Harbor Freight DC with mods vs Grizzly G0548ZP

[Jfitz]

1 hour ago, SteveKoz said:

Basically Small CFM users like a table saw (which I thought would be higher) use 350 CFM.. Router is another 350 CFM.  They didn't list a rating for a chop saw but lets play with another 350 CFM..  That's a total of 1050 CFM's.  

Only if they're all open at the same time.  Install blast gates on each run or at each tool,and then you only need to plan for the tool.  Plus, none of those DCs will be able to meet the requirements of airflow for 8" pipe. DC is all about airflow (CFM), but you need to maintain some amount of linear speed of the air in order to keep the dust/particles moving.

 

 

[Carl10]

Steve,

As Jeff stated you only need the larger main with multiple tools running at the same time. Most of us are in a single person shop only running one tool at a time so with blast gates you only need to worry about the CFM required at one tool.  350CFM is the minimum for collecting chips, bump it up a couple hundred CFMs for the dust you can see and another couple hundred for the dust you can't see (but your lungs can).

If you are going to do option 3 then the 1029 is a better deal.  The big difference is the output immediately necks down to a 5" flex hose and then exhausts into a cloth filter.  Both are restrictions you would eliminate with the option 3 design.  The picture is just an example to show any blower will work.  I have an old Oneida cyclone I got for free and made numerous upgrades, including two Donaldson air filters (Donaldson torit p190817 or p190818 DFT ULTRA-WEB CARTRIDGE 13.84"OD X 26.00"L 9.46ID), found new on eBay for ~$100 each.  They were a deal but can be found ~$125-140 each.

So if you target ~500CFM at each machine minimum and have relatively short runs, your overhead will probably be around 7" of static pressure.  With 5" lines you will be able to maintain enough velocity to keep your lines clear.  If you set up the 1029 like option 3 you probably could get away with 6" lines but it all depends on your runs and how much resistance in your system.

You are definitely on the right track.  Let us know what you do.

Carl

[SteveKoz]

12 hours ago, Jfitz said:

Only if they're all open at the same time.  Install blast gates on each run or at each tool,and then you only need to plan for the tool.  Plus, none of those DCs will be able to meet the requirements of airflow for 8" pipe. DC is all about airflow (CFM), but you need to maintain some amount of linear speed of the air in order to keep the dust/particles moving.

 

 

Thanks. I was under the same impression and planned to close off the ducts not in use.  I had to go back and reread what it said and of course I misread it.  Amazing how one word in a sentence can change it's entire meaning..    My original plan was to run 6" ductwork from the blower to all the tools with blast gates and then attach a 4" or even a 6" flex line reducing it just at the tool.  Is there a flaw in this approach?  With these 2hp motors pulling 1550 CFM's and with no leaks and gradual bends I can't see not having more than 350 cfm at the tool. 

While researching what I thought I "might" need based on my reading comprehension I came across the Jet JCDC 3hp cyclone.  Putting money aside (and extra $665) that unit has an 8" inlet or 3 4" inlets.  Taking the approach of feeling the pain once when purchased I started researching 3hp cyclones.  Boy is this a slippery slope to be on.   

[SteveKoz]

11 hours ago, Carl10 said:

So if you target ~500CFM at each machine minimum and have relatively short runs, your overhead will probably be around 7" of static pressure.  With 5" lines you will be able to maintain enough velocity to keep your lines clear.  If you set up the 1029 like option 3 you probably could get away with 6" lines but it all depends on your runs and how much resistance in your system.

You are definitely on the right track.  Let us know what you do.

Carl

Thanks.  I have to draw out my system to get exact lengths.  Trying to learn Sketchup.  Rough numbers have my longest run to my table saw being 30 ft. at the ceiling.

[Jfitz]

16 minutes ago, SteveKoz said:

Boy is this a slippery slope to be on

It absolutely is!  just remember that both CFM and linear speed are important.  If you're only getting 350cfm at the tool, then you'll also be getting 350CFM all the way to the collector, so be sure any larger pipe still gets decent linear speed.  Also, a horizontal run needs less linear speed, but a vertical line up from a tool needs better linear speed in order to keep all the dust moving in the right direction.

 

[SteveKoz]

6 minutes ago, Jfitz said:

It absolutely is!  just remember that both CFM and linear speed are important.  If you're only getting 350cfm at the tool, then you'll also be getting 350CFM all the way to the collector, so be sure any larger pipe still gets decent linear speed.  Also, a horizontal run needs less linear speed, but a vertical line up from a tool needs better linear speed in order to keep all the dust moving in the right direction.

 

Would linear speed equate to sucking power?  So dropping from a 6" pipe to a 4" pipe would increase the sucking power?   

[Chestnut]

6" can run 2 tools 8" is too big for ruining 1 tool at a time on a 2hp system and is probably to big for a 3hp. Note the power doesn't mean a ton the impeller design housing size and system efficiency change more on how well the system works. 

3 minutes ago, SteveKoz said:

Would linear speed equate to sucking power?  So dropping from a 6" pipe to a 4" pipe would increase the sucking power?   

