TS Over Arm Dust Collection HOOD Ideas

[fred everett]

Designing over arm collection on my '02 Jet contractor's saw. Saw sits 8ft from a 1200 cfm collector/SSD cyclone vented outside. I played with different configs closing in the saw and lower collection is dialed in nicely..... moving on to the table collection. I don't want to interrupt the lower air stream so I plan to use a shop vac.

There's a number of store bought options, but I'm furloughed from work so they're out. I have everything needed laying around to do a shop made hood. This (https://www.youtube.com/watch?v=cxZOO_zcpNM&feature=emb_logo) is one I find interesting....just wish he showed it being used.

What have you built for a hood?

Thanks!

[Jim Becker]

Years ago, I build a "more productive" hood for an older Delta Uniguard that didn't actually have dust collection capability. I used .25" Lexan and assembled the components using MEK solvent. (only use outside and still with PPE!) It was strong and easy to make. The hood is the easy part. Engineering your actual overarm setup is the crux of the project. Lots of folks have made them, however. There are some threads here to me memory and undoubtedly some videos on the 'Tube, too.

[fred everett]

Years ago, I build a "more productive" hood for an older Delta Uniguard that didn't actually have dust collection capability. I used .25" Lexan and assembled the components using MEK solvent. (only use outside and still with PPE!) It was strong and easy to make. The hood is the easy part. Engineering your actual overarm setup is the crux of the project. Lots of folks have made them, however. There are some threads here to me memory and undoubtedly some videos on the 'Tube, too.

Thanks Jim. Funny thing is I have the over arm complete....actually have a couple mock ups that work well. Unfortunately the hoods I've mocked up don't get the job done when.

I've looked at everything here and on the 'Tube and circled back to Jason Beam's design.....looks intriguing with the independent sides/ft/rr. Unfortunately he doesn't show it being used AND seems to be the only design out there like that.....normally when that happens it tells me the design is either brilliant, or it doesn't work.

[Jim Becker]

I unfortunately no longer can find the photos of the guard/collection head I built but it was pretty simple...a rectangular box with an open bottom that was long enough to do the job as well as accommodate one of those black 2.5" ports from a woodworking store. How you mount it to the arm is up to the attachment design for your over-arm setup but it's easy to create mounting points with the same clear Lexan and the solvent to suit. Balancing/counterbalancing is the other thing that needs done. There was someone in the last year or so that posted photos of what they did there. I unfortunately cannot remember who the community member was.

[Robert Engel]

Looks like a good design. There are scads of them out there also check Dan Pattison, Justin Depew and Atilla.

[fred everett]

I unfortunately no longer can find the photos of the guard/collection head I built but it was pretty simple...a rectangular box with an open bottom that was long enough to do the job as well as accommodate one of those black 2.5" ports from a woodworking store. How you mount it to the arm is up to the attachment design for your over-arm setup but it's easy to create mounting points with the same clear Lexan and the solvent to suit. Balancing/counterbalancing is the other thing that needs done. There was someone in the last year or so that posted photos of what they did there. I unfortunately cannot remember who the community member was.

The rectangular box/2.5" port is how I mocked it up but I was not happy with the amount of dust it picked up. I read around on those type designs and folks say "95% or better" is collected.....I was able to get maybe 75%. The counter bal/cantilever arm I mocked up works perfectly. I have the Lexan and 3/4" x 3/4" aluminum that I plan to use for the production build, but only enough to do one build.

[fred everett]

Looks like a good design. There are scads of them out there also check Dan Pattison, Justin Depew and Atilla.

Thanks for the links Robert.

Dan Pattison is very detailed and I like him, but it didn't work for me at all.

Justin's design is a leading contender. Using the air stream created by the blade makes sense vs. suction on the upper side of the hood. This is a macro level of the "catching it at the source" principle we use with our central collections systems vs ambient collection. Only reservation (maybe) is seeing the blade....I never stand in front of it away so maybe non-starter.

While I have not seen Atilla's exact design, I am considering a "moustache" concept build.

I want to try for an advanced design. I've given it a lot of thought but it's good to bounce thoughts/ideas with brains stronger than mine.

