HF Neutral vane pictures Reposting

[LCHIEN]

The links on all my Neutral vane posts have been broken so I thought I'd repost all the pictures again.
This is for the HF 2HP Dust collector (DC), suggested by Bill Pentz. I made the measurements and fitted this one for the HF unit.

I have a template measurements for it and a full size 11x17 PDF template I can send if you PM me.

[Parkingmeter]

LCHIEN,

Sent you a PM for info about your HFDC upgrade, thank you.

[gettools]

LCHIEN,

Sent you a pm about the neutral vane

[LinuxRandal]

You might also look at Cgallery's (Phil Thien's) baffle. Just another option.

[ironhat]

You might also look at Cgallery's (Phil Thien's) baffle. Just another option.

I wonder if the two together would complementary.

[Rodango]

Hello, it's 13 years later, lucky! I'm trying to design a cyclone for a 1.5HP bag style dust collector.
I bought it used. Not planning to use it with the bag though. I plan to put the motor/impeller above a medium-large scale homemade cyclone, which
will sit over a drum (~30 gallon), and then exhaust to a stack of ~MERV15 cylinder filters that
have a small box below. I'll attach photos of the design that I have found. It looks very sound
but will depend on a good cyclone.

I'm hunting up elements for the design. I have a copy of the Esco spreadsheet. I believe use of the
'neutral vane' has partially superseded this info, so I'm looking for additional design ideas. Having
trouble pinning down what this vane should look like. I believe it's the spiral inside the dust inlet,
which pipe enters the top-mounted cylinder at ~15° downward slope.

Thanks for any help you could offer, Tim

[[note: the last picture is my starting place; 2 & 3 are likely final designs; 1 with the plenum and
side-by-side filters is probably ambitious for a one-person garage shop]]

[LCHIEN]

found these old documents - reposting for your download pleasure

Neutral Vane template (11x17" PDF)

HF dust collector with neutral vane PDF file

[Rodango]

found these old documents - reposting for your download pleasure

Neutral Vane template (11x17" PDF)

HF dust collector with neutral vane PDF file

Saw your post today, thanks for the info. 2021.08.28 !
If you had the link to that 2nd doc, he talks about using a DC controller - sounds interesting.
Bet it's lost in the mists of time. Meanwhile, thanks for the info

[LCHIEN]

I wrote that.

I also wrote this:

https://www.sawdustzone.org/articles...ay-booster-box

Relay Booster box: Describes how to control your DC or other high power device (higher current and/or voltage) with wireless remote, tool trigger, without blowing up the remote which are frequently only rated for a few amps, resistive (non motor) load only..

Poof! out of the mists of time.

[Brian G]

I've been using your relay booster box design since shortly after you first posted it. It came in exceptionally handy when the switch on my HF DC failed (a common problem years ago). I was able to wire the DC motor directly to the relay booster. I had to open the box recently to make the power cord longer because I had to relocate my DC. I appreciate you every time I fire up the DC.

[dbhost]

How does the Neutral vane compare in efficiency to a Thien baffle? I stumbled on some articles today showing huge CFM drops through a Thien cyclone and, well trying to keep CFM up I was thinking maybe a neutral vane. Maybe, just maybe Bill Pentz knows what he is talking about...

[LCHIEN]

To be honest, I never ran the DC without the neutral vane I just built it according to Pentz's recommendation. Seems to work. Still using it

After I installed it I ran a current draw test and it pulled 15A running at nearly open input. This is supposed to be a restriction test, if there is any restriction then there will be a reduction of current because properly sized, the proper impellor and motor combination will draw maximum current (rated current) with no restriction. which is the maximum rated airflow.

I wish I had run a baseline current test when the unit was brand new and unclogged new filters, both before and after installing the neutral vane. And then I would check the current periodically to determine the state of health of the system. I would recommend this to anyone setting up a new DC system. Also to check the new system with non piping (open input) and with piping installed (restriction) and then with the input blocked off (This is zero air flow condition - should be the least current even though the DC is making the most noise in protest, sounds like its working the hardest when its really the opposite.

I have the full size N.V. PDF somewhere if you need it.
Oh, here is is:
neutral_vane.pdf

Frankly, the logic behind the Thien baffle has always eluded me. If you say it causes a large drop in CFM then it doesn't really seem all that good an idea to me.
What I got from reading all of Pentz's stuff is that the duct size and CFM and related air velocity are all important.

