Final (?) Tweak on my DC System

[Rick Hubbard]

Late last summer I upgraded to 6-inch ductwork for my Jet DC1100 and at the same I also removed the DC motor/impeller assembly from the factory stand and mounted it to the shop ceiling so the main-trunk airflow was completely straight. I anticipated some improvement in the system’s effectiveness- there was some but I would not call it dramatic.

In early fall I relocated the dust bag and filter to a small “closet” that I built on the outside shop wall. As I expected, that did nothing to improve performance, but it freed up some floor space and helped reduce the ultra-fine particulates from the air (the ones that were too small for the filter to capture). It also made emptying the dust bag much easier and cleaner

This week-end I took yet another run at the system configuration. This time I removed the factory bag and filter from the system altogether. Now the dust and chips move directly (via 5“ flex-pipe) into a 5’ X 4’ X 2’ box in the closet. I fitted the box with a full width downward folding door (to permit easy emptying) and a 16” X 25” hi-MERV rated furnace filter to facilitate air flow.

I was astounded at the result! I immediately could tell that dust collection had improved exponentially. I did a few experiments and determined that I can actually have 3 blast gates open and have about the same vacuum effect that I used to have when running with only ONE blast gate open. I can’t describe how tickled I am.

There is no question that if I calculated the cost of my time (assuming that it is worth anything) and the upgrade materials, I could have probably purchased a pretty decent cyclone, but any case I am pleased to have achieved such good performance from a system that lots of folks dismiss as “barely adequate”.

Rick

[Keith Outten]

Rick,

Now you can see why I have been telling everyone that when I removed the bags and filters from my 1.5 hp dust collector and started using a chip box the performance increase is awesome :)

Even an inexpensive dust collector will perform well when you remove the downstream resistance and let-er-blow :)
.

[Joel Earl]

Rick - is there any chace you could post a picture of this setup?
I'm not sure I understand it and in trying to visualize it I see all kinds of weird things inside my skullcap:confused:

[Rick Hubbard]

Yes, well I’m certainly a believer.

The amazing thing is how EASY it is to do. I’d think just about anyone could build a box to put outside their shop-space (even if they had to disguise or camouflage it a little to hide it from the neighbors) to do the same thing.

What is also interesting is the prospect of being able to save some $$$ if there is a source for DC motor/impeller assemblies. After all, there would be no need for the bags of base.

Rick

[Rick Hubbard]

Rick - is there any chace you could post a picture of this setup?
I'm not sure I understand it and in trying to visualize it I see all kinds of weird things inside my skullcap:confused:

Sure, I'll break out the camera when I get home this evening. There's not much to see though. Just a box inside a closet with a flex hose running into it :)



Rick

[Scott Wigginton]

I'm interested in how feasible this is for a two-bag DC like my Powermatic 75?

http://s7d2.scene7.com/is/image/WMHToolGroup/1791073_main?hei=400&wid=400

[Anthony Whitesell]

I've always proposed that the higher CFM results listed in the catalogs are partly due to the poorer filter bags (ie., 30 micron instead of 1 micron). Which also explains why the 1 micron Wynn canister filters allow the DC system to collect better than the 1 micron bags (more filtered surface area). The same can be said for the American Fabric over sized filter bags...more surface air, less back pressure restriction.

I think your changes (and Keith's) show that there must be some restriction in the housing from the blower to the bag stand. Such that when the blower is ported directly to a box, the restriction is removed and the performance increases.

After writing this down, the engineering trade-off becomes obvious...better CFM or better small particle collection.

[Andrew Duncan]

I converted to Outtenism some time ago. As Keith himself might say, "If there's any way you CAN get rid of the filters, then you MUST get rid of the filters." As the newest acolyte Hubbard has found out, the difference is night and day.

Try it and you too will believe.

[Rick Hubbard]

I converted to Outtenism some time ago.

