose. a 6" port just wouldn't work for them even though it WILL result in better DC from a 2hp -3hp system ducted at 6". Most forum member here are significantly above average.

Also commercial shops aren't applicable here. They are required to meet EPA standards for air quality that results from collection at every machine at the same time with no compromises. 4" ports on commercial machines allow for good enough collection to meet standards but not require a 100 HP dust collector. It is possible to go above and beyond EPA standards, as some forum members are achieving with their hobby level DC systems.

[BillyJack]

On 11/3/2022 at 12:45 PM, Chestnut said:

It's complicated.... it really depends on the blower, the power of the motor, and the losses in the system between the inlet to the blower and the outlet, be it through a filter back into the space or externally vented. Keep in mind that if it's externally vented makeup air will be necessary or the whole shop will turn into a pressure vessel and the blower will stop functioning. To keep losses down the makeup air should be significantly larger than the inlet to the blower.

Long answer short a 2hp DC with a 13" impeller could more than likely run 6" ducting even if the port is 4". Even a 1.5hp collector may work better with 6" ducting. A long taper reduction fitting would essentially compress the air into the smaller inlet.

The gains are significant. These aren't commercial machines designed for commercial collectors. These are hobby machines designed to be the most user friendly. A 6" dust port is a significant hurdle for the average woodworker. I'd venture to say the average wood worker is goign to collect with a shop vac using a 2.5" hose. a 6" port just wouldn't work for them even though it WILL result in better DC from a 2hp -3hp system ducted at 6". Most forum member here are significantly above average.

Also commercial shops aren't applicable here. They are required to meet EPA standards for air quality that results from collection at every machine at the same time with no compromises. 4" ports on commercial machines allow for good enough collection to meet standards but not require a 100 HP dust collector. It is possible to go above and beyond EPA standards, as some forum members are achieving with their hobby level DC systems.

 

 

All you have to do is prove it.

 

Has it been documented?

[JohnG]

On 11/3/2022 at 1:55 PM, BillyJack said:

 

 

All you have to do is prove it.

 

Has it been documented?

I think you’re the one that needs to back up your statements. OP modified tools from 4” to 6” and saw much improvement. Chestnut offers data that supports this. You post pictures of random tools and DCs that aren’t related and say they are wrong. I can post pics of large DC systems too. Here’s one I looked at a few days ago.

[BillyJack]

I’m fine with you disagreeing or not. 
 

I can tell many resent my participation on the forum because of my background.. 

[JohnG]

It’s not because of your background, it’s because of the way you say that your background makes you right and everyone else wrong, even when their experience (and science) disagrees with your opinion or when your experience is materially different than the one being discussed. Yet you just say “that’s how it is” and don’t add anything meaningful to the discussion.

You’ve actually had some posts recently that I’ve really enjoyed. This thread, not so much.

Mods, feel free to delete this post. I know it doesn’t add anything meaningful to the original thread. 

[BillyJack]

Didn’t say I was right. I didn’t say I was wrong.. I would be talking to the manufacturer techs to find out if this is an advantage.

 

the whole point of my post is so new comers don’t come here thinking they should automatically start enlarging all the dust ports because one individual said so. 

Enlarging the post hole isn’t always the solution..

[wtnhighlander]

Mine's bigger...

[Tpt life]

I ran a Jet table saw in a shop that had a four inch port and pipe. Each week I had to open the cabinet and clean the material that never left the machine. A bigger port would not automatically fix the bad internal design. In that way, I can see why BillyJack is commenting. You’d have to drill holes for air to enter the enclosure in a way that would clear that material. That is not the path I would ever chase. If I put a larger duct at the table saw, it would be so a single duct would carry that material, and could split to over arm to get the fines that blow at my face. I think too many get stuck thinking of mess, but miss the lung clogging tiny stuff. 

[gee-dub]

Just an add-on.  My tablesaw has gaps between the cabinet and top, at the handwheels, and various other spots; plenty of return air.  I did have to increase the return air capacity for my router table and may still need to allow a bit more in, still playing with that one .

[Mark J]

How's this for a dust collection issue:

One of the SawStops at the highschool.   I thought this must be years and years of use, but the saw was cleaned out a month ago.  The blade compartment door that forms part of the internal duct work had been left open so that probably contributed.