You need a certain CFM to pull chips and dust into the air stream. Otherwise they'll find other ways out.
You need a certain linear velocity to keep the chips suspended in flight so they don't fall out and clog your system.
The air velocity is calculable as the CFM/cross section area of the ductwork.
To achieve a minimum air velocity with a given CFM the duct size matters. Too large and air speed falls too low. Too narrow and the restriction kills the CFMs rapidly. So every DC has a minimum and maximum circular duct size. Given that the duct sizes are integers 4", 5" and 6" you have very limited choices for a home DC of a reasonable size for one machine and a limited amount of duct distance before you kill the CFM.

In general, ducts of 6" are usually too big for DCs in the 2 HP range/1600 CFM. And 5" are really hard to find.
My thought was Parallel runs of 4" duct was more area than 5" and less than 6" would be the way I would go for a shop DC system with the HF or similar sized system. OTOH, the wall drag (air flow resistance) is proportional to the circumference of the wall that the air touches as it flows... 2 x 4" ducts will theoretically have a greater air flow resistance than either 5" or 6".



Haven't thought about this for many years now.

[woodturner]

If you are interested in researching further, the so-called "Thien baffle" was in common use in dust collection systems in the 1890's and is discussed in engineering texts from that era. They do explain the engineering and function of the baffle. I don't have a link offhand but found it previously by searching for dust collector engineering.

[dbhost]

Just ran into a bit of a bug here. Uh... The printers I have access to don't go as big as 11x17. Can I take a flash drive with the file to say Kinkos / Fedex to get it printed? I'd seriously like to knock one of these out like... yesterday.

[LCHIEN]

Yes, Kinkos should be able to print it for you. Make sure the print setup is actual size and not scaled. I printed mine on the office printer which did 11x17.

As for dust separator, the center ring of the HF DC is a separator to some degree. The coarse fall into the lower bag and the fines go up into the upper bag/canister.

[LCHIEN]

also look at this one

MyDustcollectorstuff2 (1).pdf

[dbhost]

LCHIEN do you know if a short segment of 5" snap lock would work, just cut the swoop out and press it into place?

I am just wondering if there is an easier way than cutting it all out, drilling and riveting it...

[LCHIEN]

Dave, don't know. Its not that hard... tin snips make short work of it. At least two sides just use the natural straight/square sheet edges. so there's only two sides to cut. You have a paper template with the hole locations precisely marked, just use a nail or center punch to locate the holes. Its thin sheet metal. But its been about 14 years since I made mine.

[mpc]

If you don't have tin snips, an alternative is a metal cutting blade in a scroll saw. Sandwich sheet metal between thin plywood, mdf, hardboard, etc. sheets. You'll be surprised how easily scroll saws with fine metal cutting blades actually cut metal. I used mine to cut thicker metal when making a riving knife for my BT3 with Lee Styron's plans.

mpc

[dbhost]

I want to take this opportunity to officially and publicly thank LCHIEN for posting up this information. I sat down tonight and made up my neutral vane and installed in in my HF DC. This was way easier than I expected, and while still wet, TItebond 2 will more or less wash off with Dawn dish soap, so I was able to kind of shotgun this through... I did rivet mine in place to secure it but other than that, followed the instructions to the letter. I should measure at the end of my 5" hose, and basically determine what the difference is compared to the now mostly dismantled 55 gallon Thien...

Since dust and chips are going to go into the bag, I guess I now need to order up some bags now!

[LCHIEN]

You are very welcome. I have no idea how many people who have downloaded the plans made one and you are really the first to have thanked me and confirmed they actually made one. Now I'll await confirmation that it worked well. Curious because at the time I made mine I did not think to measure the before and after effects and was always too lazy to go back and undo the mods.

[dbhost]

It's going to be hard to tell because I ripped out the Thien separator, added the Wen impeller, so my airflow is massively improved already. Just impeller alone through the separator, the difference in air flow was already very noticeable. I suspect there will be a difference in frequency of blow downs of the filter being needed. But at the rate I work, and I have a tendency to blow down the filter each time I dump the dust bin. I don't expect it to be much different, and may have been OCD on how often I was blowing down / cleaning up. My hanging air filter though, that is another story. I think I may actually get around to finally cleaning the filters on that. They are looking funky...