Fitting a silencer

Thought I’d try out one of the exhaust silencers on the ShopVac to see what difference it could possibly make.

The design is pretty basic – a tube with an opening and exit the diameter of the exhaust of the vac, and a wider diameter between with a foam tube inside.

When fitted to the outlet of the ShopVac, there was a noticeable difference, although not particularly significant.  The noise is more the motor than the exhaust it seems.  Nor does the silencer work particularly well in its as-supplied state.

And yes, given how simple the design is, you could easily make one at home.

What I am thinking is to block the outlet, and cut slots around the circumference instead, and see if that makes more difference. I’ll research that another time.

Out of interest, I measured the sound levels in the workshop.

Outside (at the time): 40dB
Inside workshop: 38dB
1m from Sherwood dust extractor: 77dB
1m from ShopVac (no silencer): 86.5dB
1m from ShopVac (silencer): 84dB

 

Litres of dust

Picked up the cyclone separator from Hare & Forbes as Phil suggested (thanks again for letting me know about it!)

It is quite reasonable quality – I’m happy with it. Has a window to sight when the bag is full, and it can take a plastic bag as well.  You would normally expect the bag would be sucked up into the cyclone, but there is a secondary hose to the base of the collection bin, so some of the suction pulls a vacuum under the bag and holds it in place, until the weight of dust can take over.  This doesn’t cause any loss in power – once the bag is sucked down no further air will leak past so this doesn’t sacrifice any performance.

So working from the dust extractor out.

The extractor inlet is 8″.  This is pretty phenomenal, and at full power can really suck your hand against the grate.

I have sourced an 8″ to 2x 6″ Y piece, but not from your normal expected suppliers.  I couldn’t find anything 8″ from the normal woodworking suppliers, but found a hydroponics supplier in NSW that had exactly what I wanted, and at a really good price.  For $30 (+$12 delivery), I got a galv metal Y piece.

The equivalent from one of the woodworking suppliers has a 200mm (8″) to 2x 5″, for $110.

 

The outlet for the cyclone is 180mm, so close enough to 8″.  It comes with a reducer to 6″.  I haven’t been able to find any 8″ hose, so am contemplating running dual 6″ from the cyclone to the extractor.  Either that, or I have a spare 6″ inlet for the extractor going to waste.

Until I get the 6″ pipe, I am currently running dual 4″ from the cyclone to the extractor, via a Y piece at either end.

The inlet to the cyclone is 6″, and it comes with a 6″ to 2x 4″ Y piece.  I have currently connected it to my 4″ pipe run, so performance is down at every transition.  (Effectively I have reduced the 8″ inlet for the extractor all the way down to 1x 4″, so not ideal!)

Fired it up, and fine dust does manage to get through to the filter bags, but I don’t have a problem with that – the cyclone is there for bulk material separation in this case.  The smaller cyclones I use separate everything, and even fine dust doesn’t get through, but this is not a cyclone for that purpose.

In saying that, I sucked up about 100L of sawdust, primarily MDF, and about 500ml managed to find its way into the collection bags of the dust extractor.  It is much easier to empty the bin of the cyclone than remove the bags from the extractor, so this will make a lot of difference.

I am still contemplating where the extractor and cyclone will sit – it might need another small (and tall) external enclosure – will give that more thought.

Compare the cost of this setup though, to a dedicated cyclone extractor.  That has 2200cfm through 3x 4″ inlets, and costs $3300.  I don’t know what flowrate I am getting through the cyclone, how much it is reduced from the 2900cfm of the extractor, but total cost: $1285.

I still want to boost the overall performance, and either 8″ to the cyclone or 2x 6″ will help, but no matter what, you can only suck so much through a 4″ pipe that connects to the machine.

Deep throat revisited

It is actually called a Big Gulp, but got your attention!

I got this hood back in 2008, with the idea of using it on the lathe.  I never really was able to get it working well enough for me – just not enough draw from the dust extractor.

Think I might have just solved that problem.

This is the dust extractor I have just purchased, from Timbecon

Looks small in the picture, but it is quite the monster.  3HP, 2900cfm, 22.5″H₂O static pressure.  8″ inlet, 400L of dust collection capacity. $900.

I was watching a timelapse I made of a process on the CNC, and I’d occasionally come in with a shot of compressed air to keep the working area clean.  Occurred to me that this would be right where the big gulp would come into its own – firstly sitting behind the CNC, drawing air and therefore any airborne particles away from the cutter, the workshop, and me.  And secondly, to catch any and all dust that gets sprayed back when I do use the compressed air.

You may wonder why I don’t have collection right at the cutter –  two reasons.  Firstly, I don’t want to pull the small parts up and out from where they are cut during nesting operations (particularly when they are only held down by the vacuum table), and secondly, it gets in the way of the camera!  I still have a lot of refinement to go, but these sorts of things are popping into my head now the issue of dust extractor power has been taken care of.

