I think you'll be underwhelmed with the
performance of either. With one port
on the saw I doubt you'll see a big bump
in dust collected by going to the larger
vacuum. Either is only going to catch the
dust the saw is shooting right out the port
anyway.

 

I see Loren's point. A big rectangular dust hood behind the saw connected to a portable dust collector with a 4" hose might catch much more but can still remain relatively compact. Maybe there's a way to attach a little rubber flap behind the saw blade that rests on top of the wood being cut and ramps much more of the dust into the port on the saw. I think the festool miter saw has something like this.

 

You are never going to get the results that you desire with a shop vac. I was in a similar situation and found a perfect solution. What I did was buy a Big Gulp Dust Hood from Rockler, and a clamp from them as well so that I can mount the hood directly behind the miter saw, positioned very close to the back of the saw. I then went out and purchased a 2HP Harbor Freight dust collector which cost me $169 with a coupon. Say what you want about Harbor Freight, but their dust collector is great, and I own several. Now I have excellent dust collection at my miter station. The entire setup was $169 for the 2HP dust collector, $30 for the Big Gulp Dust Hood and $20 for the clamp plus $10 for shipping. Total cost was approx $230. This setup would be perfect for you, and would be soooo much better than a Shop Vac.

 

Ditto to all the above responses. The best way I have seen someone get more dust with a shopvac on a MS is to build a custom shroud/pickup around the blade exhaust. If you look on youtube and search for miter saw dust collection you will get several ideas. Of course they are all saw dependent. The only way any suction will be effective on a MS is to narrow the focus of the flow. With the little air from a vac, the most success has been to narrow that flow around the blade output.

BTW looking at the CFM of the 2 units you describe it appears the larger unit has almost 3x the airflow. Your best results, especially if the vac is stored below the saw will be to have a separator like a Dust Deputy to keep the filter clean. I could not imagine using the smaller vac without a separator and a large bin next to my MS. That little vac would clog up so fast and become useless in minutes. Just make space for a removable bin under the separator next to the vac for the significant amount of dust you will be collecting. The surface area of a vac filter is so small they cake up really fast and performance drops fast.

Hope this helps. Let us know what you do.

Carl

 

If you just want to get 50%, you'll be fine with a shopvac. On my Makita 10" non-slider I get about 80% with a 3hp shopvac using a 1.5" hose. I think that non-slider is best case as the dust port is straight in back, whereas sliders tend to be more problematic.

I would suggest the 4.5hp shopvac, I don't think the smaller one would be enough, and it'd fill up really easily.

Worst is you try it and it doesn't work, then you look for further solutions.

 

i've been looking at a Rousseau 500 for my saw but mine is not stationary. i think something like this, as mentioned above, will benefit more than the difference in hp of those shop vacs

https://www.amazon.com/Rousseau-5000-Solution-Miter-Silver/dp/B00MFGRT06

 

My miter saw has it's own dedicated vac only because I don't have blast gates and I use it all of the time. It's a cheapie Lowes vac that sits on top of a 5 gal bucket so a shop vac would do at least as well and is hooked up to one of these.

This setup has virtually zero cost to make and works as well as anything I've seen.

 

I like this concept. That's the switch I ordered. And the vac is really only there to get all the stuff that already shoots out of the back of the saw. It's not a slider so lots of dust should get sucked up. I usually open up the garage after projects and use the leaf blower to get it all out. Bulk collection is all I'm worried about.

My miter saw has it s own dedicated vac only because I don t have blast gates and I use it all of the time. It s a cheapie Lowes vac that sits on top of a 5 gal bucket so a shop vac would do at least as well and is hooked up to one of these.

This setup has virtually zero cost to make and works as well as anything I ve seen.

