Scary Dust Collector

[Bill Webber]

Hi folks,

There are a couple posts below on dust collectors and dust collector design that I could have piggy-backed onto, but since this is my first post on the Creek, I figured I'd offer a different story on dust collector installation and ask a few questions, too.

I've been doing a lot of stuff putting together my so-designated dream shop. I bought a bunch of new equipment (miniMax) and I bought a 3hp Oneida Commercial dust collector. The dust collector goes in a small alcove, about 32 x 22 inches,. I've measured it several times but I couldn't tell you exactly what it is. The problem was/is the dust collector fan is 26 inches in diameter with a projection off to the side for the air exhaust. I wanted the air exhaust to be pointed into another room. I was either too lazy or too stupid to be able to plan or calculate exactly how I would be able (or not able) to lift and turn this thing into position with knowledge of whether it would go or not go.

I mounted the bracket in the center of the available area in this little alcove. I cut out as much of the wall as possible for the outlet to go into the other room. I enlisted the help of my young neighbor to try to throw this thing into place. I gotta tell you, I was actually a little freightened! I don't know exactly what this thing weighs, 125 to 150 pounds I think. I didn't know what I would do if it didn't go. I had no plan B. It was a bit of a struggle to get this thing tossed up over our heads. We got it angled into the alcove and started to turn it into the hole in the next room and that is when it got hung up. The flange on the exhaust port was still under the hanger bracket. We couldn't turn it anymore and couldn't get it unhooked either. Now we are both sweating! So, now its all or nothing. We started bouncing the thing around, managed to twist it free of the flange and, lo, it settled out nicely on the bracket and flange!

I knew how I wanted it installed and, golly it came out exactly as I'd hoped! Gotta say I really didn't know how it would wind up. Anyway, the collector is in where the machinery is and the filter is in a cleaner area. This design will keep back pressure into the equipment room and contain any sawdust regardless of whether the dust collctor picks it up or not.

So, an observation and a question. Some folks were questioning Oneida's piping design. What has been recommended to me, as a preliminary design, Is 8 inch pipe to the first 'Y' then 7 inch from there, going down to 6 inch if I care to. All 'Y's are 5 inch to a blast gate and then 5 inch hose to the machines where they get mostly adapted to 4 inch or similar metric ports. Again, preliminary design.

A question on ductwork. As of today, I'm pretty certain I will go with Nordfab ducting. Is there any price variation from different suppliers? Has anyone identified an alternative to Nordfab as in flexible quick disconnect systems? I'm going for pretty here; no duct tape, no caulking. Any info much appreciated.

I have three pictures to try to put in here. I'm not sure what annotation options the site will give me but one is a view of the cutout and clearances viewed from down low. Another is the filter in the other room (I need to add some trim) and another is a more normal shot of how it will hide back in the corner. (It is not put together yet because the center drum was damaged in shipment) Anyway, I keep reading ya'll want pictures...

(apparently I cannot preview my pictures... I hope they show up)

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[Jim Dunn]

Bill,

Welcome to the Creek. I'm so happy to be able to gloat and say I've seen your work/art and am impressed by your abilities.

To anyone else who hasn't seen Bill's website it's more than worth your while to look and drool;)

Jim

[Bernie Weishapl]

Welcome Bill. Bill looks pretty good so far. Hope you get your damage worked out. Thanks for posting the pictures. Yes I have drool all over my keyboard from looking at your site.

[Bill Webber]

Jim, Bernie, thanks for your kind comments.

Lest anyone get the wrong impression, the main barrel on the dust collector was damaged by the shipping company. Oneida has already shipped a replacement. I was so relieved to get the blower hung I just admired it for a while and called it a day.:)

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[tod evans]

welcome to smc bill, i`ve visited your site via another forum, you`ll fit in well here. tod

[Mike Weaver]

Bill,
Welcome to the creek!

Again, your nice work is inspiring!

I finally managed to finish my Pentz cyclone and it sure sucks...small chunks of wood, small animals, kids, etc...:eek:

It definitely isn't as nice looking as yours though.

Cheers,
-Mike

[Ken Fitzgerald]

Welcome to the Creek Bill! Neat place to exchange information!

