# My new (old) HF DC



## Larryh86GT (Feb 13, 2013)

A friend gave me this Harbor Freight DC today.


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## thegrgyle (Jan 11, 2011)

There you go! Getting that from your bud for the right price is like hitting the DC jackpot! 

Now make a Thien Baffle for it, and you won't regret it. The DC will work more efficiently, and then maybe a little later on, you can upgrade to a Wynn filter, so you aren't breathing in all the fune dust (that is really bad for you).


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## Larryh86GT (Feb 13, 2013)

My friend had 2 filter bags on the machine when he gave it to me. Today I took the bottom filter bag off and put a heavy duty plastic bag on and fired it up. I think it will do very well on the dust and chips from my surface planer. As the air pressure holds the upper filter bag up in the air is there really a need to use the hanger rod with this?


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## Dave Paine (May 30, 2012)

Larryh86GT said:


> My friend had 2 filter bags on the machine when he gave it to me. Today I took the bottom filter bag off and put a heavy duty plastic bag on and fired it up. I think it will do very well on the dust and chips from my surface planer. As the air pressure holds the upper filter bag up in the air is there really a need to use the hanger rod with this?


You may not need a hanger rod. Most folks do not like seeing the top bag flop down when the machine is off.

However you may want to consider replacing the upper bag.

The open area of the original machine was designed for the two bags. Using plastic on the bottom means you have halved the open area to discharge the air. This will have a big impact on the performance of the machine.

Normally when the bottom is plastic, the top is a cannister, which has a lot more open area.

If you replace the top bag with a low micron bag, of larger size, you can get back the original open area, perhaps even get more open area and you will see the performance benefits.

Another option is a Wynn filter - another type of cannister filter.


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## toolguy1000 (Oct 4, 2012)

i'd humbly suggest adding a baffle to the drum ring of that collector. improves the efficiency of the separation function sending more debris to the collector bag and less to the filter bag thereby maintaining airflow and maximizing dust collection performance:

http://lumberjocks.com/topics/40189

the frying pan can be replaced with a thien baffle. when wood magazine tested DCs in their latest issue, they noted that a thien baffle improves the performance of single stage DCs.










FWIW, here's a link to phil's site. lots of good dust collection info there:

http://www.jpthien.com/cy.htm


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## Dave Paine (May 30, 2012)

toolguy1000 said:


> i'd humbly suggest adding a baffle to the drum ring of that collector. improves the efficiency of the separation function sending more debris to the collector bag and less to the filter bag thereby maintaining airflow and maximizing dust collection performance:


Yes it does. I should have included in my reply.

I added a Thien baffle to my Jet dust collector. A big improvement in performance. Easy to make.

http://www.woodworkingtalk.com/f32/making-dust-collector-cone-separator-44695/


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## Larryh86GT (Feb 13, 2013)

Dave Paine said:


> However you may want to consider replacing the upper bag.
> 
> The open area of the original machine was designed for the two bags. Using plastic on the bottom means you have halved the open area to discharge the air. This will have a big impact on the performance of the machine.
> 
> ...


Thanks Dave - I have to roll the DC in and out of my shed and with the hanger on it the DC is too tall.

But I am puzzled about the plastic bag. The HF description says:

This 5 micron dust collector is the ultimate solution to your clean up frustrations. Easily eliminate the finest sawdust, dirt and debris with this remarkably effective dust collector system, complete with a clear bottom bag so you see what's been collected. Four locking, swivel casters enable easy transport of your dust collector to anywhere it's needed.

Clear bottom bag, so you’ll know when it’s full
Four locking swivel casters for easy transport
Lockable toggle switch
4" diameter intake and 4" diameter exhaust
Includes two collection bags, casters, hex wrenches
Overweight Item subject to 14.95 additional Freight Charge.
And their photo of the DC shows a plastic bag on the bottom.


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## Dave Paine (May 30, 2012)

Some folks like to use a plastic bag on the bottom some like the cloth bag.

Some like to see the level of dust. It is very handy to have a plastic bag on the bottom. Some folks ditch the bag. I transfer into garbage bags which are less expensive.

The HF is not likely to explain the performance difference between a standard 5 micron bag, a 1 or 2 micron bag and a Wynn type cannister.

For an experiment remove the top bag and turn on the dust collector, then go to a machine and feel the airflow at the inlet to the duct system.

Turn off the dust collector, replace the bag, then turn it back on and feel the difference in air flow.

A smaller micron bag or Wynn type cannister will have lower pressure drop, which translates to higher airflow at the machine.

Take a look at the Wynn site for more information.

http://www.wynnenv.com/35A_series_cartridge_kit.htm

I have been working on improving my own dust collection system by reducing various pressure drop losses.

I started by removing the "Y" at the blower since I only connect a single duct. I made a replacement donut out of a scrap of plywood cut to rough shape and then used a small drum sander on the drill press to get the final inside diameter for the fitting and outside diameter to be a snug fit on the blower.