[Steve Eure]

I built one very similar to the one in the video. Have gotten mediocre results with it. It would still spray out the bottom of the lexan, so I installed a saw stache on it from FastCap. Improved the performance, but not enough for me to use it regularly. I tried dedicating my shop vac on it with a 2 1/2" port. Still not as great as I would have liked. The blade spinning faster than the vac can suck it up is the culprit, I suspect. I have not tried moving the port to a different location on the hood. That would be my next try, if I decide to continue with it.

[fred everett]

I built one very similar to the one in the video. Have gotten mediocre results with it. It would still spray out the bottom of the lexan, so I installed a saw stache on it from FastCap. Improved the performance, but not enough for me to use it regularly. I tried dedicating my shop vac on it with a 2 1/2" port. Still not as great as I would have liked. The blade spinning faster than the vac can suck it up is the culprit, I suspect. I have not tried moving the port to a different location on the hood. That would be my next try, if I decide to continue with it.

Many thanks Steve. You probably saved me the time and materials! It looks like I'm going with a box w/ a 360 moustache or the thinner design that utilizes a ramp and vac crevice tool.

[Jim Becker]

The farther it extends in front of the front of the blade, pardon the expression, the better the pickup. But there will always be material that escapes. Nature of the beast...

[fred everett]

The farther it extends in front of the front of the blade, pardon the expression, the better the pickup. But there will always be material that escapes. Nature of the beast...

I sketched out the Shop Notes version on 3/4" ply and glued it up. We'll see how good I can get it, but I agree material will escape.

[Andrew More]

I built my own, I've since gone to a shop vac attached to the SawStop blade guard attachment.

Two things I've learned from this:
First, make sure that you've got a design that isn't very wide. I had a build like the one in the video, and found it was limited by the width, which would leave me no place to run the push block through. My current design is about 4 1/2" since I had a 4" port, and I was coping the SawStop/Excaliber floating arm guard. If I re-do it, I'll put the port on the side, not the top, and reduce the width to 1-2".
Second, make sure that you can get it out of the way easily. I've yet to see a design that doesn't get in the way with extremely narrow cuts, so you need to make it so that it can be pushed out of the way, or removed entirely. If it's not easy you'll get annoyed with it, and remove it sooner or later.

I found this design to be pretty good. In particular I like his guard, very cool.
https://www.youtube.com/watch?v=nhEZEnu9Gak

[Bob Jones 5443]

Could this design from Lisa Starr be adapted to be used in the overhead hood?

https://sawmillcreek.org/showthread.php?287820-Table-Saw-Sled-Dust-Collection-Success!&highlight=

[Steve Rozmiarek]

HAve you looked at the way Felder does theirs? It's the best design I've used, and could be adapted by a creative mind. I personally prefer the riving knife mounted Felder one usually, it's smaller. You could probably combine the two concepts and glean a few ideas. I just drop a vacuum hose t'd into my dust collector to my overhead guard.

[Jim Becker]

OTOH, the riving knife mounted guard/collector I have on my slider is not very worthy because it's too constrictive to air flow...so it almost never gets used. I plan for an overarm guard in my "next shop" where I can accommodate it. (can't do it right now because of that pesky stairway that overhangs my slider currently)

[fred everett]

I built my own, I've since gone to a shop vac attached to the SawStop blade guard attachment.

Two things I've learned from this:
First, make sure that you've got a design that isn't very wide. I had a build like the one in the video, and found it was limited by the width, which would leave me no place to run the push block through. My current design is about 4 1/2" since I had a 4" port, and I was coping the SawStop/Excaliber floating arm guard. If I re-do it, I'll put the port on the side, not the top, and reduce the width to 1-2".
Second, make sure that you can get it out of the way easily. I've yet to see a design that doesn't get in the way with extremely narrow cuts, so you need to make it so that it can be pushed out of the way, or removed entirely. If it's not easy you'll get annoyed with it, and remove it sooner or later.

I found this design to be pretty good. In particular I like his guard, very cool.
https://www.youtube.com/watch?v=nhEZEnu9Gak

Good points as most that documented their builds say the wish they had gone with a thinner design that is easily removed. I saw Mike Farrington's design awhile back - that is a very cool design. Unfortunately I have almost zero budget.