[Rob Blaustein]

Welcome Bill. Awesome website--very impressive collection of things you've made.
-Rob

[lou sansone]

hi bill
welcome to the creek.. as others have said ... beautiful work on your web site. great looking shop as well. I think you are going to like the company here at SMC

lou

[Steven Wilson]

Nordfab is pretty much the same price everywhere. I went with Nordfab from the blastgate/hose adapter to the machine fittings (blastgate adapter, hose fittings, reducers for hose size, and machine adapters). I had Oneida order them from Nordfab. I had them make 5" to 300mm reducers to fit my Minimax equipment. The run from the blastgate to the dust collector is Oneida snaplock pipe and adjustable elboes; going with more robust fittings is not needed with my 2hp commercial system. At 3hp you can go either way, at 5hp you should use (per Oneida) the heavier guage pipe and fittings. I thought about going with Nordfab all the way but was talked out of it by Oneida to save a bit of money; besides it would buy me anything.

[Bill Webber]

Ah, Steve Wilson, I'm glad you chimed in here. I've been looking at your pictures on the MiniMax site... good to see it is back on line again.

So, you've confirmed what I kinda figured regarding the Nordfab piping. My new shop is pretty small and I figure I'll want to be rearranging the ductwork more than once. Plus, I want something prettier than the rivets and duct tape look.

Now questions:
What size flex hose do you have connected to your table saw guard and would you do it that way again? What is the 'wye' you are using there? Looks like 7-5-4?
On your port connections to the saw and shaper you have what looks to be a metric to 5" adapter, and you are using the Nordfab Quick Fit to make the connection. How do you like the QF? Is it easy and repeatable or would prefer a simpler slide-on friction fit?
The connections on your bandsaw appear somewhat convoluted. It looks like an adapter at the machine to a reducer, then the reducer to 5", then to the 5" hose... comment?
Your blast gates, at least the ones in your pictures are mounted horizontally (as opposed to 45 degrees coming off a 'wye') have you had any problem with them getting clogged so they don't close properly? I had to modify some plastic ones because the clogged quickly and badly. I notice there is a thumb screw to hold the gate position. If I mount the gates at a 45 degree angle, coming off a 'wye', will I need to use the thumb screw to keep it closed? I think mounting it directly on the wye would help reduce any tendency to clog, also.

There have been some slightly negative, or at least questioning, comments about Oneida duct design service. Care to comment? There seems to be as much science as engineering in the design of these systems. For example Oneida gets different numbers than I do when I use the Pentz spreadsheet. I went with the 3 hp unit becasue my layout resembles the 'don't do this' picture in the Oneida design guide. :D

Basicly my system will be 8" duct to the first wye then 7"and perhaps down to 6" at the end. Each drop is a wye to a 5" gate and 5" hose to whatever adapter I need. Except the table saw will be like yours.

An aside... I plan to try to use the X-10 controller I've been using on my 2hp double bagger. It should last a while. Problem with the new house is X-10 stuff keeps coming on by itself...:confused:

Thanks for your continued help,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[Chris McKimson]

There have been some slightly negative, or at least questioning, comments about Oneida duct design service. Care to comment?
Bill, since I started a thread called "Onedia duct design" recently, I wanted to make the comment that I only questoned the use of 4" ducting in the plan given me, since I have read much about the use of 5" and 6" piping "to the tools" and very little about those using 4". My post wasn't meant to be negitive toward Oneida, rather my intent was hopefully to hear from others who had Oneida design drops of 4" that were happy with the results.

Chris

[Steven Wilson]

Let's see, the drop from the ceiling that connects to the Combo Machine is 6" that terminates into a 6x5x5 wye. There are two 5" blast gates and then two 5" Nordfab QF connectors. In table saw mode I run a 5" hose to the bottom connection of the saw (terminates in a 5"QF-300mm ID RAW reducer). The run to the blade guard consists of a 5"-4" QF reducer (Nordfab), followed by 4" flex hose, and terminated in a 4" QF-60MM ID Raw reducer (Nordfab). The flex hose is supported from the ceiling by rope in a block and tackle arraingement. Supporting the flex hose is key to not torquing the blade guard. I would definately do it again.