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## Larryh86GT (Feb 13, 2013)

toolguy1000 said:


> i'd humbly suggest adding a baffle to the drum ring of that collector. improves the efficiency of the separation function sending more debris to the collector bag and less to the filter bag thereby maintaining airflow and maximizing dust collection performance:
> 
> http://lumberjocks.com/topics/40189
> 
> ...


The baffle would be put in place at the top of the drum ring? Above the manufactured baffle ring?


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## Dave Paine (May 30, 2012)

Larryh86GT said:


> The baffle would be put in place at the top of the drum ring? Above the manufactured baffle ring?


No, this picture is showing the bottom of the drum, the side which will face down when in normal operating position.

More details in my thread I linked in an earlier reply.

Making a dust collector cone separator


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## toolguy1000 (Oct 4, 2012)

just to follow up on dave's reply, if you go to his linked thread, posting # 10 shows my set up with the second pic looking into the drum ring inlet hole. when using a flat thien baffle plate, the top surface of the baffle plate will line up with the lowest point of the 6" inlet into the drum ring. th e 3 /4" thickness (if using 3/4" ply wood or mdf for the baffle) of the plate would be below the lowest point of the drum ring inlet hole. that way, material entering the drum ring flys around the surface of the baffle where it slows down and drops into the collection bag at a reduced speed.


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## Shop Dad (May 3, 2011)

toolguy1000 said:


> ...when wood magazine tested DCs in their latest issue, they noted that a thien baffle improves the performance of single stage DCs.


I haven't looked at this issue yet but did it matter if it was before or after the impeller? Glad one of the mags took this on.


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## Larryh86GT (Feb 13, 2013)

Thanks guys. It looks pretty easy to do. :thumbsup:


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## MT Stringer (Jul 21, 2009)

I modified my HF unit from the git go. I mounted the motor/fan on the wall. I built a Thien separator and put it inside a 32 gallon plastic drum. It is plumbed upstream of the fan. That way, the big pieces and any unwanted foreign paterial drop out into the drum. I originally put a 42 gallon trash bag on the HF unit, but switched back to the clear one to see how the separator is doing. I have very little fine dust in the plastic bag. Everything else is in the drum.

I also bought the Wynn Nano filter canister. It seems to be working great.
Hope this helps.
Mike


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## Larryh86GT (Feb 13, 2013)

toolguy1000 said:


> just to follow up on dave's reply, if you go to his linked thread, posting # 10 shows my set up with the second pic looking into the drum ring inlet hole. when using a flat thien baffle plate, the top surface of the baffle plate will line up with the lowest point of the 6" inlet into the drum ring. th e 3 /4" thickness (if using 3/4" ply wood or mdf for the baffle) of the plate would be below the lowest point of the drum ring inlet hole. that way, material entering the drum ring flys around the surface of the baffle where it slows down and drops into the collection bag at a reduced speed.


My wife donated a large frying pan to be used for this today. It looks like the bottom surface of your frying pan is about 1" down from the hole?


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## toolguy1000 (Oct 4, 2012)

Larryh86GT said:


> My wife donated a large frying pan to be used for this today. It looks like the bottom surface of your frying pan is about 1" down from the hole?


yes it is, assuming the hole referred to is the large horizontal hole that, in the first pic of my lumberjocks link, is covered with saw dust. but with the mounting method i used, you can experiment with that depth by merely changing the single mounting bolt. theoretically, the more in line the flat part of the pan bottom is with the bottom of the drum ring's 6" inlet (where the blower connects to the drum ring), the better. that way it more closely resembles a thien baffle.


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## Larryh86GT (Feb 13, 2013)

Yes, the manufactured "baffle" hole is the one I was refering to. In the pictures the bottom (flat surface of the frying pan that is now facing up) looks to be close to the center of the intake hole in the ring.


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## toolguy1000 (Oct 4, 2012)

yes, but in my application, it should probably be lower. that way, more of the pan's bottom will be at the bottom of the 6" opening in the drum ring that receives the flex hose from the blower. this should, if a flat baffle works better than a cone or dome, improve the performance of whatever baffle is used.


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## Larryh86GT (Feb 13, 2013)

toolguy1000 said:


> yes, but in my application, it should probably be lower. that way, more of the pan's bottom will be at the bottom of the 6" opening in the drum ring that receives the flex hose from the blower. this should, if a flat baffle works better than a cone or dome, improve the performance of whatever baffle is used.


How's it working for you the way it is now? It would seem if the bottom of the frying pan (now being the top) lined up with the bottom of the intake hole it would force more of the intake upwards to the filter bag. But like you say the way you mounted the pan it is easy to adjust the position.


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## toolguy1000 (Oct 4, 2012)

Larryh86GT said:


> How's it working for you the way it is now? It would seem if the bottom of the frying pan (now being the top) lined up with the bottom of the intake hole it would force more of the intake upwards to the filter bag. But like you say the way you mounted the pan it is easy to adjust the position.


quite well, so far. when i initially installed it, the filter had quite a bit of debris in it. after the installation, i just turned on the blower and then inspected the filter. it was actually cleaner than before the bafle install.

re: your statement that "it would force more of the intake upwards to the filter bag", that would probably be more a function of the extent to which the pan you'll be using is flat vs. domed. maybe if this thread catches phil's attention, he'll chime in. get two bolts. one like mine and one maybe 4" longer. try each and see which one works better.


