Thread: Dust Extraction for Lathes

John,

As you know I have been reading this thread with interest, no not to stalk you but to find out if it comes up with a better solution then what I have.

There are two aspects to working with a lathe.

The first is fine dust control, which is visible under correct lighting which you would have for turning, this I collect similar to what Soundman says with a 4" hose close to the work when sanding. As my pipe run is smaller then yours and possibly longer I have incorporated the fan and motor from a 1 HP cheapy DC ( without any bags) as an in line booster. I only use this for sanding and I also have a room filter going all the time. This works fine for me.

The second is the chips and curlies when turning. By it's very nature of turning this gets thrown all over the place with the bulk just in front and beneath the lathe. I don't bother with this as at the end of the day I sweep them up and put in a bin for our composting bins. They are not the type that you can breathe in, too big, but if concerned I would mount a big gulp type of tray underneath the lathe, coming out in front of the lathe by say 150 mm with a second hose direct to your system. This would get most of them.

As my lathes are mounted on a bench the 4 " hose is fitted onto a flexible goose neck arm from a old fashioned desk lamp with the lamp removed so it can be twisted to the position I want. You can also use a free standing post with the flexible arm attached or even the now common adjustable desk lamp arm fittings.

Hope that helps.

Peter.

Originally Posted by soundman

the two biggest are that they are wastefull on air flow and suction, the second is that they are unavoidably large and inconvienient.

One needs to define large. It is tall, but I love the tiny footprint of the CV ... smaller than a 1 or 2 HP dusty.

Originally Posted by soundman

A third is that if you have insufficient or disturbed air flow their seperation efficiency plumets from above 99% to well below 50% if you slow the air down enough...and then you get lots of dust comming out of them.

Correct. A good reason to avoid disturbance. Any dust collection system has this problem. It is not unique to cyclones.

One great way to slow down the air is to connect a 4 inch flexy to a 6 inch duct with an impeller and motor designed to pull through 6 inch ductwork. Air velocity will plummet from about 4,000 FPM to about a third of that or less as soon as the stream enters the 6 inch pipe. Not only can this make a mess of cyclone performance, but also it can cause blockages. And yet we still find people saying that its OK to hook up a 4 inch flexy to a system designed for 6 inch ducts.

Originally Posted by soundman

As for the whole big duct thing...yeh....that is nothing new...we had blokes running 6 inch duct arroud then too.

So you have coughed up for this cyclone thing....had to buy a blower bigger than a conventonal system needs and had to duct it because the cyclone is too big and combersom to wheel round....

No, I bought it in part because I wanted a ducted system ... it was one of my requirements. Feel free to drag machines around. I choose not to.

Originally Posted by soundman

Of course if you have lost a fair whack of static pressure (suction), thru the cyclone and you have had to run long ducts.....well ya gona need big pipe just to compete with a simple mobile dust extractor running short ducts and close by
AND by the time you baught the cyclone...the output filters and installed it and all the ducting..you could have baught 2 decent mobile dust extractors.

Again, not really. The pipe work provides minimal losses. The big losses come from tight R/D bends, flexy, chip seperators, clogged filters and poor hoods/shrouds. I have 10 M of duct between my cyclone and the linisher, and it will still suck-start a Jumbo jet. Mind you, the only 90 degree bend has a R/D ratio of about 3.5. That helps.

Originally Posted by soundman

as far as ya saw bench and the corigated duct...yeh buddy..been there.....the corigated duct is lossy as hell..and I bet you got about 2 meters of it between ya dust extractor and ya saw bench.....yeh been there too.

There are many types of flexy. Most of those with wire in them are as rough on the inside as they are on the outside. But there are others that don't use wire, rather they use a thickened PVC spiral that sits between the corrugations, making the inside of the flexy much smoother than the outside. Losses with this flexy are still more severe than with pipe, but far less severe that the other types. We can't eliminate the losses, but we can minimise them. My drop saw has 6 feet of this flexy ... made necessary my shop layout and size, but it still pulls small offcuts off the table and into the duct and dust control is excellent.

Please don't tell me I can't pull good airflow through 10 M of duct or through 6 feet of flexy when that is exactly what I do every day in the shed. If the fan curve is good enough, it can be done.