- Andybb

 

That should work well for you. I use the leaf blower solution also. Except for the miter saw, my main DC system is based on a big ass shop vac inside of a plywood cabinet which makes it almost silent with a DIY cyclone and a long ass hose that I just swap around depending on the tool I'm using, . All of the other tools go into a long power strip which plugs into this switch which gives me the ability to turn the vac on independently for clean up etc. Very handy. The cabinet is on wheels and doubles as a stand for my drill press, scroll saw and grinder.

 

I've used this setup on my Bosch Glide with great results, 95% collected when not cutting aggressively.

 

I have the 12" Bosch Glide and the one of the Bosch Vacs dedicated to it and I would say it easily gets 50% of the dust. I modded the dust chute on the saw similar to what Andy did in his pic.

And my 36v Makita Blower will easily take care of any dust that vac didn't get

 

I like the Rigid (Home Depot) shop vacs. I have one of their smaller ones (5 gallon?) hooked up to my SCMS. I'd say it get 50% or more of the dust.

 

I've had 3 different DC setups over the years. I think the best way to collect some machines like sanders, miter saws and routers is to have a dedicated vacc. You can pick up shop vacs quite cheaply at flea markets and garage sales so it is very cost effective to have several dedicated vacs.

I have to disagree with some of the comments in that shop vacs give me very adequate collection on both my miter saw, sanders and router. No doubt the miter saw is the hardest to collect, but a through-the fence/under the table type system works really well. Keep in mind the efficiency of collection depends somewhat on the saw design but I think you should be more than able to achieve 75%.

Regarding the switch boxes, be aware if you run a large vac on the same circuit as the saw, you may have an issue with breaker tripping due to start up amp draw the saw generates. This happens to me so I have to plug the vac into an outlet on a diff circuit.

 

Why even mess with a shop vac when you can get a good 2HP Harbor Freight dust collector for around the same price, if not less than a shop vac + dust depuity? The HF unit is $199 and with a 20% off coupon it comes down to $160. Assuming that you have the space, that would give you much better performance than a shop vac, plus, since it has two input ports, you could run one hose to your miter saw station and the other side could feed to a table saw, router table, planer, jointer or any other tools that you might have.

 

Why even mess with a shop vac when you can get a good 2HP Harbor Freight dust collector for around the same price, Assuming that you have the space,
- SweetTea

As you said, space is the issue for me. I still need to get 2 cars in my garage occasionally, like when it snows, so on "my side" everything is on wheels and lines the walls. My shop vac is inside of this cabinet which has 3 other tools on top of it and the cyclone is mounted high on the wall. I'm happy with the performance. I keep a bag in the shopvac to catch the overflow and any fine dust from the cyclone. Only need to empty it a few times a year.

 

i have made up a few of these .i really like a dust deputy in front of the vac .keeps filter from plugging so fast from the fine dust . i figure the bigger the vac better chance of getting dust . my last vacuum for this was a big ridged , i picked one that was relatively quiet . do not know what saw your using but try to design a scoop or something to help funnel the dust . Kapex has a good one ,look at the pictures and get an idea .i saw the big cobalt at lowes has a decent scoop .the big 12" milwaukee does also . i made up flaps with duct tape for a job i was doing inside a home for a nonsliding dewalt .it did very well at catching the dust .also keeps the air in the room your in a lot nicer .

 

Ok. Did some work this weekend and whoever ignored my "I'm not building a hood or anything" statement, you're both hard headed and 100% correct. I connected my 5.5hp 14 gal to the dust port alone and got about 50% of the dust. That was the goal but the goal has changed. I need more than that. The Kapex boasts 78% of dust collected and if I remember using it, it still felt like a lot was escaping. So my Dewalt will be a project. New challenge is where to put a hood when it's already up against the wall. I'll take a pic or two to show you what I'm talking about.

 

James,

I am in the same situation with my DW708 SCMS. I am planning on something like Andybb posted above where my stock DC port is useless with a vac attached. I am thinking of unscrewing the little collection port and using the mount to put a more useful custom made shroud closer to the blade. Or try something like I found on YouTube where they made a custom box behind the fence. These are the most effective 'vac" DC setups for MS I have seen. The big hoods and shrouds are better suited for DCs that move massive amounts of air. And to be really useful need to be closed around the front so it focuses the air around the blade. Attached are the kind of custom setups I have seen.

