Another newbie with questions

[spes]

Hello,
I just ordered a HF dc and want to make a separator. I'm not trying to re-invent the wheel. I would like some kind of separator, and plan on getting a Wynn filter after the separator is established.

Just going to throw out some questions and see what I get for responses.
Anyone i.e. Phil, ever think of making a sticky post that just has facts/absolutes/reference numbers... stuff like

mouth position relative to the baffle -Phil's testing suggests the position to be 1/2 the pipe diameter

.
Just as a reference guide for the newbies.
---What's the height of top hat with 4"or 5" outlet?
---I'm not sure if I should go 4" outlet or 5" outlet on the HF
( I currently do mobile connections to table saw, jointer,bandsaw,thickness planer. In current shop I cannot do fixed piping.)



Am I correct that this site heavily leans towards "top hat" design and not "in the bucket" design?
Why?

Some of the designs I like are retired2's
http://www.jpthien.com/smf/index.php?topic=563.0
   
Q: Is the square to round duct custom made or off the shelf?


This seems to be a perfect off the shelf solution to a bell fitting.
http://www.parts-express.com/precision-port-psp-4if-4-inside-flare-for-port-tube--268-377
It looks like the connecting ring
http://www.parts-express.com/precision-port-psp-4rg-4-connecting-ring-for-port-tube--268-380
Would allow adjustable height connection to the port tube
http://www.parts-express.com/precision-port-psp-4tb-4-dia-x-12-long-port-tube--268-382



Ok, what about a direct mod of HF like this?
https://woodworkingweb.com/creations/59-harbor-freight-dust-collector-conversion
I like the way this keeps the setup mobile and relatively compact.
(I read somewhere questioning the safety of flipping the motor and impeller from vertical to horizontal.)

Again, just trying to improve my dust collection, not trying to perfect it.
( Right now the shop runs a 20 year old Grizzly 1hp that has never had the top bag replaced,, it puffs when u turn it on)

Sorry for the rambling...

Thanks,

[spes]

Hmm,

Ok, lets try this ONE question.

If I am going to go top hat/ 4" in and out/  what should the height of the top hat be?

[retired2]

Hmm,

Ok, lets try this ONE question.

If I am going to go top hat/ 4" in and out/  what should the height of the top hat be?

The short answer is "greater than 4".   ;D

Do you have space to make it higher?  Are you going to transition to rectangular?  No, you can't buy one like mine off the shelf.  I have only heard good reports from people who have built their units double high, so 8" is a good choice.

[spes]

When you all are talking about 4,5,or 6" duct size being best are you referring to fixed duct work?

So if I plan on top hating my brand new HF and manually attaching 4" to one maybe two machines over pretty short runs I should be sucking my socks off right?

[retired2]

When you all are talking about 4,5,or 6" duct size being best are you referring to fixed duct work?

So if I plan on top hating my brand new HF and manually attaching 4" to one maybe two machines over pretty short runs I should be sucking my socks off right?

Yes and yes.

[spes]

What is the circumference.. or should I say length of the lexan piece?
Not exactly,, for purchasing estimates.

[spes]

If I went with a 2H, would this 3-1/2 x 10 transition to 4" range hood transition be useable or is it too narrow?

[BernardNaish]

I do not think it is too narrow but I would prefer to use a longer transition. This one looks as though it is less than 4" long and I think the air flow will exit it still more or less circular. 8" would be better and I have seen three time the diameter of the pipe quoted and that would make it 12" long. These are easy to make. Take a rectangular block of wood the width you want and the other dimension slightly more than the id of the pipe you are using. So 3 1/2" by perhaps 41/2" in this case.  Squeeeze the pipe until you can put the block inside the pipe and hammer the pipe down until it is a rectangle the width you wanted at its mouth and as smoothly faired back to the round section as you can get it. Job done. A few minutes work.

r2 suggests the area of the rectangle should be (I think he said) 10% greater than the cross sectional area of the pipe and although you could still make this, it is probably not worth the extra effort unless you are a skilled sheet metal worker.

[retired2]

I do not think it is too narrow but I would prefer to use a longer transition. This one looks as though it is less than 4" long and I think the air flow will exit it still more or less circular. 8" would be better and I have seen three time the diameter of the pipe quoted and that would make it 12" long. These are easy to make. Take a rectangular block of wood the width you want and the other dimension slightly more than the id of the pipe you are using. So 3 1/2" by perhaps 41/2" in this case.  Squeeeze the pipe until you can put the block inside the pipe and hammer the pipe down until it is a rectangle the width you wanted at its mouth and as smoothly faired back to the round section as you can get it. Job done. A few minutes work.

r2 suggests the area of the rectangle should be (I think he said) 10% greater than the cross sectional area of the pipe and although you could still make this, it is probably not worth the extra effort unless you are a skilled sheet metal worker.

