Drop Box Thread

Ned Bulken

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Lakeport NY and/or the nearest hotel
OK Todd and Marty, So we don't totally hijack Ken's oneida thread...
rain just cancelled my truss assembly plans for tonight (built one before dinner, was going to go try and do two more under the lights before falling into bed). But I'm still thinking about the shop and tools and what not.

Todd, You suggest getting a material handling fan then designing the drop box around that and the motor. Are you talking about a squirrel cage from a furnace or something else? I've been on the lookout for a used HVAC squirrel cage for an air cleaner. Since I've been focused on the shop itself this summer, I haven't looked very hard.

I've got all that volume up above the top sill, almost 6' of vertical space which I would gladly put the DC on a platform to get it out from underfoot in my limited floor space. I'd even put it on its own mini-loft so I won't lose storage space in the attic. Or should I put it in a bump-out on the back of the shop for ease of access?
Thanks guys.
 
Ned,

Sorry to hear the weather's put a damper on your trussing... :doh:

But, thanks for starting the new thread. Ken can participate here, in addition to his Onieda thread...;)



Anyway....NO...NO...NO!

A squirrel cage fan is NOT NOT NOT what you want. They can move some air, but not with any sort of pressure! They BLOW in HVAC systems, but wouldn't be able to SUCK in a DC application...and they certainly couldn't take the abuse of material going THROUGH the fan. That's what the "material handling" in the term comes from. The material passes right through the fan.

Here's a link to Cincinnatti Fan, the company that makes the blower I picked up from Craigslist. (I have a 7.5hp PB15, for what it's worth). Have a read through some of the introductory information, and look at the different sorts of fans they offer. They do a far better job of explaining the requirements for a DC blower and system than I ever could!

Also, here's a link to a material handling blower that's currently on eBay...link... Although, I think that's a little pricey for what it is.

In general, I think you'd be better off watching Craigslist, or some other locally based venue. I say that because shipping can become an issue. My blower weighs somewhere in the vicinity of 300 pounds!!!!

As for the space you have overhead...a few things to keep in mind...

I was originally going to place my blower (and phase converter) up in my attic...but was quickly dissuaded when I learned the nightmare harmonic vibrations they'd create! Weight is also something to keep in mind as noted above.

As for the drop-box up in your overhead...you'd have to come up with a creative way of emptying it....:huh:

My personal opinion is that a bumpout would be your best bet. Recall that shed I put out back? It keeps the noise to an absolute minimum...(I only hear the rushing of air..no motor sounds). It also contains any sawdust mess OUTSIDE! ;)

The other thing to keep in mind is tod's advice of determing what you need, port sizes and CFM requirements, then design a system to your needs. Figure out what you need in terms of air movement, then figure out what components you'd need to meet those needs. Designing it the other way around is a real risk.

Ok, I think I covered your initial volley. I'm sure tod will add to my response when he gets to the shop in the AM.

- Marty -
 
Hey Marty and Ned! Glad you started this thread. I enjoyed watching you get set up in your shop Marty and I have seen Tod's first hand (wish I'd taken more time to look at it though!). With a little luck, I may have the beginnings of a good sized shop in the next few months and will be thoroughly interested in the process of designing a good system! Looking forward to following along!

Ed
 
Ned, if I were in the US, I'd buy the impeller (fan thing) and a good motor, and then build the fan shroud, it is easy to do with MDF and a router, plus some sheet metal and some long bolts, dead easy.

Then you will have to decide on a drop box and filters like Marty, or a cyclone like mine, either way, you can do it for a LOT less money, than buying one, but it will take a LOT more time. That being said, once you build a good system, you will be able to move it to your next workshop fairly easily.

My cyclone building pages are here Dungeon Cyclone Build

Cheers!
 
marty-n-stu covered most stuff very well.....i`d like to add that a dropbox and cyclone are not mutually exclusive! same with bags and pleated filters...
a person could set a cyclone on top of a drop box.....it`s done all the time in industry.....filter bags are designed to work with a "cake" of dust imbeded in the media and if memory serves me(?) bill pentz claims that bags don`t get the finest dust......sooooo, instead of investing in a large and expensive submicron pleated filter designed to take the occasional impact (when you forget to empty the cyclone) a person could do as marty has with his plenum room only installing submicron filters before the wall grates and after the bags....all of this can be designed and sized to fit within your space,(within reason).....finding a material handling fan that`ll suit your requirements is the biggest hurdle but expect to pay 150-450 depending on what it is and how sick of looking at it the seller is, over 450 would be 36"+ in diameter and generally powered by a 25+hp motor... keep the questions commin`
 
another idea for ned....
one of the simplest and least expensive dropbox set ups i`ve ever seen was designed by an old man who did scrollsaw intarsia, what he`d done was take a small tai/chi blower, hf/griz/delta ect. and remove it from the monstrosity it comes attached to. the input was 4" pvc ran to his saws, drill and sander(25"woodmaster) the discharge went straight outside to a plywood box that used window screen for a filter that he could fit his wheelbarrow under. conditioned air was lost when the system was on but i`ll bet he had under 300 bucks in the whole system....just an idea.
 
