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 :confused:

[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.

[Joe Jensen]

Even though I'm not an expert I'll toss in my 2 cents worth. As a community we woodworkers seem have concluded that more is better with DC airflow. Its hard to argue that more isn't better, but I'm not sure more is needed for most tools. I just looked at a Powermatic 25" double drum sander and if only has two 4" ports. I'd be surprised if they under sized the inputs on a drum sander. I suspect that if I ran the right size duct to each, I'd have great dust collection. Think about the table saw. When cutting, the wood is forming a pretty good seal against the top. The blade is cutting wood, and sawdust is pulled by the tooth gullets down under the saw top. Some of this sawdust stays in the gullets and is thrown above the saw top, but most falls below the top into the cabinet. The dust collection port mainly pulls the dust from the bottom of the cabinet. More airflow will pull more dust out of the gullets, but I don't think 2 or 3 times the airflow will matter much. My new SawStop has a nice hood down in the cabinet that has a 4" flex duct to a 4" port. I have that connected to a 5" duct for 10 feet and then 4 feet of 7" duct. I get very very little dust on top of the saw. Maybe little more than the blade creates when the teeth are coming back up through the board at the back of the board.

Also, make sure you maintain enough velocity in the duct. If you have a 6" or large duct connected to a 4" port, you may very well end up with dust pooling in the duct. Also, you need enough air input to the cabinet. If you were to seal the cabinet to the top, and seal all the other cracks, leaving only the gap between the blade and the blade insert, you would end up with very little airflow...joe

[martyphee]

It is my real name. Try putting a space in there and it's spelled Phee. If some admin wants to correct it go ahead.

[martyphee]

Really not much to show. On the inside there is a shelf between the base that flares out and the sides of the cabinet. I lined that with plywood and sealed around the edges and then cut a 6" hole at the base of that new "floor". I used a 6" ventilation starter(?) from McMaster. It has a foam gasket with adhesive and holes for screws. Could used something better, but the metal is thicker than your standard 30g vent stuff at the borg.

For a better design take a look at a newer 66. They did something similar with metal though. Made a tray that angles down from the sides and directs everything to the port in the back, but still only 4".

[Luciano Burtini]

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
Precisely my point as well.... The 4" is more than adequte for moving dust and air and at an acceptable speed to ensure that it actually clears out the saw. Making the port bigger is not necessarily going to be more effecient and unless you are using a humungous DC, it is likely that your dust removal ability will suffer, not improve. Seems to me like a lot of the discussion is purely hypothetical (solutions looking for problems??) - kind of like the more horsepower arguments tend to be....

[Jim O'Dell]

I agree that the manufacturers need to step into the the new century. I like the idea of the dust ports being on a removable door, not welded into the cabinet. That way, they could offer different doors as accessories so we could choose the right size for our needs. That way no modifications would have to be made to the machine. And for those that don't have the high CFM cyclones, the 4" would still be the best bet for them. Some of the machines have the ducts on a removable door, Delta TS maybe?? Seems like the Griz jointer DC ports are on doors or hatches that appear to be removeable. Can someone that has one of these confirm that? The other thing I've mentioned before is that the port needs to be on the right side of the TS also. Most left tilts are on the left side, or in the back. Right tilts are on the right side or the back. I prefer the left tilt, but the only obvious place for an overhead duct to get to a TS is at the right side of the saw where it is not in the way of a cut. Having the port exit on the right side would also reduce the number of 90 degree turns by 1 or 2 depending on left side or rear port.
Don't seal your cabinets up too much. Others are right, there has to be air flowing in as well as out. You need the same area of air getting in as you have area on the port hook up.
My guess is that the optimum setup would be a 5" port on the saw, and a 2" overhead guard running from one 6" line. Those would need to be different if you had a larger (7 or 8') line.
Anyway, just my ramblings on a Friday night. Jim

[Jim O'Dell]

Luciano, a 4" port may be all that is needed. If that is so, then I would think any vertical run to an overhead pipe needs to be the same size. Don't do a drop with 6" then reduce at the machine. I know that is contrary to popular belief right now, and I fuly admit that I'm not an expert here and could be wrong. But it seems that if you only have 4" pipe area coming in and it changes to 6" or larger to go over and up, you going to lose velocity, and could find some problems in keeping the heavier particles suspended. UNLESS!! you also have another opening at the point of transition that you can open up to keep the airflow high enough for the larger pipe. I wanted to run 6" to my table saw. It's a contractor saw, lots of openings. I modified the factory accessory hood from a 2.5 inlet to 6". My 6" vertical run also has a 6/6/4 wye with the 4" going over for a future o/h guard for the blade. (That will have to reduce to 2 or 3" for the guard.) I'm lucky that I was able to get a cyclone that should produce enough CFM that I can handle alll of this. Not everyone has that luxury. Jim.