Now that I too have converted to “Outtenism” (however unwittingly)I wonder if I should petition our Human Resources department for recognition of another religious holiday?

But more to the point: I wonder if there are any sources for dust collector motor/fan assemblies that would be less costly than the conventional configurations offered by Jet, et al?

It seems to me that I saw such units offered in a WW catalog I was looking through, but have forgotten which one (also don’t recall the price).

Rick

[Steve Leverich]

Rick, I too have the Jet - mine's the 1100RCK and I've been kicking myself for not researching more several years ago before plunking down half the price of a REAL DC since discovering this site and Bill Pentz' site.

Anyway, here's one alternative (not real cheap tho)

http://www.clearvuecyclones.com/Order_Page.htm

The blower/impeller/motor would run about $720 for 15", $820 for 16" incl. shipping, still with no cyclone... Steve

[David Giles]

For any given DC system, one restriction often sets the overall air flow. Fix that one problem and the air flow increases until another restriction sets the flow. Each improvement is proportionally less, but can still be noticeable. If you haven't already done so, increasing the machine port size is probably the next step. At some point, the blower/motor capacity is limits any further major improvements.

[Rick Hubbard]

Rick - is there any chace you could post a picture of this setup?
I'm not sure I understand it and in trying to visualize it I see all kinds of weird things inside my skullcap:confused:

Hi Joel-

As threatened here ares some pics. First are some of the inside showing how the motor blower is mounted to the celing and a couple of shots of the ductwork.

Rick

[Rick Hubbard]

Here are some more pics of the outside part of the setup.

First is the not-quite-done outside storage closets next to my shop, then a picture of the DC collection box inside one of the closets and finally a little detail about the collection box itself.

As you can see there is nothing particularly fancy but it works GREAT.

Rick

[Scott Wigginton]

Do you have a floor sweep? If so how do you keep metal from impacting the impellers?

[Ron Bontz]

Since I can't vent my dust outside, I was wondering if anyone has checked what micron the alternatives are giving you? My winter time wood working would get expensive if I were to heat the great out doors. My 1250cfm Delta does noticeably better when I clean the bags including the 1 micron bag.

[Rick Hubbard]

Do you have a floor sweep? If so how do you keep metal from impacting the impellers?

Floor Sweeps? Up here in Maine we call'em brooms :D

Actually, no I don't use a floor sweep at all. The DC is used strictly for dust/chip extraction on the power tools. Hence, no problem with metal impacts on the impeller.

Rick

[Rick Hubbard]

Since I can't vent my dust outside, I was wondering if anyone has checked what micron the alternatives are giving you? My winter time wood working would get expensive if I were to heat the great out doors. My 1250cfm Delta does noticeably better when I clean the bags including the 1 micron bag.

I really have not looked into the "micron issue" yet, since I've only had this thing up-and-running for 2 days AND since I really am not concerned right now how much fine material escapes from the box (because it is outside).

Since it gets down to minus 35 or 40 degrees here in the winter I will have to look into this before snow falls tho. This past winter I had the dust bags and frame in the closet and vented back into the shop (through the bag and 2 hi MERV furnace filters mounted in the wall between the closet and the shop). This coming winter I won't have the DC bag to pre-filter the return air so I'm not sure what I'll do (maybe buy some bag-filter material and cover the opening in the box?).

Incidentally, all winter long I vented the DC outside and because of the return filter did not seem to lose much heat. From November through March I only used about 82 gallons of propane. Thats not bad considering I am in the shop with the heat on AT LEAST 20 hours a week in the winter. Of course the shop is very well insulated, so that makes a big difference too. Also, I don't run the DC continuously. If you look at the pics I posted earlier you can see the shop-built fan that DOES run non-stop whenever the lights are on so that does a superb job of keeping the air pretty well scrubbed. It doesn't vent outside- in fact I depend on it to keep the warm air circulating in the winter (notice how the flex pipe points at the ceiling).

Rick