Only 4" port on Cabinet saw, Jointer ect....???????

[chris del]

Some of you may have seen my recent DC gloat on my 3hp Gorilla purchase.
I am in the process of plumbing it in and I now wondering if it is necessary to install larger DC ports on my large tools.....
It is really strange that my $2500 cabinet saw and DJ20 jointer only come with 4" ports..... Making a larger port in both tools could be very involved and I am wondering how important this is?
I am afraid that with the ducting necked down at these tools I will be getting no better performance with my Gorilla than I did with my 1.5hp delta.....

Chris

[Cliff Rohrabacher]

No.

The reason the ports are suzed as they are is to create high speed air flow.

Look at it this way.
You run a huge line a-l-l t-h-e w-a-y a-c-r-o-s-s your shop to the tiny port. What you will have done is bring your Dust Collector Impeller as close as humanly possible to the actual dust because the large duct will have fewer restrictions and turblence. In short you will have the best possible shot of getting a high speed flow that will suck more stuff outta your machine.

Works the same way with plumbing. Next time you are re-piping a line replace it with 3/4" pipe. the flow at the faucett will be way greater even though it's the same faucet.

Doesn't work the same way for electricity though.
Bigger wire won't make the machines go faster.

[Jim Becker]

I unfortunately need to respectfully disagree with Cliff on this one. The 4" ports, IMHO, are an artifact from before dust collection and the kind of cyclones we now tend to use were mainstream. Most of the DCs could only handle a 4" port. The issue is that at whatever reasonable FPM you can get the air moving, you can still only fit so much air in the pipe, leaving the available CFM below the mark that provides the best results. Given you have a system that can move mucho air, updating the dust ports (and hoods) on some of your tools will have a material effect on the quality of the collection you experience. This has been demonstrated by a number of folks, like Terry Hatfield, and others who have taken a special interest in dust collection. Yes, you will get some venturi effect reducing at the smaller port, but it will not do as much for you as increasing the actual CFM you can move through the machine...which in turn moves more dust with it.

[martyphee]

I'd have to disagree also. The problem is you have a huge volume to move out of the cabinet. I opened mine up to 6" on my PM 66. One of the big problems with cabinet saws is their not sealed in anyway so you drawing air from every where you don't want to. The more volume you can draw out the better. I can feel and see a draft around the blade insert, which is good. Although I still should seal around other areas.

[Greg Funk]

I don't think it is worth it to enlarge the ports on either the jointer or the table saw. I see very few chips leaking out of the jointer as the cutters are completely covered 95% of the time. For the table saw you'd be better off adding dust collection to the top of the blade before bothering with the main port. You could make the main port 8" but you will still get lots of fine dust flying off the blade on top without secondary collection.

[glenn bradley]

I'll land in the middle with no real world experience to speak from. Others here should be listened to wayyyyy before me. That being said; running the 6" up to the last possible moment should be better than running a 4" hose all the way to the DC. Unless it is going to be a real PITA to adapt the tool's port, I would do it.

[chris del]

My table saw a 2005 Canadian made General is found more often in professional cabinet shops (at least up here in the Great White North) than in most hobby shops. The cabinet itself is sealed very well compared to most with weather stripping around the motor housing and the only real air leakage other than the table insert would be thru the front where the handwheel moves to bevel the blade.
Knowing that this is a professional quality saw, and a very late model at that, you would think General would have put in a larger port.
As it stands now, the port is a 4" cylinder welded to the cabinet body.
There is easilly room in this location for a 5 or 6" port. If I could weld, this would be a easy change out.

[Luciano Burtini]

Some of you may have seen my recent DC gloat on my 3hp Gorilla purchase.
I am in the process of plumbing it in and I now wondering if it is necessary to install larger DC ports on my large tools.....
It is really strange that my $2500 cabinet saw and DJ20 jointer only come with 4" ports..... Making a larger port in both tools could be very involved and I am wondering how important this is?
I am afraid that with the ducting necked down at these tools I will be getting no better performance with my Gorilla than I did with my 1.5hp delta.....

Chris

What in the heck are you trying to suck? Do you have any idea how much material can flow through a 4" port? Tablesaws cannot produce enough waste (even with a 3/4" dado blade), to overwhelm a 4" dust port.

BTW, I too have a General 350 and have never found the 4" dustport to be an issue.

I'm a little confused by this issue

[Jim Becker]

Luciano...it's all about moving air, not dust. The higher the volume of air you can move at a given velocity over a period of time (CFM...cubic feet per minute), the more effective your dust extraction will be. Relative to the dust, yes, it's not a large amount, but capturing all of it is important. That's where increased air flow makes the difference.

[chris del]

Would I benifit from adding a second 4" port, or should I grind my current 4" off and have a 5" or 6" welded on? What have you guys done?

Chris

[Doug Shepard]

I'd have to disagree also. The problem is you have a huge volume to move out of the cabinet. I opened mine up to 6" on my PM 66.....

Marty - I've been thinking of doing that to my PM66 down the road (still have to finish getting the DC actually installed first though). You wouldn't happen to pics would you? I'd be interested in seeing the inside as well as outside so I can figure out how much modification I'm lkooking at.

[Ben Grunow]

For the record, I have an Oneida Super Gorilla hooked directly to my Sawstop (no other machines) with 7" hard pipe (heavy gage steel HVAC pipe- only about 15' ) that reduces to 4"and goes thru 1 4" elbow into the saw. I can feel resistance from the suction created at the ZCI when pushing a board thru the TS and the inside of the TS is CLEAN. How much more flow could I handle? Any more and sawing would be difficult or the added air flow would have to be drawn from other openings in the saw.

[Al Willits]

Excuse the newbie here, but have you even tried it yet?

Granted this forum is "the bigger the better" crazed, but is it possible 4" will work, and work well?

Like I said, excuse the newb, just wondering...

Al

[Mitchell Andrus]

My grandmother used to try to cool her house by aiming a window fan in each room OUT of the window. To 'get the hot air out' she said.

Jim's got it right... There is a tipping point at which volume and velocity each contributes equally towards the desired result. ie: don't be concerned about all of the openings under the table saw. They need to be there in order to get more air through the cabinet and to get more dust to move. Dust doesn't move in a vacuum. Likewise, air moving too slowly (say, in a 6 or 8 inch pipe) will drop it's contents just as the water in a wide, deep stream does. I've seen 8" piped half closed with dust - nature shows that a smaller tube would have been fine in that part of the system.

I'd stick with 4" AND make sure that all of the air that COULD fit through the pipe is getting into the cabinet in the first place.

Mitch

[glenn bradley]

Good point martyfee (don't we use our real names around here ;-)), I plugged areas where the table meets the cabinet, etc with whatever was at hand. Super firm faom like some items come packed in worked well. Also, (I'm such a space commander) I am so used to having above the table dust collection I sometimes just assume everybody does. IMHO you should. With that DC it should be no problem to clear the cabinet and run an over-arm.