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.

 

RapidAir Fittings

There are 2 main fittings used in the RapidAir system (not counting those that screw into the aluminium mounting blocks).

There are L fittings

& T fittings

There are also L fittings with a 3/5″ threaded end

These are useful to screw into the manifold, and for attaching fittings to convert the system to fit standard air fittings, such as Nitto. You may need an adapter to resize the thread from 3/8″ to 1/4″. These are easily sourced from Masters in those awesome drawers in the bolt section.

The fittings have mounting points so they can be screwed to the structure

And failing that (or for longer hose runs) there are hose clips

Add all that together allows some pretty sophisticated layouts, very easily

SSYTC065 RapidAir Installation Update

Most of the system is now in place and connected up, just need a few extra connectors to finish it off.

Have shot this quick walking tour so you can see the setup that I have put in place.

As mentioned, the system is sourced through Professional Woodworkers Supplies, and it makes it very easy to create a professional looking setup around the workshop.

RapidAir

As indicated in my previous post, I have begun installing the RapidAir system around the workshop.

It is as easy as the product suggests to create a comprehensive pneumatic system around the workshop.

After preparing each of the outlets (which realistically didn’t take a lot of time), I began mounting these around the workshop.  Each set up with the inlet from the top, and drain at the bottom.  The plan is to run a ring-mail around at roof level (the underside of the mezzanine), and by using a T piece, drop down to each outlet.  The manifold has three outlets, one will feed a local outlet, the other two will supply the ring-main.

After mounting the outlets (and deciding that 2 more would properly finish the setup), I started connecting the tubing.  It is pretty rigid, so although it means it isn’t designed to go around corners (that is what L connectors are for), it does mean that each run is able to be done neatly, easily creating a professional-looking (and functioning) setup.

The tubing is easily cut square using the provided cutter

As mentioned, there are T and L connectors, combinations of which provide the different configurations required.

The tubes happen to still be hanging in free space, as I haven’t secured them in position with clips while I finalise the layout.

I will change the configuration of the manifold slightly, so the standard nitto fitting from the air compressor can plug straight in.

Proceeding very easily- another installation session will pretty much see it done.

Threading Up

Spent the time while watching the Melbourne F1 Grand Prix (well done Daniel!), getting the outlets for the RapidAir (from Professional Woodworkers Supplies) all threaded up, with thread sealant rather than Teflon tape.

Probably the slowest part of the whole install!

There are 7 outlets set up identically (capped off rear inlet, front outlet, air inlet at top, drain at bottom), 1 which is for the mezzanine (capped off rear inlet, capped off top inlet, air in from the bottom and front outlet- no drain so lower outlets will have to be the reservoir), and one manifold, with all 4 ports with a hose connector.

Next job is to physically mount the outlets in the shed.

Compressed Air Supply

Compressed air and woodworking definitely go hand-in-hand.  There is a whole collection of air tools to use, and they are typically quite a bit cheaper than their electric powered equivalent machines as the energy conversion from electricity to mechanical is done by a single machine (air compressor) rather than each and every tool doing the same (there is a small step of converting the potential energy in the compressed air to mechanical kinetic, but that is pretty simple).

That concept does harp back to the workshops of old, with line drive, belts and pulleys etc, but compressed air is a lot easier to move around the workshop!

Other than nail guns, impact wrenches, sanders etc, there is always the convenience of a burst of compressed air to clean out a cut, clean off a tool, and even to sweep the workshop floor!  I also have a few vacuum clamps that use compressed air to generate significant grip on the component. (Using a venturi effect to produce low pressure, then the atmospheric pressure does the rest).

Getting air around the workshop can either be with long hoses, or in my case I am going to use the RapidAir setup from Professional Woodworkers Supplies.

The initial kit provides the tubing, and a bunch of quick-connectors, so running it around the workshop is a ‘breeze’

After running what will effectively be a pneumatic ring main around the workshop, at strategic points there will be individual tap points, to plug the tool straight in.

These come with the valve, and aluminium mounting block, so will fit in very well with the workshop layout.

This is an approximate layout for the air run, with the air compressor in a shed near the top right corner.  The red squares are air outlets, the circle is an air outlet then connected to a hose reel (which then allows air to be used elsewhere in the back yard)

I might put an outlet up on the mezzanine, and probably one by the drill press.

The ring main then allows a balance of air to each outlet (especially if there is more than one demand on the circuit at the same time), and for others to be easily added for future design changes or needs.

Will probably start installation next weekend.

Rediscovering tools

Back in the dim depths of the past, when there was still a company called GMC, selling cheap Chinese-made tools, I bought an air compressor.

It was a direct drive, GMC 40L air compressor, and I thought it might be useful in the workshop, but I wasn’t sure – the compressed air for cleaning up sounded promising.  Well that was then.

These days, I am convinced that compressed air is a great resource for any workshop, and even so I am not maximising how much I could use it. I have used it to clean up (compressed air), inflate basketballs, pool toys.  The impact driver to free rusted bolts from reclaimed timber, and nail guns obviously, large and small.

The one tool that came in the various kits of cheap air tools that I have never used is the paint/finish sprayer.  With 30 metres of lattice to paint (15 m double sided), spraying was definitely the method of choice.  My (budget) HVLP paint sprayer was missing the pickup nozzle (haven’t used it for a few years), so decided to try the paint spray attachment. (Similar to the one pictured)

Worked really well – perhaps not surprisingly, but I shouldn’t have been ignoring it for so long – would make an interesting finish applicator.  (I have 2, so one dedicated to paint and one to wood finishes is easy enough to prevent cross-contamination).

