Dusting up a storm

Some further thoughts and developments on the dust extraction system.

I’ve been giving some thought to what happens next – as in how does the dust run get to the dust extractor, and just how far that is – how much more length, how many more bends are required.  The simple answer is “too far and too many”.

Hmm. So the question arose in my mind again – just why did I think the original idea of having the dust extractor on the mezzanine floor was a bad one?  Back in mid Feb, I had thought about it, and opted to bring the dust extractor back down from the mezzanine where it had just been put (and what a pain that was!)  However, now that the machine positions have settled, it is really looking like the mezzanine was a good idea after all.

Looking back at my earlier musing on the subject, I highlighted good points to be
a. free up workshop floorspace
b. for it to be inside the main shed, as it draws a lot of air, and if outside the main shed, that is a lot of hot (or cold) air that would be drawn into the workshop, and
c. as that would make it generally central to the machines it is drawing from.

On the other hand, I had thought having it in the timber store next door gives better access, better noise separation, better workshop air quality (particularly on the mezzanine).

Now that I have been working in the shed for over 1/2 a year, more informed decisions can be made.

These lead to the following justifications for relocating the dust extractor back to the mezzanine:

1. Significantly shorten the length of ducting, and minimises the number of bends required.
2. Noise isolation would be the same as having the dust extractor in the area I currently have placed it.
3. Dust isolation from the main shed is maintained, although the mezzanine will not be as clean, it is not used as I was anticipating. If I ever do start to make use of it for something other than storage, I can look at physically isolating the extractor at that point. It still has a pleated filter, and I can still run an air filtration system up there if I choose.
4. It does not draw air from the outside (hot or cold), so running the dust extractor will not significantly impact on the shed environment
5. Changing bags is as easy (if not a little easier), and I do have the hoist to remove full bags from the mezzanine.

To compare the two locations, let’s take the biggest producer of sawdust in the workshop (which also produces the heaviest particles), being the thicknesser.

With the dust extractor outside in the side shed, it would involve approx 12m of ducting (up, across and down), and a total of 6x 90 degree bends (each elbow is estimated to be the equivalent of 2m of straight pipe), so a total of 24m equivalent length.

With the dust extractor on the mezzanine, it would involve approx 4m of ducting and a total of 4x 90 degree bends (at worst), giving a total of 12m.  That is one significant saving to be had, for the machine that needs the most drawing capacity.  All other machines benefit to lesser degrees, but each ends up saving about 10m in equivalent straight pipe length, if not more.

So I guess that makes the decision an easy one.  The ducting is a lot less complicated, and shorter.  There is power already available (I originally placed a GPO up there to be dedicated to the dust extractor).

The future plan will be to look at continuing to improve and upgrade the dusting system – moving as much up to 6″ ducts as possible, rather than the current 4″.  But let’s see how the system works once I get it up and running, to see just how much that will be a priority.

Onwards and upwards (quite literally!)

A Clean Sweep

For people getting into woodworking, the router tends to be a tool that is either disregarded due to an (incorrect) expectation that it has fairly limited use, or one that is treated with a degree of mistrust. After all, holding a tool that is primarily a motor spinning at up to 20000RPM hardly fills the new woodworker with much confidence.

However, those fortunate to discover the sheer brilliance of inverting the router and mounting it under a table find a whole world of possibilities opens up, and the need to handhold a screaming banshee is something that doesn’t have to be the norm of router operations.

It has always been a source of bemusement to me that of all the machines in the woodworking workshop, the router table is both one of the most useful and yet is typically made rather than purchased, or is an afterthought tacked on the side of another machine. If you surveyed 100 workshops that used a router table, 99%* of them would be home made to one degree or another.

The requirement for components for router tables is being recognised by a few companies, and if you bought the various components together, the resulting router table becomes an impressive machine. Long time readers of this site will be aware of the attempts I have made thus far to create the ultimate router table. At one stage I did look at a spindle moulder, and that may one day become part of my workshop setup, but although they can have an adapter to fit router bits, they do not have the speed range needed to drive them properly. If you are intent on using router bits (which have an incredible range of functions and profiles), then there is still a place for router tables. Spindle moulders get up to around 8000-9000 RPM. A router can achieve 21000-22000 RPM.