Hope that helps. Let us know what you do.
Carl

 

My simple and inexpensive collector. I don't use the saw alot, but I am happy that almost all of the saw "splash" is contained, and alot of the dust. I also run a JDS air filter. I started with a cardboard template, then made box of hardboard. I will remake this summer to close up even more, and properly seal the seams. A couple of pics show the paper deflecting from the airflow. The vac is an older 1.25HP shop vac. It is connected to homemade Thien type baffle. Most of the shavings and dust go to the bucket. The finer dust still goes to the vac, which has a HEPA filter. Nothing fancy, but works for me. Even a shop vac system can help alot.

 

I don't have a MS so cannot contribute to the solution but I highly recommend the Cleanstream shop vac filters. You can clean and reuse them and IMO they work much better than the disposable ones. HD & Lowes sometimes carry them but you can get them directly from the manufacturer for about the same prices with free shipping. A little more expensive than the disposable ones but they will save you money in just 2 cleanings. I have a 5 gallon homemade Thien separator so only the finest dust makes it to the vac and I only clean the filter about every 3rd bucket full of dust. When new, you can actually partially clean the filter by tapping the vac. I've had my current ones for almost 4 years now and have not detected any loss of suction or dust making it through the filter.

 

708 was the one i was referring to . sorry no pictures .take duct tape and experiment . design flaps to extend dust shoot out ,down and closer to blade .you will get surprising results . I have kapex also which claims to be so good .It seemed like this modification gave me similiar results .you still will get over spray and some cuts just do not get dust to the suction area .
back to the 708 ,once you get results with the duct tape you can make the flaps from some stiff rubber .i never did follow through and permantly attach mine but l did get results compariable to my kapex.
also had the big 12" milwaukee which did a great job hooked to a DC .seems like the only saw with a shoot designed for a 4" hose .wish other saws would do this .

 

It's really interesting that you dedicated (I think?) a dust collector to the miter saw. Curious though, why would a 2HP dust collector do better than let's say a 4 HP shop vac? I guess it's about the CFM?

You are never going to get the results that you desire with a shop vac. I was in a similar situation and found a perfect solution. What I did was buy a Big Gulp Dust Hood from Rockler, and a clamp from them as well so that I can mount the hood directly behind the miter saw, positioned very close to the back of the saw. I then went out and purchased a 2HP Harbor Freight dust collector which cost me $169 with a coupon. Say what you want about Harbor Freight, but their dust collector is great, and I own several. Now I have excellent dust collection at my miter station. The entire setup was $169 for the 2HP dust collector, $30 for the Big Gulp Dust Hood and $20 for the clamp plus $10 for shipping. Total cost was approx $230. This setup would be perfect for you, and would be soooo much better than a Shop Vac.

- SweetTea

 

Because there is no such thing as a 4hp shop vac. It would violate the laws of physics to generate 4HP on a 120v 20 amp circuit even with a 100% efficient motor. Shop Vacs usually only draw about 12 amps or less.

 

What about a 2.5 or 3 HP shop vac? Just trying to understand what made you do with the dust collector. I'm not challenging you; I'm trying to learn.

Because there is no such thing as a 4hp shop vac. It would violate the laws of physics to generate 4HP on a 120v 20 amp circuit even with a 100% efficient motor. Shop Vacs usually only draw about 12 amps or less.

- Lazyman

 

Not my area of expertise but shopvacs are tailored toward strong suction but lower CFM, DCs are tailored for high CFM not necessarily high suction.

Compounding the confusion would be the tendency of vacuum makers to put the "peak" (surge) horsepower on the label. Which is garbage. As Nathan said you'll open a breaker at 20A, which is 3.2 electrical HP on 120v and likely well below 3 mechanical HP.