[Terry Hatfield]

I enlarged the ports on my cabinet saw and jointer to 6" and I personally would recommend it. It is easily acomplished with 6" HVAC register boots. I cut the hole in the cleanout door of my 1023 larger with a jig saw and mounted the boot on the inside. The combination of the 6" port in the cabinet and 4" to the overhead is quite effective.

50379

50380

I made a new plate that fit the original mounting holes on the jointer and mounted a boot to that.

50299

50300

I also ran 6" to my planer......you get the point. I've enlarged the ports in every tool I can. Amazing difference moving from the 4" ports to 6" ports really. Jim has it right...the more flow you can get the better off you are. As long as you have enough collector to power the 6" ports, I would upgrade every tool you have.

Terry

[Ben Rafael]

I agree with Jim Becker.
Having a powerful cyclone connected to a machine with a 4" port is not allowing the cyclone to draw as much as as possible.
It's kind of like drinking water through a coffee stirrer vs. a normal straw.

I will not be upgrading my TS until someone makes one with a 6" port.
On other equipment this will probably never happen, on the TS it may.

[Ben Rafael]

A 4" port will not collect all the fine dust, it does not allow sufficient CFM to do it. You can get most of the easily visible dust, but that's it.

[Jim Becker]

I will not be upgrading my TS until someone makes one with a 6" port.

Unfortunately, my feeling is that this is less likely to happpen that you might want. Upgrade your saw when you need to and just do what is necsesary to put a larger port/hood on it.

[Ben Rafael]

My next upgrade is to my BS, and that's a few years away. The only way I'd buy a better TS is if some deal comes along, like a PM66 for $400. Otherwise I'm fine waiting.
The manufacturers have been getting a lot of complaints about the 4" port, they'll come around eventually.
It's really pretty stupid when you think about it. Make a 6" port and anybody who needs 4" can buy a $2 reducer. Making a 4" into a 6" in a pain.
I doubt it costs more for them to make the port 6", it's only a bigger hole. Less metal, should be cheaper.

[J.R. Rutter]

I've used table saws with both a 4" and 6" dust port. Either one should keep the cabinet base from filling up with dust, which is their primary duty. With the TS, any dust that you get on top is coming from the back of the cut. No cabinet port is going to capture that. You would be better off splitting you TS branch and running a top-side collection point in a blade guard. Now you can get most of the stuff coming off the blade as well as the stuff flying off below the table.

For the jointer, and most other machines, the more air the better . . .

[Travis Porter]

Strange, my DJ-20 came with a 5" port, not a 4". Personally, i enlarged the ones that were simple enough to do. I did run 6" pipe to every machine and reduced it from there to minimize different sizes of pipe and to make it easier when and if I change the inlet sizes.

[John Piwaron]

No.


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

But it'll reduce voltage drop and allowing that the breaker is sized right, give the motor everything it wants.

[John Piwaron]

Sounds like the DJ-20 was shipped in a couple of configurations.

Mine has a chute that dumps the chips out the end through a huge square opening.

[Mike Canaris]

Chris...you can pop another 4 inch on the motor door on your general ...it would make better sense than cutting into the cabinet. 2x4" will flow a little over 6 in in total.

I didn't read all the posts here..but what about overhead dust control?

[chris del]

I've used table saws with both a 4" and 6" dust port. Either one should keep the cabinet base from filling up with dust, which is their primary duty. With the TS, any dust that you get on top is coming from the back of the cut. No cabinet port is going to capture that. You would be better off splitting you TS branch and running a top-side collection point in a blade guard. Now you can get most of the stuff coming off the blade as well as the stuff flying off below the table.

For the jointer, and most other machines, the more air the better . . .

I plan on adding a overhead blade guard as well...... In Canada I have only seen one brand ,Exclaibur that was just purchased by General international. What are some of the popular brands in the US?

[chris del]

You sure get around eh Mike!!!!

If I put a second port in the Motor door, I would not be about to open it. I could however put a second 4" beside the existing 4" in the bottom of the cabinet......

Chris

[Ben Roman]

Terry That is the cleanest shop I have ever seen !!! :)

Ben

[Pete Bradley]

I'd try it out before you modify anything. It's entirely possible that the designers of the saw knew what they were doing.

Pete

[Terry Hatfield]

Terry That is the cleanest shop I have ever seen !!! :)

Ben

seeeee.......it's all due to those 6" ports. :D

Seriously, thanks Ben. I'm kinda anal about the shop being clean and organized. ;)

t

[Bob Dodge]

A 4" port on most cabinet saw bases is "more than enough", but, it depends on how it's configured and piped.