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## Larryh86GT (Feb 13, 2013)

This is the donated frying pan. It's 3" deep by 12" and it should work.


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## toolguy1000 (Oct 4, 2012)

IMHO, with a pan that flat, i'd try lowering it so the pan bottom is level with the bottom of the 6" opening in the drum ring which receives the flex hose from the blower.


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## Larryh86GT (Feb 13, 2013)

I appreciate your suggestions with this but I guess I am not grasping the dynamics involved here. Putting the pan that low it would seem to me it would block most of the air flow from going down into the plastic collection bag and direct most of the air flow upwards into the filter bag. I tried to draw this out but I can't draw on paint worth a darn. :no: But I have plenty of bolts and spacers and steel stock to work with and can move the pan up or down with ease.


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## toolguy1000 (Oct 4, 2012)

FWIW, it doesn't do that. with your pan (although it seems a bit small for this application. mine is closer to 16" in diameter), i'd start low and move up. phil's baffle plate sits with the top surface of the baffle plate level with the bottom of the drum ring inlet (6" flex hose receiver). there is a 1" -1 1/4" slot cut into the outer edge of the plate for 240° of the plate's circumference. the other 120° of the baffle plate forms a "ramp" directly in front of that same 6" inlet. as material slows, it drops into the collection bag through the 1-1 1/4" 240° slot. the pan does the same thing, albeit more closely resembling the jet vortex cone. mine is higher up as it's more "dome" shaped than flat.

remember, the blower is pushing the material into the drum ring. as soon as the debris enters the ring, it starts to slow down and starts wanting to drop into the collection bag. at least that's what i think it wants to, and appears to, do.


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## Dave Paine (May 30, 2012)

Larryh86GT said:


> I appreciate your suggestions with this but I guess I am not grasping the dynamics involved here. Putting the pan that low it would seem to me it would block most of the air flow from going down into the plastic collection bag and direct most of the air flow upwards into the filter bag.


That is the beauty of Phil's design. He intended for the air to stay in the top and the debris to go down - and stay down.

A well placed baffle will not have a lot of air swirling in the bottom bag by Phil's design. Swirling air and debris are just wasting energy.

The baffle is a separator. Ideally you only want the debris in the bottom. Practically, this will mean some airflow will be needed.


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## Larryh86GT (Feb 13, 2013)

Dave Paine said:


> That is the beauty of Phil's design. He intended for the air to stay in the top and the debris to go down - and stay down.
> 
> A well placed baffle will not have a lot of air swirling in the bottom bag by Phil's design. Swirling air and debris are just wasting energy.
> 
> The baffle is a separator. Ideally you only want the debris in the bottom. Practically, this will mean some airflow will be needed.


When I tested the DC with the plastic bag I did see considerable swirling going on. 



toolguy1000 said:


> FWIW, it doesn't do that. with your pan (although it seems a bit small for this application. mine is closer to 16" in diameter), i'd start low and move up. phil's baffle plate sits with the top surface of the baffle plate level with the bottom of the drum ring inlet (6" flex hose receiver). there is a 1" -1 1/4" slot cut into the outer edge of the plate for 240° of the plate's circumference. the other 120° of the baffle plate forms a "ramp" directly in front of that same 6" inlet. as material slows, it drops into the collection bag through the 1-1 1/4" 240° slot. the pan does the same thing, albeit more closely resembling the jet vortex cone. mine is higher up as it's more "dome" shaped than flat.
> 
> remember, the blower is pushing the material into the drum ring. as soon as the debris enters the ring, it starts to slow down and starts wanting to drop into the collection bag. at least that's what i think it wants to, and appears to, do.


 
Now it is starting to sink in. I think I will get a larger pan to do this right the first time. Thanks for your patience and help


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## toolguy1000 (Oct 4, 2012)

FTR, I believe a flatter baffle is better than a domed baffle. Domed would more closely resemble the jet vortex cone. If I recall the results in the wood magazine DC test in the may issue, the flat baffle supposedly works better than the dome.


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## Dave Paine (May 30, 2012)

Larryh86GT said:


> When I tested the DC with the plastic bag I did see considerable swirling going on.
> 
> Now it is starting to sink in. I think I will get a larger pan to do this right the first time. Thanks for your patience and help


Why not just cut out a Thien baffle. I made mine from 1/4in plywood. Does not get much cheaper.

I feel this will give you better performance that a larger pan.


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## Larryh86GT (Feb 13, 2013)

Dave - I just went back and looked at your thein baffle and that looks easy to make and install also. I've got a nice piece of 3/4 ply for it. I'll give this a try then. Thanks all for the help and discussion to get me here.


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## Dave Paine (May 30, 2012)

Larryh86GT said:


> Dave - I just went back and looked at your thein baffle and that looks easy to make and install also. I've got a nice piece of 3/4 ply for it. I'll give this a try then. Thanks all for the help and discussion to get me here.


I was surprised how easy it was to make the Thien baffle and install.

Please update with pictures of your installation. :thumbsup:


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