When I'm using the shaper configuration I run 5" to the shaper hood and 5" to the shaper cabinet.

As for the blast gates they work great, never clog, no problems. The metal ones are completly different than the plastic ones. You will need the thumb screws.

The bandsaw fitting isn't the best. Since most of my other machines have 4" ports I purchased a few 4"ID-4"QF Nordfab machine adapters. I then share a 5"QF-4"QF reducer. On the other machines it works great, on the bandsaw it sticks out too far. One of these days I'll get a 4"ID raw - 5"QF machine adapter made and that will cut down on the length of the stack. It does evacuate the machine well though.

All in all I have one piece of 4" flex hose terminated with 4"QF hose fittings, and 3 5" flex hoses. When I'm cutting normal pieces on the table saw I use 1 5" flex hose and 1 4" flex hose. When I'm crosscuting a 4x8 sheet of plywood that requires the jointer fence to be off and a clear top, I add 2 more 5" flex hose sections (with QF fittings) so I can get a lot of room to clear the plywood. It's not as efficient but it still works fairly well. As for the QF fittings they're not as easy to change as a friction fit but the seal is much better. With time the QF fittings loosen up a little bit to make changing the bands easier. I wouldn't change a thing if I were to do this again.

Since I'm running the 2HP system my duct work starts out at 7" and then runs to two 6" branches. I run 6" branch to the wye's which are either 6x5x5 or 5x5x5 (to get 3 gates at one terminus I stack a 6x5x5 on a 5x5x5). For the lathe I have one long 5" run that terminates in 5" flex hose and a custom hood from Oneida. I've been turning a fair amount of cork for fishing rods and cork dust really bothers my nose. Eventhough my lathe is 30' from the DC it still manages to get all the cork dust and my nose never notices a thing.

Oneida's duct design service worked well for me - not perfect but it was a good experience being able to bounce ideas off of someone who is fairly knowledgable about designing dust collection duct work. Of course you need to check and recheck the design and work up the bill of material on your own just to be sure. My overages were 3' of 6" snap lock and one reducer. Not bad

[Bill Webber]

Hi Chris,

I'm not trying to bust on anyone either. I think if you poke around Bill prentz' site and understand at least part of what he is doing then you can check what the manufactuer/vendor recommends. When I use Bill Pentz' spread sheet to calculate CFM I get numbers that are quite a bit different from what Oneida calculates. That is a little worrisome. I bought a 3 HP system so I'm pretty certain I'll get what I need using either calculation. So far, in my conversations with Oneida, there has been no, "this is best , but if you do it that way, you'll reduce this at that point..." , etc.

Anyway, my caveat, would be to do your own homework as you would with any machine purchase. Seems more important for this kind of purchase than for other machines. My limited experience, YMMV... :rolleyes:

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[Bill Webber]

Thanks for the detailed reply, Steve. Nordfab sounds like nice stuff. The only negative you mentioned was the need to use the thumb screws on the blast gate.

My saw (S315) is positioned with the right extension against the wall. If I need to lock the thumb screw, I'll need to walk all the way around the saw to get to to the blast gate. Maybe I can locate the gate on the near side. Guess that is the one really good thing about Nordfab... easily rearranged.

Many thanks,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[Steven Wilson]

Bill, Your 3HP system might have enough suck so that you won't care about a leaky blast gate. I loosen them (thumb screw), move the gate, and tighten. You can set them sort of tight and just move the gate but I find the gate will not seal 100% and then vibrates. Personally I wouldn't worry about it, just install it, play with it, and you'll make it work for you. A little caulk on the gate might provide enough pressure for your likeing. Of course you can always install the fancy automatic blast gates :)

[Tim Marks]

When I use Bill Pentz' spread sheet to calculate CFM I get numbers that are quite a bit different from what Oneida calculates.

It comes down to: who are you going to trust, the amateur hobbiest who has assembled a lot of information from various sources, or the professionals who actually design and build dust collection systems for a living, who employ engineers and HVAC technicians who understand the theory and perform hundreds of system design calculation every year?

