Replies

1. 
   jc21 | Nov 16, 2004 02:30pm | #1

   I think the main thing required when comparing dust collectors and their specs is a healthy skepticism. I bought a Delta 50-850 (1200cfm, 5 micron bag) this fall and currently use it for single machine hook up .......it works well. I was going to get a smaller machine but am glad I didn't. In dust collection my motto has become, "Too much is never enough". What is it that you like about the canister type dust collectors? .............. they seem pricey to me. The canister version of my machine (50-850A) does offer 2 micron collection vs the 5 micron of mine but the price nearly doubles. I can buy an optional 1 micron bag and still have plenty of $ left over. The $500 price tag of the canister systems seems to be getting into cyclone territory.

1. 
   forestgirl | Nov 16, 2004 07:10pm | #4

   Hi jc, thanks for you input on this.  I was originally looking at the 1.5HP units, but listening to Knotheads helped me realize that would be marginally effective.

   Canisters.......I definitly want the increased filtration ability, which would cost extra using bags.  The increased filtering area seems like a good thing -- sure makes a difference with my vacuum (cloth filter vs. pleated HEPA filter).  And finally, the ability to knock the dust off, down into the lower bag and just close it up and drag it out of the shop seals the deal.  I really don't want to struggle with bags and end up with dust all over me and my surroundings.

   A cyclone would be nice, but the stretch to a canister is absolutely as far as I can go -- holding out for one has already cost me a year or so of postponing a DC acquisition.  If I went to a cyclone, I'd still want 2HP, and it looks like the cost on that would be close to $800, significantly more than the $450-$500 for a canister.  It's the final "big piece" for the shop, so that's a relief anyway!

   Oooops, gotta go -- breakfast "date".forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

1. 
   highfigh | Nov 17, 2004 08:22pm | #5

   I don't know what you do with your shavings and dust, but if you compost it, you get a lot of free dirt. Or, if you don't do any gardening, your neighbors or friends get it."I cut this piece four times and it's still too short."

1. 
   forestgirl | Nov 18, 2004 04:03am | #7

   I garden sporadically -- not very organized, but do have a compost heap or two.  So far, all my sawdust has gone there or around trees to keep the weeds down.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   Michmesquite | Nov 18, 2004 12:51am | #6

   fgI have the Jet DC 1100C running at 110v. I have it supplied by about 15' of 4" S&D PVC pipe (2 90's) and then I drop to the machines with 10'of 4" flexible hose.It has NEVER failed to keep up with my MiniMax even when planing an 1/8" off a 10" wide board (Redwood)._________________________________

   Michael in San Jose

   "In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell 

1. 
   forestgirl | Nov 18, 2004 04:13am | #8

   Hi Michael.  I'm mostly concerned about the table saw hookup.  I have the Penn State Ind. overhead blade guard, and will be using a Y-fitting to gather dust from both above the blade and from underneath the contractor's saw.  Based on Kent's reports, a 1HP definitely isn't going to do the job.  Do you think a 1.5HP would cover it??forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

1. 
   Michmesquite | Nov 18, 2004 04:32am | #9

   Yes, absolutely.My MiniMax combo has a riving knife arrangement with dust collection in the blade cover. I run the 4" hose to the saw's main dust fitting and from another location along the 4" S&D backbone, I bush down to a 2.5" hose for the blade cover.The 1.5 HP Jet work's just fine. The main reason I didn't go with the 2 HP model was it needed 220v and at the time I didn't have enough circuits._________________________________

   Michael in San Jose

   "In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell 

2. 
   Patto | Nov 18, 2004 08:51am | #10

   You have heard that old saw .....you dont know what you dont know....

   This thread has me in that space at the moment because I am in the same position as yourself - about to invest in dust collection (me because I will have a new house and garage in three weeks).

   How did you start to design this? tools to be supported, total room space or area allocated to wood work etc?

   Have you addressed the issue of dust collection inside out through the wall, and ideas about the combination of collection and separate air filtering?

   Huge question, eh? and I thought it would be straight forward untill you started this.

   David

3. 
   forestgirl | Nov 18, 2004 10:01am | #11

   "Design" might be a bit of an exaggeration, LOL!  More like a process of elimination.  Decision to go with a 2HP (or now, maybe a 1.5) based on the following disparate facts:

   I definitely can't afford a big system with all that piping.  $450 is a big stretch for my budget.

   A small, roll-around portable isn't going to do the job with the contractor's saw.  That and the band saw are the biggest dust producers

   I need as fine a filtration ability as I can get.

   I really don't want to mess around with bags -- I love the canister design

   I already have an air cleaner -- lucked out on a new JDS system at an estate auction for $85, couldn't pass it up.  My shop is in our garage, which has never held cars anyway, so it's a free-for-all what I want to do with the space.  It's going to be a squeeze to get the DC in there, but it will live inside for awhile anyway.  Probably can put it outside next year if I want, just have to build an enclosure.

   I suspect there isn't going to be enough of a price difference between the 1.5HP and the 2HP to justify cheating myself.  Will just go for the 2HP.

   A few more details?  I'll use the DC to collect from the planer also, and the disc/belt sander when it's in use inside.  The big shop vac works great for the jointer, unlike other machines, so I'll probably leave that off the system.  I have a big downdraft table (from the same auction) that'll serve when sanding with the ROS or finishing sander.  I'll start out with the plastic hoses at first.  If I ever get to where the machines seem permanently in place, maybe I'll run metal.

   Congrats on the new shop!  (Oh, and the house too <g>)forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   Kent_F | Nov 16, 2004 03:40pm | #2

   FG, you're correct that machines with the same HP, impeller size, and inlet size should produce about the same CFM. The difference is the exaggeration factor applied by the marketing department.

   Most consumer grade DCs are rated by "free blower" CFM, which is the maximum airflow the blower can produce, unencumbered by duct work or filters. This is obviously not a realistic performance test. It's reminiscent of the auto HP wars of the 60's, when manufacturers were testing their engines without exhausts, air claners, and cooling systems to get the "maximum advertisable HP."

3. 
   RandMCapozzi | Nov 16, 2004 06:51pm | #3

   Forrestgirl,

   Kent is correct about the "free air" stat. The Jet rating of velocity isn't all that useful since we don't know how much SP or pipe size the system is under. Both numbers are probably free air. Now free air is normally the amount of air the blower can push/pull without anything attached (filters, ducting, etc). It's possible you are seeing the difference because perhaps Jet's number is with the bags attached and the Grizzly is without the bags attached. Either way, these numbers are virtually meaningless since you aren't going to operate your DC that way. (I'm assuming you're going to attached ducting to the DC)

   Likewise, the SP numbers are meaningless because long before the DC ever reaches those "Max SP" numbers, it will not have enough CFM or velocity to be effective at collecting dust.

   Unfortunately, what you need are the actual fan curves that will tell you the CFM the unit can provide at a specific SP. That will enable to you determine the DC's real ability to meet your needs.

   Realistically, you will likely never see even 50% of the CFM that the manufactures are providing. American Wood Working did a DC comparison some years back. When they stuck a 10' pipe on the DC's with clean bags attached, they typically saw 50% reduction in CFM from the "free air" numbers.

   Of course, most filters require a "cake up" on them to reach their claimed filtering efficiency. That will also result in reduced CFM performance. And if you want to use any pre-separators, count on a pretty big hit on performance their also.

   Good luck on your continued research,

   --Rob

   
   

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   Edited 11/16/2004 10:57 am ET by Rob