Thread: Filter or cyclone?

Thanks BobL I will get off my bum and make the effort.

I'm not trying to hijack the thread, but this may help others.

If I move my dusty outside and duct it, from what I'm understanding, I should b able to add a section inside or next to the enclosure for my Shop Vac and run 50mm PVC inside and around my shop to duct it also? How much of the 50mm flex that Carbatec sells can I put on the end of the ducting?

I'm using a Pullman Wet/Dry with a cyclone attached.

Originally Posted by johnredl

I'm not trying to hijack the thread, but this may help others.

If I move my dusty outside and duct it, from what I'm understanding, I should b able to add a section inside or next to the enclosure for my Shop Vac and run 50mm PVC inside and around my shop to duct it also? How much of the 50mm flex that Carbatec sells can I put on the end of the ducting?

I'm using a Pullman Wet/Dry with a cyclone attached.

It's not 100% clear what you are doing.
In the section in bold above I assume the enclosure you are referring to is the DC enclosure outside your shed?

RE: How much 50 mm ducting?
To give you an idea of what is involved, a typical VC loses about 6% of its sucking pressure for every 5m of 50 mm diameter smooth plastic ducting.

For corrugated hose like aVC hose it loses about 15% for every 5 m - hence do as much as you can in smooth wall PVC and only what is required in the flexy form.

It's really important to duct a VC in 50 mm ducting as anything much smaller than this will really impact the flow.

Originally Posted by johnredl

I'm not trying to hijack the thread, but this may help others.

If I move my dusty outside and duct it, from what I'm understanding, I should b able to add a section inside or next to the enclosure for my Shop Vac and run 50mm PVC inside and around my shop to duct it also? How much of the 50mm flex that Carbatec sells can I put on the end of the ducting?

I'm using a Pullman Wet/Dry with a cyclone attached.

Yup thats a goer, I did something similar. I have a 2hp dusty in an enclosure vented to outside the shed. Above the motor section I put a small shelf that a shop vac sits on. I used the blower outlet to run a pipe down and out the vent as I was slightly concerned about heat buildup around the shop vac. I then have some 50mm dwv coming out the side of the enclosure and into a cheap aliexpress cyclone (that works very well) and then out to the normal shop vac hose.

My runs are currently pretty short (~2m pvc to the cyclone from the shopvac, then another 3 odd m of shopvac hose) My current plan is to replace the shopvac hose with the larger diameter american hose (~2.25 inches) as it is easy to get a variety of fittings etc. As Bob has said the pressure drop on a shopvac is not anywhere near as much of a concern as with a dusty so you can add some reasonable long runs without much ill effects (50mm is the ideal size iirc)

Originally Posted by johnredl

I'm not trying to hijack the thread, but this may help others.

If I move my dusty outside and duct it, from what I'm understanding, I should b able to add a section inside or next to the enclosure for my Shop Vac and run 50mm PVC inside and around my shop to duct it also? How much of the 50mm flex that Carbatec sells can I put on the end of the ducting?

I'm using a Pullman Wet/Dry with a cyclone attached.

Just to support wobbz ... I followed BobL's advice and put my 2 HP vac outside under a hood and ran about 6 metres of 50 mm PVC pipe into the shop. I also removed the filters from the vac (careful, BobL says this is not always a good idea and that you should check your power draw first).

It works like a bought one, with no noticeable loss in suction. I think the removal of filters has balanced the additional PVC pipe.

BobL is right when he says that vacs can be terrible producers of fine dust.

Back at it after a couple weeks on leave.

