# Prototype over arm table saw dust collection



## DrRobert (Apr 27, 2015)

Messed around with this, looked at Mike Farmington’s version, thought about buying the PSI unit which is in a sale now. 

Please critique don’t hold back!


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## JIMMIEM (Oct 12, 2014)

Pretty elaborate. I like it.


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## Rebelwork (Jan 15, 2012)

Did you not like the ones offered?


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## woodnthings (Jan 24, 2009)

To get a better seal at the bottom perimeter think about using wall paper or asphalt brushes brushes like these:


https://www.lowes.com/pd/Marshalltown-1-in-x-24-in-Plastic-Asphalt-Brush/1000101905#preview-reviews








Zinsser 12 in. W Green/Yellow Wallpaper Smoothing Brush - Ace Hardware


Zinsser Flexible Smoothing Tool lets you easily smooth out creases and bubbles in your wallpaper or wallcovering projects. Simple, flexible design is easy to use with multiple applications. Complete your project in less time with Zinsser Wallcovering Tools.Find the BRUSH WLPPR SMOOTHER 12 at Ace.




www.acehardware.com


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## DrRobert (Apr 27, 2015)

I did all the testing with 3/4 MDF, mostly b/c that’s what bothers me most, and produces fine dust. I did edge cuts, IOW just skimming off 1/8. My blower is only 1 1/2HP, if I shut off the cab duct it works great. Till I get the Clear Vue I’ll get by that way, an occasional clear out of the cab saw (SawStop has a unique system the flex inside will get clogged if you don’t clear it out occasionally).

@rebel, the stock SS guard actually does an excellent job hooks to a shop vac, but I despise them & simply cannot can’t work using a blade guard. Saw Stop has 2 different models overarm. If I were to get one, it would be the 4” ($450).

I looked at Shark Guard, didn’t like the idea of something mounted to riving knife and probably works best with a shop vac. And again, it’s the blade guard thing.

The PSI looks ok, but I’m a little leary of the 2 1/2” duct. Mixed reviews. When I put a 4 x
2 1/2 fitting on the flex it cut the suction by dramatically.

Im going to try putting a ski on the front and see if the guard will lift up there will only ever be that much space.

@WNT The brush idea is something to think about, too. Thanks.

All I have in this is $10 for the plastic and $8 for the bar steel.


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## Rebelwork (Jan 15, 2012)

I thought sawstop offerd a better, n were blade guard system then what we had.. Even on the Altendorf the overarching is 5". This is the reason liked the Altendorf. It left ed up or dropped depending on what your doing...


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## HoytC (Dec 30, 2019)

Nicely done. The hose connection is at the front where it should be. I like the use of 4" hose too.
One thing you might consider is opening up the back to allow plenty of flow and increase the back to front velocity. It can make a big difference.


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## Rebelwork (Jan 15, 2012)

Seems it needs a scissor action versus the wood being and across. The systems I've worked with had a scissor action you simply lift out of the way and push back down. 

Because my saw moves I haven't tried, but might.

Is your saw in a similar locked location?


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## Dave McCann (Jun 21, 2020)

Rebelwork said:


> Seems it needs a scissor action versus the wood being and across.


Anything is possible, depending on how much money one wants to throw at it.



DrRobert said:


> All I have in this is $10 for the plastic and $8 for the bar steel.


Nicely done.


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## Rebelwork (Jan 15, 2012)

Not much money in the scissor action and a lock knob..


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## Dave McCann (Jun 21, 2020)

Rebelwork said:


> Not much money in the scissor action and a lock knob..


Please share with us your design and the cost there of. It would be most helpful for your fellow woodworkers and might save them some wasted effort.


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## Rebelwork (Jan 15, 2012)

I'm sharing with you how Altendor and SCM do their saws. There systems offer out of the way movement with a simple push. 

Most users are looking at Powermatic, Unisaw, Sawstop overhead dust collection. Move up to the larger more expensive saws for options..


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## DrRobert (Apr 27, 2015)

HoytC said:


> Nicely done. The hose connection is at the front where it should be. I like the use of 4" hose too.
> One thing you might consider is opening up the back to allow plenty of flow and increase the back to front velocity. It can make a big difference.


