Thread: Sturdee’s main dust collection system. or The Sturdee Midi Cyclone.

Originally Posted by zenwood

Good idea using the two blowers in series. Do you switch them on from the same switch so that they power up simultaneously?

No, the switch to the cyclone is in the middle of the workshop on the wall between the front and back section and easily accessable from each machine and the booster TS blower switch is on the TS together with the switch operating the vac for the mini cyclone attached to the over head guard.

The other booster blower switch is on the wall in the centre of the back part near the machinery that needs that booster.


Peter.

Originally Posted by Sturdee

The air ramp is designed to push the airflow into a cyclonic direction and is a sheet metal circle fixed above the inlet duct at one end and finished below the inlet duct after one turn.


Photo 1 shows the air ramp, again with edge lips folded over to help fix to the cylinder. I used self tappers for this, but pop rivets could be used as well.

Photo 2 and 3 show a view of the inside, the air ramp is in and the outlet duct. The gap between the outlet duct and the air ramp is sealed with a small plastic tube cut along its length and slit over the edge.


Photo 4 shows the top of the cylinder closed with another piece of chipboard.


Peter.

Hi Sturdee,

What a great idea and well documented in this thread - thank you.

I'm impressed and plan to build one shortly. Only question I have at this point is in relation to the positioning of the outlet duct. How far from the base of the cylinder should it be positioned? (Photo 2) ie. How far above the connection point of the cylinder to the bowl should it be terminated? Is there a formula or rule of thumb to determine its positioning?

Now, having asked that question, I'm prompted to ask if the positioning of the inlet duct is determined by any similar formula/rule?

Thanks

Ian

Thanks for your kind words Ian.

To answer your question about the outlet pipe I had a look at the cyclone and by sticking a stick up the outlet to the bin I measured that the distance between the outlet and the top of the connection point of the bowl is 180mm.

Couldn't find any formula except that it has to be a bit lower than the air ramp. So I based it on my mini cyclone (for use with a vacuum cleaner for hand tools etc,) and it seems to work well enough.

The inlet pipe should be as close to the top of the cylinder as any space above the inlet is wasted.

Peter.

Originally Posted by Sturdee

Thanks for your kind words Ian.

To answer your question about the outlet pipe I had a look at the cyclone and by sticking a stick up the outlet to the bin I measured that the distance between the outlet and the top of the connection point of the bowl is 180mm.

Couldn't find any formula except that it has to be a bit lower than the air ramp. So I based it on my mini cyclone (for use with a vacuum cleaner for hand tools etc,) and it seems to work well enough.

The inlet pipe should be as close to the top of the cylinder as any space above the inlet is wasted.

Peter.

Thanks for the response Peter. I've bookmarked this thread and looking forward to having a crack at building one as part of the overall dust control solution in my new shed - but that's a little way off yet.

I have a couple of simple questions Peter:

1. Where do you get pvc pipe that matches the diameter of standard 4" flex hose? If you have mismatched diameters how do you make the connection?

2. You mention you use self tappers. Can you be more specific about which screws to use?

Cheers

Chris.

Originally Posted by Psych 101

I have a couple of simple questions Peter:

1. Where do you get pvc pipe that matches the diameter of standard 4" flex hose? If you have mismatched diameters how do you make the connection?

2. You mention you use self tappers. Can you be more specific about which screws to use?

Cheers

Chris.

Chris,

I use the standard 100mm pvc sewer pipe which has an internal dimension of 100mm. I insert into this pipe a short bit of 100mm metal downpipe, which will fit into the pipe when cut with a tinsnip, onto which the standard 4" flex will fit.

I then seal it all up with duct tape. If you have a bit of thin sheetmetal you could make this kind of fitting easily rather then buying extra pipe.

The selftappers are a type of screw designed to screw and hold into metal. They have a different thread to ordinary woodscrews. Bunning sells them, look for screws to screw into metal.

Peter.

Originally Posted by Sturdee

Chris,

I use the standard 100mm pvc sewer pipe which has an internal dimension of 100mm. I insert into this pipe a short bit of 100mm metal downpipe, which will fit into the pipe when cut with a tinsnip, onto which the standard 4" flex will fit.

I then seal it all up with duct tape. If you have a bit of thin sheetmetal you could make this kind of fitting easily rather then buying extra pipe.

The selftappers are a type of screw designed to screw and hold into metal. They have a different thread to ordinary woodscrews. Bunning sells them, look for screws to screw into metal.

Peter.

Thanks for the quick response Peter.

What type of head do the self tappers have and what gauge and length did you use?

Originally Posted by Psych 101

What type of head do the self tappers have and what gauge and length did you use?

Chris,

The description on the packet of self tappers is : "Zenith 1072 - binding head self tappers - 8G*12mm - ZP hardened steel ".

The lenghts is 12mm the width of the slighly rounded head is 8mm. They are designed to cut their own thread in mild steel or sheet hetal after you have drilled the appropriate pilot hole.

Peter.

Sturdee, Well done on the cyclone, especially on using whatever is on hand, working with the restrictions (lack of hieght) and making it work

A small point probly for those following your example is to point the inlet down (where it enters the cyclone) at the same angle as the air ramp.
I would've thought that the inlet outlet box on top of the cyclone might give u probs but prolly your booster blowers help u overcome losses there. Have u noticed any problems?

I take it that the basic idea is from the Bill Penze site, I built mine based on his design with the cone being 3d but I don't know really if I needed to, how can a 1.64d cone work just as well and now your light bowl fitting seeming to work so well, I'm a bit about cone length and now shape

The other thing I took a bit of a stab at was the pipe length down inside the straight barrel section, I couldn't determine from the plans how long it had to be, Did u find a length?

