Approaching milestones

The site is approaching a couple of milestones, picking up net additional followers each week.

Not sure which will be first (and they are related).  The first is being about 50 off having 2000 followers overall.

This is made up of direct subscribers (email and WordPress blog followers), Twitter (which is already over 1000, and not surprising given the rich content that Twitter now displays), and Facebook.

Facebook is the other milestone, now only 30 off 500 followers of Stu’s Shed.

The 2000 is a bit arbitrary, as there are over 240 RSS followers which are not counted, and I have no idea how many iTunes followers.

Vac in a bucket

Take 2

With the vac stuffed unceremoniously into a rubbish bin, with acoustic absorbing material all round. Sides, base and top.

A gap at the back for the motor cooling air to escape, and the silencer sticking out the top, new measured sound level: 79dB

  
Likelihood of the vac dying prematurely due to overheating? Probably now at 85%!

But at least it is quieter!

Get inspired

Some of the recent ads by Toolstoday.com look pretty good to me! (And yes, I provided them the photos so they used them with permission).

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I know there have been one or two others, but haven’t been able to find them.

The designs (plans) came from makecnc.com

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.

AT102-4

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!)

Photo 29-08-2015 11 38 46

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.

Photo 28-08-2015 08 54 03

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

Y

 

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!

DBGULP

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

557867-DC-2900_1Looks 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.

 

Solent Mk4

With its roots firmly entwined in a WWII aircraft (the Short Sunderland) that combated German U Boats and was in combat in the Korean war, the Short Solent was operated as a civilian carrier in Australasia, the UK and the USA in the late 40’s and 50’s.

This model, from MakeCNC.com has been, without question, the most complicated build that I have assembled so far.  224 individual parts may not be the most of any model (not that I have been counting), but the assembly took a couple of nights.  And plenty of glue.  The hot glue gun is proving particularly useful for these models.

Made from 3mm MDF, using the #45190, 1/16th straight router bit from Toolstoday.com on the TorqueCNC.

SolentPhoto by Kara Rasmanis

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