No suction is the difference in pressure and partially the volume of air moved. The blower will create X negative pressure and losses in the system will decrease that. The larger the pipe the less losses with Y amount of air. System design is important. Ideally you have 1 strait trunk and branches to individual tools. That isn't always possible.

[Jfitz]

What he said.

"suction" is best described as the pressure differential.  A shop vac has great suction - but is terrible for CFM, which is what you want for a dust collection system.

However, you're on the right track - for the same CFM, dropping the pipe diameter increases the air speed.  

[blackoak]

,I also started w/ the grizzly DC, added a cyclone . I made a change on the outlet side as well as the inlet. Bought the 7" inlet for the 3HP model , but also increased the  discharge  side , opening that from 6 x 8  to 6 x 9 inches w/ an oversized "plenum" down to my filter stack .  I cut apart the DC housing and made the increase , then welded it back together . This changed it from  48 to 54  sq. inches, roughly 11 % . I have no test measurements to offer , but hopefully it helps . Trying to get everything possible from a small DC is a "rabbit hole "for sure , but all it costs is my time . I'm planning an impeller change also . Continental Fan has something I think will be an improvement . We will soon see.This will get me up to $1000 on a shop built cyclone . I will report back the results .

[SteveKoz]

Appreciate the response.   Blower will create X negative pressure in the pipe.  Negative pressure is the removal of air which causes the sucking. .  Losses in the system, tight bends and leaks and such will decrease the negative pressure causing less sucking power..  The size or ability of the same blower to create the amount of negative pressure will fluctuate based on the size of the pipe.  So if the blower has a 6" inlet rated at 1500 CFM and you connect a 6" pvc main line pipe straight out of the blower inlet for 30' and at the end of that 30' you should still have about 1500 CFM and X amount of suction?  If you cap off or blast gate close the 6" pipe you will create a maximum negative pressure that the blower can produce.   Open the 6" blast gate and you flood the negative pressure with 6" of air.  Lots of air but will get minimum or the same X amount of suction.  Reduce the end of the 6" to a 4" pipe and you reduce the amount of air feeding the negative pressure.  Because it's a smaller diameter it's going to produce more suction trying to feed the negative pressure so you should get greater suction than the original X.

Am I on the right track?  I don't think so cause I'm still confused...   So why does the CFM go down at the end of the 4" pipe if it's sucking more air at a greater speed.  If I open my outside water faucet all the way I can fill a bucket in 1 minute.  Lots of volume with little pressure.  If I spin the nozzle reducing the outlet size it increases the water pressure BUT it still fills the bucket in 1 minute.  Same water going through the same hose just at a faster pace.  Why wouldn't the 4" duct work that sucking more air at a quicker pace produce the same?

[SteveKoz]

1 hour ago, Chestnut said:

6" can run 2 tools 8" is too big for ruining 1 tool at a time on a 2hp system and is probably to big for a 3hp. Note the power doesn't mean a ton the impeller design housing size and system efficiency change more on how well the system works. 

So instead of building my own system.. which I haven't thrown out yet.. I started looking at cyclone systems.  Jet has two that look interesting.  Their 2hp model states 938 CFM with a 6" inlet.  Their 3hp model states 1240 CFM with an 8" inlet.  I have to believe that reducing the 8" inlet to a 6" will decrease the CFM but should increase the sucking or velocity?   So in the end you might end up with two machines producing the same CFM BUT the 3hp will have more sucking power at the tool? 

[blackoak]

you should look at Oneida's V-systems for small shops . Great for 1 man situations, if you have the budget .Short cyclones { jet , laguna , grizzly , etc. }have limitations.

[SteveKoz]

31 minutes ago, blackoak said:

you should look at Oneida's V-systems for small shops . Great for 1 man situations, if you have the budget .Short cyclones { jet , laguna , grizzly , etc. }have limitations.

Thanks.  I don't like the short cyclones either.  Guessing that's why users are seeing more dust in the filter collector.  I'm installing in my basement so I do have height restrictions.  Building my own had me excited and I feel it might even do a better job but not over confident it will be strong enough for the distance I have to run.    I'm pushing the limits of what I want to spend too.  Started out with the HF unit and HF with mods and now a 3hp 2 stage system.  Once I got on this slide I couldn't stop.   I'm leaning heavy towards the Jet JCDC 3hp. system.  They are also on sale for 10% off and free shipping until Monday so I'm giving myself the weekend to come to grips with it.  I figure the 2hp should work and the 3hp will definitely work.  Rather do overkill for a couple bucks more than be sorry I didn't get it.    Is there ever a problem with going bigger on the collector?   

[wtnhighlander]

11 hours ago, SteveKoz said:

  If I open my outside water faucet all the way I can fill a bucket in 1 minute.  Lots of volume with little pressure.  If I spin the nozzle reducing the outlet size it increases the water pressure BUT it still fills the bucket in 1 minute.  Same water going through the same hose just at a faster pace.  Why wouldn't the 4" duct work that sucking more air at a quicker pace produce the same?

