Commissioned!

With a little more time, and some minor changes to the layout once the dust extractor was relocated to the mezzanine, the dust extraction ducting was finished.

At least the first stage!

Stage 1 – connect up a functional dust extraction run from each of the main machines to the dust extractor, with blast gates isolating each machine.

Further work to be done as time, energy and motivation permits:

Modify base of dust extractor so it fits properly in the available space.  This may also involve shortening the legs by a couple of inches to assist with clearances (to be assessed).

Capture dust from the tablesaw dust guard.

Improve (straighten) path from thicknesser to vertical ducting.

Break into existing ducting to add a run towards the wood turning area.  Includes a pickup from the bench for the bench-mounted tools, and a quick coupling connector for the superflex hosing for cleanups.

Set up extraction as appropriate from the lathes.

Increase diameter of trunking from the dust extractor along the main run to 6″

Add a cyclone separator if possible.

The Super Dust Deputy is $US239, or $A626 for the metal version.

Alternately, the latest version has a standard size, or an XL size for larger HP extractors.

Not sure if and when they will be available in Oz, but they cost $US239 for the XL version, and $US169 for the standard version. It will be interesting to see how the price compares.

Things get worse before they get better

The workshop certainly is an apt demonstration of that point at the moment!

Started off the weekend with the workshop being a little messy, after last week’s rush build to get the magazine articles finished.  Ended the weekend with it looking like a bomb site.

So what went wrong?  Nothing!

It was just time to finish off a job that I started almost two years ago, and has been notably absent from the current workshop: a fully functioning dust extraction system.

For the past 8 months, I have been working with a flexible hose running from the dust extractor, through a door and across the floor to whichever machine I am using at the time (although primarily focused on the jointer and thicknesser, so the other tools have been venting free).

Decided this weekend to do something about recommissioning a fully laid out system, given the machines seem to have migrated to relatively stable positions in the workshop.

I’ve had all the odd lengths of pipe, tube, hose and fittings sitting aside from the previous workshop (and the collection above is a small portion of what came out of the previous shop), so that is where I started – working on the complex areas of the dust extraction.  The combined area around the tablesaw, jointer, thicknesser and bandsaw, which are all in close proximity (particularly where the dust ports from each machine are involved).

It took a bit of trial and error, but I am pleased how it came together.  It is a bit hard to show it looking anything but a mess, but it looks better than the current photos!

One day, I’d be tempted by the metal dust extraction system, but that is an upgrade for the future (if ever).  At the moment, simply having each machine connected to the dust extractor, with blast gates isolating each is the plan.

So far, the bandsaw comes in the bottom (with two hoses, one from the bottom of the bandsaw, and one from just beneath the table), then the tablesaw.  I haven’t worked out how I want to have the tablesaw dust guard connected in yet, but I am still thinking the genuine SawStop solution looks to be an attractive option.

There is a port visible that has nothing connected – I have placed a quickconnect port on there, so can easily connect the super-flexible hose with the floor sweeper when I do need additional cleanup.

I have the run overhead towards the dust collector, but that run isn’t finished yet.  I still need to drop it down, past (and pick up) the outlets from the second bandsaw, drum sander and Torque Workcentre.

The run continues to the other side of the shed, then drops down to the router table and drill press.  The run then continues (smaller diameter) to the Kapex

Still to work out how I am going to pick up an outlet near the lathes, I might have to cut into the run I have just completed by the looks.  Oh well, better done as right as I can.

Some work still to go – another day should knock it off, so long as I have all the parts I need (so better I plan ahead).

 

Stu’s Shed is moving!

Sorry about the delay in posts in the last couple of days, but I’ve been a bit distracted.

Just to add to workloads, early in the new year we are relocating (confirmed today), and Stu’s Shed will be relocating at the same time.  Just what I need: more work!  What this will mean for the physical shed is a bit unknown – at the moment the new property has a 3mx3m, and I just don’t see downsizing from 41m² to 9m² is a viable option!  So the 36m² double garage will have to do until a new shed can be built.

There will be some good out of all this I’m sure.  I will be aiming for the new shed to be closer to 60m², and with greater head height than current.  A lot of the ideas over the years can be built in – better dust extraction concepts, better layouts (in general, and also for filming), better storage.

One thing I am trying to ignore at the moment though – just how do you move such a significant amount of machinery?!!

Around the Corner

Another small window, another small amount of progress on the re-configuration of the dust collection.