I have a Delta UniSaw. The rear dust-port is a rectangular opening, probably 3 1/2" tall and 8" or so across. Delta supplies a 4" hood with widely-flared mouth. When I bought the saw, I had anticipated going with a larger duct to the base, possibly 5". Well, I simply tried the included Delta hood, and it worked REALLY well. Mind you, the saw has an effective dust-ramp.

Furthermore, I didn't even run a 5" pipe to that hood. I have a 6" pipe running to a small pre-separator (35 gallon drum). Out of that pre-sep, I run two 4" ducts. One to the oa-bc, one to the base. The dc, is a small 2hp industrial unit from Pyradia/Belbab, with 12.5" impeller. The saw base is clean as a whistle.

How much airflow do you need in a base with a good dust-ramp? Very little. As long as "dust" doesn't escape through the openings, you're 'good to go". As far as 'waste removal" goes, don't forget, that waste is being removed in 'real time". If you're sawing a piece of wood 1" thick, and you have a feed-rate of of 20 FPM, you'll produce a kerf four inches long every second. That's about 1/2 of one cubic inch of dust/waste every second. Now, with 400 CFM flowing through a 4" hose, how long of a column of air would you have "per second"? How long would your column of waste be?

Answer; 76.43 feet. (flow-rate 400 CFM / 4" pipe = 4586 FPM)

Your 0.5 cubic inch of waste would be spread out over that length in a 4" pipe. Visions of massive waste-flow through the pipes simply do not apply.

[Chris Livingston]

My Grizzly 12" G5959 TS has a 4" port and originally dust collection was terrible but there was really no way to enlarge the opening or relocate it. The inside design was mostly to blame. Yes there was a slope to the dust port but it was the entire width of the saw base with no angles to make everything move toward the opening.

Using cardboard I figured out the shape I would need for adding angled pieces. Once I got them right I used those as templates and cut the final pieces out of plexiglass and epoxyed them in place. Then using bondo I smoothed out everything right into the 4" port opening, sanded it, and painted it to match.

That made a big difference but not enough so I went about sealing the gap between the base and the top using metal heating duct tape with mastic backing. After that I was getting the kind of suction at the zero clearance insert that could hold wood down but I would still get a lot of chips kicked out the front opening for the angle adjustment is I was using a dado blade.

I took some two pieces of black rubber sheet cut to the correct size, tapped some holes around the opening and bolted the pieces of rubber so the top piece hung down over the bottom piece and no mater what angle the motor was at the flap would still deflect any chips.

Now the inside of the cabinet is very clean and I get great dust collection.

[chris del]

Just a update.....

I ordered a Shark Guard with 4" port and ran a 4" branch from my 7" main directly over the saw blade. This branch is on its own blast gate so it could be isolated when not in use or be used for my router table that is in the saw wing.
I also ran 5" duct right to the saw's 4" port and reduced from 5" to 4" right at the saw.
I have not recieved my shark guard yet, but so far the Gorilla keeps the saw cabinet spotless. I will most likely silicone the saws dust ramp, but that is all I have planned for the cabinet.

[Jim Becker]

Chris....avoid the silicone in a woodworking shop. Use non-silicone caulk or HVAC sealer. Traces of silicone can really whack the finishing process...

[Chris Livingston]

True but this was the floor of the cabinet with nothing getting near the table top. I didn't have anything else on hand at the time.

[Rob Will]

Jim,
What brand of table saw guard / top mounted DC is that installed on your saw?

Thanks,
Rob

[Jim Becker]

Rob, I have the Excalibur guard on my saw. It's an earlier model...they've updated the way the tube is set up since then. I do have a review on my site. I like it as it does the primary job I bought it for quite well...over arm dust collection. The "safety" aspects are just icing on the cake when I'm using it.

[Matt Moore]

So I read this whole thread and the reality is that there is no conclusion. Some say more than 4" is better, some say it does not matter....

Who to believe is the question of the day or year or maybe decade for dust collection. :)

[Rob Will]

Sorry to hi-jack the thread.........
I can't find a web site for Excalibur Blade Covers
??????
Rob

[Jim Becker]

Sorry to hi-jack the thread.........
I can't find a web site for Excalibur Blade Covers
??????
Rob

Sommerfield was purchased by General...you can find the information here (http://www.general.ca/excalibur/pagetitre/an/welcome.html).

[Charles McKinley]

If you want a mathmatically proven answer go to Bill Pentz's site. Then put in the 6" port. The reason for buying a large cyclone is to catch the fine dust that you can't see.

If you just wanted an empty cabinet you can get that with a small portable chip collector and flex hose.

THe clogged 8 inch lines were from under sized fan and or choked off air supply.

[Al Willits]

Just wondering, how do you know in each case the 4" isn't catching the dust you can't see???

Al