Yes 10% larger is the number I've quoted.  It comes from the HVAC industry.  Rectangular ducts are about 10% less efficient than an equivalent round. 

I don't know if that rule of thumb means much when the rectangular pipe is very short like the one shown here.  I agree that a longer transition is better, but I don't know how much.  One thing for sure, I would not suggest a smaller area on the rectangular end.

[dabullseye]

you could get any drafting book and find info on how to make one yourself.
or
http://www.billpentz.com/Woodworking/Cyclone/ducting.cfm#fittings
has some info @middle of page.
i used an old drafting book when i made mine. i used cardboard at first to work out the bugs (more beer) then welded up the metal one. i used an old mouse pad for the gasket between top hat and fitting.

[spes]

ok, i figured that was coming.

I deliver to an HVAC place and a sheet metal place, I'll have to ask if they can make me a transition around  4" round to 8 x 5   12" long.

So if I do this on a 32 gal Brute the lexan for the th would be roughly 72" long?
Where you all order that?

[retired2]

ok, i figured that was coming.

I deliver to an HVAC place and a sheet metal place, I'll have to ask if they can make me a transition around  4" round to 8 x 5   12" long.

So if I do this on a 32 gal Brute the lexan for the th would be roughly 72" long?
Where you all order that?

C=3.14D  My separator diameter was 19-5/8" so the circumference is about 61-1/2".  The walls of a top hat separator are not a complete circle, but that number will put you in the ballpark.

Now with regard to your inlet size.  I'm not sure why you are making it so large.  Your 4" round has an area of about 12-1/2 sq in.  So the rectangular end needs only be about 15 sq in., but you can treat that number as the minimum.  However, you are proposing 40 sq. in. 

I assume you got the 8" height because you want it the full height of your planned double high chamber.  I'm not the expert on double highs, but I think some people have made the inlet full height and some have made it half height and brought it in near the top.  Maybe some of those folks will chime in here and give you some advice, but at 8"x5" I'm not sure you are gaining anything over just using a 4" round inlet.

Now with regards to the width.  I would reduce it to at least 4", and maybe less.  The reason for a narrow inlet is it keeps the incoming waste stream against the outside wall and over the drop slot.  It also keeps the incoming waste stream farther from the outlet pipe which helps avoid waste by-pass.

[spes]

Thank you for your patience r2,
I obviously haven't a clue what I'm doing here.
I don't care if it's a 2h or not,,,just throwing numbers out.

This is why in one of my first posts I said there should be a sticky post listing factoids
For example, almost everyone is using either an aluminum can or a 20 or 32 gal Brute,,, shouldn't there be a wealth of numbers relating to these?

[retired2]

Thank you for your patience r2,
I obviously haven't a clue what I'm doing here.
I don't care if it's a 2h or not,,,just throwing numbers out.

This is why in one of my first posts I said there should be a sticky post listing factoids
For example, almost everyone is using either an aluminum can or a 20 or 32 gal Brute,,, shouldn't there be a wealth of numbers relating to these?

Lots of newcomers would like to be able to go to a single post and get everything they need, but there are just too many combinations and variations to catalog, and none of us want to be librarians.  In some ways the thread describing my build is typical of the whole forum.  It evolved over time and now it is just too much work to separate the wheat from the chaffe.

There is something to be said for digging for the information.  The most important thing is you will learn "why" things are done a certain way rather than just building to a set of numbers.  Understanding the why will help you if you ever need to change your configuration in the future.

However, if you are in a hurry and don't want to spend hours on end reading old posts, here is a good suggestion for you.  Don't try to reinvent the wheel.  Go copy my build right down to the last dimension.  Don't worry about the 5" connections, just put a 4"x5" reducer on them.  It will work fine and if you ever build a bigger system with larger plumbing, you are set to go.

[vietnamvet2]

I am in the same boat as you.  Many years ago I built a cyclone system and used a 1 HP blower.  I think I really chintzed on the blower and while it does work, it seems to lack sufficient suction for some of my machines.  I believe the cyclone I built is a good design and ideally I would use the HF blower to upgrade this system but it doesn't appear to be easily adapted to this cyclone.  I'm struggling with modifying the cyclone to fit this new blower or maybe just making a separator based on the Thien design.  My system has a "Baghouse" type filter which is a wood frame that is 6' tall and about 2-1/2' wide and deep.  The frame is covered in cloth that air can move through.  I have no idea how many micron it filters to but with a good separator that may not be much of a factor.  I'd appreciate any input anyone could offer.