There are already fences, featherboards, switches, stands, tops, and through fence, or above-table dust collection has been built in, there hasn’t been a commercial solution for below-table collection until now. Some routers dealt with this onboard, which allows the finer dust collection, but clogs with the heavier production.

The router table would be about the second largest waster of wood (and I say that with love – using the term to mean turning the timber machined into shavings, rather than offcuts), following only the thicknesser. The jointer generates a lot of shavings, but as it only typically takes a few light passes to achieve the job of flattening a side, it doesn’t make as much overall sawdust as the router, especially when used for edging, shaping, template copying and joinery (and often all in the same project). Of course, if you have a lathe, then this jumps right into first place!

So dust collection. To really handle dust production, both fine and coarse, light and heavy, you want to be using a 4″ collection system (at least!). But how do you plug a 4″ hose into a router?

Simple – you don’t! Instead, you can box the entire router in, and collect not only everything that falls under the table, but also draw air and dust from above the table as well.

Given so many of the improvements and refinements for the router table are Incra, it would come as no surprise that the latest improvement comes from that stable as well.

Incra CleanSweep

Incra CleanSweep

This is the CleanSweep. It attaches to the underside of a router table, and surrounds the router completely. At the base is a blast gate leading to the 4″ connection. The rear door has a clip to secure the power cable, minimising dust leakage. The front door is also steel, and is on a very simple, foolproof (and fault-proof) mechanism – dropping down to allow access.

I know what the CleanSweep looks like in the photos – a bit of a box. However, what you get in practice is significantly more spacious than what appears in the photos. It is designed with a specific purpose in mind, and is well constructed. You get to appreciate that during assembly.

Mounted under Table

Mounted under Table

My current router table (not pictured!) has the Incra frame, the LS Positioner fence system and the cast iron top, and although now very functional still feels unfinished.

My next mod will now be to remove the current surrounds, fit the CleanSweep, and create new sides, shelves and drawers. I can already testify to the benefits of 4″ dust collection from under the router- the amount of dust drawn from above the table is impressive, let alone keeping dust from building up under the router (and in the air- fine dust has no chance!)

detail5

You may be concerned about dust being drawn down, past the router, but let me reassure you on a couple of points. Firstly, and speaking from experience, the only time I have had dust issues with an inverted router is when I wasn’t actively collecting dust, and the MDF (particularly) got into the switch and the plunge shafts (and bearings & gears of the height winding mechanism). When collecting, especially with 4″, I have had no reoccurences.

Secondly, the cooling for the motor is often on top (and therefore underneath when the router is inverted), and will get very little dust in (if not sucked immediately away).

Thirdly, although the air can get a lot of dust entrained into it, overall the amount of relatively clean air that the router is exposed to is significantly higher than times it has to deal with dusty air.

detail6

If the router table is flat, it is very easy to attach the CleanSweep directly to the bottom of the table.

If not, then some infill can be made with MDF. It doesn’t have to be a 100% tight seal- the 4″ system will still create a decent degree of negative pressure irrespective of a few gaps.

detail2

I haven’t any pictures (yet), but I have checked the CleanSweep on the bottom of the Triton Router Table, and I am very confident it can fit with some infills. For any infills, you can add space filler, but it really is messy stuff. On the Triton table, the CleanSweep will block the sliding table, but I never used it in that fashion anyway. It was always a much better option to use the sliding extension table if you want that function.

detail3 detail4

So if you have an existing router table (Trition, homemade, or even just a wing on a tablesaw), the CleanSweep is a stylish and functional upgrade that will significantly decrease the amount of uncontrolled dust that your router table will produce.

Available (as with all the other best router table upgrades!) from Professional Woodworkers Supplies.

*This statistic is not based on any real-world survey

Tubes, Tubes and More Tubes

This is still a continuation of the implementation of the dust system – yeah, not the most interesting thing to continue with (although I am enjoying the progress), but it is what I am currently working on after all.

Wishful Thinking?