Bracket

At the end of the tablesaw, I finished with a coupling, so the tablesaw can be detached at any time if moving it is ever required. To hold up that end, I decided to make my own support, which is nothing more than a hose clamp (90-120mm) riveted to a bracket.  This in turn is bolted to the end of the tablesaw fence.  Easy to remove/replace, undo, and it swivels around the rivet.  Holds firm too 🙂

Flex Coupling

Next, I used a piece of flexible hose (reasonably compressed) to get around the corner, but also provide a very flexible coupling in case of any movement of the tablesaw – saves breakages/failures of hangers etc.

The duct tape is to seal against air leaks leading to a drop in suction.

Transitions

Moving from the PVC downpipe, to a short piece of flex, into the new clear tube run, then into one of the new blast gates.  As you can see, I’ve already made my standard modification – a hole drilled into each bottom corner for sawdust clearance.  The gate is held in another of the Rockler blast gate mounts.  They are very cool, simple, and cheap.  Why they are not in Australia makes no sense to me.

Of course, why the Taiwanese cannot design a blast gate that doesn’t clog is also beyond me. How hard is it to get some basic engineering right?  Not like it isn’t a commonly experienced flaw with the design – don’t they use the stuff they design, or listen to feedback?  The fix is so simple – 2 x 13mm holes.

Around the bend

So here is the result of the latest session.  From the left is the duct to the tablesaw.  From above is the extraction from the dust guard (a new blast gate will be put at the quick release coupling directly above the guard).And from there, it is off to the transparent dust trunking, and to the next tool (which happens to be the thicknesser, and the drum sander) before exiting the main shed and over to the dust extraction unit.

I’m debating running a secondary pipe over from the bandsaw (probably), and potentially also from the lathe.  I’d like to do the jointer, but don’t think the extraction unit would cope with the amount generated by that unit, having to lift it over 6 feet in addition to the distance to the extractor itself.  I’ll test it, but not holding out much hope.

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

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

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

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

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).

More on Dust Collection

I’ve been doing quite a bit of research and reading on the topic over the course of the day, and the amount of information out there is huge, somewhat conflicting, and the bottom line on it, is the problem is not particularly straightforward.  So much for finding a simple answer.

Some of the things I have been determining are:

a large pipe size for the main trunk line would be best.  Whether I am prepared to increase the size of the pipe run I currently have is a difficult question.  There is a definite cost element there, although the pipe I have could be redeployed to a water catchment system I have wanted to do for ages, so that may be an option.

the flexible pipe that is typically sold for dust extraction is really inappropriate for long runs, and at best should only be used (as I have) between the machine and the main trunk line.  It is not smooth inside, so that dramatically increases the friction in the pipe, significantly affecting performance.

the flexible section I was using at the end of the main trunk to connect to the DC is a bad idea, so moving the DC is probably the most sensible, and perhaps erecting some noise damping is the best compromise.

keeping the pleated filter as clean as possible will really affect collection performance.

you can overdo the amount the motor can pull – in other words, if you run the collector pulling too much air (too large a pipe, and/or venting without collecting, you can result in the motor drawing too many amps and burning out.  Still getting my head around that one – something is not quite clicking on the logic states.

Improving Dust Collection Efficiency

When installing a dust collection system, you’ve spent good money on the biggest collector you can afford, and then are trying to get it to maximise its range to collect from as many machines as possible over the longest distance needed to maintain the shop’s machine layout.

One very common aspect of this is to install blast gates so that machines that are not currently being used are not unnecessarily having air drawn from them, decreasing the amount of suction at the tool in use.  There are a number of different blast gates available, with one of the most common ones on the market being the plastic 4″ – 4″ blast gate.  They are a low cost solution that seemingly works well in shops across the country, and world (I guess).

Don’t know who designed the original, that is now so often copied, but all I can say is…. it’s bloody stupid!

The problem: the bottom corners of the gate (in the channel where the gate itself slides) quickly get filled with crap, and once that happens and the shavings / dust etc get packed in there, the gate cannot ever close properly again, leaving a permanent leak through every gate that is (theoretically) closed.

Original, Clogged Blast Gate

Here is a very typical blast gate, and in the very typical state of being so blocked in the lower corners that this is as much as it can close.  Looking at the opening this leaves, you can see that it wouldn’t take too many gates in this state that the amount of leakage would add up to being the equivalent of a fully open gate. A complete waste of suction.

