Thread: Dust Extractor and No Cyclone

With no bag or filter, I would imagine 25 m of smooth pipe would be no problem for any of the standard DC impellers.

Gravity would have very little effect.

I'd put the impeller at the top, and keep it out of the weather.

Note the use of the word "imagine", though.

Since you've posted this in the turners forum, I am assuming that the DC will be used primarily with the lathe, although you mention "machines" plural.

Most woodworking machines make more noise when running than the dust extractor. So installing the fan inside shouldn't be too noisy. It's when the machines are idle that you will notice the extractor fan. I often leave my dust extractor on all of the time.

If you are not planning to filter the dust or chips, then install the fan in-line. No need to have anything more than the extractor fan. Given the length of the run, you might even consider the merit of installing two extractor fans, one near the beginning of the run, the second just outside the shed wall before the drop. This way, you will have maximum draw throughout the shop, and minimise the noise by installing one outside. The one inside could be encased in a sound-reducing box.

I have my cyclone/filter outside my shop in a seperate area under the house, and one inline inside the shop. Both are one hp, but their combined draw is more than adequate for a small shop.

Originally Posted by DPB

If you are not planning to filter the dust or chips, then install the fan in-line. No need to have anything more than the extractor fan. Given the length of the run, you might even consider the merit of installing two extractor fans, .

Considering that the run is 25 metres I think you will need 2 machines as Don has suggested.

Peter.

If 6 of those metres will be a vertical dropper out the back of your shed, I reckon you'll get away with 1 machine, provided you ensure all joints are air-tight. Hint: duct-tape.

Personally I dislike in-line fans as I find there's always something sucked up that shouldn't be... something that'll possibly damage the blades as it passes through, or possibly adhere to one and throw everything out of balance. Then you'll really know how noisy a fan can be.

If you use a 44-gallon drum with a quik-lok top (eg. a livestock feed-bin) as your collector, you could simply run the duct-work direct to that and then another short length of duct out of the bin to the fan... and possibly a final filter. The collection bin could even be inside your workshop, shortening the length of duct the dust actually travels, with only the fan mounted outside.

Originally Posted by DPB

I have my cyclone/filter outside my shop in a seperate area under the house, and one inline inside the shop. Both are one hp, but their combined draw is more than adequate for a small shop.

Could you describe in more detail how you installed the inline fan and where in the system it is? Does it draw or push the air? A fan could be put at the dead end of the ducting to push the air or it could be installed at some point further down stream to draw the air. If this were the case the fan would have to be sized to fit in the duct????

Originally Posted by Mini

Could you describe in more detail how you installed the in-line fan and where in the system it is? Does it draw or push the air? A fan could be put at the dead end of the ducting to push the air or it could be installed at some point further down stream to draw the air. If this were the case the fan would have to be sized to fit in the duct????

I first got this idea from Sturdee. See this post. http://tinyurl.com/ozylx

In my case, the blower/sucker is between my lathe and my primary dust extractor which is outside my shop, but still under my house. My ducting from the main unit runs through a wall into the shop where it branches in two directions via a "Y" shaped junction. I have installed two gates here so that only one branch is functional depending on the machine I am using.

I installed the second unit close to my lathe which creates a lot of dust. The drawing capacity of the primary unit had little effect at this point which is at the end of one of the split runs. So, remembering Peter's post I purchased a cheap portable dust extractor, removed the dust bag and the grate that blocks chips, and installed flexible hosing on both ends, i.e. where it would normally go into the dust extractor, and where the dust bag goes.

I guess between the lathe this auxiliary unit is sucking the dust and beyond it, it is blowing the dust. Somewhere along the line the power of the primary unit takes over.

Hope this isn't too confusing.

Originally Posted by Skew ChiDAMN!!

If 6 of those metres will be a vertical dropper out the back of your shed, I reckon you'll get away with 1 machine, provided you ensure all joints are air-tight. Hint: duct-tape.

Personally I dislike in-line fans as I find there's always something sucked up that shouldn't be... something that'll possibly damage the blades as it passes through, or possibly adhere to one and throw everything out of balance. Then you'll really know how noisy a fan can be.

If you use a 44-gallon drum with a quik-lok top (eg. a livestock feed-bin) as your collector, you could simply run the duct-work direct to that and then another short length of duct out of the bin to the fan... and possibly a final filter. The collection bin could even be inside your workshop, shortening the length of duct the dust actually travels, with only the fan mounted outside.

i am considering building something like that with a festo extractor;attached straight to the side of a bin with 40 or 60 mm pvc pipe;and the duct going in the top;

The other thought I had was to build a purely push system using the air speed down the main duct to draw the air from the branch going to the machine. The main problem I see with that idea is the main duct will want to be a fair bit bigger than is normal and it will want a fairly big fan. Put the intake fan outside one end and the exhaust and debris exit the other end. The branch to duct joint may want some special design to do this as it will have to have a fairly large air depression at that point. By doing it this way there does not have to be a fan in line at any point. I suspect the duct air speed would want to be fairly high, certainly higher than is normal practise. Any fluid engineers here?