Actually sounds like a good idea to me. Make sure any and all vents or openings in the cabinet are sealed up so all intake is through the blade area and it should work great. I hung a skirt around my little tablesaw to stop all the dust from blowing out under it.

 

The cabinet is pretty well sealed up, the only big hole is the slot for tilting the blade, and I'm sure I could figure something out for that. Maybe a piece of vinyl magnet or something.

I'm tempted to just remove the whole shroud and everything and run 6" straight to it.

 

You can always put it back if it don't work.

 

Yeah I could really easily test it with just straight 4" without doing anything but removing the shroud.

That's a good idea.

 

scrubs,

My PM 66 has no shroud and is connected to a 6" dust collection system with plenty of suction. The cabinet is sealed.

I find that plenty of saw dust is captured but a disappointing amount of dust accumulates in the cabinet and spews out onto the table, especially with skim cuts. I suspect there is insufficient air flowing past the saw blade to dislodge dust in the gullets of the blade.

If too little air passes through the insert plate then increasing suction, with or without the shroud, would offer limited, if any, improvement. Increasing the size of the opening in the insert plate would be a defeated effort since lumber often completely covers the insert plate. When air cannot enter the cabinet through the insert plate, an alternative path for air to enter the cabinet is needed to avoid starving the dust collector. That front slot in the cabinet for tilting the saw blade could be that source of make-up air and therefore should probably not be blocked off.

It seems to me that dust collection would be improved when sufficient make-up air to balance the air sucked out by the dust collector flows directly over and around the saw blade. One way to achieve this is an air intake piped into the shroud along with an exhaust pipe leading to the dust collector and positioned so that air moves around/past the saw blade. This arrangement could offer the greatest chances for improving below-the-table dust collection. But I doubt such a modification would be possible and even if possible and it improves dust collection, it may not provide the satisfactory results.

Other LJs have previously posted that they were generally satisfied with table saw dust collection only when an overhead/above-the-table dust collection apparatus was added.

One last comment concerning the dust collection system is that if too little make-up air enters the dust collection system, dust could settle in the dust collection pipes. That lack of make-up air could slow air speed within the dust collection pipe and allow dust to settle.

 

JBrow,

Thanks so much for the reply! I had not even considered make-up air, that makes perfect sense.

I may just leave it as is and try and convert the port to 6".

Today I just unhooked the internal hose and changed nothing else, closed it up and turned it on. Collection was improved probably 200% if not more. Kind of amazing yet disappointing all at once!

I'd probably be better off getting a bigger hose on there and leaving the rest of the airflow alone.

Thanks again for your reply! Very, very helpful.

 

The far biggest improvement you can do is to add an overhead solution. about 33% of sawdust is thown in the air from thr blade and it is practically impossible to catch it from underneath.

 

The Sawstop cabinet saws are made like that, just a 4" port that is connected to a hose that runs to the blade shroud. How they could put such a half-arse arrangement on an otherwise well made saw is beyond me. But I was thinking the same as you, if I could get a bigger post it would work better. But I can't see a way to do it….at least not in an easy manner. I will say that if you have a lot of air movement it doesn't work awful…just not as good as it should be.

 

I'd just run a 6 inch line (assuming you have a 6" trunk in your system) to a wye fitting, with one 4" going inside the cabinet to the blade and the other attached to an overarm setup. You really want to collect dust as close as humanly possible to the source.

 

First things first….what dust collector do you have? How much cfm are you getting? How well is the dust collection working with the 4" port. With the internal plumbing of your saw will it make a difference. On my saw, it would not make a difference.

Before making the change you should try to understand what improvements you will get.

I have a Sawstop PCS and the dust port works fine and when using the over blade dust collection works great. With the 4" port on the saw I am getting 670 cfm at about 10" SP.

 

An over arm collection setup for me isn't really possible. Mostly because my saw gets moved around fairly regularly and to be honest, I hate those things. They are clumsy in in the way all the time. I have yet to use/see an overarm solution I liked. I"ll gladly accept the dust off of the blade rather than use anything overarm. Plus, I make so many cuts where the blade guard has to come off (ie; use a crosscut sled probably 70% of the time) it's just not really practical for me.

Dust collector is an Oneida DGP 2HP, 1330CFM, all piped 6". Works great actually with just the 4" to the cabinet and the shroud unhooked.

At this point I'm just going to look at leaving it like that and making the port 6". Just need to find a good bolt on flange.

 

Many overarm setups can be used with crosscut sleds. Look into the Excalibur one. Lots of them are not attached to the blade guard and thus can be used on non-through cuts and with sleds.

 

Yeah I'll pass.

Just nothing I ever want in my way or want to deal with honestly.

 

scrubs, instead of over-arm dust collection, have you looked at a Sharkguard? I put one on my PM66 with happy results. I too, did not want an actual over the arm boom (mostly because I have my Unisaw and PM66 face to face).

