Dust collector upgrade decision

[Carlos]

I want to upgrade my Harbor Freight dust collector to something a bit more powerful. The HF unit is the one rated at 2HP "peak" but it's probably more like a realistic 1HP. We have central plumbing for collection in a three car garage (5" main with 4" drops to tools and 2.5" where needed). There's a gate for each tool, but there's a loss from all the plumbing. The collector worked pretty good hooked to a tool directly or with low-need tools, but not so good for our big tools and the central system.

These are my top two picks from Craig's list locally:

Powermatic 075, 3HP, $500
http://www.powermatic.com/Products.a...3CK&cat=332148
This is surely a killer machine. It's way more than we need. But is that bad? We could probably run two tools on this at once. Is there anything bad about running a DC with less flow than it's meant to? Also the one on CL doesn't have the canisters, it has bags. We have one canister on the HF unit, would have to buy one more. I'd probably eliminate the trash can chip collector if I got this, canceling out the extra space usage.

Grizzly 2HP, $225
http://grizzly.amazonwebstore.com/Gr...B00012WUGO.htm
Rated at 1550 CFM, but Grizzly is just a bit above HF quality. Based on the power usage, it's obvious that this will definitely move more air than the HF unit, but will it be enough to be worth it?

Thoughts?

[Uncle Cracker]

It sounds as though you have provided adequate size in your ductwork (assuming your main and drops are smooth-wall ducting, rather than spiral hose). That said, the Grizz should work, particularly if you are only opening one gate at a time. I know my Delta 1.5hp has plenty of grunt through 4" PVC across a 3-car garage, including ups and downs.

But still, that PM monster would sure suck! See if you can work the price down. If he won't budge, grab the Grizz.

[Carlos]

All the mains and connections are smooth metal pipe. There is a mix of smooth plastic and metal reducers to the 4", and from there a mix of pipe and spiral flex hose. I tried to keep the hose to a minimum, but many of the tools need some flexibility. Most tools have under 5 feet of hose.

[Carlos]

One of the goals, that I didn't mention specifically before, is to capture more of the junk that comes off many tools. For example, the stuff off the top of the bandsaw and DP. I bought Locline collection kits for those, but now I think I've just got too many openings. For example the 18" bandsaw has a 4" main to the lower box, a 2.5" below the table, and the 2.5" Locline above the table. That's a lot of airflow.

[Uncle Cracker]

Well, truth be told, you can't really have too much DC suction, so there is really no downside to the PM machine, as long as you got no other use for that extra $275...

However, you may also find that improving your airflow with the Grizz may negate the need for all the auxiliary drops on your bandsaw. I have a single 4" on my bandsaw, and really only get a little dust on top or underneath the table. Of course, if you are resawing 12" boards, then maybe more really is better...

[geeoh]

Carlos, if you feel the need to upgrade I'd go for the PM or a similar size (check Amazon etc.). Check whichever unit you may purchase uses the bag(s) and or canister filter(s) to meet your needs before throwing extra $$ at something close. You probably won't be satisfied otherwise. You can always sell the HF on the BT3 or CraigsList and use that $$$ towards the PM

[drumpriest]

Having done a fair amount of veneer sawing on the bandsaw, I can say that any additional DC is a huge win! I have the 1.5 hp Jet canister (little brother of that PM monster), works well for my situation, as I have all short runs, and it's not plumbed. I would personally not trust the surface area of the Griz to pull enough air flow if I were to plumb a shop, I'd probably go for something akin to that PM or a cyclone, the equiv Griz looks a decent deal...

http://www.grizzly.com/products/3-HP...ollector/G0562

But for 500$ if the PM is in working order, that's a pretty darn good deal, so long as you can power it!

[dbhost]

Carlos,

Not sure about your setup. Do you mean that your entire 3 car garage is setup as a workshop? If so, you are one lucky pup....

I have seen at least 4 different shops first hand, the largest of which was 20x24, run with a HF 2HP DC, at least 3, but I think all of them are the newer one that shipped with the 2.5 micron bag, all are equipped with Canisters now, 2 Wynn, 2 Grizzly. One was using sch 40 PVC, the other 3 were using some kind of smooth metal pipe. All of them were plumbed 4". Rumors are that this DC can be adapted to 6" and will actually get a pretty good CFM boost but drop some static lift.

So long winded explaination aside, I guess the big question is, is your DC the newer one with the 20a motor, or the old so called 2HP one that shipped with a 20 micron bag? If so I think I know where your problem is...

I am wondering if you have lost airflow as well through poor duct design. Remember every single time you turn you lose CFM and static lift. Straightening out your lines will get you some noticable performance gains... Also you may have a canister that is losing its ability to breathe. If yours is cleanable, is it clean?