Could this design from Lisa Starr be adapted to be used in the overhead hood?

https://sawmillcreek.org/showthread.php?287820-Table-Saw-Sled-Dust-Collection-Success!&highlight=

That is quite interesting. I guess it's in essence the "stache" design that I see out there on Tube and Google.

[fred everett]

I got as far as a full mockup yesterday. First, the upper arm must be moved back one joist so things line up. Second, that arm too wobbly which I have to figure out....may be deflection from the ply spanning the the floor joists or the arm itself or both. The smaller cantilevered arms are red oak and seem very solid at this point.

I'm also rethinking the need for the upper arm to swing away. Also, I have 12ft of 1/8" angle steel 1.25" x 1.25" so I'm thinking about that.

All ideas/thoughts are welcome.

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[Jim Becker]

That's a really nice setup, Fred!!

I do agree that a method for swinging the overhead guard/collector away or easy removal/reinstallation is necessary. There will always be "those times" when you need clearance for something big or odd-shaped that the guard/collector will interfere with, even retracted as high as it can go.

[Robert Engel]

This guy is pretty clever (https://www.youtube.com/watch?v=7IAII9r65eQ) you might want to check it out for ideas.

[fred everett]

That's a really nice setup, Fred!!

I do agree that a method for swinging the overhead guard/collector away or easy removal/reinstallation is necessary. There will always be "those times" when you need clearance for something big or odd-shaped that the guard/collector will interfere with, even retracted as high as it can go.

Thanks Jim. The cantilever gets me 15" above the table. Right now the only thing I can think of that may have a problem with a fixed arm is my tenoning jig. At this point I'm thinking the angled steel may allow me to stay with a swing away design but not sure. Unfortunately my brain thinks in terms of of wood not metal....haven't welded since HS metal shop.


This guy is pretty clever (https://www.youtube.com/watch?v=7IAII9r65eQ) you might want to check it out for ideas.

Ha it's funny how we're all watching the same things. Forget how I discovered Young Je but man he's brilliant. His design is amazing but I'm already down the road with the thinner design which is far less forgiving with movement (wobble in my case).

[Matt Day]

I was going to go this route, but decided it was much easier to buy a Shark Guard mounted to the splitter. Hose goes up to my DC pipe.

[Jim Dwight]

I built one which pivots out of the way. When pivoted it is still in the way sometimes, however. It works fine for through cuts but when the blade is not buried in the wood I get a lot of dust out the front. I may modify mine to something like the "board room" design. Mine pivots up and down on little aluminum pieces and I don't really like that arrangement. If I build another hood piece I will probably include a drop down plexi glass piece to trap dust on cuts where the blade is not buried.

I use a 2hp HF DC with a super dust deputy and vented outside. The run to the table saw is 5 inch snap lock and necks down to 4 inch at the saw. When I added the overarm I cut the 5 inch pipe for a saddle wye for 3 inch flex which goes to the overarm. It has not hurt dust collection from the enclosure of my PCS noticably. The four inch port goes to a chute around the blade and there is still enough flow to get this dust so that nothing builds up inside the saw. Flow through the 3 inch might be part of the reason mine doesn't work better but it will suck up small offcuts.

[fred everett]

I built one which pivots out of the way. When pivoted it is still in the way sometimes, however. It works fine for through cuts but when the blade is not buried in the wood I get a lot of dust out the front. I may modify mine to something like the "board room" design. Mine pivots up and down on little aluminum pieces and I don't really like that arrangement. If I build another hood piece I will probably include a drop down plexi glass piece to trap dust on cuts where the blade is not buried.

I use a 2hp HF DC with a super dust deputy and vented outside. The run to the table saw is 5 inch snap lock and necks down to 4 inch at the saw. When I added the overarm I cut the 5 inch pipe for a saddle wye for 3 inch flex which goes to the overarm. It has not hurt dust collection from the enclosure of my PCS noticably. The four inch port goes to a chute around the blade and there is still enough flow to get this dust so that nothing builds up inside the saw. Flow through the 3 inch might be part of the reason mine doesn't work better but it will suck up small offcuts.

Thanks for the info Jim. I 90% finished my build today. I was also planning on drop down plexi but I'm wondering if they're needed. I did a couple kerf cuts and I was surprised with how little dust I had. When the blade is buried in the wood there's almost nothing.....I am extremely happy with the performance.