Originally Posted by soundman

Put ya dust extractor right next to the saw bench and get some straight 100mm pipe, less than a meter long..using the same dust extractor and things will be different.

But I don't wan't to drag machines around the shop. I want a ducted system. In addition, I want to vent outside. Both the dustys I owned leaked dust, despite my tender ministrations.

Originally Posted by soundman

Oh have you worked over the saw bench and modified it for best dust capture.

Yes. Happy as a pig in mud. Dust capture is brilliant.

Originally Posted by soundman

As far as the ideal solution......it does not exist.

Sure it does. It means most suitable or best possible. It does not necessarily mean perfect.

Jefferson has already told us his budget is $4,500, so ideal sounds like it would be the best system he can buy for that much. I'm guessing that in this case "best" or "ideal" means maximum airflow and dust collection that can be had for $4,500. Sounds like CV Max with a VFD to me. If anyone knows of a system that pulls more air for a similar cost, I'd love to hear about it.

Originally Posted by soundman

As I have posted elsewhere, this dust extraction part of the forum seems to be dominated by those who are chasing magic numbers and are prepared to spend a lot of time and money fiddling to achieve them.

Don't know about the forum being so dominated, but it might be true for this thread. I already have the magic numbers, and am pleased to have them. Jefferson sounds like he is trying to get them. This is my thread. May I discuss what I choose; or do I need permission to discuss magic numbers, fine dust and the CV cyclone?

Originally Posted by soundman

As I say, some of us have been round long enough to have seen it before, had the discussion before and know that there are reasonable and economical solutions, that do work.

Unfortunately, your definition of "do work" and mine are different. For my shed, if it won't pull 1,000 CFM it won't work well enough. If it is not vented outside, I don't want it. You get to decide for your own shed, but please allow me to choose for myself what happens in mine.

Originally Posted by soundman

the physics and the maths remains the same, the difference is the better off the shelf dust extractors are more effective, flow more air and are cheaper than they where 10 years ago....making cyclones even less attractive.

Can you tell me which inexpensive off the shelf solution will give me the 1,000 CFM I want through 10 M of ducting and the port for the linisher? Recall please that a ducted system is one of my requirements. So is venting outside.

Originally Posted by soundman

dont think so...an alternative view that represents what most people can achieve and afford.

I am not most people. I am me. I want what I want, not what anyone else thinks is OK.

I wanted 1,000 CFM at 4, 000 FPM so I don't get fine dust in my lungs. I wanted a ducted system. I wanted a small footprint. I wanted to vent outside to avoid leaks. I wanted to breathe clean air.

And now I have all of that. It cost me about $4,000 and the only regret I have is not buying the CV Max rather than the CV 1800. Chris still owes me a beer for failing to convince me of that.

If my shop was set up twenty or thirty years ago I likely would have gone for Bob's optimised 2 HP system, (if Bob were around to develop and test it) because the costs of a young family would have made it difficult to stretch to a Clear Vue. But now, in the shadow of retirement, I can afford it. I have been in full time work for forty five years. Please allow me to indulge myself and to protect my health.

Originally Posted by soundman

...Sturdee probably remembers (I cant recall did Sturdee build a cyclone)....

I remember them and yes I did build and use a modified version of a cyclone. As some of you are aware my workshop is excavated underneath my house and the amount of head room is fine for us but not for any tall persons.

Between the extra thick foam matted floor and the lowest beam (thankfully only one) I have 65 mm of head space, so my version is a modified system with 4' ducting along the walls. Ducting is longer then I would like but is compensated for with on each main line with a 1 HP fan and motor from a GMC cheapy as an inline booster which works well enough. Jefferson could use his small ones on a similar basis.

The unit is outside the workshop, still underneath the house and is switched from inside.

Not perfect according top Bill Pentz, but gives acceptable results with fine dust but not the chips and curlies from turning and fits my limited headroom and unusual shape and was something I could afford.

Peter.

Originally Posted by Sturdee

John,

As you know I have been reading this thread with interest, no not to stalk you but to find out if it comes up with a better solution then what I have.

There are two aspects to working with a lathe.

The first is fine dust control, which is visible under correct lighting which you would have for turning, this I collect similar to what Soundman says with a 4" hose close to the work when sanding. As my pipe run is smaller then yours and possibly longer I have incorporated the fan and motor from a 1 HP cheapy DC ( without any bags) as an in line booster. I only use this for sanding and I also have a room filter going all the time. This works fine for me.

