The 'Blokebox' drop-box

[Mr Ed]

is emptying your extractor so hard?

Well I've been wondering the same thing. If you suck up a Kilogram of dust, its a kilogram wherever you empty it from. I don't see why its any more trouble to empty it from the extractor than it is to empty it from a wooden box.

Maybe I'm missing something...

Ed

 

[MikeG.]

What you are missing is really 2 important things:

1/ the box can hold many times as much dust as your extractor can

2/ by preventing dust getting to your extractor, you prevent any getting into the air. It isn't dependant on a filter to keep the air clean.

Mike

 

[woodbloke]

Maybe I'm missing something...

Ed

Not only is it the filters (see previous post) but you could make a box that could hold a lot more than the 90L capacity of the C386, which we both have
Edit - dropbox guru and world supremo beat me to it :lol: :lol: - Rob

 

[DavidE]

Not that it makes much difference, but you won't have laminar flow (where all the air is moving parallel to the pipe sides) anywhere in any dust extraction system. The summary of how the particles are dropped from the air flow is right but the energy loss in doing it is huge comparred to a cyclone system. Whilst these box thingys look like a nifty way to spend a few hours, is emptying your extractor so hard?

Aidan

Agreed Aidan, it's not hard to empty the extractor. The main benefit though is that the filters in the vac won't get clogged as all the dust will be in the box, not caked on the outside of the paper filter, in which case losses will be just as high...I think - Rob

From my point of view the RSDE1 dust extractor design is such that the dust enters the drum in line with the filter so a lot of it hits the filter straight on. Therefore, I invariably spend quite a lot of time lifting the lid up and brushing the filter down (not necessarily emptying the extractor). So although I've not used mine long term yet I envisage I will spend less time doing this and introducing dust into the air. I was concerned how lossy it would be, however, from my initial tests it's not bad and the average level of suction will increase as it won't rely on me going and clearing the filters.

Cheers
David

 

[sometimewoodworker]

is emptying your extractor so hard?

Well I've been wondering the same thing. If you suck up a Kilogram of dust, its a kilogram wherever you empty it from. I don't see why its any more trouble to empty it from the extractor than it is to empty it from a wooden box.

Maybe I'm missing something...

Ed

That will depend on your extractor.

In my case my CT22 uses bags at a bit over a fiver each as well as filters and so far I am still on the first bag after about 3 years.

I would guess there is may be 1/2 a liter of dust in the bag and none on the filters.

Right now I've probably saved myself something north of a hundred quid.

 

[Qwibble]

Not that it makes much difference, but you won't have laminar flow (where all the air is moving parallel to the pipe sides) anywhere in any dust extraction system. The summary of how the particles are dropped from the air flow is right but the energy loss in doing it is huge comparred to a cyclone system. Whilst these box thingys look like a nifty way to spend a few hours, is emptying your extractor so hard? Aidan

I totally agree that I won't achieve laminar flow, but minimising turbulence should help to some degree. Don't know how much difference it'll make, but I've got a black bin and a Henry, and enjoy a challenge (trying not to burn my fingers with the glue gun).
I extract my routers/sanders straight into Henry at the mo. So I'm hoping the bin would reduce the number of dust bags I get through.

I've had a look a some DIY cyclones but I have to admit I don't yet understand them. :? That might be project #2

 

[woodbloke]

The O's has been fitted and tested. Everything is airtight and the inlet tube from the vac to the box is squashing up nicely, so no leaks.

However, resluts are dissapointing The big stuff is getting stopped nicely but the smaller, fine dust is still getting through to the vac. I cleaned it out thoroughly and put on a new paper bag. Holes in all the baffles are 6mm thick...any suggestions Mike? - Rob

 

[Mr Ed]

Not only is it the filters (see previous post) but you could make a box that could hold a lot more than the 90L capacity of the C386, which we both have

I emptied my Camvac, for the first proper time since I bought it, at the weekend and found it about 1/4 full, with relatively little on the cloth filter and nothing on the paper filters. I still use my ADE1200 for planer chips, so the 386 is for fine dust only. In my hobby environment it appears I can go some considerable time without filling it so I will stick with that.

I'm sure the dropbox concept is a good one, I just don't think I need it.

Ed

 

[woodbloke]

At Mike's suggestion, I've put in severial new baffles with smaller 3mm holes (and less of them) but it doesn't make any difference...my WV1000 just produces too much suck to stop the finer dust from being drawn through to the vac canister. No room either in it's present location to build a bigger box, which is what Mike suggested.

So on this occasion, it's a 'wrong bong' - Rob

 

[wizer]

I wonder why this works for some people and not for others. It appears to me that Mike may have got his design spot on first time without realising it. You may have to keep tweaking the design til you get it right, Rob.