For the $$, a good setup would be that HF 2HP DC / 1 micron or less canister like a Wynn, and a plastic bag on the bottom. Build a custom frame, and move the motor up, so that the 90 degree bend from the impeller to the inlet ring is done away with (known HUGE restriction on this style of DC). Build a Thien Cyclone Separator lid on a 30 gallon steel trash can right under it so you have a SHORT straight run of hose, and come out of that into your jump hose to some 4" S&D. Use only SWEEP elbows and wyes, and as few of those as possible. If you can, reduce using bell reducers instead of the normal step reducers as they present less restriction, and turbulence in the airflow. I don't recall the MFG, but I believe that Peachtree carries bell type reducers. fit good gates to the system, SEAL your plumbing system with sufficient quantities of duct tape, and if everything is set up right, you should be able to pull chips and dust from all of your equipment no problem. and that Thien Cyclone will help keep that canister much cleaner than it would have been...

[LCHIEN]

having read a lot and esp Bill Pentz's stuff, the main objectives of a DC system ought to be:
1. Sufficient airflow (not velocity) to assure a high percentage of small dust particles don't go flying away from the machine collection point.
2. low overall restriction because restriction = higher suction pressures (head) which in turn lowers the CFM available
3. Sufficient velocity in the ducts to suspend the bigger particles so they don't fall out of the airstream and clog the pipes.

My observations:
2 and 3 are often at odds with each other as smaller pipe = faster velocities but higher head and loss.
As you note, you can meet all three by using a bigger DC motor an impellor.

Recommendations:
If you use tools with small ports you effectively negate the ability to even a big DC to suck a lot of airflow through that hole since choking a 4-5 or 6 inch pipe through a 2.5" port has a huge restriction. If you want to have more airflow/higher collection efficiency you can change to bigger ports and/or use multiple points of collection in parallel e.g. on a BT3000 a 2.5" hose to the port in the rear, a 4" hose to a belly pan an a 2.5" hose to a port on the blade guard. Airflow-wise that gets nearly the euqivalent of a 6" hose to the machine. On a bandsaw, split the incoming hose to suction on the upper an lower housings an a hose opening under the table by the blade an lower bearings.

[Carlos]

Do you mean that your entire 3 car garage is setup as a workshop? If so, you are one lucky pup....

Yes, and yes!

Rumors are that this DC can be adapted to 6" and will actually get a pretty good CFM boost but drop some static lift.

The native input for mine is 5", which I use with hard 5 metal duct to go to a trash can chip collector. From there the 5" continues throughout the shop. It's all hard metal, except for a short section of flex so the trash can isn't rigidly attached to the DC or main plumbing.

is your DC the newer one with the 20a motor, or the old so called 2HP one that shipped with a 20 micron bag? If so I think I know where your problem is...

I didn't know there was a new one. Mine shipped with a 30 micron bag, and the motor is definitely not 20a. In fact you can run the DC and some tools from the same outlet, proof that it's low-powered.

So this kind of brings me to another option...the HF 3 HP version...??

I am wondering if you have lost airflow as well through poor duct design.

I am not an expert on duct design, but I did seek a lot of help with it. I have made the runs as straight as possible, and used the largest-radius bends I could buy. I bought it all from a commercial supplier and got a lot of design help from their people.

e.g. on a BT3000 a 2.5" hose to the port in the rear, a 4" hose to a belly pan an a 2.5" hose to a port on the blade guard.

That's my setup. I think I am loosing too much flow/velocity on tools with that much flow.

[wardprobst]

Do a leak test on your duct work then go with the 3HP, you won't regret it. Also, Loring has a great point about multiple connections on a machine. Band saw, drill press and miter saw all need help and the BT does very well hooked up as he suggests.
DP

[Carlos]

Ok, I'm picking up the Powermatic at 4:30 today. It's another $500, but hey, I'm "never" going to have to upgrade the DC again. Now I hope my canister fits on it. The 4:30 pickup gives me time to get another 220v run put in for it I guess. Crap, and now I need to buy a 220v version of the central switch box.

I went through and fixed a lot of tiny leaks the other day. It's as leak proof as it's going to get (and I'm down two rolls of duct tape).

[dbhost]

Congrats on the PM for sure, nice rig. I would definately leak test your system, AND go with a Thien cyclone setup in your trash can separator.

Yes, there is a newer model, sorry I had the micron filtering wrong, it ships with a 5 micron bag. It's HF Item # 97869, and has a reputation for being rated actually reasonably close to the marketing rating... Meaning it works like a 2HP DC should.

That Thien cyclone I will hit on again and again because one of the biggest restrictions I come up with in my system is when the filter kills airflow, the Thien Cyclone, or any well designed cyclone for that matter, keeps more crud from reaching the filter, to where it is only the ultra fines reaching it.

By the way, nice Sketchup, It looks like you might have used my clamp rack model. Wish I had done a better job with that one...

[cgallery]

Hehe. That big DC is gonna ROCK!

[Carlos]

I don't know how to do any further leak testing. I used a combination of smoke and sound to hunt down leaks. In the end really I just ended up taping every single joint and seam.

I was planning to (probably) get rid of the trash can. With that much power and two bags, I don't know that it will do any good. Otherwise space might be an issue. Not sure yet.

It looks like you might have used my clamp rack model. Wish I had done a better job with that one...

Are you kidding, that clamp rack is awesome. I just wish I could find a tool box model that's more like the size of mine. That model makes me look like a have a small tool...er tool box.