The second is the chips and curlies when turning. By it's very nature of turning this gets thrown all over the place with the bulk just in front and beneath the lathe. I don't bother with this as at the end of the day I sweep them up and put in a bin for our composting bins. They are not the type that you can breathe in, too big, but if concerned I would mount a big gulp type of tray underneath the lathe, coming out in front of the lathe by say 150 mm with a second hose direct to your system. This would get most of them.

As my lathes are mounted on a bench the 4 " hose is fitted onto a flexible goose neck arm from a old fashioned desk lamp with the lamp removed so it can be twisted to the position I want. You can also use a free standing post with the flexible arm attached or even the now common adjustable desk lamp arm fittings.

Hope that helps.

Peter.

Appreciate your input, Peter.

I am a lazy sod, and because of this will try to catch as many of the curlies and chips as possible, but know that a certain proportion of them will escape. That's fine. As you said, we don't breathe them in. It's the fine stuff I'm really after.

Your ideas are in my shed note book ... thanks. It also seems that we need to consider the design and layout of the lathe itself, and what kind of work it does. For example, I am into furniture, and so things like table legs are high on the list of lathe products. But this evening I was imagining myself turning a 700 odd mm leg and had a thought (does not happen too often). How do I get the inlet of the dust collection system to follow me as I work my way along the leg?

Food for thought.

Cheerio!

John

Originally Posted by John Samuel

It also seems that we need to consider the design and layout of the lathe itself, and what kind of work it does. For example, I am into furniture, and so things like table legs are high on the list of lathe products. But this evening I was imagining myself turning a 700 odd mm leg and had a thought (does not happen too often). How do I get the inlet of the dust collection system to follow me as I work my way along the leg?

Food for thought.

Cheerio!

John

John,

The design and location of your lathe is very important. Whilst they can all do bowl and spindle work for dust collection you should have it set up for either bowl work or for spindle work. That may mean two lathes rather then one.

For spindle work I think the bottom should be open and have a lower shelf underneath for a large big gulp type of dust collection tray connected at the bottom with a flexible hose and to the system (what ever it may be , no free plugs from me ) to remove most of the chips etc as well as a hose inlet close to when sanding. Both can be moved along as you work up and down your spindle work.

Bowl work is again different and also depends on whether you do outboard turning or not as the direction of throw is different for them. You would need to place similar on flexible arms connected to stand near where the majority of chips tend to fall. Very few lathes seem to be designed for chips collection and for outboard turning it's worse.

So the selection and stand of your future lathe is possible more important for your needs of trying to collect as much as possible.

Peter.

Originally Posted by Sturdee

John,

The design and location of your lathe is very important. Whilst they can all do bowl and spindle work for dust collection you should have it set up for either bowl work or for spindle work. That may mean two lathes rather then one.

For spindle work I think the bottom should be open and have a lower shelf underneath for a large big gulp type of dust collection tray connected at the bottom with a flexible hose and to the system (what ever it may be , no free plugs from me ) to remove most of the chips etc as well as a hose inlet close to when sanding. Both can be moved along as you work up and down your spindle work.

Bowl work is again different and also depends on whether you do outboard turning or not as the direction of throw is different for them. You would need to place similar on flexible arms connected to stand near where the majority of chips tend to fall. Very few lathes seem to be designed for chips collection and for outboard turning it's worse.

So the selection and stand of your future lathe is possible more important for your needs of trying to collect as much as possible.

Peter.

Thanks again, Peter.

I'll be looking at spindle work to start with. Nearly all my woodworking is furniture, so my lathe (when I get one) will be chosen on that basis and as you indicated, the dust collection system needs to be designed around spindle work.

You said, "very few lathes seem to be designed for chip collection". Bother, spit and darn, none of my machines were well designed for chip or dust collection. When I upgraded my dust extraction system last year upgrading the ports/hoods/shrouds was a bigger job that installing the machine or the ductwork. The good news is that I only have one machine to defeat, the combo jointer/thicknesser.

Here's a thought. Commercial shops need pretty good dust collection systems to meet the OHS criteria. Surely someone, somewhere has a commercial operation that includes lathes. How do they handle dust collection? We may not be able to copy their systems, but can we get any ideas from them?