I’ve decided to try the tie the jointer into the system after all- not confident that it will work, but I have a plan 😉  I still have a portable dust collector, a small 1HP one designed to couple up to individual machines – not what I want to do, but it will be an interesting blower, or inline booster.  At the moment the jointer is coupled directly into the vertical trunking, but what I am thinking is adding a Y section , with one side connected to the outlet from the blower, giving a significant boost to the airflow through the trunking when required.    At least it might be one way of getting the dust from this far into the shed to the dusty at the other end (and out).

The T section here is to lead to the lathe, and provide some collection from there.

Overhead

The trunking goes over the doorway (and this is all the clear stuff from the latest pack) – goes together very easily.  One kit sounds like quite a lot, but more would be rather useful.  At least it is compatible with existing fittings.

Angles and Dangles

Bringing the dust up from the bandsaw, through a blast gate (attached with another Rockler mount) and off to the rest of the new system.  This is going to head straight over the shed to the system on the opposite wall (from the tablesaw).

Dusting off the Bandsaw

Back of the bandsaw – this is the 17″ Carbatec, and it is interesting in that it has dual 4″ outlets.  One from the bottom of the cabinet – where the dust finally falls, and a second from under the table, near to where the dust is generated.

I’ve opted for the flex hose for the bandsaw so the machine can be moved a bit (and if really necessary I can always put in another flexible section).

The shed is rather chaotic at the moment – running systems like this makes a real mess.  Looking forward to getting this job finished, and once again restoring some sanity out there.

Floor Dust Collection

Just a quickie – been cutting quite of MDF recently, and not all the tools I was using were fitted into the collection system, so there is a bit of mess on the floor.  In the past I’ve been connecting a super-flexible length of 4″ hose and doing the sweeping by hand, which is slow and annoying (but effective).

So instead I’ve coupled a typical nozzle to the end, and am partway through the build of a simple sled to hold it just off the ground.  When I’m happy with the height and function, I’ll add a handle to it.

Pity I don’t have one of those robotic sweepers- I could mess up the shop and find it neat and tidy the next day (and it would be rather discouraging for my recent possum visitors to boot).

dustbroom-1

4" Broom - WIP

dustbroom-2

Determining the required clearances

Originally there was no MDF portion planned, but the brackets I used were too weak for the job.  Next prototype will either place the wheels out nearer the corners of the MDF, or the MDF will be absent and stronger brackets used.   The actual clearance looks about right, although it would ideally be adjustable so I can first do a sweep to pick up the heavy shavings, then a second to pick up the fine dust.

Developing the Dust System

I’m not sure if a dust system ever gets finalised.  At least it never seems to in my shop – I seem to be constantly changing my ideas, tool positions, and dust system layout concepts.  Oh well – it’s like a real-life jigsaw puzzle that can be assembled many different ways, and how well it works tells you which picture you’ve created.

As I’ve mentioned recently, I have capitulated and have moved the dust collector back into the main shed.  There are a number of reasons for doing so, and a number of reasons why I didn’t want to have to.

Reasons why I wanted the DC located in a different shed (or at least outside the primary workshop)

* Noise. DCs are noisy (not brushed motor noisy), but still, sounds of lots of air moving would be better elsewhere if possible.

* Dust. If air is passing through a filter, then there is a probability that dust will also be carried through, even if the filter is a 1 micron filter.  If the unit is in another location, some minor dust leaks are inconsequential.

* Space. The footprint of a dust collector is going to consume about 1 metre square of valuable shed floor space.

Benefits of having the DC in the main shed

* Starting and stopping. There isn’t the issue of requiring expensive remote starting systems.

* Blockages. Easier access to clear blockages, empty dust bags, clean filters.

* Airflow. Simply the less distance the air needs to move, the better the system works.

Relocated Dusty

Relocated Dusty

I’ve relocated the dusty into the same corner where the original 4″ tube to the other shed went, but now instead of joining the two halves of the system into one pipe, I’ve coupled each arm up to its own intake. In addition, I’ve also run the 15″ thicknesser directly in to maximise its collection.  More on that in a sec.

My primary influence on relocating the DC was performance.  After my recent air velocity tests, I decided that I was compromising the performance too much to have the luxury of it being in the other shed.  There are some other minor benefits as well, but they were not enough to sway the decision either way.

