Overarm Dust Collection

[Kevin Gagne]

My new Grizzly G0548Z dust collector is being delivered tomorrow and I am thinking about adding an overarm dust collector to my G1023 saw. I saw this PSI Woodworking guard and it seems like a really good price. Does anyone have this? What are other people using for overarm dust collection? Are they useful or do they end up getting in the way most of the time and you stop using them?

[Cary Falk]

The PSI tends to get poor reviews. I have the Excalibur and like it since I replaced the basket. It does seem to get in my way but I am learning to get used to it after a liftime of not using any guards.

[Van Huskey]

The PSI tends to get poor reviews. I have the Excalibur and like it since I replaced the basket. It does seem to get in my way but I am learning to get used to it after a liftime of not using any guards.

Agree with Cary. With the PSI you get what you pay for. The Excalibur is much better.

[Rod Sheridan]

I don't know about the PSI however I really liked my Excalibur overarm guard.......Rod.

[Callan Campbell]

I have the larger Brett-Guard model for saws with 50" rails. Very sturdy, dust collection port on top, heavy duty clear guard body and it's moveable or "removeable" if you need it to be. Downside, price isn't cheap, and the anti-kickback pawls located at the rear section of the guard are mostly a joke. I rely on a riving knive set-up from Biesemeyer to prevent kickback.
I've heard great things about the other over-arm guards out there, and they tend to have a 3 or 4" dust collection system/piping that probably works better than the small 2" port of my BG. But I've never done a comparision test side by side, so that's a guess on my part.

[Alan Schaffter]

I have the larger Brett-Guard model for saws with 50" rails. Very sturdy, dust collection port on top, heavy duty clear guard body and it's moveable or "removeable" if you need it to be. Downside, price isn't cheap, and the anti-kickback pawls located at the rear section of the guard are mostly a joke. I rely on a riving knive set-up from Biesemeyer to prevent kickback.
I've heard great things about the other over-arm guards out there, and they tend to have a 3 or 4" dust collection system/piping that probably works better than the small 2" port of my BG. But I've never done a comparision test side by side, so that's a guess on my part.

That is a good point. If you are hooking your over-arm guard to a DC (as opposed to a shopvac) you need to remember what affect duct size has on DC type airflow- small pipes kill CFM so the larger the better (up to the size of your DC main). I posted in another thread that in reality, over-blade dust collection is MORE important than from the cabinet- minimal suction in the cabinet may not pickup all the dust but it won't escape. Over-blade dust is hurled at you from the blade gullets and tips at high velocity and spreads into the air quickly. The tablesaw insert, especially a ZCI, prevents cabinet suction from collecting dust from above, and visa versa. So, you must decide how big of pipe is too big over your table. Another issue is that there are a lot of operations where an over-blade pickup just won't work- tenoning jig, etc. You just need to do what your can, since no guard is perfect, not even my homemade soft-sided pickup.

[johnny means]

No doubt this collects dust very well, but does it really qualify as a guard?

[Alan Schaffter]

No doubt this collects dust very well, but does it really qualify as a guard?

Absolutely NOT!!! In fact, I usually put that disclaimer in big, red, bold type in my posts about it here and elsewhere. I forgot it this time.

[Jim O'Dell]

I made my own from plans on the internet. http://www.woodcentral.com/bparticle...m_guard3.shtml I use a 4" hose to the cyclone for the o/h pick up, so I modified the guard part to accommodate that. Clear plastic, so you can see through it to the blade on cuts. The next generation will have independently pivoting sides. Jim.

[Bill ThompsonNM]

I also have a Brettguard. It's not the best at dust collection, but it does okay. It does offer a LOT more protection than the other overarm guards. very rigid, you crank it up and down for different thicknesses of wood. The antikickback pawls will scar the wood if place properly.. but I've been thinking about replacing them, or putting a rubber/plastic edge on them and trying them using that. I use board buddies for most of my ripping anyway. Overall, I'm very happy with mine for both dust and protection. between my Exaktor sliding table and the Brett Guard, I don't feel the need for electronic brakes etc.. The brettguard can even be supplied with an electric interlock (e.g. for schools) which won't allow the saw to be turned on unless it is in place...!)