The principle is similar, but the compressability of air introduces another level of complexity. Water is not compressable.

[SteveKoz]

17 hours ago, blackoak said:

you should look at Oneida's V-systems for small shops . Great for 1 man situations, if you have the budget .Short cyclones { jet , laguna , grizzly , etc. }have limitations.

I took another look at the Oneida's V-3000 system and I was sold.  I was trying to decide between building my own using a 2hp Grizzly blower or getting the Jet JCDC 3hp setup and neither one was satisfying what I was looking for.  I felt the Jet was the better of those two options but seeing how much dust makes it into the filter just didn't seem right.  The V-3000 seems to have everything I was thinking about building into my own system.  Yea it doesn't come cheap BUT I know I'll be happier in the long run.

I really do appreciate everyone's help!  Wasn't an easy decision for me to figure out on my own..  

[Chestnut]

Ok i have a keyboard so i can type and not get frustrated.

As stated before air is compressible so that changes everything. Your water faucet example is flawed if you restrict the opening you won't fill the bucket as fast even if that time difference is a couple of seconds the time it took to fill got longer you just didn't notice. The velocity of water leaving the opening will increase but there will be a small net decrease in flow. The same happens with air in a duct system. The losses due to friction on the inside of the pipe as well as the bends will slow the air down decreasing the volume of air that is moved. What makes things complicated is at the fan you'll have lets say -22" of water at 1200 cfm. Over 30 feet you'll always move 1200cfm but the negative pressure at the port will be something like -15" of water. Say you increase the pipe length to 40' your flow will decrease to say 1100 cfm and the pressure at the inlet will be -13". Take that drastically and choke the port down to 2.5" 40 feet away you'll only be able to flow 400 cfm but because air is compressible the pressure at the port will be something like -18" of water.

The reason we run larger lines to smaller drops is to take advantage of the fact that you can extend the lower suction as far away from the blower as possible. This way the difference in pressure from inside the pipe to where the dust is generated is greatest. The choking down from 6" to 4" also spikes the velocity of air at the port which is beneficial. You need air velocity to capture the dust as well as volume. If the dust is coming of the cutting device at say 50 mph but your air column is only moving 25 mph you won't capture any dust. Moving a high volume of air captures dust from a large area. You need BOTH high volume and high velocity.

This stuff is complicated... ask all the questions you want. I'm kind of (aka a really big) nerd and this stuff is interesting to me so i could probably talk about it for days. The trouble is your basically trying to get the cliffs notes version of a Jr. or Sr. level fluid dynamics college course.

Another thing to note, I'm not sure how this works with grizzly, but a lot of blowers are designed with some losses built in. If you increase too much flow to them or modify the blower or change it you can easily over drive a motor and burn it out. If you are planning any mods to this make sure to take amperage readings on the power system before the mods and don't exceed the nameplate amperage rating of the motor.  With DC systems moving more takes more work than moving less air. So your collector is drawing LESS power when you have all the dust gates shut than if you open them all. This is another reason why it's highly beneficial to run gates and only collect from the tool you are using. If you try and collect from every tool at once you'll waste electricity moving air that you don't need to.

[blackoak]

hOne thing I believe is the Oneida cyclone body itself is the best for a limited height situation . I found it tough to build my system and keep it short enough. The blower / cyclone in 1 piece -vs- a stacked blower on a DD xl was my challenge . A possible solution is a very small bin or barrel, but I didn't want that either.   Chestnut  has helped many people here, myself included . Great information.

[Mark J]

36 minutes ago, Chestnut said:

With DC systems moving more takes more work than moving less air. So your collector is drawing LESS power when you have all the dust gates shut than if you open them all. This is another reason why it's highly beneficial to run gates and only collect from the tool you are using. If you try and collect from every tool at once you'll waste electricity moving air that you don't need to.

Huh!  That explains why my DC came with an 8 inch port stopped down to three 4 inch ports (which is half the area),  OK, but at what point  of closing off ports do you overload the motor because there is no airflow.   Am I better running two ports open instead of one?  What happens if you close all the ports?  

[Chestnut]

8 minutes ago, Mark J said:

OK, but at what point  of closing off ports do you overload the motor because there is no airflow. 

Never.

Think of it like shoveling snow. If you have a snow flake on the shovel you can move it a lot with no effort. If you have a shovel full  it's heavy and hard to move. Air has mass the more air you move the more energy it takes. Most big DCs are induction motors that are cooled by their own fan so choking off all the air flow just enables them to consume less power and will allow them to stay cooler. You run a higher risk of overheating the motor the MORE air you move through the DC system. The amount of air going over the motor will generally stay the same as it is dependent on the motors RPM which for induction motors is roughly consistent.

The 8" port with 3 4" ports is also for convince It would be better to say run that 8" line and have the 4" ports close to the machines. The manufactures recognize that not everyone is going to install duct systems so they provide an option to run flex hoses yo our machines.

[Fugs]

FWIW 

Wen has the same impeller for $35

Part # 3403-22 but you have to call to order.