Modding the Harbor Freight Dust Collector the (relatively) easy way

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Blog entry by ScottStewart posted 09-24-2012 03:33 AM 54111 reads 29 times favorited 13 comments Add to Favorites Watch

So you want to be a woodworker? Good. Like a lot of people I had to try to figure out if I was going to put my woodworking in the garage or basement. Then like a lot of people you hear about dust collection…then you go to Bill Pentz’s site, and you learn you are going to die unless you are willing to shell out 2k for dust collection (Clear Vue cyclone with 6 inch lines) before you think about letting a blade touch a board.

Fear not! I, and many others before me, have used our wits and the wonders of Google to devise a reasonably good 1 tool dust collector at a decent price (I’m guessing around $500 if you are cheap like me).

Silently give thanks to the folks at Harbor Freight, and give thanks out loud to Phil Thien.

Rationale for the project:

Dust collection is right up there with politics and religion on what people think. You can always find someone to tell you you are an idiot and you are doing it wrong, but here are the general concepts that I (and I think a lot of other people) have come away with after a lot of reading: I do not claim to be an environmental air quality engineer and I didn’t stay at a Holiday Inn last night.

1. More airflow is better.
2. Dust particles down to about 1 micron are bad for you to be breathing.
3. Keep the big chunks away from your expensive filter that allow you to do 1 and 2 and also away from your impeller on your DC.

I know there is a lot of information spread out about the HF DC, but I wanted to review my experiences so other beginners can see this is a very doable project. I also know the “top hat” style of modding these is in vogue now, but I wanted to keep this as simple as possible.

This is the project as it is now… used on weekends for the last 6 months:

Amassing the goods:

First of all is the basic DC, the HF one we know and love. I had mine for a year in the box before I had the cash to buy the canister. Believe me, the canister is very important.

1. The DC:

A huge number of us on this board have this thing, it seems to be one of HF’s hidden gems. Try to abuse HF’s coupon policy as much as you can to get this thing as cheap as possible. The felt bag that comes with this thing should be donated to some needy art teacher as a school supply. it will let particles from 1-5 microns through with ease.

2. The canister:

The Wynn people are as nice as can be, they do not have an online ordering form, you have to call them.

3. 5” Pipe to go from impeller to bag/filter:

I used 2 flexible elbows and a straight piece of galvanized pipe. It’s hard to find it online, but it took about 10 seconds for my local Ace hardware guy to lead me to it in the store. If you use Corrugated pipe on your DC, Bill Pentz will haunt your dreams.

4. Brute 30 gal trash can (The brute seems to be a bit heavier walled than a lot of the other can’s I looked at.
Purchased at blue borg.

5. 4” S&D elbow and straight piece. Blue borg.

6. Plywood for the 2 circles for the Thien Separator and the base.

7. Casters for base. Cheapest way I have found to do this is to buy the HF moving dolly on sale for about $10 and repurpose the casters.

8. Hose to go from Thien collector to impeller and from collector to tool: 10’ from Rocker. You really want to minimize the use of rough walled hoses.

9. Fittings to go from hose to port on impeller and port on tool:

10. Fittings to fit the S&D pipe fittings on your Thien collector:

11. Gold plated dust tape:

12. Hose clamps to hold hose onto your expensive fittings.

13. Some 2x stock from the borg to reinforce your base and make your handles.

14. 1/4” all thread and 1/4-20 nuts for Thien collector

15. Silicone or caulk to seal around S&D fittings.

16. 8-10 feet of small guage wire for static control.

17. Few other screws, hardware etc, but if you’ve made it this far, I have faith you can figure it out.

Prep for the build:

We are going to build a Thien Separator, so go here and do a bunch of reading…

Before we go, You CAN do this. It took me a year to get over my fear of making this thing, it’s actually pretty easy once you read the forums.

Note the forum link, I actually like these directions better:

Dbhost’s plans made much more sense to me than Phil’s pictures. I built mine based on his directions, and it seemed to work very well.

So you have your Thien Separator, now what?

I wanted mine mobile, so I made a cart that has the separator and the DC all on it. I started with a 23”x 48” piece of 3/4 ply. I mounted the casters to the underside and put a couple 2×3’s on edge under the platform for stiffness. I used the holes in the HF base to mark my mounting holes for the impeller/motor and canister stand. Mount the motor/impeller per the directions and the canister stand withe the directions. Place your nice new Wynn 35a on top of the green donut. There are some turnbuckles that came with your canister filter that you use to attach the canister to the donut. You want an airtight seal, but the donut is flimsy, so don’t overdo the tightening. Next figure out how to get your flexible elbows set so that the ends are in a straight line. This takes some doing and some patience. Then you will probably need to cut your straight section of pipe to get the right length between these two. Once everything is in place, tape every joint with your nice rubber tape. Silicone/caulk the S&D adapters into the Thien pieces. These adapters don’t fit great, but eventually I go them to work. I wish I knew something better to make this adaptation, but without heating and modifying the PVC, I don’t think it’s possible. Figure out how much space you need to go from your separator to your impeller and cut your 10’ hose in two. Mine from the separator to the impeller is a bit too long. I put a clamp over the ends at the separator, the dust right fittings seemed to screw into the hose pretty tightly. Same thing on the end going to the tool. The last 2 things are to jury rig some type of handle to move the cart, and place a small wire somewhere on the metal of the collector and on the metal rib on the hose that goes to the tool. My planer is the only thing that seems to build up static, but the wire takes care of this. Finally attach the plastic bag to the bottom of the donut and attach with the large hose clamp provided. I got mine from Wynn, I can’t remember if I paid extra or if it came with the filter.