Cut the hole to accept the flange from the impeller. What's not shown here is the original intake on the other side which I cut off and patched up with a piece of aluminium (and lots of silicon).
photo 1.jpg


Here is the flange connecting both parts of the extractor. It was quite fiddly to get right. The guy who made this for me didn't get the radius quite right . With some rubber gasket from Clark Rubber, I was able to bolt it all up and compress the rubber to form a solid seal. I then lathered it all up with silicon inside and out just to be sure.
photo 2.jpg


Here's the currently working set up. 6" all the way to the tablesaw which is working nicely from what I can tell. The gate was a bit of work though. For some reason it was quite a loose fit (probably made to accept that flexi tube stuff). Again, I surrounded the joint with a strip of rubber and it formed a very nice tight seal. The suction is such that when all gates are open the bag is blown out full. When I close the 4" gate to the jointer/thicknesser the bag collapses very very very slightly. Does this mean I should open up some more room in the tablesaw cabinet to allow for more airflow?
photo 4.jpg


Still to do at some point in the (near) future:

• Change the port on the jointer/thicknesser to 6". It's only a month old so I'm not game to take an angle grinder to it just yet!

• Above the tablesaw is currently still the original 2"ish tube. I've set up the ducting for 4" to this and will build a new overhead guard to suit once I get a chance.

• Build an enclosure for the extractor. I have an idea to place it outside but it will take some manoeuvring and removing of bricks, etc. So will need to give all this some thought.

I must say a huge thanks to BobL for all the advice and tips on this so far. It's been invaluable and I certainly couldn't have gotten this fair without him.

Cheers,
Af.

Originally Posted by Afro Boy

Back at it after a couple weeks on leave.

Cut the hole to accept the flange from the impeller. What's not shown here is the original intake on the other side which I cut off and patched up with a piece of aluminium (and lots of silicon).



Here is the flange connecting both parts of the extractor. It was quite fiddly to get right. The guy who made this for me didn't get the radius quite right . With some rubber gasket from Clark Rubber, I was able to bolt it all up and compress the rubber to form a solid seal. I then lathered it all up with silicon inside and out just to be sure.

Nice flange
photo 2.jpg

. The suction is such that when all gates are open the bag is blown out full. When I close the 4" gate to the jointer/thicknesser the bag collapses very very very slightly. Does this mean I should open up some more room in the tablesaw cabinet to allow for more airflow?

Most likely - how is the ducting attached to the TS.
Rather than relying on the extent to which the DC bag is inflated a U-tube manometer with one arm connected before or after the impeller would enable you to quantify this. e.g. "This" is better/worse than "That" etc

Thanks Bob. Might give that a go to help quantify things more exactly. I used the new system in earnest today and noticed a few things.

• The jointer/thicknesser DEFINITELY needs an larger port. It's way too underpowered and I can really notice it now. Will need to get a steel worker person to cut into my existing one and modify it for me.

• The overhead port on the tablesaw is next to useless. Again, very noticeable now that other parts are working well.

• There is a lot of static build up. I've used PVC tubing before but this 150mm version seems to be more "staticky". I'm not terribly worried about it but just to be sure I might run some wire around all the tubing and earth it at one end. Anything I need to be aware of in this regard?

• The impeller fan runs for quite a while after you switch it off. I never noticed it before so not sure if it did that before as well, but it seems to be swirling the fine dust around for a minute or two after I hit the off switch.

Cheers,
Af.

Originally Posted by Afro Boy

Thanks Bob. Might give that a go to help quantify things more exactly. I used the new system in earnest today and noticed a few things.

• The jointer/thicknesser DEFINITELY needs an larger port. It's way too underpowered and I can really notice it now. Will need to get a steel worker person to cut into my existing one and modify it for me..

Most thicknessers are under wheming in their DC performance.

• The overhead port on the tablesaw is next to useless. Again, very noticeable now that other parts are working well..

Have a look at what John Samuel did for overhead extraction on a TS.

• There is a lot of static build up. I've used PVC tubing before but this 150mm version seems to be more "staticky". I'm not terribly worried about it but just to be sure I might run some wire around all the tubing and earth it at one end. Anything I need to be aware of in this regard?.

That's because you have more air moving around. The only reason to ground the system is if you don't like getting zapped.

• The impeller fan runs for quite a while after you switch it off. I never noticed it before so not sure if it did that before as well, but it seems to be swirling the fine dust around for a minute or two after I hit the off switch.

That's another indication that the system is more free flowing