As a bonus.. there's one for sale now in the SMC classifieds, about the third page down.

[Leigh Betsch]

The next generation will have independently pivoting sides. Jim.

Jim this looks like something I need to make. Why do you think you need pivoting sides?

[Dave MacArthur]

so you can do cuts on the end of a board and just have one side lift up, the other stays down on table and improves dust collection. That's the way my PM66 guard worked.

[ian maybury]

Interesting stuff guys, and territory i'm heading into in the next month or so when i get the shop refurbish finished and my Hammer panel saw set up.

I've looked at a few of these top guard systems, and find myself left with a few questions.

First the actual guards seem very wide, yet most of the dust seems to be thrown in the plane of the blade. Especially by the upcoming teeth. Is the width really necessary i wonder, especially if you have lots of suction using the big 4in duct suggested by the likes of Bill Pentz?

With the same point in mind i'm cautious about set ups using a large boom or horizontal tube to support the guard and double as a dust hose - the ones i've looked at seem pretty restrictive in the context of Pentz style levels of airflow. My instinct is to drop the shortest possible 4in hose from a 6in roof level duct.

My intention is to try a modified version of the relatively narrow stock Hammer top guard first - to cut a slot along the area hit by most of the dust, and to bond the flattened end of a 4in dia poly connecting stub into it. This means quite a large part of the length of the top of the guard will be an active outlet, and hopefully that the fairly large volume of fast moving air it creates around it will avoid the need for a wide guard.

The Hammer guard is clear polycarbonate, and mounted off the top of the riving knife - and if it's not a success it's easily replaced.

That said the real priority may be below table collection - so that the dust carried down into the chute by the blade teeth never makes it back out into the open air.

I think we've discussed it before - the issue of getting enough air flow with a tight throat plate, and stock hooding and duct connection arrangements.

The plan for the Hammer is to install a new 5in duct (Pentz style again) right to the dust chute, and to if necessary (not sure yet) modify the chute to manage air flow. There may (also as discussed) be something to be said for carefully positioning the air inlet opening and the duct connection in the chute so that a decent air flow across the plane of the teeth is generated to pull dust (that will otherwise be carried around and back up over the throat plate again to be spewed into the air) out from between them.

Time will tell, and comments appreciated...

ian

[Rod Sheridan]

Interesting stuff guys, and territory i'm heading into in the next month or so when i get the shop refurbish finished and my Hammer panel saw set up.

I've looked at a few of these top guard systems, and find myself left with a few questions.

First the actual guards seem very wide, yet most of the dust seems to be thrown in the plane of the blade. Especially by the upcoming teeth. Is the width really necessary i wonder, especially if you have lots of suction using the big 4in duct suggested by the likes of Bill Pentz?

The stock Hammer guard collects most of the dust and it's narrow because it tilts with the blade. The overarm guards need a large box because the blade tilts inside it. (I had an Excalibur guard).

With the same point in mind i'm cautious about set ups using a large boom or horizontal tube to support the guard and double as a dust hose - the ones i've looked at seem pretty restrictive in the context of Pentz style levels of airflow. My instinct is to drop the shortest possible 4in hose from a 6in roof level duct.

My intention is to try a modified version of the relatively narrow stock Hammer top guard first - to cut a slot along the area hit by most of the dust, and to bond the flattened end of a 4in dia poly connecting stub into it. This means quite a large part of the length of the top of the guard will be an active outlet, and hopefully that the fairly large volume of fast moving air it creates around it will avoid the need for a wide guard.

Try out the Hammer guard first, mine is connected with a 2 1/2" hose reduced to 50mm at the guard. It works very well.

The Hammer guard is clear polycarbonate, and mounted off the top of the riving knife - and if it's not a success it's easily replaced.