One tip I’ve come across in the past, is to cut off those lower two corners, so the gate effectively becomes self-cleaning.  When the gate is closed, the slide blocks the resulting holes.  When it is open, there is a minor additional leakage caused, but nothing like the loss from a single, unmodified closed gate.

Modified, and properly closed again

Here you can see the protruding corners of the blast gate slide.

Exposed corner

And the small hole that now exists in the corners.

I’m not sure if this mod is the best way (or the neatest) – I’m sure I saw (or at least read) about this mod in a mgazine somewhere!

So that is the basic concept to the modification, and it does work.  However, it isn’t the neatest version, and so my amendment to the concept is to drill the corners out, allowing the slide to continue to push dust clear, but better maintaining the overall physical (and visual) integrity of the blast gate.

During the drilling of the corner, the dust that is packed in the corner is immediately apparent.

Dust Packed Corner

I’m much happier with this second version.  Also because it is my take on the idea, rather than a copy of someone else’s (although I’ll be stunned stupid if I’m the only one to have ever thought of it!!)

Modified Blast Gate (V2)

Dust Extractor Efficiency

I’ve done some preliminary proof-of-concept testing to see if the anemometer I’ve bought is going to provide the sorts of readings that will be useful, and valid.

The anemometer I have can provide airflow rates from 1m/s to 30m/s (200ft/m to 6000ft/m)  When used to measure flow rates in 4″ trunking, this equates to 14cfm to 425cfm (given that dust extractors all seem to be sold with their cfm listed).

My initial trial was using a 1HP / 750W GMC portable dust extractor, with a rated flow rate of 470cfm. My first trial gave a flowrate of 26.7 m/s, or 377cfm. So that seems to validate the initial test (assuming my maths stacks up), but it does seem to reveal a couple of things.  Firstly, the rated airflow of this dust extractor seems to be 20% higher than as tested, and secondly, this isn’t even with the resistance back pressure of the dust bag.  I’m sure when they supplied the flowrate, they assumed you wouldn’t ever actually use the unit with a pointless dust collection bag.

Dust Extractor and Concertina Hose

Next, I tested the airspeed with a concertina hose attached – 650mm compacted.  The airflow dropped to 346cfm, or a loss of 8%.

Then I expanded the concertina hose to its full 2650mm length, and tested again. The airflow dropped again to 274cfm- a loss of 21% over having the concertina hose closed up.  This demonstrates that there appears to be a reasonable correlation between performance and resistance.

Concertina Hose Expanded

Finally, I coiled the expanded hose through 1x 360 degree loop, and got 195cfm (29% loss over straight hose). So the initial tests seem to hold true.

Next, I tried testing the output airflow from the air cleaner.  The first test was with the filters in place, and not cleaned, and got 8.3m/s  After cleaning the filters (simply banging the dust out), the airflow increased 14% to 9.45m/s  This may be a useful figure in the future – assuming the filter was reasonably clogged at the point I ran this trial, I could in future quickly test the output airflow, and use this figure to determine if the filter needs cleaning.

My main dust extractor is rated for 1200cfm, so well above the max rating of the anemometer.  By the time it gets through all the tubes to the machines, that will probably have dropped well into the range of the anemometer.

My next set of tests will be about real-life dust extraction runs.  I want to know just how expensive (on performance) a 90 degree turn costs, a metre of tubing, the difference between a metre of smooth pipe vs flexible dust pipe, the flow rate loss when reducing pipe size from 4″ to 1″ etc. Finally, it will mean that I will be able to test the condition of the pipes – whether they are getting clogged with uncleared sawdust (woodwork cholesterol).

Episode 31 Tour of Dust Extraction

Another few metres

Had another 40 minutes or so available tonight, so got a few more metres of the dust system built. The right side of the system is now coupled up to a T intersection that leads through the shed wall to the dust extractor. It meant I had a chance to block the other outlet and fire up the dust extractor for the first time in ages. (I have run it since decommissioning the original system, but only through temporary tubing). Didn’t put much, if any, dust through, but wanted to have it run anyway.

Next, on the second leg (left hand side) of the system I placed another T intersection which was fitted with a straight pipe (vertical) that ended with a blast gate, and a splitter so two 1″ hoses can lead to the drill press table. The bandsaw was also fitted with hose and a blast gate, so now there is only “deep throat” (for the lathe), and the tablesaw to go.