[Jim Becker]

Welcome to SMC, Bill. And I remember well lifting my 2hp blower up over-head as it not only needed to clear the brackets, but also have the motor fit up between the joists. I had Fred Voorhees to help, but even then it was an interesting experience. I can imagine your situation with a heavier machine!

'Can't wait to see more shots of your shop!

[Paul B. Cresti]

Bill,
Your shop looks so clean! ... suspended acoustical tiles, closers on your doors, actual one paint color on the walls let alone paint!:eek: Are you turning into one of "those guys" on me?;)

[Allan Johanson]

When I use Bill Pentz' spread sheet to calculate CFM I get numbers that are quite a bit different from what Oneida calculates. That is a little worrisome.
Hi Bill,

Keep in mind that for a key thing like a specific hood type, the SP entry loss values can vary a lot. This can dramatically mess with the final cfm values you calculate. I believe Bill is using estimated hood entry loss values for a flared inlet. This is between the major loss of a plain end pipe and a nice bellmouth.

I've also seen folks set up a simulated duct run with Bill's spreadsheet and then take that SP/cfm combo and compare it to Oneida/Grizz, etc. A common problem is that folks will also enter a value for the cyclone resistance in Bill's spreadsheet. But you shouldn't do this when planning the system for a cyclone with a published system curve - the cyclone resistance is already factored in. So often the SP values are out by 2.5-3" with this problem alone.

Can you post your sample duct run and I'll give it a shot and see what values I come up with?

Cheers,

Allan

[Bill Webber]

Hi, Paul, good to hear from you. I don't believe you have pi... er caused any controversy in what, two three days now? ISSH.

I'm not sure what one of 'those guys' might be. My shop is not a 'make do' or a room stuck off in a barn. (I some times wish I had a barn and I'm not bustin' on folks who have barns...) My shop has been an integral part of my home, a living space, for many years. My retirement shop will be the same only prettier. Much of my design/layout focus is on making a pleasant working environment, one that can be used without worry of dusting up the rest of the house, easily cleaned and always accessible, part workshop, part showroom and simply an extension of what pleases me.

In my new shop I get the whole basement. The builder-guy broke it up into some offices for his model showroom. For me, I've made some mods and kept some of what the builder did. My shop has a clean room (old tools, collectibles, pianos, victrolas, the 'yuppie workbench', etc.) a small shop (grinders, buffers, scroll saw, hand tool work bench) a big shop (all the new MinMax stuff, my old RAS's, my Robland K-26 [did I ever tell anyone it is better tool than a K-31?])?<-- (looks like swearin', eh?) There's another room for the exercise equipment. Gotta have that stuff or we won't live forever! I'm thinking we need to use it, though.

Lessee, I was thinking of something zippy and funny here, for Paul, but it's not working. LOML and #1 daughter picked the new home and I went happily along. My shop will be long on tools and short of assembly space. Oh well, the K-26, big RAS, table wing on the S315 will likely double as assembly surfaces. I sure hope the K-26 will fit in there! There are too many special things I use it for.

After spending the day at the hospital, I'm pleased to report I can bring my gutsy, beautiful bride of 39 years home tommorrow... I'm so pleased and proud of her!

Where was I? Oh, Paul, love the garage doors in your shop! Did you put them in as part of the original desiign or later? ISSH.

And, Steve, yeah what you said. I'll go with the gates.

Best regards ,:)

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[Bill Webber]

Hi Allen,

I gotta admit I haven't pursued the design details of my dust collector system in a very studied manner. I know that my 3HP Oneida with appropriate duct sizing will deliver the best performance I am willing to pay for in the size and configuration I've chosen. I didn't sort out Bill Pentz' spread sheet but I'm thinking he uses 800CFM and 4000FPM as constants and that may be part of my confusion.

I'll take you up on your offer. I'll start working on my ducting design shortly. It may take up to 8 weeks to get something on paper... we won't be moving for quite a while yet. :) Oneida says my replacement drum is in the mail.

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/

[Paul B. Cresti]

Bill,
Not sure what happened but glad to hear your wife is coming home. As is sounds you feel the same, my wife is my best friend not quite sure what I would do without her.