Once again great job.
Peter.

Originally Posted by pjt

I would've thought that the inlet outlet box on top of the cyclone might give u probs but prolly your booster blowers help u overcome losses there. Have u noticed any problems?

I haven't noticed any less suction with the cyclone because of the unusual outlet box on top (without the booster motors) compared to when I had a normal DC, in fact the opposite I had a much better suction rate.

Actually the size of the rectangular outlet carries the same quantity of air as a normal 4" pipe would.

Originally Posted by pjt

I take it that the basic idea is from the Bill Penze site, I built mine based on his design with the cone being 3d but I don't know really if I needed to, how can a 1.64d cone work just as well and now your light bowl fitting seeming to work so well, I'm a bit about cone length and now shape

Yes I got most of it from Bill Pentz, but adepted as needed to suit my space limitations.

I'm sure Bill's specs are ideal and the optimum but alass the optimum don't always suit, so I altered where needed and went for say 90 % of the optimum rather than nothing.

The shape of the cone, lenths etc does affect it but the more critical part is the straight circular part with the air ramp where the cyclonic action is started.

Originally Posted by pjt

The other thing I took a bit of a stab at was the pipe length down inside the straight barrel section, I couldn't determine from the plans how long it had to be, Did u find a length?

Bill's plan does give some directions in that it should be (based on a 6" pipe) about 18" below the top of the inlet pipe. So 6" for the inlet pipe, 6 " for the ramp down and then a further 6". Mine is similar to that but using 4" pipe I ended up with 180 mm from the bottom of the inlet pipe to the top of the bowl.


Since building and posting this I have lined and soundproofed the outside walls of the workshop, enclosed all motors and shop vacs in soundproofing boxes and am soundproofing the ceiling area above the cyclone.

The noise is now so minimal that I hardly hear the dust collection as it is much less than the noise made by my TS.

So I have as efficient dust collection that the unusual conditions of my workshop will allow and no hearing problems. It has taken a while and was more expensive than I would have liked but my lungs and hearing are worth it.

I would encourage everyone to convert their DC to a cyclone as it really isn't very difficult to do.


Peter.

Very informative. I appreciate your effort sharing this with us all.

I plan to make a cyclone to go with the DC (that I know I need) later in the year. Posts like this one that gives step by step instructions (and photos) for the ignorant and uninitialed such as me are great. Thanks again!

Originally Posted by Sturdee

Yes I got most of it from Bill Pentz, but adepted as needed to suit my space limitations.

So I have as efficient dust collection that the unusual conditions of my workshop will allow and no hearing problems. It has taken a while and was more expensive than I would have liked but my lungs and hearing are worth it.

I would encourage everyone to convert their DC to a cyclone as it really isn't very difficult to do.

Peter.

Two years experience with your cyclone and you are still obviously very pleased with it, Peter. Well done.

Now the difficult question: if you did it again, what would you do differently? Bill Pentz would imply bigger pipes and a bigger motor.

Secondly, on another thread Bobl has suggested that so little dust gets past the cyclone that filter bags become redundant and you can vent strait into the atmosphere - peeing in the ocean analogy. Your picture of the wheelybin and filter residue seem do confirm this view. Do you concur with this opinion?

Cheers

Graeme

Graham, I would agree with Bobl and the pics of sturdee's amount of dust in his filters, with my cyclone DC system which is based on the pentz info, I don't use any filters, the whole unit is located outside so I just exhaust to outside, there can be some discharge of very fine dust at times, since putting a muffler on the exhaust I think I have had a reduced flow thus the cyclonic action is reduced and more dust, I might just be able to see it more now tho I'm not too worried atm as I know I can improve the flow as I have more work to do with fixed piping and lessen the amount of flex hosing I currently have from all my machines.

If I think I am getting too much dust I just have a small spray of water directed into the air stream to wash the dust particles and not be so floaty kinda
It would only be a tiny amount if I was to catch it in a filter tho as I reckon 99% of chips and dust end up in the collection box.

Peter

Originally Posted by GraemeCook

Now the difficult question: if you did it again, what would you do differently? Bill Pentz would imply bigger pipes and a bigger motor.

Graeme,

Because of my unusual set up, being excavated under the house, I'm limited with head height and also the shape of my workshop so I would do it the same.

I don't have headheight to run 6" pipes and the lenghts of the runs really necessated the booster motors. The good thing was that the cost of the booster motors was much less than the difference between 6" pipes compared to the 4".

Also when I originally bought the 2hp DC that was the norm and considered adequate. Also there was little information on setting up a system and I learned as I went along.

Originally Posted by GraemeCook

Secondly, on another thread Bobl has suggested that so little dust gets past the cyclone that filter bags become redundant and you can vent strait into the atmosphere - peeing in the ocean analogy. Your picture of the wheelybin and filter residue seem do confirm this view.

With an optimum designed cyclone the filterbags are not needed and they can vent straight to the outside.

But mine is not optimum so the filter bags are useful in containing any dust especially if I forget to check the bin. If the bin is full and I don't realize it than the filterbag system will act as a normal DC. DAMHIK.

Also the underhouse part near it has been converted into storage areas and I don't want any unneccessary dust there covering the items stored there.

Ofcourse if I knew what I eventually needed 50 years ago when I first started digging out underneath the house I would have dug out another 400mm to give a better headheight and also a different shape for the workshop and then my answers might be different. But I don't regret the way it has turned out.


Peter.