I haven’t decided if I will do anything to counteract the additional noise, other than running it when I need it rather than constantly.  I might investigate building a fake wall around it with noise dampening, but that is a project that will probably never actually eventuate.

To counteract any issue with fine dust leakage (and dust during bag changing), I have located it right near the overhead air filtration unit (which is also a 1 micron filter), so between the two, any dust I collect shouldn’t end up back in my environment.

Underneath the DC, I have used both 4″ inlets, as much to allow a smoother entry of air as anything.

DC Inlet

DC Inlet

I’m not happy with the result however.  The tubes you can see are – from the right hand side is a solid connection from one of the 2 main shed trunk lines.  It doesn’t have any flex section at all, and this is what I want to modify.  As much as flex sections have a greater internal roughness, a short section is going to have a tiny effect on the overall flow.  It would however, make removing the nozzle to clear out blockages much easier so that is the first change.

Into this same trunk line through a Y section is the output from the thicknesser.  However, after testing it out, it failed. Inside the DC nozzle are some grates/blocks to catch heavy particles before they hit the fan.  The amount of chips produced by the thicknesser formed a mass that caught there, and immediately blocked the pipe.  Without any airflow, the thicknesser then rapidly clogged its discharge nozzle.

I have 2 ways forward.  Removing the grates (which I am still dubious about their value), but I’m not sure if that will then result in the blades becoming blocked up, and accessing them is even harder.  The other solution is a pre-separator to catch the majority of the output from the highest producing machines.  I’ll start with this, and see if it is enough.  Damn- it looked to be an elegant solution.  But this is Bauhaus – form must follow function.

In the background is a flex end to the second trunk line, and that works well.

To improve functionality, I have replaced the flex hose to the tablesaw with another length of PVC pipe.

Tablesaw Extraction

Tablesaw Extraction

I’ve used a Y section which I’ve capped to allow cleaning of the system, and also as a way to add a bit of flexible hose when cleaning up around the place.

Jointer/Planer Extraction

Jointer/Planer Extraction

I’ve kept the extra flex from the jointer so I have the ability to move and angle it depending on the length of stock I’m trying to plane.  Each item has a blast gate (my modified version).

New Shed Dust System

I finally, after I can’t remember how long, started to rebuild the shed’s dust extraction system. It was decommissioned so long ago, I don’t even remember at what point it became non-functional. It is pretty academic these days given the whole shed upgrade. ‘Back then’ I bought a number of lengths of 100mm downpipe, being significantly cheaper than the actual flexible dust extraction tubing. So I finally got to start cutting into it, and putting it in place.

The first step though, was finalising (as best I can) the machine positions. Once that was decided (taking into account where possible, the dust extraction needs of each machine), the next step was planning the pipe run(s).

It was a bit of a debate, but I have finally decided to run the tubing at ground level. It means the extractor doesn’t have to work so hard, lifting the dust and shavings the 2.5 meters off the floor, in addition to overcoming the friction from the walls. Given the tool layout, it won’t cause me any undue grievance loosing that small amount of floorspace behind each tool against the wall.

I haven’t gotten very far – balancing shed time with work time and family time (especially when everyone is sick). But at least it feels like a good start.

Here’s a pic of about as far as I’ve gotten (I said I didn’t get far).

What is shown here is the right side of the machinery area (against the front wall). Each machine is connected in via flexible tubing, and a blast gate. The blast gate on each machine is obviously so I can shut off all the other machines to maximise the flowrate from the one currently being operated. The modified T section has 2 advantages. Firstly, it isn’t a straight T section – it is angled to minimise the losses from forcing the dust through a tight 90 degree corner. Secondly, it provides an inlet so any blockages can be cleared relatively easily.

I am planning to add an extra length of flex into that end so I can make a temporary run to the thicknesser when required.

The second one is not ideal, but is only to draw a (relatively) small amount of generated light dust from two sanders (the belt & disk and the spindle sander). The belt & disk also does its own active dust extraction, feeding into the tube, so it ‘should’ help.

Next job – the router table.

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