I will try this. It’s all screwed together so I can take 1/2“ or so off?


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## DrRobert (Apr 27, 2015)

Rebelwork said:


> Seems it needs a scissor action versus the wood being and across. The systems I've worked with had a scissor action you simply lift out of the way and push back down.
> 
> Because my saw moves I haven't tried, but might.
> 
> Is your saw in a similar locked location?


I wanted the hood to move out of the way. I thought about the brackets and lock knobs, but this just came to me and it sort of evolved from there.

I’ll stick with it a while an see how it works out. But it’s a huge, long overdue improvement for my shop!


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## woodnthings (Jan 24, 2009)

My early attempts used a horizontal suction pipe and a rotating end of PVC. I could either swing th entire pipe out of the way OR adjust the suction tip for different thickness of material from resting right on top to totally vertical, out of the way. It was pretty simple to make and used a shop vac rather than the DC 4" hose which made for higher suction, in my opinion.
That is not to take anything from your design, just showing a different approach:










Because I now keep my splitters on the saw at all times, I came up with an easy way to attach the PVC suction inlet.
It simply attaches to the splitter plate which is high enough to allow for cutting the max height capacity of the saw:


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## woodnthings (Jan 24, 2009)

DrRobert said:


> I wanted the hood to move out of the way. I thought about the brackets and lock knobs, but this just came to me and it sort of evolved from there.
> 
> I’ll stick with it a while an see how it works out. But it’s a huge, long overdue improvement for my shop!


My question concerns the weight of the unit and how much effort is requires to slide it up?
Most over the blade units I've seen are either spring balanced or counter weighted to reduce the effort. You might consider that if you find the effort is "excessive"?
The Penn State guard/cover uses a "scissors" type action:







That may be what rebelwork is getting at, I donno? But, if it works, don't change or fix it!


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## Rebelwork (Jan 15, 2012)

I'm thinking scissor action with the use of a friction strut×2

Most sliding tablesaw of size also have a simple push button removalable blade guard for access....


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## Tool Agnostic (Aug 13, 2017)

DrRobert said:


> [...]
> [The] stock SS guard actually does an excellent job hooks to a shop vac, but I despise them & simply cannot can’t work using a blade guard. [...]


I am trying to parse this sentence. I think you said, "I despise shop vacs." and "I simply cannot work using a blade guard." 

Shop vacs are loud and they are a pain to keep the filter clean. I get that. 

_-> Can you explain more about why you cannot work using a blade guard?_ 

(I try to use the table saw blade guard whenever the cut allows it, mostly because it is a manufacturer-supplied recommended safety device. I have observed that very few woodworkers on TV and professional demos use blade guards. I don't see blade guards much on YouTube, not that YouTube is a good source to learn safety by example. Many of my local woodworker friends do not use them either. I seem to be one of the few who use the blade guard.)


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## HoytC (Dec 30, 2019)

DrRobert said:


> I will try this. It’s all screwed together so I can take 1/2“ or so off?


I was thinking more like 2 or 3 inches. If that's a 4 inch hose it's area is about 12 square inches and needs a lot of flow. You won't get that without a decent size entrance. 
The main airflow should be from back to front. That catches the dust in the same direction that it's spraying off the blade and keeps it moving toward the hose fitting.


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## woodnthings (Jan 24, 2009)

Blade Guards!
The purpose of a blade guard is to prevent your hands or fingers from entering the blade, which normally results in an amputation or something less traumatic.
An unintended consequence is it also prevents you fingers from getting clos enough to feed and control your workpiece which results in the use of "pushers".
Pushers come in as many shapes and size as woodworkers themselves, but some are far better than others.
The best pusher will not only apply forward feeding pressure, but downward pressure to prevent "uplift" from the rotating blade. That downward pressure can and should be also be used to maintain contact of the workpiece against the fence. This will prevent it from rotating and kickback.
A splitter or riving knife will do the same thing and require less operator input. A lapse of concentration and lack of lateral pressure may result in a kickback, but the splitter won't allow it.