I didn't want to interrupt the airstream so I'm using a shop vac for now. Inside my saw does accumulate some dust inside which I also need to address.

[fred everett]

I'm 90% complete with the overarm collection. Mounting the arm with steel angle to the joists improved the wobble issue. I have to cut off some bolts, seal up the crevice tool and think about a permanent hose, pipe or combo. In a perfect world I'd have a dedicated shop vac that came on when the saw was turned. At the end of the day I'm happy with how the thing works.....pleasantly surprised actually. You can see what my pants looked like after a with/without kerf cut.

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[Jim Fox]

Since I already have a Shark Guard, I am going to try their new mod for installing it overhead, say for nested steel tubing mounted to ceiling. It was $40 so what the heck.

[ChrisA Edwards]

This topic has caused me frustration for a while.

I like to use crosscut sleds for the majority of my cross cutting, which seems to be majority of of the cuts.

I've watched lots of videos of overhead dust collection designs, but haven't found what I think is the solution for decent dust collection when using a sled.

So night, after reading a few more posts here, this thought came to me.

When using my sled, I don't really need to see the work piece enter the blade or finish the cut, I can hear both of these. So what I need is a skirt that will form a wall around the blade, but will not stop the near side of the sled from going under this skirt. So then I thought about using a tall CNC type brush around the bottom of the guard. The arm supporting the guard is height adjustable and is mounted to the ceiling.

The near side of my sled fence is 3.5", so a 4" to 6" would allow me to push the sled through and under the brush to complete a cut.

I'm sure this would collect a lot more sawdust than not having it there.

My two concerns, how much resistance will the brush impose sliding the into into the brush and what will happen to the non-secured off cuts as I retract the sled.

Thoughts?

[fred everett]

Since I already have a Shark Guard, I am going to try their new mod for installing it overhead, say for nested steel tubing mounted to ceiling. It was $40 so what the heck.

I like the idea of a steel arm.....I'll likely add on to my setup at some point.


This topic has caused me frustration for a while.

I like to use crosscut sleds for the majority of my cross cutting, which seems to be majority of of the cuts.

I've watched lots of videos of overhead dust collection designs, but haven't found what I think is the solution for decent dust collection when using a sled.

So night, after reading a few more posts here, this thought came to me.

When using my sled, I don't really need to see the work piece enter the blade or finish the cut, I can hear both of these. So what I need is a skirt that will form a wall around the blade, but will not stop the near side of the sled from going under this skirt. So then I thought about using a tall CNC type brush around the bottom of the guard. The arm supporting the guard is height adjustable and is mounted to the ceiling.

The near side of my sled fence is 3.5", so a 4" to 6" would allow me to push the sled through and under the brush to complete a cut.

I'm sure this would collect a lot more sawdust than not having it there.

My two concerns, how much resistance will the brush impose sliding the into into the brush and what will happen to the non-secured off cuts as I retract the sled.

Thoughts?

Bob Jones posted this link above by Lisa Starr which may help you a lot.

https://sawmillcreek.org/showthread.php?287820-Table-Saw-Sled-Dust-Collection-Success!&highlight=

[William Hodge]

I have found that a shop vac works best for spray off the top of a saw blade. The high static pressure in a shop vac seems to work better than the high cubic feet per minute from a 4" or 6" line to the dust collector. I have those lines though the saw cabinet, to keep the saw empty and catch airborne dust in the cabinet. The crevice tool tight to the blade catches the spray before the stream widens. I trim the front of the crevice tool enough to allow flung dust to enter the nozzle.

Getting a crevice tool that close to a saw blade varies by what I'm cutting. For edge trimming sash, a box bolted to tapped holes in the miter slot serves well. The rippings are feathers. It's worth setting up, as it acts as a guard and dust collection. Installing the guard and hose takes about two minutes. Trimming four edges of a pile of sash produces a lot of dust.


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This doesn't work for ripping wood.