Cheerio!

John

What a start to the morning - almost 10 posts to digest!

Soundman, you keep banging on about the money. It's my money! At last count, I have maybe 13 Vicmarc chucks, well over 120 chisels so what's another $5K? And I repeat, I want an uncluttered workshop and not 3 separate DCs.

The magic numbers that John refers to seem mandatory. When I attend events like the Down Under Turn Around (DUTA) the dust kills me. It's killing me now, though the A/C will flush most of the dust out over summer. So I have some time to get it right.

I've spent some time Googling dust shrouds for lathes and most use the (useless) large gulps. I'll keep looking.

My needs are clearly different to most. I turn mostly redgum, a notoriously short-grained and dusty turning wood. More chips than curlies. And yes, my tools are Tormek sharp.

I'll be talking with the cyclone guy today and hopefully will get some answers. I'll keep you all posted. A very informative thread.

Originally Posted by Sturdee

As my lathes are mounted on a bench the 4 " hose is fitted onto a flexible goose neck arm from a old fashioned desk lamp with the lamp removed so it can be twisted to the position I want. You can also use a free standing post with the flexible arm attached or even the now common adjustable desk lamp arm fittings.

Hope that helps.

Peter.

Peter,

If possible, would you please post a pic of your flexible arm? Also, Can you (or anyone else) point me at a supplier of such arms where the arm is stiffer than a flexible lamp arm? I am trying to find something that will not droop when holding up a piece of 6 inch flexy and PVC bell mouth. My attempts with a lamp arm were OK when holding up to 4 inch flexy, but I need to put the arm on viagra if it is to hold up bigger flexy.

Thanks,

John

How about a computer monitor arm?

Craig

Originally Posted by CMB

How about a computer monitor arm?

Craig

Well ... bugger!

Just had one of those "how could I have been so stupid" moments ... again.

Thanks a bunch, Craig. Did a quick Google search and for under fifty bucks a good strong arm can be had. Will continue to look around until I get around to doing the upgrade on the drill press (I do a lot of sanding of small, curved components like short cabriole style legs on the drill press), but if nothing better comes up you have already given me a solution.

Thanks!

John

Strolled around the CV forum site and grabbed a couple of pics.



It seems from the discussion so far that lathes require different pick-ups depending on the type of work being done (Peter suggests platters and spindle work need differing approaches, and that makes intuitive sense). The clear plastic shroud in the first pic looks better than a big gulp, but it also looks like it would not project the negative pressure bubble quite as far forward as a bell mouth. But perhaps there are good reasons for the wider opening.

Cheerio!

John

Peter is certainly correct in saying there are significant differences between spindle and face plate turning. To make matters worse (for me), the Stubby has two beds and banjos so I can work on both faces of a platter at the same time. So the dust hood (of whatever kind) needs to be moveable. I don't know how I'm going to achieve that with 6 inch flexi due to the weight. And the Stubby is in the middle of my turning room.

Any and all suggestions welcome.

Adding to the computer mount. There are lots of swing arm TV screen mounts that would work too. Great excuse to take the one from the living room and upgrade to a bigger TV.

The "clear plastic shroud" could be improved by giving it a bell mouth shaped lip all around.

For spindles I can't help think that there must be a simple way to have a bell mouth duct follow the lathe tool along the spindle with some kind of motorized track and an electric eye tracking the tool on the tool rest. I see similar robotic stuff all the time on science news programs so some high school kid science project might be the saviour of us all.

Pete

Originally Posted by QC Inspector

For spindles I can't help think that there must be a simple way to have a bell mouth duct follow the lathe tool along the spindle with some kind of motorized track and an electric eye tracking the tool on the tool rest. I see similar robotic stuff all the time on science news programs so some high school kid science project might be the saviour of us all.

Pete

Pete,

Great idea! Many years ago the business I worked in was in desperate need of a simple book laying out certain principles and techniques for quality improvement, in plain English. Several attempts had failed. I was on the phone to the boss one night when he related the latest failure. I groaned and exclaimed that I was tempted to write the darned thing myself. Immediately I wished those words could be taken back. Too late. The CEO said, "Have the first draft on my desk by Christmas", and hung up.

So, Pete. When can we expect to see your prototype?

Cheerio!

John