Given I also now have capacity spare in the dust extractor (as mentioned, it can take 1×8″ (200mm) in, which is the same cross section as 4×4″ tubes simultaneously.  Using anything less than 4 is only restricting flow, it doesn’t mean that the one or two being used are suddenly given a huge power boost (sadly)), I can plan to do some simultaneous collecting – such as one collecting on, or near the tool and one down at floor level where shaving accumulate/can be swept (or kicked) towards etc.  If I don’t close the blast gates to every tool other than the one being used, that won’t cause a real problem either.  It is going to take a bit of planning to reroute the dust extraction system to maximise the flowrate, even if that means running a much larger trunk line, or dual smaller lines across the workshop.  Who would have thought a 4″ (100mm) pipe would be regarded as a smaller line?!

One thing I am going to work on, is positioning the dust extractor in one of the storage areas I have alongside the main shed, so I don’t loose any valuable floorspace in the main shed, and minimise noise (not that the unit is particularly noisy).  The unit is 2600mm high (mostly those bags), so I will have to work out how to make it work with a lot less head-room.  The main workshop has no trouble with that height, and even a lower roof would be ok (the bags could just press against the roof – it would decrease overall airflow, but not massively).  However, where I have to put it, this may prove a real test.  What I will need to do is come up with a way to allow that much air to pass through something that has a lot less overall height.  Pleated filters may work (increased surface area because of the pleats means less overall height required), but I want to see what else I can come up with.  Ballooning bags perhaps?  (same surface area, larger diameter, and therefore less height).

The other ‘issue’ I see, is drawing that much air out of a workshop draws the same amount of air in from outside.  Where it could be really hot (summer) or cold (winter) – neither of which is desirable.  So instead, my thought is to place a filtered vent from the area the extractor is stored back into the main workshop.  That way the shop air is recirculated, not lost.  So long as I am not then pumping micron-sized particles back into the workshop (which is what filters are for), I don’t see this would be a particular problem.

Watching the timelapse, I see a huge amount of sawdust on the floor of the workshop (bad collection practices).  I think that will become more and more an issue of the past.

 

Dust Control

Dust really is an insidious pest in the workshop.  Whether it is the heavier shavings created from bulk material removal, down to the finest particles that can remain airborne for hours, days, even weeks.

I know for a fact that I don’t do enough to contain dust at either end of the spectrum.

The reasons for and against may be a bit of a seesaw of justifications, but if I was to be honest, I don’t think that the seesaw is well balanced, or particularly justifiable for what I have on one side, versus the other.

So on the first side, I have

cost
noise
laziness
complacency
convenience

See what I mean, other than cost, and noise (particularly at night when it is often the only time I get to do anything out there, and I can’t afford to antagonise the neighbours) there are no really compelling reasons against doing something about it.

On the other side of the seesaw, I have

safety – (lungs)
safety – (slippery floor)
lost tools
increase in rust of tool surfaces
potential damage to finishes
untidy working environment

I am sure there may be a few more examples for both sides, but they would follow the same trend.

Cost is a bit of a bugbear, I will admit.  You need a good extractor to get the required performance – not only in the amount being extracted, and the distance it is pulling the dust from, but also in the performance of the filters.

Not much point extracting dust from the point of generation if you are only going to pump the most harmful portion straight back into the workshop atmosphere (dust below 1 micron in size that is).

My existing at-tool dust extraction is good in theory, but in practice I know that I am expecting too much of the current dust extractor – the distance I am trying to get it to draw over is far too great for it to be efficient.  There are a couple of options- decrease the distance, or increase the power.

So I’m thinking of doing both.

If I relocate the current 2HP TruPro extractor to the back of the timber store shed, it can just service the lathe/CNC area of the shed.  A new 3HP dust extractor would then be plugged into the existing extraction ducting.

Interesting idea, so I’ve been researching what is out there in the way of large dust extractors.

First thought – Powermatic. a 3HP extractor is $2000.  Other than it being a traditional design (as opposed to a cyclone), this would be a gold-plated solution.

A Carbatec cyclone is $3200, but is too tall for my current location (not that a redesign of the layout is impossible).  Getting pretty pricy – Like you can almost get a SawStop for that sort of money, and I think there is just a bit more build quality and technology in a SawStop than a dust extractor.  On the other hand, a cyclone is a superior extraction solution.

Of course the Powermatic looks like a traditional bag collection system, but it does have a conical separator built into the top above each collection bag.

Another option is to put a cyclone separator in line, before whichever extractor is chosen.  At $500, it is a lot of money for some rolled steel.