Yes those OH doors were part of the original design! :) They were installed about 20+ years ago. We have only been here for about 2 years now. It took me a year to begin to set up the shop after we moved and just tonight I "finished" the "final" connection to my new MM160 ;). I never got around to painting like my last shop, heck I never even finished spackling some of the tape on the ceiling! Yup my shop is a real looker, a testament to my Architectural prowess. Since I will never leave this house, until they carry me out in a box this might be as good as it gets but my machines make up for the lack of ambiance.

I have done a fair amount of research on DC through my evolutions over the years and I have to say one of the biggest things is the duct size and making sure eveything is as sealed as possible. I do not care what you use but cover every little nook and cranny on those ducts it will make a big difference.

[Bill Webber]

Hi again... I'm not sure where this message will show up in the message tree, but here's an update on the dust collector installation. I've got the skirts installed to trim up the through-the-wall filter installation. I covered half the opening with a board and fired it up. It turns in the correct direction. I didn't expect the dust collection bin to leap up off the floor... that startled me a little.

Allan, you offered to do an air flow calc for me so here's a diagram. The pipe is 8" from the collector to the first wye and then 7" the rest of the way. Each wye has a 5" blast gate and ultimately 5" hose to machine adapters as needed. There is one wye that has a 4" drop to the saw guard on the table saw. I haven't ordered any of thi$ Nordfab $tuff yet, so the design is open to suggestions. Notice how I cleverly incorporated the "don't do it this way" installation from the Oneida diagrams. :rolleyes:

Tell me what you think... and, yeah, I know, way too many tools for this small area.

Regards,


Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/</pre>

[Bill Lewis]

Bill,
My gut reaction is that you should step down your pipe diameters as you go. Run the 7" to the Table saw main wye, then step it down to 6". Run the 6" to the second "Misc" wye/drop and step it down to 5" for the final run to the floor sweep. This should maintain the velocity throughout the system, and save you a little money too.

BTW, I meant to ask you where you are located in Howeird Co.? I've over in Monkey Co. in the Laytonsville area. If you'd like to come take a look at my system I'd be more than happy to show it to you sometime. I've got the Oneida 2 HP com. unit in a basement shop.

[Jim Becker]

Nice installation. Personaly, I wouldn't do Nordfab through the whole system, but might us it for any quick disconnects or in specific places where you know you'll need to open it up with "some frequency". The stuff is very expensive, no matter where you buy it. (I believe there is a bit of "price control" there, just like with major power tools) Spiral manufactured locally or heavy snap lock is more affordable and can be mated with Nordfab where desired. IMHO, of course.

Onieda uses the Nordfab in their lab to connect to the Mini Max equipment so hoses can be moved easily, but uses regular duct back to the system(s).

[tod evans]

bill, in my dust system i salvaged 1/8 wall steel pipe from a defunct grain elevator. welded it together in the attic. it`s smooth on the inside and will never collapse. just some food for thought??? tod

[Jim Becker]

I don't recall seeing too many grain elevators in Maryland, Tod!! LOL (nor here in PA) But that's a great idea!

[Bill Webber]

Yeah, Bill, I think the step down you are recommending is probably correct. However, I want to see if this compromise can work for two reasons. (1) I want to keep as many of the components similarly sized so I can rearrange it. And (2) there is a shaper at the end of the run that has two 4" ports (metric actually).

The shaper is the MinMax T50. It has the two ports, but my limited experience with my Robland shaper suggests the second port could likely be blocked and chip pick-up probably would not be changed much. (The second port may come into play more when the spindle is tilted.) Maybe Paul or one of the other Minimax owners will jump in here and I can get someone to do an experiment. :D I wouldn't mind reducing the size of that last leg to save some money. Another problem I've just encountered is the price of these long radius elbows really jumps for sizes under 8 inches. Hey, it's a work in progress. :)

Bill, I'm in Highland, right around the corner from you, but all this new stuff is up in Pennsylvania.