That said the real priority may be below table collection - so that the dust carried down into the chute by the blade teeth never makes it back out into the open air.

I think we've discussed it before - the issue of getting enough air flow with a tight throat plate, and stock hooding and duct connection arrangements.

The below table blade shroud is cnnected to the port at the rear of the cabinet with a 120mm diameter hose. The below table shroud works very well to capture the dust.

The plan for the Hammer is to install a new 5in duct (Pentz style again) right to the dust chute, and to if necessary (not sure yet) modify the chute to manage air flow. There may (also as discussed) be something to be said for carefully positioning the air inlet opening and the duct connection in the chute so that a decent air flow across the plane of the teeth is generated to pull dust (that will otherwise be carried around and back up over the throat plate again to be spewed into the air) out from between them.

Unlike the standard machinery, dust collection on the Hammer is exceptionaly good. They meet the EU standards, and your machine will come with certification that it was tested to DIN 33893 and that emmisions are notably below 2.0mg/cubic metre.

A lot of engineering time and testing has gone into the dust collection design, because it has to meet test limits for use in the EU. Bill's comments apply to the typical poorly designed dust collection on North American equipment.

In addition actual airflow requirements are listed for your machine to achieve the above emmisions.

I wouldn't start modifying anything, I'd supply the specified airflow and vacuum requirements first.

Time will tell, and comments appreciated...

ian

Ian, my comments are in red. regards, Rod.

[Callan Campbell]

Interesting stuff guys, and territory i'm heading into in the next month or so when i get the shop refurbish finished and my Hammer panel saw set up.

I've looked at a few of these top guard systems, and find myself left with a few questions.

First the actual guards seem very wide, yet most of the dust seems to be thrown in the plane of the blade. Especially by the upcoming teeth. Is the width really necessary i wonder, especially if you have lots of suction using the big 4in duct suggested by the likes of Bill Pentz?

With the same point in mind i'm cautious about set ups using a large boom or horizontal tube to support the guard and double as a dust hose - the ones i've looked at seem pretty restrictive in the context of Pentz style levels of airflow. My instinct is to drop the shortest possible 4in hose from a 6in roof level duct.

My intention is to try a modified version of the relatively narrow stock Hammer top guard first - to cut a slot along the area hit by most of the dust, and to bond the flattened end of a 4in dia poly connecting stub into it. This means quite a large part of the length of the top of the guard will be an active outlet, and hopefully that the fairly large volume of fast moving air it creates around it will avoid the need for a wide guard.

The Hammer guard is clear polycarbonate, and mounted off the top of the riving knife - and if it's not a success it's easily replaced.

That said the real priority may be below table collection - so that the dust carried down into the chute by the blade teeth never makes it back out into the open air.

I think we've discussed it before - the issue of getting enough air flow with a tight throat plate, and stock hooding and duct connection arrangements.

The plan for the Hammer is to install a new 5in duct (Pentz style again) right to the dust chute, and to if necessary (not sure yet) modify the chute to manage air flow. There may (also as discussed) be something to be said for carefully positioning the air inlet opening and the duct connection in the chute so that a decent air flow across the plane of the teeth is generated to pull dust (that will otherwise be carried around and back up over the throat plate again to be spewed into the air) out from between them.

Time will tell, and comments appreciated...

ian

Ian, just adding to what Rod S. said. I should have added that my 2005 Delta Unisaw does not, of course, have the much better blade shroud systems of the newest saws. However, with the standard 4 inch port that it came with for the cabinet section, I have little to no dust inside the cabinet, and only a slight build-up on the trunnion. I chalk this up to not having that better "surround" shrouding around the blade itself, BUT, at least having good DC on my part, and a clean cabinet interior that also includes a ramp at the bottom to help direct sawdust to the port at the rear. In other words[] it's WAY better than my open base previous saw!!! But, not as good as the latest stuff , or what I might get if I make my own mods.