Thanks guys.

I've got a one tool dust pump right now, and that will have to suffice for the first few months in the shop. My little old Jet works great on the TS, not so great on the planer of course. (mainly that it fills up so quick). It got to the point in the old shop that my partner who was doing most of the mess-making before we parted ways, just said to heck with the DC on the planer, which resulted in the expected huge pile of chips.

So, I still want a squirrel cage for a shop built air handler/filter, but I want an impeller eventually to drive the drop box/dc. Todd I actually like the idea of canibalizing a tai/chi DC or similar at some point.

Marty, roger that regarding the vibrations etc... All along I've been planning on doing the bump-out for DC housing, just a matter of when/where. As for emptying it, wherever it is, I'm thinking that a chute of some sort at the bottom might wind up in the design, mounted so I can just put a refuse bin under it and roll that to the curb as needed. (with a heavy duty lawn/leaf bag so I won't annoy the trash haulers.)
 
so you allready own a tai/chi pump....by removing the stand and bag assembly and routing the exhaust to an outside box you could have a chip collector as large as you want...if you chose to bring the air back into your shop up high you could reuse the filter media you allready have and only spend a few bucks on hvac pipe from the borg...the pipe would be presurized and if you where to run it straight up out of your chip box to the peak of the roof i doubt much debris would make it to your filter.
 
so you allready own a tai/chi pump....by removing the stand and bag assembly and routing the exhaust to an outside box you could have a chip collector as large as you want...if you chose to bring the air back into your shop up high you could reuse the filter media you allready have and only spend a few bucks on hvac pipe from the borg...the pipe would be presurized and if you where to run it straight up out of your chip box to the peak of the roof i doubt much debris would make it to your filter.

Todd,
it is a blue-era Jet 600cfm (on a good day with a tail wind) 3/4 Hp DC... I'd be More inclined to buy a tai/chi machine and rebuild the new machine vs canibalizing the little guy. I don't think it has the HP to be any more useful in the chip box than it is stock.

I'm not too worried about conditioned air, not yet anyway, still working out the kinks on the whole heat thing (this is the northeast, so Heat is the priority over AC). Running it up to the peak would definitely ensure little or no debris would come back, anything that could make it all the way up 10 to 14' would be pretty small anyway. Gotta get the roof done first of course.


I know one thing for certain, I happen to have MOre than enough black flex hose that if all I wanted was an air return I've got it on hand already. I have about 40' of the darned stuff that I got for free a couple of years ago.
 
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Ned, Heat is easier than AC for sure.

If you use a radiant heat source, you will not heat the air, but the things in the shop, this is a very good way to heat (remember, I'm from Canada eh ;)).

In this situation if you do run it outside and loose a bit of the heated air, it is not such a big deal, as the walls, floors, etc will still be warm.

My Buddy Stu in Edmonton put one in his shop a couple of years back.....

stu_in_ed_heat.jpg

And this is what he says about it......

Stu in Edmonton said:
I wouldn't go any other way than radiant. Here's my heater hanging from the ceiling. I've had it a couple of years now [Winters] and don't know how I did without it. I don't remember the brand but I could dig it up for you. There will be several to choose from. As you can see the clearances from combustibles are not bad at all, and I could have been closer. 16 inches I think. Mine is "U" shaped and has a double wall pipe so air comes in the outside wall of the pipe and exhaust goes out the inside wall. The pipe is horizontal thru the wall. Some units are just long pipes and take intake air from one end and exhaust out the other end. Depends on the application.

Best thing I ever did. I used to use a 220 volt electric heater. What a difference. Now with the thermostat I just "set and forget!"

Infrared or Radiant does not flow persay. It heats whatever it hits [ie.] the concrete floor , the steel table top etc. It is much like heating a stone slab taking it out of an oven and then cooking pizza on it.

My shop is 24 x 24 with R12 walls and R 20 ceiling [soon to be R40.] Drywall ceiling and walls, concrete floor, one steel man door and a wooden 16 x 7 overhead door. I did not honestly notice much change in my heating bill last year. I doubt that any of you guys will get as cold [-40 C] as we do here. [unless maybe Minnesota ;) ] My unit is about 9 feet long - 45,000 BTU which is on all the time and controlled by a thermostat. Not home, set it cooler!

I was just out there for 20 minutes in my jeans and no shirt cleaning something and it is toasty warm. Its about -8 C outside right now. Don't know how long it takes to warm up but it ain't long and you can feel the heat right away if you stand close, under it. I don't know anything about HOT DAWG but it can't be better than this! As for cleaning it; I did it last week with the new Leaf blower. Took 10 seconds!!!!

You can see the whole thread HERE at TWW.

Cheers!
 
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