It was a hot day, and although I had thinned the paint right down, it became increasingly difficult as the day progressed.  A few blockages as the paint inside the container dried on the walls, then some flaking off blocked the jet.  The paint that I had watered down (thinned for spraying) was trying to form a skin, so I used a kitchen sieve to capture any lumps of paint as I refilled the container.    The 40L air compressor really struggled to keep up – I could have finished the job in half the time (or better) if the compressor had a larger reservoir, and/or refilled faster.

The heat of the day really did play a part, not only on the paint and the tools, but on me as well.  Hydration only goes so far, I needed to keep the sun under control.  A hat is fine, sunscreen as well, but I needed to really get the sun off me, and my solution would have made Ford Prefect proud.

Still, I am impressed with the air compressor – I have shown it no love for the years it has been languishing in the back shed, pumping away without care or maintenance.  The last time I emptied the tank of water condensation, about 20L of water came out!  I am constantly amazed the whole thing hasn’t failed years ago, but it keeps pumping away.  It wasn’t until near the end of the day that I remembered the compressor was still buried in all that sawdust from the failed dust bag.  When it does finally give up the ghost, I will replace it with a serious compressor with a decent reservoir, but until then, it can keep pumping away!

Back to the spraying, and it really got difficult – it was spluttering, bursting (as in a puff of paint, then just air, then paint), and often spraying so little paint that I was painting with air.  It wasn’t until late in the piece that I realised what was happening.  After the first few fills of the container, paint was building around the upper edge and lid, and it became (semi) airtight.  The air was blowing, but without atmospheric air pressure inside the container, no paint was being drawn up!  I solved it temporarily by opening and closing the container regularly, and finished the job, but in the long term it will need a hole drilled.

But despite the setbacks, and the lessons learned, it worked, and the lattice got painted.  And my sprayer finally got commissioned – only been about 10 years!

Wearing pleats in the workshop

As a general rule, wearing pleats in the workshop is not the best idea. Other than being just a little too frilly to be shed-like, you’d get a lot of really weird looks from visitors!

Of course, there is a place for pleats in the workshop, and that is in the cartridge of the dust extractor. So why would something frilly be a practical accessory in the workshop?

Many dust extractors use a cloth bag. Cloth bags are great. They are cheap, which is great. They are easy to clean, which is great. And they are great at spreading as much fine dust as you’d ever not want to see around the workshop. Sure, the large stuff gets captured, but that is stuff you can sweep up with a broom and shovel, so one way or the other it is easy to dispose of. The fine stuff will get you every time. In Australia, all wood dust is regarded as carcinogenic.

Many cheap dust extractors would have a cloth bag at the top and bottom. Awesome – two cloth bags to let the dust fly!

It is probably not fair to badmouth cloth bags too much – reasonable ones are running 5 micron, which isn’t much worse than what a pleated filter can achieve anyway.

So what is the advantage of a pleated filter?

A dust extractor pushes through a certain quantity of air. And what goes in, must come out. If you have a cloth bag, the air that leaks through the holes in the cloth to equal the amount of air that is sucked in the hose. As the holes clog, the total amount of air that will flow will decrease. So a filter that is easy to clean is an important consideration. Cloth bags can be banged out, blown out with compressed air, even washed in the washing machine. The limiting factor though, is the total surface area of the filter (the bag).

If you increase the surface area, the total amount of air that will need to pass through doesn’t change, so as the surface area is bigger, the holes can be smaller and still achieve the same through-put of air.

Where it comes to cleaning, pleated filters have a system where you wind or move a handle, that causes the internal baffles to be impacted, dislodging dust and allowing it to fall into the lower half (collection) for the extractor.

Pleated filters used to be only available on expensive dust extractors, but these days you can pick one up to retro-fit to your machine for under $180.

Considering a cloth bag replacement is around the $80 mark, this is a viable, and a superior option.

Even so, in saying that, any dust extractor that is allowing particles back into the workshop environment is not ideally placed. I get a bit of flack on here about my preference in not having the dust extractor in the main shed, but then I’m not breathing air that has been filtered to allow the lightest particles to remain. Once the dust-ladened air is removed, it doesn’t matter how fine the filter is.

However, when used in combination with a good air filter you can get the dust collection, and the air quality you are looking for, or at least closer to achieving the ideal.

So if you have a cloth-bagged dust collector, consider the pleat as a desirable fashion accessory, that is also a desirable feature improvement!

Episode 88 Pneumatics in the Workshop

Episode 88 Pneumatics in the Workshop

A brief discussion of compressed air in the workshop, and a look at a very flexible option!

Crossing off the list

Had a mate drop in on the weekend, and we were able to cross a couple of items off the shed’s to do list.

We hung the Carbatec Air Filter (finally), and although it is not an ideal location for optimum performance, given the size of the shed, everything has to be a compromise.  Still, it is the dustier end of the shed, and with a fan placed in the opposite corner to encourage air movement towards the filter, I think it will do a pretty good job.  It certainly seemed to be working, even when it wasn’t plugged in…….

At least where it is, it is not intruding on my working area, and the noise level is very low.  In a very short time I forgot it was even running, so it is not going to negatively impact on my shed time.

With the combination of it, and the dust extraction system I found my nasal passages and lungs were a lot happier at the end of a day of dust generating activities!

The other (minor) bit was getting to hang the air hose reel (seen in the corner).  Given the length of hose, it can reach all areas of the shed from there (and well beyond).  As I have mentioned in the past, compressed air is a real asset in a woodworking workshop, from powering equipment to simply blowing dust off the tools etc.  The air compressor itself is in the small shed next door along with the dust extractor, so I don’t have to put up with the noise they generate.