Given Timbecon now have a store in Melbourne, thought I’d check out online what they might have.

First thing that caught my eye – their 3HP 2 bag extractor…..$500.  Say what?  Even if you take the pleated filter option (which is mandatory personally – a cloth bag is a dust pump, not a dust extractor) it is $1000.  I’m not a fan of Sherwood Orange, but that price can make one choose to be colourblind.

I need to get more information though – there wasn’t any detail on their site to be able to accurately compare it to other machines out there.  They also apparently have a cyclone extractor, so it will be interesting to get more detail of that too.  Guess a roadtrip to north Melbourne will be in my near future.

One other aspect that I am seriously considering, is being able to accurately assess the air quality in the shed.

There is the Dylos unit that can detect down to 0.5 micron (and can be set to alarm if the dust concentration passes certain thresholds)  I haven’t found anything else that competes with that for price/performance yet – if anyone knows of something, I’d be interested to know.  The Dylos Pro is $US260

 

Mindfulness and the workshop

Circle around various corporate entities, and you’ll find the term “Mindfulness” cropping up more and more, as the latest trend takes increasing hold.

Now I say that in somewhat irreverent terms, but without any real intent.

I am not really on strong terms with mindfulness yet, there are many long courses all about it, but what strikes me early, is this concept of being in the moment.

Many of us drive to work each day, and yet can’t remember how we actually got there. We are walking around the house, put down our keys, and cannot remember for the life of us where they are a little later on.

These (and many others) are perfect examples of taking actions without being mindful.  Being in the moment, actually tasting the food we are eating, focusing on the activity, being particularly aware of what we are doing, not just going through the motions without concentration, without being mindful.

It got me thinking about the shed.  Some of what we do out there is without real thought – cleaning up for example, yet daydreaming (or just not concentrating).  Yet a lot of what we do, especially while working in the shed had better be very mindful, or you might find yourself fingerless, or worse.

To turn that around, I find that the shed activities really do focus the mind.  You cannot have random thoughts bubble up and become a distraction, and the activities really allow you to concentrate intensely on the task at hand.  It is like a form of meditation, and why I find I feel really refreshed after a good session out in the workshop.  Better than sitting around with your eyes closed, focusing on breathing and saying “Om”!

When I am shaping wood, solving design questions, cutting, planing, joining, gluing, polishing, there is no room for abstract thoughts, distracting thoughts, and problems at work and other stressors do not get a look in.

That is not always the case unfortunately. When having an unsuccessful day, it either allows an opportunity for these external pressures to creep in, or it is because those external pressures have been there all along, and not shut down enough to allow a successful day.

The next time I am having a bit of a bad shed day, I’m going to focus a bit more on why – am I being distracted by thoughts, or just me having a bad woodworking day.  Of course, like the golf saying goes, a bad day in the shed is still better than the best day at work!

In the Firing Line

I recently met with a new owner of the SawStop, and took them through some of the specifics of the machine, including some of the basics of safe operation of a tablesaw.  As they were an experienced operator, the focus was certainly around the brake mechanism.

Six months later, and I get a call.  Turns out the SawStop mechanism got tested for real.  Scared the bejesus out of him – not only when it activated, but more fundamentally, that it happened at all.  So we are going to have another session, and this time running through the A, B, Cs of tablesaw use.

Had my own experience last weekend.  Not of the SawStop mechanism, but a reminder of basic safe operation.

I try to ensure that I am not standing directly in line with the blade when it is cutting.  That isn’t always possible, but it is a good practice, and this time was no exception.  I was standing to one side while ripping a piece of timber, and a piece of the offcut splintered from an unknown internal fault in the timber.  It got spat out by the blade, and sailed right past my ear.  Close enough for me to hear it pass by.  Close enough that I felt it brush the ear.

Reinforces why I like standing to one side while cutting!  Even if it had hit, it is unlikely to have done any damage, but it is a good reinforcement why we practice safe use.  And why eye protection is mandatory.

I finished off the cut – nothing wrong there, so the technique was fine.  It really came down to a weakness in the timber.

As much as I was out of the line of fire, it was a full-depth cut.  And while having the riving knife fitted helps protect against kickback, having the full dust guard fitted when it was appropriate for it to be used would have prevented this happening at all, at least as far as having a small missile launched in my general direction goes.

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.

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!)

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).

 

Episode 108 DadoStop!

Had a look at the blade(s) after the fact, and found out where the significant cascading sound comes from when the brake activates.  12 separate tungsten carbide teeth ripped loose of the blade.  Most presumably are due to the spacer blades not being in direct contact with the aluminium brake, so were able to move when the blade was (rapidly) decelerating, and knocked the teeth off as they slid past.

It is a good effort, stopping that much spinning steel on a dime!