J. Phil Thien's Projects

Yes, there's that $64K question again. At $169 that's an appealing solution to be considered. http://www.oneida-air.com/inventoryD.asp?item_no=AXD002030A I've had the original 12" tall metal DD for @ 5 years now and it's been great.
Yes, the exhaust port off the blower on a 50-760 is different from most others.. rectangular. I will have to have a closer look and take some measurements to see what possibilities are obvious, and report back.

What Wilburpan is proposing s what I had in mind basically for my Delta 50-760. http://www.jpthien.com/smf/index.php?topic=845.msg0#new
It has a 5" dia inlet so I should be in the 6-8" dia hole or chimney to filter.

Quote from: retired2 on March 09, 2013, 10:26:17 AM

Quote from: Rick T on March 09, 2013, 09:25:52 AM

Quote from: alan m on March 09, 2013, 09:10:11 AM
from what iv been reading lately. it doesnt matter whether you put the same resistance before or after the blower.

my thining is that if the material is going through the impeller then the moter has more work to do because of the extra mass of the material.
also it is easier to build a pre seperater to minimise the losses. be they from too small a diameter or the height of the seperater etc


my preference is for pre seperaters because nothing goes throught the impeller

Alan, again just thinking out load here again, if virtually the entire loss of the pre-separator is eliminated and replaced by that of the baffle which doesn't hinder most air flow (to the filter), is that not a substantial gain?
I'm not sure how much actual loss relates to the dust and crap sent through the DC. Suppose it may be an issue but without testing in some way, I don't have any idea.
If the baffle design works on a Harbor Freight conventionally designed DC, can't it work in the same way on a 50-760?

I know this is a very odd time to be considering this since so much work has been done on the 'top hat' but we need to be confirming progress compared to some datum, and I suppose it's a naked DC sans filter.

Well, it shouldn't be too difficult to cut a baffle from tempered hardboard and come up with some temporary attachment method for the sake of testing.

The immediate downside I see is you are still left with emptying the plastic bag, which on this DC I find to be a real PIA.

Without actually trying it, I don't know if this would do much to improve separation versus no baffle.  It seems fines have a way of getting to the filter no matter what, so you will still be stuck with cleaning your Wynn filter eventually.  I haven't added one to my system, so I don't know how much of a chore that is.  The Wynn's recommend using compressed air on the outside. 

My feelings are that placing a baffle in the location you are discussing would create little or no additional cfm losses as opposed to no baffle since the plastic bag is already ventless and all air must exhaust through the filter.

Give it a try.  You should be able to do a "non-destructive" test and it shouldn't cost very much in material.

I certainly agree,  the bag routine is challenging. I hear people recommend bag on the outside of the ring, temporarily use magnets to hold bag in place and use large hose clamp.
I visualize much of the loss in the 'top hat' system being the energy expended spinning the air around the pre-separator. It also expends some energy spinning it again in the normal collar, but perhaps to a lesser degree.
When I get a bit of time maybe I'll give it a go.
Thx for the input.

Quote from: alan m on March 09, 2013, 09:10:11 AM
from what iv been reading lately. it doesnt matter whether you put the same resistance before or after the blower.

my thining is that if the material is going through the impeller then the moter has more work to do because of the extra mass of the material.
also it is easier to build a pre seperater to minimise the losses. be they from too small a diameter or the height of the seperater etc


my preference is for pre seperaters because nothing goes throught the impeller

Alan, again just thinking out load here again, if virtually the entire loss of the pre-separator is eliminated and replaced by that of the baffle which doesn't hinder most air flow (to the filter), is that not a substantial gain?
I'm not sure how much actual loss relates to the dust and crap sent through the DC. Suppose it may be an issue but without testing in some way, I don't have any idea.
If the baffle design works on a Harbor Freight conventionally designed DC, can't it work in the same way on a 50-760?

I know this is a very odd time to be considering this since so much work has been done on the 'top hat' but we need to be confirming progress compared to some datum, and I suppose it's a naked DC sans filter.

Quote from: retired2 on March 09, 2013, 08:39:50 AM

Quote from: Rick T on March 09, 2013, 08:36:16 AM
Have you seen any comparisons of loss, top hat vs baffle using a 50-760?
I sure like the separation and less cleaning of filter, but it isn't of much benefit if the flow is insufficient. That's why I'm curious about the possibility that the baffle may institute less loss and perhaps not do quite as good a job at separation.
I remember years ago when consumer versions of the pleated filters appeared, like my Wynn, some people made shop conversions to add a paddle that dislodged the dust which fell into the collection bag. Now most of the filter perhaps come with paddles for this purpose.
On the flow issue, my table saw is the biggest offender. I notice dust congregating in the large cavity under the blade and a fair amount being flung off the blade above the zero clearance insert rather than being sucked off the blade on rotation. I really need to get an overarm guard connected to the DC.
Either way lower flow challenges the 50-760.

How would you use a baffle with a 50-760?

Could it not be made just as for other conventional DCs and installed in the lower area (just below the entry port and  above where the collection bag installs with the expanding clamp in the lower portion of the steel ring. Use either thin metal or hardboard, cut drop slot similar to top hat and baffle design ie 240 deg).
I'm just thinking out load here as I don't recall seeing anyone do this but that's not to say they haven't.
When I was emptying the collection bag I notice there is a small semi-circular metal ring @ 1/4" dia that is installed into the deck of the steel ring. It doesn't go completely around the opening to the collection bag.. only partially. Wonder what purpose that serves? 