Overall…I have never had any experience with DC’s before this, so I don’t know how well it does compared to other DC’s. It seems to work great on my sawstop and planer, and ok on my jet Jointer. My only other mod I might do would be to add weatherstripping to the groove in the plywood on top of the Brute can. For filtration, I get less than 1/4 cup of dust for every time I have a full can of shavings/dust. The bit of stuff you can see in my bag is because I let the can get too full and the separator doesn’t work then :)

If anyone has any other wisdom to add on these or issue’s with my build, I am willing to listen.

13 comments so far

View DIYaholic's profile


19921 posts in 4165 days

#1 posted 09-24-2012 03:58 AM

Nicely detailed blog.

I’m trying to determine whether to go the “simple” route (as you have done), or do it the more “difficult” way. I’m torn between the just “git-r-dun” modification or the full blown “Top Hat”, reposition the motor/impeller rebuild. I know that either way, it will not get “redone” for a veeeeeery long time. I already have everything for the “top hat” mod, with the exception of the motivation. Lol. I’m leaning towards the more involved “top hat” mod….....

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

View ScottStewart's profile


120 posts in 3622 days

#2 posted 09-24-2012 04:49 AM

I see benefits to the top hat configuration…I had 2 reservations.

1. Mine is on a mobile base. I have this irrational fear of creating that much torque that high off the ground on a mobile base. As a practical matter, it could have been done with a much heavier frame. If I had building for a stationary tool, a top hat would have been more appealing.

2. Bearings. I know the top hat has worked for a lot of guys… but I worry about the side load on the bearings. This looks like a case where thrust bearings would be appropriate. These things seem to work very well, but we ARE starting with a HF tool. We all know they aren’t putting any better quality bearings in these things than they have to.

I can see why the top hat works for a lot of people, but for my situation, the benefits don’t outweigh the risks.

View HalDougherty's profile


1820 posts in 4727 days

#3 posted 09-24-2012 11:41 AM

Great blog post and you’ve got a great dust collection system. I bought the Harbor Freight DC a couple of years ago and it’s still sucking… I didn’t get the improved canister. My DC sits outside my shop and the hose runs inside the building.

-- Hal, Tennessee

View Grumpymike's profile


2504 posts in 3805 days

#4 posted 09-24-2012 05:15 PM

I have looked at the HF DC’s, and now I think that I will have another look with a diferent eye. They are in my price range, but I was afraid the It wouldn’t last long enough to justify the expence. Thanks for a great blog with good detailing.

-- Grumpy old guy, and lookin' good Doin' it. ... Surprise Az.

View bbc557ci's profile


699 posts in 3564 days

#5 posted 12-24-2012 02:54 AM

Dbhost’s plans made much more sense to me than Phil’s pictures. I built mine based on his directions, and it seemed to work very well.

Great stuff!! But…. when I click on to the link (both of them), they both take me to Phill Theins directions. Is there a way to get to the plans by Dbhost? Thanks !!

-- Bill, central where near the "big apple"

View ScottStewart's profile


120 posts in 3622 days

#6 posted 12-24-2012 03:49 PM

link has moved, here is the new link.

View bbc557ci's profile


699 posts in 3564 days

#7 posted 12-24-2012 11:55 PM

Thank you ScottStewart. Christmas obligations will be holding me up from jumping over to the link you posted for the next couple of days. But plan is to check it out as soon as time allows….especially since I picked up a new 2hp HF DC today :o)

Just so happens that whilst I was out doing a little Christmas shopping for others, my truck suddenly pulled to the right as I was passing the local HF store. Gotta have that l’il misalignment in the steering system checked out asap!! LOL

-- Bill, central where near the "big apple"

View Randy_ATX's profile


882 posts in 3932 days

#8 posted 10-04-2013 08:25 PM

This link is no longer working:

2. The canister:

-- Randy -- Austin, TX by way of Northwest (Woodville), OH

View ScottStewart's profile


120 posts in 3622 days

#9 posted 10-05-2013 03:11 PM

that’s the instructions, I don’t think they have a web store, when I called them they were as nice as could be.

View Marchmann's profile


3 posts in 3142 days

#10 posted 04-28-2014 01:50 AM

DIY—I’m with you. Started with the HF collector, and recently invested in a super dust deputy and Wynn filter. All the basic pieces and now gunning for the top-hat design. Have yet to find anyone online with a build that is similar to my equipment, so I’ve been experimenting with designs on paper to this point.

Scott—great post, and thanks for the info.

-- -- The sky is NOT the limit, however, the ground IS, so shut up and jump! ~Unknown.

View MrFid's profile


910 posts in 3394 days

#11 posted 09-21-2014 06:05 PM

Great info here. Favorited. Thinking about pulling the trigger and stepping up to a HF DC pretty soon.

-- Bailey F - Eastern Mass.

View timbertailor's profile


1594 posts in 2914 days

#12 posted 11-23-2014 04:44 PM

Here is my space saving version of your HF dust collector. Thanks for sharing your work with us.

-- Brad, Texas,

View Gjs's profile


1 post in 2389 days

#13 posted 12-10-2015 03:18 PM

Just got my HF DC and will be doing my mods. Wait for it to go on sale for $209 and use the 20% off coupon and get it for $167.

You can’t use a 20% off coupon on a coupon special but you can use it on a non-coupon sale price.

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