Blade guards are often "in the way" and restrict the view if the cut.
After the blade enters the work, there is no need to watch the cut being made since it's basically "too late now" to change anything.
The feed rate is determined by the sound the blade is making as it's cutting and whether the motor is laboring.
Experience also tells the operator how fast to feed the work, depending on the depth of cut and the type of wood, whether it's hard or soft.
I haven't used a blade guard in years, even decades.
My 1st simple rule is don't enter the "red zone", that area of the throat insert is painted red for a reason ...DANGER!
My 2nd rule is don't place your hand in direct line with the blade/cutting path. This rule is best unbroken, because in a lapse of concentration, you may forget where it is and that will result in an injury.
My 3rd rule is "Never reach over, around or behind a spinning blade to retrieve a cutoff or workpiece." An outfeed table is one of the most important "safety" accessories you can make for your table saw, although it is never stated as such! I've watched You Tubers do the most stupid things, and that is one of them.
This practice has kept me safe for over 55 years of table saw usage, but in all honesty, as a novice I did not know what I know now and often violated those rules.


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## DrRobert (Apr 27, 2015)

Tool Agnostic said:


> I am trying to parse this sentence. I think you said, "I despise shop vacs." and "I simply cannot work using a blade guard."
> 
> Shop vacs are loud and they are a pain to keep the filter clean. I get that.
> 
> ...


I guess I mean both. Guards get in the way for me and the constant taking off/putting on doesn’t work for me. Maybe it was the guards on the old Jets I had were very poorly made. The SS guard is admittedly a very good one, as is the dust collection is, too. IIRR you can’t lift it up with the hose attached.

This dust hood/guard I’ll mainly be using it for rip cuts, which, its a blade guard, too, that should make you happy 🙂.



> My question concerns the weight of the unit and how much effort is requires to slide it up?


It works very smoothly!

Final setup after a little duct mod and some bracing

Stowed position:








In use:


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## jdonhowe (Jul 25, 2014)

HoytC said:


> Nicely done. The hose connection is at the front where it should be. I like the use of 4" hose too.
> One thing you might consider is opening up the back to allow plenty of flow and increase the back to front velocity. It can make a big difference.


I'm confused. It's been my impression that most of the above table dust results from dust caught in tooth gullets, which escape when that part of the blade reemerges above the table surface, i.e., at the back. So, the best location for the dust port is over the back half of the blade, not at the front. Please elaborate and correct me.


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## woodnthings (Jan 24, 2009)

A slow motion video would settle that, but I think the dust in the gullets gets spun out by centrifugal force into the base cabinet of the saw before it can get around to the rear of the throat plate. But I could be wrong? It would also depend on the number of teeth on the blade and the size of the gullets. Rake angle will play a role also. Notice there is no sawdust in the gullets that are entering the cut on this video:







jdonhowe said:


> I'm confused. It's been my impression that most of the above table dust results from dust caught in tooth gullets, which escape when that part of the blade reemerges above the table surface, i.e., at the back. So, the best location for the dust port is over the back half of the blade, not at the front. Please elaborate and correct me.


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## HoytC (Dec 30, 2019)

jdonhowe said:


> I'm confused. It's been my impression that most of the above table dust results from dust caught in tooth gullets, which escape when that part of the blade reemerges above the table surface, i.e., at the back. So, the best location for the dust port is over the back half of the blade, not at the front. Please elaborate and correct me.


The dust is escaping from the gullets as soon as the blade leaves the wood. The rate of dust flow from the blade is the highest at that point and decreases continually around the blade. So when the blade is above the table, yes, the highest dust flow is is just as it leaves the table top but there's still plenty left to blow forward. Surely you've experienced dust in the face while cutting without any blade covering.
If you draw from the back then your airflow direction is opposite to the top of the blade. 
The blade tips are moving at around 10,000 fpm and sending dust out at that speed. There's no way to get that kind of air speed with a dust collector, so the blade wins. With the pickup point at the front you only need to slightly redirect the dust instead of forcing it to make a U turn.


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## BigCountry79 (Jun 2, 2021)

woodnthings said:


> Blade Guards!
> The purpose of a blade guard is to prevent your hands or fingers from entering the blade, which normally results in an amputation or something less traumatic.
> An unintended consequence is it also prevents you fingers from getting clos enough to feed and control your workpiece which results in the use of "pushers".
> Pushers come in as many shapes and size as woodworkers themselves, but some are far better than others.
> ...


