Shop-Vac as DC in small shop

[lrogers]

Shop vacs work pretty well, but not as well as a full-blown dust collector. The worse problem is the filter clogging up and reducing the power. This can be over come by making a pre filter out of old pair of panty hose. Cut the legs off and tie a knot in the ends, slip the panty part over the filter. When vac power seems to be dropping off, open the lid and pull the panty hose pre-filter a couple of inches away from the filter and let it go. Snapping back in place knocks a lot of the dust off. Self cleaning! You still have to clean the filter, but nearly as often.
Another trick to make dust collection more effective is to get one of those "cyclone separator" lids that fit over a 5 gallon bucket. Shop vac to bucket, bucket to tool. About 3-4" of water in the bucket trap most of the dust before it gets to the shop vac. It turns the dust to "mush", but it's easier to get rid of without turning brown or breathing dust when it's time to empty!

[docrowan]

I recently started using the filter bags which has made a HUGE difference. The filter doesn't get clogged like it used to. I will also be making a chip separator on a 5 gallon bucket. I'm copying the larger Shop Notes style. I could use the pre-made tops, but I'm cheap, and making it won't take long.

JoeyGee,

I've been looking at the production tops at Rockler, but I too am cheap. How will you make your chip separator? You mentioned ShopNotes - is there an article on how to do this?

Thanks,

[ksum]

I had a vac that I would hook up to each tool and a 5 seporator between them. I quickly went to the filter bags to keep fine dust down. You don't know what you are missing until you move to a regular DC, even if it is a bag type. The difference for me in cleanup time went from 5-10 minutes to 1-2 minutes. I use the vac as a hook-up to my sander and to clean off the minor dust that doesn't make it into the DC.

One tip: If you use a preseporator that works with a 5 gallon bucket, get 2 buckets, and make sure you have a lid for 1. Cut the bottom off 1 bucket, put it on top of the lid and trace that hole on the lid. Cut the lid and put it on the other bucket, and make a seporator twice the height. I used super glue to glue the lid to the bottom of the top bucket. One 5 gallon bucket just filled up way too fast! You could also use a trash can if you are making a custom seporator. As long as it seals well, the increased chanber size shouldn't hurt. If no suction exits the can, suction in should equal suction out.

Karl

[nicer20]

Hi Docrowan,

I am also looking for dust control solutions and found this. Thought you might want to look at this. This is not the Shopnote Chip Separator that JoeyGee mentioned but I am assuming its pretty close.

http://www.woodworking-news.com/wood...ts/index.shtml

Will also see what JoeyGee posts.

- NG

[JoeyGee]

Oh man, sorry guys, I didn't know I was on the clock. It's not normal for people to be waiting for answers from ME

I still have not gotten around to mine, but I really need to. My SN issue is in my attic (I think) so I haven't looked at it to even know what issue number it is--BUT thanks to Google, here it is:

http://www.woodworkingonline.com/wp-...07/Upgrade.pdf

I don't think that's too detailed, but you should be able to get the picture of what I am talking about. I'll see if I can dig up the issue to get more detail. Note--that is for a DC system, I plan to shrink it for a 5 gallon bucket with SV. No, I'm not going to use the three outlet control box, my SV is not that big

[nicer20]

Shop Vac for DC

Hi Guys,

Just starting into WW and based on some recommendation from other guru's here I have decided to start on using shop vac with my saw.

Any recommendation on size and HP rating ?

I am seeing a great variation in size i.e. gallon capacity and Horse power. So any experience will help.

TIA,

NG

[gsmittle]

Something like this that Shop Vac sells?

http://www.shopvac.com/detail.asp?id=393

I believe Rigid sells one too....

g.

[eccentrictinkerer]

While reading this thread (I'm setting up a shop-vac system for my shop) I tried the link


http://www.shopvac.com/detail.asp?id=393


Shop Vac has this item on sale for about half of what Woodcraft and Rockler are selling it for.

[Jeffrey Schronce]

I believe Rigid sells one too....

g.

They have been on clearance for around $30 at the Home Depots I have been to recently. I know Lancaster PA has at least one set up for $30. Don't know model or sku.

[siliconbauhaus]

I'm using a sears vac and the lid/5gallon setup. It works pretty well for me as long as I remember to A) swap the hose and B) turn the bloody vac on.

My hepa filter does get caked up in dust but I dont notice any audible indication of it. I just open it up and cart it outside in a bin liner and whack the crap out of it.

I've considered the piped in option with the shop vac / rigid kits but I don't personally think they're much of an improvement over what I'm doing now. I'm probably going to buy another cheap sears vac and lid and run one for one side and the other for the other side.

Of course I'm saving for a festool so I'm being uber cheap.

[djkert]

Any recommendation on size and HP rating ?

I am seeing a great variation in size i.e. gallon capacity and Horse power. So any experience will help.