Personally, I think I'm going to go down the cyclone route when\if I ever get there.

 

[DavidE]

At Mike's suggestion, I've put in severial new baffles with smaller 3mm holes (and less of them) but it doesn't make any difference...my WV1000 just produces too much suck to stop the finer dust from being drawn through to the vac canister. No room either in it's present location to build a bigger box, which is what Mike suggested.

So on this occasion, it's a 'wrong bong' - Rob

Rob, if you suck a pile of dust up - how much gets through (rough %) and what size would you say the smaller particles are that break through?

Wizer - it is highly dependant on flow rate and the design. It's a bit of a black art. I was reading a textbook yesterday talking about the designs of these systems and the volumes they were suggesting you needed for fine particles were pretty crazy. (When I finish it off I will post some calcs for Mike's box and my own version)

Cheers
David

 

[woodbloke]

Rob, if you suck a pile of dust up - how much gets through (rough %) and what size would you say the smaller particles are that break through?

Cheers
David

I put say a large jam jar full of sawdust (Haywards pickled onion size) through and of that, a cupful of finer stuff (like flour) was in the bottom of the vac bin and coated round the paper bag, which is not satisfactory. If a much less powerful vac were to be used (as in Mike's original) then nothing gets sucked through, which is as it should be, but with a powerful sucker, the problems seem compounded - Rob

 

[DavidE]

Rob, if you suck a pile of dust up - how much gets through (rough %) and what size would you say the smaller particles are that break through?

Cheers
David

I put say a large jam jar full of sawdust (Haywards pickled onion size) through and of that, a cupful of finer stuff (like flour) was in the bottom of the vac bin and coated round the paper bag, which is not satisfactory. If a much less powerful vac were to be used (as in Mike's original) then nothing gets sucked through, which is as it should be, but with a powerful sucker, the problems seem compounded - Rob

Flip! What is the flow/power rating of the high powered one?

I wonder if it worth trying it with one of the upper sections removed and a deflector put in to stop the flow short circuiting. The other thing that might work is putting a baffle over the holes between sections and take the baffle plates out you have now. (hopefully you can see what I mean in this picture, I also tried to get the flow to snake round.

I suspect on a similar test with mine I'd get less than a tea spoonful of very fine dust (keeping the cooking sizes going!)

David

 

[woodbloke]

The whole idea has now been binned and I've connected the vac directly to the K419...time to start making things instead of ar$ing around - Rob

 

[wizer]

I think that's probably a good idea. These drop boxes are probably more trouble than their worth. I've had my RSDE2 for four years and I've changed the filters about once every two year (it need changing now).

 

[DavidE]

The whole idea has now been binned and I've connected the vac directly to the K419...time to start making things instead of ar$ing around - Rob

Oh dear the dreaded bandsaw

It's a shame you've given up... remember it took Dyson 5127 prototypes to get his product to market! I made mine with the intention of having to tweak it - hence the clear front. unfortunately, fluid flow is a bit of a black art especially with all the turbulence so fettling is needed.

Wizer - I guess it depends what dust your processing. I've needed to change the paper filters a lot more often than I'd like on the RSDE1s I've got and also been narked by how quick they blind - wishing they had a blow back system.

Cheers
David

 

[wizer]

I've been using the cloth filters. I had the .5 micron one for MDF on but it made a significant reduction in flow and was a ***** to clean. So I took that out and just have the corrugated paper one and the cloth that covers it. I just vacuum it every time I empty it.

 

[DavidE]

I've been using the cloth filters. I had the .5 micron one for MDF on but it made a significant reduction in flow and was a ***** to clean. So I took that out and just have the corrugated paper one and the cloth that covers it. I just vacuum it every time I empty it.

Okay - I tend to brush the filters off when emptying. I've found when using Oak or Sapele they coat up really quick so I'm brushing them off well before the bin needs emptying. If your vaccing them off where's that dust going and what happens to that filter!

David

 

[wizer]

I use the Henry to vac it off.

 

[woodbloke]

Oh dear the dreaded bandsaw

It's a shame you've given up... remember it took Dyson 5127 prototypes to get his product to market! I made mine with the intention of having to tweak it - hence the clear front. unfortunately, fluid flow is a bit of a black art especially with all the turbulence so fettling is needed.

Cheers
David

No, not this time...it's just been dumped outside the workshop, ready for the bin men. I was happy to have a little play with it to see if I could get it to work, but I haven't got the patience for this endless tinkering and my 'shop is for making furniture. I know that Mike advoctes a rough and ready approach to the build, but the constant use of a 'hammer and nail' to make it was starting to irritate :x It would be very useful if we could have some sort of rule, or ref guidlines on flow rates and suitable sizes of sucky machines and boxes etc - Rob