Have you seen any comparisons of loss, top hat vs baffle using a 50-760?
I sure like the separation and less cleaning of filter, but it isn't of much benefit if the flow is insufficient. That's why I'm curious about the possibility that the baffle may institute less loss and perhaps not do quite as good a job at separation.
I remember years ago when consumer versions of the pleated filters appeared, like my Wynn, some people made shop conversions to add a paddle that dislodged the dust which fell into the collection bag. Now most of the filter perhaps come with paddles for this purpose.
On the flow issue, my table saw is the biggest offender. I notice dust congregating in the large cavity under the blade and a fair amount being flung off the blade above the zero clearance insert rather than being sucked off the blade on rotation. I really need to get an overarm guard connected to the DC.
Either way lower flow challenges the 50-760.

I built my 'top hat'- style separator several years ago... when they first appeared on this forum. I consider it very good when it comes to separating the dust, which is important because I have a Wynn pleated filter that isn't equipped with a shaker paddle to dislodge dust that becomes embedded in the pleats.
I'm now questioning the overall effectiveness of my DC doing it's basic job which is to intercept and collect dust from my woodworking equipment. I've read somewhere in the myriad of threads and info that the top hat separator introduces @ 30% loss in air flow. Does that reduce the air flow to an unacceptable volume? I'm pretty much on the fence at tis point.
For the last while most concentration has been on 'top hat' design. Any thoughts on it's performance vs a straight baffle design in terms of a) ability to separate dust and b) impact on air flow? Does the simple baffle design flow more?

I'm working with a Delta 50-760 equipped with Wynn poly pleated filter and 10' length of clear 5" dia flex hose. My table saw has 1- 5" port. I move the DC from machine to machine as necessary.

Alan, this might be helpful to you. http://www.science-house.org/index.php/flight/109-build-a-manometer
I haven't made one but these folks should know what they are doing. Note the angle required to negate gravity etc.
Good luck.

Were/are you using 5" flex hose and if so how long to the BS?
I've been using the 5" on my 50-760 (@ 10' length) and moving it from machine to machine with the exception of my jointer where I add a piece of 4" to extend it another 8 or so feet. The tapper increases the velocity of course. As you say it's hard to judge the flow rate without equipment.
My setup might benefit from a run of solid 5" and reduce the length of flex hose.

Quote from: phil (admin) on April 09, 2012, 06:58:54 AM

Quote from: Rick T on April 09, 2012, 06:10:15 AM
Has anyone measured the actual loss/difference in air flow resulting by inserting the separator into the loop for the various configurations?

This question comes up from time to time.  But with no two units being alike (side inlet/top inlet, tight/sorta leaky, various diameters, etc.) it would be a pretty large undertaking to offer any #'s that would be widely applicable.

I've taken some measurements of not only "my" units, but also conventional cyclones.  At one point I thought it would be interesting to make comparisons.  But without holding everything else constant (same blower, same ducting, etc.), it just wasn't possible.

I hear you.
My experience anecdotally is that it's negligible for mine.. (Delta 50-760 with top hat, 5" in and out, side entry, Wynn poly pleated filter).
I seem to recall Retired2 and some of those guys doing some semi-scientific measurements when they tested the Bell-end and 30% lose sticks in my head.. which seems bogus and I must surely be off-cue on that recollection.
This came up in a round-about way on a discussion about the Oneida Super Cyclone. It escapes me why the air flow would be more efficient than a top hat like mine. It might be more efficient at separating dust out.. but mines batting in the high 90's% range consistently so why would I care? Maybe i have to clean the pleated filter 1 more time/year. No big deal.

Has anyone measured the actual loss/difference in air flow resulting by inserting the separator into the loop for the various configurations?

Doug, you may be interested in this modified under-saw hood as well. A simple and effective way to collect and remove saw dust. Look here https://sites.google.com/site/sawsuckerproject/home

I think they were pretty common a number of years ago when the importance of dust collection was just being realized.

Quote from: rjhanby on February 06, 2012, 11:43:09 AM
Has anyone installed and tried one of thee boots yet? I've got one on the shop and haven't made time to finish "dust proofing" my saw yet...

Quote from: davidrn on February 05, 2012, 07:15:11 AM
I don't have a contractors saw, but I like that "boot".
I have a 15 year old Grizzly cabinet makers saw, and the motor was not enclosed. I ended up building a box extension, inside my extension table, and then put a 6" hole for the dust piping in the end. It did require that I give up the shelf space under the saw, but it seems to work fine. I also taped up the small door on the left side of the saw, that way air flows downward thru the blade area.

Here's another way to enclose the back of the saw around the motor http://store.thesawshop.com/catalogue/default.php?cPath=6&osCsid=30189b2d6f720197f28f698744ac1842 .

Pcott, IIRC the Steel City 1.5 hp unit can move a lot of air. Does it not have a 6" dia flex hose between the impeller housing and filter ring and at least a 5" or maybe even 6" dia port into the impeller housing?? If that is the case, and if you have positioned the top hat and collection pail beside the DC, you can go bigger than the 4" line. I use 5" dia flex hose equipment to Top hat and Top Hat to impeller housing and that seems about right based on air flow and velocity for my 1.5 HP Delta 50-760 which is equipped with a Wynn pleated filter. The 5" hose is @ 50% larger x-sectionally than a 4" hose. I also replaced the port into my TS with a 5" HVAC fitting so there's no bottle neck.