Just get the biggest one you can. A 6 or 6.5 HP/16 or 20 gallon shop-vac should do just fine. Haven't seen much bigger really. Not sure what brand is the best though. I'd be curious what others have to say between rigid, craftsman and shop/vac?

[niki]

I'm so sorry to spoil the "HP Party" here but I think that somebody is "working" on you guys...and in big...

6.5 HP ???!!! come on guys, buy it quickly...take out the motor and change it with your table saw and you get 6.5 HP Table saw...

I don't know about USA but, here in Europe everybody would laugh...

Lets see...
1 HP = 746W
6.5 HP = 4849W
4849W : 120V = 40.4 Ampere!!!!

I think that before you buy it, make sure that your fuses or circuit breakers will not blow already at 20 Ampere...but don't wary, they will not blow, because in very small letters, it's written...11A motor
11A x 120V = 1320W
1320W : 746 = 1.77HP considering that the motor efficiency is 100% (normally 50~60%) but this vac motor appears to have an efficiency of 370%...they must introduce it to NASA, they are looking for such an efficient motors....

In EU, the customer protection regulations demands that every machine/tool/appliance name plate will show only the Watts (input Watt)...a very strong vac has 2000W just divide it by 746 and we get "only" 2.7HP.....well, maybe the "Made in Chiwan" vacs are much better than the "Made in Germany" Festool, AEG or Metabo but I don't think so....

BTW, 2000W is the input power or if you like, the electric consumption of the vac...the output power is around half of that and if you'll look at the Metabo site, you will see;
"Rated input power - 1800W"
"Rated output power - 1050W"
http://www.metabo.co.uk/metabo/handg..._01885_00.html

I hope that an Electrical Engineer will pop in and tell us the true....

Regards
niki

[LCHIEN]

OK, I'm an EE. Its true, in the US you can't get more than 2 HP more or less from a 120V appliance on a normal 15 or 20A residential circuit.

For some reason shop vacuum manufacturers have gotten away with using this peak horsepower rating, which is based upon the stalled motor current - basically a measure of the resistance of the winding, not a real measure of actual motor strength.
In practice, you have to have ahigh current 120V supply for this and you can only stall the rotor for a moment or two before the motor will melt down. Not a usuable condition before or after since a stalled rotor does no work and a melted motor will do no work either.

The following is a description from Popular Mechanics magazine. reviewing Vacs.


The Truth on Horsepower
In addition to being designated by capacity, most wet/dry vacs carry a horsepower rating—our test units range up to 6.5 hp. But if you think that means a vac motor is as powerful as a garden-tiller engine, think again. Like many other consumer­grade tools, the horsepower rating is modified by the word “peak.” This indicates the electrical draw at the point where the motor is overloaded and stalls. The upshot? Horsepower ratings aren’t the most accurate way to compare wet/dry vacs. Looking at amperage makes more sense.

Sears used to label tools quite frequently with "developed" HP which was similar in deceit. I don't recall seeing that they do this much anymore, but was always very confusing.

I think it is also very common for air compressors to be rated in Peak horsepower giving vastly inflated impressive power ratings.
http://www.wisedan.com/aircomp.html

[Tom Slick]

You're correct Niki. they do some special math to come up with the marketing HP ratings on cheap shop vacs and cheap air compressors sold in the US. somehow the more expensive a shop vac or compressor gets the HP numbers go down. $50 will get "5hp" and $500 only gets 2hp. If you have a 5hp real DC in a home shop you have a large dust collector that runs on 220v, yet a shop vac will have "6.5 hp" and a 14 guage cord with a 15 amp plug on a 110v circuit.
Using Watts and Amps is much too simple for us Americans, we like Horsepower. sort of like how the metric system makes everything simple but we insist on using our own cumbersome system.

[niki]

Loring
Thank you so much for stepping in....I was hopping that you will...

As I noticed, all the 120V machines/tools in USA have a maximum of 15A that is 1800W.

The Hitachi M12V router is of 15A = 1800W and it's calls "3.25HP"
The European version is a 2000W (230V) but it's called "2000W"...

Tom
Nice example with HP and the cost...the problem is that a normal "house wife" (and in many cases even the "house husband") do not understand nothing about "Horses" (power) and they just see the numbers...6.5HP is much more attractive that 2HP and it's even cheaper...

Martin
I have two shop vacs in my garage and I would suggest a few point to consider;
1. Try to get the 15A motor vac
2. Try to get the lowest noise vac
3. try to get a vac with power control...many times, you don't need all the vac power...when I work with sanders, I use it on "Minimum" and even for the router, I use half power or so...only for the table saw I use it on "Maximum".

In any case, if you want to get the maximum performance from the vac, use short hoses (I use 3 feet hose for the table saw)...long hoses are reducing the performance because of "duct loses"....."steep turns" of the hose also reduces the vac performance

If you like to see what I did please have a look at my R2D2...
http://www.bt3central.com/showthread.php?t=24930
http://www.bt3central.com/showthread.php?t=32953

Regards
niki