I think all the advice you gave here is really good, and wanted to repeat it.

It's good reinforcement even to experienced people.

I tend to watch the fence contact more than the blade while I'm cutting, and I follow those exact rules about hands inline with the blade or behind the blade.


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## BigCountry79 (Jun 2, 2021)

jdonhowe said:


> I'm confused. It's been my impression that most of the above table dust results from dust caught in tooth gullets, which escape when that part of the blade reemerges above the table surface, i.e., at the back. So, the best location for the dust port is over the back half of the blade, not at the front. Please elaborate and correct me.


I think the worst dust is from exposed cuts (taking off just a hair), and from the last 5" of the cut where the blade exits the work while still above the table.

Robert 
My only comment is that it would be great if it were one handed operation. Maybe if you had a cord attached to top and bottom that you could grip while you loosen the bolt.

I like using my shop vac because I'm not stealing cfm from my DC, but that's just my intuition, not anything I've tested.


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## DrRobert (Apr 27, 2015)

BigCountry79 said:


> I think all the advice you gave here is really good, and wanted to repeat it.
> 
> It's good reinforcement even to experienced people.
> 
> I tend to watch the fence contact more than the blade while I'm cutting, and I follow those exact rules about hands inline with the blade or behind the blade.


A guard is really only useful when ripping. You can’t use them with a Inter gauge, a sled, or when cutting grooves, dados or rabbets, maybe bevel cuts. 

If you’re lining a cut to a mark, you have to lift the guard up. With hose attached they can interfere with outfeed, some, like the SawStop have to be removed entirely to lift the guard up.

Both close calls I’ve had on the table saw were when you couldn’t use a guard - one using a sled, the other cross cut dados in a narrow piece of wood using a push block.

I’m not “anti-guard” nor saying you shouldn’t use one, but I am saying they cannot be used for many tasks, and many tasks, BTW, that are riskier than ripping.

IMO if you’re using safety aids like push blocks and sticks properly, & have a riving knife or splitter, and never put your hand within 3” of the blade, IMO you’re very safe.

I think the reason most people don’t use guards is not to flaunt safety, but the taking on and off, plus many are poorly designed.


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## DrRobert (Apr 27, 2015)

Rebelwork said:


> Seems it needs a scissor action versus the wood being and across. The systems I've worked with had a scissor action you simply lift out of the way and push back down.
> 
> Because my saw moves I haven't tried, but might.
> 
> Is your saw in a similar locked location?


The reason I did it that way was I wanted the guard to slide completely out if the way for things like a tenon jig where a board is sticking up in the air.


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## BigCountry79 (Jun 2, 2021)

DrRobert said:


> A guard is really only useful when ripping. You can’t use them with a Inter gauge, a sled, or when cutting grooves, dados or rabbets, maybe bevel cuts.
> 
> If you’re lining a cut to a mark, you have to lift the guard up. With hose attached they can interfere with outfeed, some, like the SawStop have to be removed entirely to lift the guard up.
> 
> ...


You made an over arm blade guard, so you don't come across as against blade guards.

I think the safety advice woodnthings gave was pretty fundamental whether you have a blade guard or not.

I like my splitter blade guard, and think it's super simple to add/ remove. I usually put in my 80T crosscut blade when using my sled, and I put in my dado blade to cut dados, so removing the guard adds only a second or five to that process.

I don't have the issue with lifting the blade guard or the hose being in the way. I do run the house along the rafters, and routing it is slightly annoying.

I do remove the guard when I need to use my saw and outfeed table to assemble a project or do something that takes a lot of space. That might be my biggest reason for leaving it off.


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## DrRobert (Apr 27, 2015)

BigCountry79 said:


> You made an over arm blade guard, so you don't come across as against blade guards.
> 
> I think the safety advice jdonhowe gave was pretty fundamental whether you have a blade guard or not.
> 
> ...