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/</pre>

[Bill Webber]

Point well taken, Jim. I'm going for pretty here as well as functional... and whining all the way. :D

Dust collection stuff is bog ugly at best. I've done the screw, rivet, tape bit before and it doesn't age well. Another difficulty, right now, is that most of the equipment is not in Pennsylvania yet. I don't know where stuff will be located but I do know it will be crowded.

Keep the comments coming. I know what I'm trying to do is breaking a few rules (common sense may be one of them). I bought the bigger 3 hp to suck through the rules I'm ignoring. But, I haven't settled on anything yet.

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/</pre>

[tod evans]

bill, i run the next size up mm shaper and do use both ports,whether i have the standard fence or tennoning hood on the machine. .02 tod

[Steven Wilson]

Bill, your T50 doesn't have 4" dust ports, they're closer to 5" and will be properly serviced with 5" flex. You can get enough CFM if you run a 6" line to your machine and terminate it into a 6x5x5 wye and run two pieces of 5" flex; one to the cabinet port, the other to the fence system. From there you can run the 5" flex to the appropriate metric adapters. 4" would be undersized. You could (I think your machine would support it) run a 7" line the the machine and run 6" lines steped down.

[Jim Becker]

Bill, if you want to be able to rearrange from time to time, you'll probably be safe with a 7" main after the first branch with that 3hp system unless you have a really large (physically) shop. Instead of reducing via the laterals, use 7x7x6 laterals and extended reducers as necessary.

If it were me, I'd keep provisions for both hoods on the T50...you can generate a LOT of "stuff" with that shaper and you'll want enough CFM to do so no matter what you are doing...the more the merrier. The two 100mm (~4" ports) should be ok off a 6" drop, IMHO, although splitting the 7" main into two drops at the end (where you say it is located) would be even better, IMHO. (Unscientific opinion, so do the calculations)

BTW, Oneida has adapters to go from inches to both 100mm and 120mm ports on the MM gear.

[Bill Webber]

OK, that's a little more encouraging, Jim. If Oneida tells me the FPM is OK on the end of the 7", then the two 5" flex drops to the shaper will be good and everything else should be fine.

I know about the machine adapters. Nordfab will make anything. I'm going to try put together machine adapters and multiple hose connections to provide as much versatility as possible. I'll do that later after I get used to the price of what I'm looking at so far.

Jim, the shop dimensions are on the sketch I posted up above. I could say it is 20' x 12' but there are a couple other tool alleys so it's a little better than that.

I'll stick a couple pics here. They may help with the perspective. There's one looking in and one looking out. The end of the duct run would be on the wall above the shaper.

Regards,

Bill W.
Woodworkers visit me at:
http://www.oldtoolsshop.com/Galoots/wWebber/</pre>

[Michael Gabbay]

Bill -

I can only add a smart remark here... That aint no shop that's a showroom! I wished my house looked that nice! :D

Mike

[Allan Johanson]

Hi Bill,

I did a very quick calc and I figure with the 7" main duct around your shop you'll have about 900cfm flowing through a single 5" drop at the end to your floor sweep (with a 5" hookup on that sweep). The 3HP DC is a very strong machine, very similar to my Pentz cyclone.

When I was playing around with some early testing, I was getting over 1350cfm through 35+ feet of 7" pipe and a couple elbows. When I added the last 10' piece of pipe, the airflow only dropped by around 30cfm. It'll take a lot of 7" pipe to hurt the performance of this DC. The quick way to reduce airflow is to choke it down with 5" drops like you're doing though. If you want a little more flow, use 6" instead.

After seeing what choking down duct runs can do, if I were in your shoes I'd use 7x7x7 wyes instead of your planned 7x5x7 wyes. Then if you want a 5" drop, use a 7x5 reducer and 5" pipe. If you wanted to increase the airflow at that tool, toss the 5" stuff and use a 7x6 reducer and 6" pipe instead. You don't need to break apart your main duct and swap expensive 7" wyes this way.

I'm running a full 7" pipe to my SCMS and I'm getting over 1200cfm there because of it. I know there are charts out there that say you only need 350cfm for a mitre saw, but when you have 1200cfm it's a whole new ball game. I can actually see the dust stream bend downwards to the hood in the rear of the bench! It works much better compared to a lower amount of airflow.

Cheers,

Allan