 

Yeah honestly if I did go that route it would be the Shark guard, but probably 70% or more of my cuts are not thru cuts. I end up removing the guard a lot as i get close to the fence, or use the crosscut sled, etc.

But yeah one that uses the factory riving knife definitely has more appeal.

 

scrubs,

I thought it would be a nightmare to enlarge the factory installed 4" dust port on my PM 66 to 6". Therefore, I added a second 4" dust port. Short lengths of 4" flex hose from the table saw connect to a 6" x 4" x 4" dust collector adapter which is the transition to 6" the pipe. The dust collector adapter does not reduce air flow like a 6" x 4" x 4" wye. However, taking this approach I gave up about 3 square inches of air flow (28 square inches for a 6" pipe and 25 square inches for dual 4" lines; a 10% loss).

I purchased the 4" flange and the dust collector adapter from Grizzly. A 4" bimetal hole saw drilled through the cabinet without much effort.

 

Interesting idea, thanks!

I dimensioned a bunch of mahogany tonight for an upcoming project. Crazy how much better my dust collection is just unhooking and removing the shroud.

The only cuts that really made a mess were skim cuts. I know an overarm would help with that but I'm honestly not sure that I want to deal with all that extra clutter just for that. I may just take that as an acceptable mess.

 

You can reduce the amount of sawdust the blade tosses upward on the back side of the blade by using a zero clearance insert. It will also improve cut quality in some situations. It is better than nothing.

 

This thread is strange. The OP wants to improve dust collection on his table saw and looking at increasing the port size and eventually unhooks the hose inside the cabinet. Not certain how this helps as the dust collection shroud around the blade helps direct the air flow.

All that effort and still will not use a over the blade dust collection as it is too much effort. This makes little sense to me. But, everyone has their own ways.

 

This thread is strange. The OP wants to improve dust collection on his table saw and looking at increasing the port size and eventually unhooks the hose inside the cabinet. Not certain how this helps as the dust collection shroud around the blade helps direct the air flow.

All that effort and still will not use a over the blade dust collection as it is too much effort. This makes little sense to me. But, everyone has their own ways.

- Redoak49

My saw happens to work better without the internal dust shroud connected. My guess is the dust collector I have is being choked by that tiny 2.5" hose.

You can reduce the amount of sawdust the blade tosses upward on the back side of the blade by using a zero clearance insert. It will also improve cut quality in some situations. It is better than nothing.

- ArtMann

I don't have any sawdust coming off of the back of the blade at all. Just the outside when doing skim cuts now. Outside of going to an overam, which I don't want, there isn't likely much I can do about that and I'm okay with it. Better than the alternative.

 

Scrubs- I have a PM2000 and I also find that the dust collection is less than satisfactory with that factory hose contraption installed under the blade. I've been considering taking that assembly out to see if it would work better but just haven't gotten to it yet- so thanks for reporting back on your success. I'll be pulling mine out as soon as I'm done spraying finish on my latest project in the shop.

 

My old (1999) Unisaw is only set up with a single port to the cabinet, and no shroud on the blade. Thus, it is already lie the arrangement you suggest in the opening post. I am quite happy with the suction from the cabinet, and the transfer of dust out of the saw into my Powermatic DC system.

But as has been written above, the dust coming of the blade above the saw table is the source I would most like to reduce. Right now I don't have anything handling that collection point, so it just spews out into the shop.

 

Scrubs- I have a PM2000 and I also find that the dust collection is less than satisfactory with that factory hose contraption installed under the blade. I ve been considering taking that assembly out to see if it would work better but just haven t gotten to it yet- so thanks for reporting back on your success. I ll be pulling mine out as soon as I m done spraying finish on my latest project in the shop.

- TungOil

Honestly I did it on a whine because it was super easy and fast to try. With my dust collector (approx 1300cfm) it was a drastic improvement. One of my engineering buds says that little hose and shroud was choking it. If I wanted to continue to use it he suggested making a separate hole for it and piping it off of a wye.

I'm happy enough for now. If anything I'll just go to 6"
On the cabinet.

My old (1999) Unisaw is only set up with a single port to the cabinet, and no shroud on the blade. Thus, it is already lie the arrangement you suggest in the opening post. I am quite happy with the suction from the cabinet, and the transfer of dust out of the saw into my Powermatic DC system.

But as has been written above, the dust coming of the blade above the saw table is the source I would most like to reduce. Right now I don t have anything handling that collection point, so it just spews out into the shop.

- jimintx

I'm lucky that I have very litttle sawdust coming off of the blade other than skimcuts. But yeah I can see where that would be a concern.

 

Whim*

Stupid phone.

 

It would be very easy to estimate the actual flow with your system. All you need to do is measure the static pressure. Either buy a digital meter or build a U-tube manometer. Oneida has pretty accurate performance curves. Reading the static pressure and then using the curve, you can get flow.