I think we all need to stop and do a quick reassess, that’s healthy, not wait till there’s a “near miss”. It’s a personal decision, but I do think we can become over confident and a bit complacent, then when doing a repetitious task - that’s when accidents are more likely, b/c we let our guard down (PTP). That said, you can also get hurt if the fear:respect ratio is not right.

Neither of the two saws I sold when I got the SawStop had blade guards, and both guys who bought them were total newbies. I spent some time basically telling them “don’t do what I’ve been doing……”.

The best blade guard is between our ears — when faced with an unfamiliar task, new way of pushing material, bevel cuts, or a series of repetetive cuts, it should be total DEFCON 5. No Bluetooth ear muffs, no thinking about what’s for lunch, etc…..!!!


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## Rebelwork (Jan 15, 2012)

DrRobert said:


> The reason I did it that way was I wanted the guard to slide completely out if the way for things like a tenon jig where a board is sticking up in the air.



I don't run my tenon up in the air....I have a 56" limit on height for doors.


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## BigCountry79 (Jun 2, 2021)

I scuba dive. I have done 200' cave and wreck dives in near freezing waters (Missouri cave and great lakes wrecks).

There were always guys pushing to do bigger dive deeper with more gear. I always looked out for those guys.

I like to get comfortable with the basics first. Don't worry about technical diving when you can't even stay off the silt in 40' in clear water.

So yeah, over time and experience...
You learned how to keep a board close to the fence and push it straight
You learned not to spread you thumb out I n to the path of the blade
You learned not to pinch the back of the blade
You learned about cutting warped cupped or twisted materials
You learned what your saw sounds like and when it is telling you something is wrong
You learned where the blade exits when making a partial depth cut

So yeah "Don't do what I do" comes across to some people like "I'm better than you", but should be more like "I took things slowly and so should you"


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## DrRobert (Apr 27, 2015)

BigCountry79 said:


> So yeah "Don't do what I do" comes across to some people like "I'm better than you", but should be more like "I took things slowly and so should you"


 Well I never took things slowly, that’s for sure. I dove right in like a lot of newbies bought machines I had no experience with. 40 years later I still have 10 fingers (well, 9 3/4 if I‘m honest) in spite of my inexperience and ignorance. 

BTW that thought never even crossed my mind. It was intended as a self-chastisement. You didn’t hear the total conversation & context. Fact is, I spent 20 minutes with both of them going over the basic do‘s and dont’s. I told them both they should get a blade guard or fabricate one.


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## woodnthings (Jan 24, 2009)

DrRobert said:


> Well I never took things slowly, that’s for sure. I dove right in like a lot of newbies bought machines I had no experience with. 40 years later I still have 10 fingers (well, 9 3/4 if I‘m honest) in spite of my inexperience and ignorance.
> 
> BTW that thought never even crossed my mind. It was intended as a self-chastisement. You didn’t hear the total conversation & context. Fact is, I spent 20 minutes with both of them going over the basic do‘s and dont’s. I told them both they should get a blade guard or fabricate one.


Tell them to join this forum and that will do them a large favor. Plenty of info here for beginners and safety advice. 

I was 18 yrs old when I got my first 10" 1 HP Craftsman 100 table saw. No mentors, no You Tube, just the owner's manual. It had the gear drive fence that was pretty good. I added extensions on both sides and wheels on the back end so I could lift the front a make it like a "wheel barrow" to move it. I may have the original fence, but it's been modfied.
I never had a blade injury, but quite a few painful kickbacks. I'm still using parts and pieces from that saw today, namely the table. I still have the good "brown" motor which runs my 1/2" Craftsman shaper, rarely used. The blade guard is long gone, but I have them off the 3 newer saws and use the splitter plates faithfully. Since using the splitters, NO kickbacks have occurred.


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## Bob Bengal (Jan 2, 2021)

DrRobert said:


> It’s a personal decision, but I do think we can become over confident and a bit complacent, then when doing a repetitious task - that’s when accidents are more likely, b/c we let our guard down (PTP).


What is PTP?


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## Dave McCann (Jun 21, 2020)

Bob Bengal said:


> What is PTP?


Pardon The Pun


DrRobert said:


> that’s when accidents are more likely, b/c we let our guard down (PTP).


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