The crevice tool is in a stock feeder for that.
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[Lewis Mills]

Seems like the OP is well on the way to getting it done, but I'll throw in a little bit different implementation. The blade guard itself is a pretty standard shape, sized to clear the Bessemeier splitter. It is made out of .25 inch solvent-welded polycarbonate. There is a square of 1 inch PVC bolted to the top, with a hole cut to just fit the OD of 3 inch PVC pipe. The 1 inch thick PVC gives me plenty of surface to glue in a piece of 3 inch PVC pipe, which slides inside a 4 inch PVC pipe to allow for vertical adjustment. The rubber sleeve with hose clamps is sturdier than you might think. Just finger tight, I have to really bear down on a pry bar to get it budge. (I don't know why that picture is rotated 90 degrees!) The 4 inch PVC continues up to a Y that leads over to the 6 inch DC system, and up to a flange that bolts to the ceiling.

For me, combining the support with the dust collecting made it easier to put together, and it provides great support to prevent the workpiece from climbing the blade - much more so than any adjustable parallelogram arm that I've seen.
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[Alan Schwabacher]

The Justin Depew version appears to work well, using the saw blade itself to help direct the dust to the outlet. Cosmas Bauer did some experiments, finding it much more effective to pull air from the front than the back or top of the blade.

It's the approach I first saw in the Sawstop riving knife-mounted dust collecting guard. The challenge with a floating guard is the precision placement needed with the narrow guard -- which can't be widened if a shop vac is used rather than DC.

[fred everett]

I have found that a shop vac works best for spray off the top of a saw blade. The high static pressure in a shop vac seems to work better than the high cubic feet per minute from a 4" or 6" line to the dust collector. I have those lines though the saw cabinet, to keep the saw empty and catch airborne dust in the cabinet. The crevice tool tight to the blade catches the spray before the stream widens. I trim the front of the crevice tool enough to allow flung dust to enter the nozzle.

Getting a crevice tool that close to a saw blade varies by what I'm cutting. For edge trimming sash, a box bolted to tapped holes in the miter slot serves well. The rippings are feathers. It's worth setting up, as it acts as a guard and dust collection. Installing the guard and hose takes about two minutes. Trimming four edges of a pile of sash produces a lot of dust.


450752
This doesn't work for ripping wood.

The crevice tool is in a stock feeder for that.
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I also found the shop vac to be more suited to pulling dust off the blade in my shop. I'm not found of having the powerful exhaust from the shop vac. Aside from the muffler I installed or venting it outside I don't what else can be done.

Your sash DC is an excellent idea btw.


For me, combining the support with the dust collecting made it easier to put together, and it provides great support to prevent the workpiece from climbing the blade - much more so than any adjustable parallelogram arm that I've seen.
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This is a great mounting design. When designing mine, I only thought of using pvc horizontally for whatever reason.

[fred everett]

The Justin Depew version appears to work well, using the saw blade itself to help direct the dust to the outlet. Cosmas Bauer did some experiments, finding it much more effective to pull air from the front than the back or top of the blade.

It's the approach I first saw in the Sawstop riving knife-mounted dust collecting guard. The challenge with a floating guard is the precision placement needed with the narrow guard -- which can't be widened if a shop vac is used rather than DC.

Justin's design (really from an older Shop Notes article) works extremely well. I'd not seen Cosmas tests but they reinforce how smart the Shop Notes design is with a curve to direct dust to the suction. In addition the Shop Notes design brings the suction closer to the dust.

I agree placement is a challenge which is why I went with a 3/4" ply composite vs 1/2" as Justin used. It's only gives a 1/4" extra margin but it helps. I debated adding additional thickness but worried I would compromise flow or suction. As you noted widening the composite presents a challenge when using the crevice/shop vac. Though not ideal, I used a seal to fill the gap as seen below.

I cut mdf yesterday and had zero "dust" on the table.....some larger chips but very few. The chips must be too heavy for the suction to grab. It's easy enough to do a 60fps slow-mo HD video so I can see what's going on.

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[William Hodge]

I also found the shop vac to be more suited to pulling dust off the blade in my shop. I'm not found of having the powerful exhaust from the shop vac. Aside from the muffler I installed or venting it outside I don't what else can be done.

Try putting the shop vac outdoors, unless you have neighbors. Mine are 1/3 mile away. I had to attach a light to my remote switch, so that I would know the shop vac is running. The light also shines on the miter saw. Putting the shop vac outdoors negates the need for decent filtration. I wish I had a shop vac with no filter, and I could send the exhaust into the sawdust trailer. Shop vacs with no noise limit and poor filtration are cheaper.