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.

 

Maximising Yield – the Vacuum Table Story

For months I have been bantering around the idea of a vacuum table for the CNC router, but each time decided that screws or pins were easy enough, and the whole issue stayed in the too-hard basket.

As I have been doing quite a bit of nesting work recently, it gave me pause to thought – for a one-off, a few screws are all very well, but the combination of that, and the significant time wasting of using tabs to restrain the cut components (both drawing them, and then physically having to cut and remove them) was proving an incredible time waster.

So I finally was pushed into addressing the whole material hold-down issue.

I started doing a bit of research online, but the results were less than helpful, and I felt as a whole, a lot more complicated than necessary.  So instead, I decided to build an idea I had, and just see if it worked.

I did use the CNC for the following steps, but that is certainly not necessary, and secondly, while I am using this on the CNC router, there is absolutely no reason this cannot now be applied to other areas of woodworking.  Nor do I expect I have come up with anything novel, but in going back to first principles, hopefully I have significantly simplified the solution.

So to start, I took a thick piece of MDF (22mm or so, which I had to hand.  I would have used thicker, but the 32mm MDF I bought last time from Bunnies was only some of their promotional stock.  Not sure what they were promoting, because they don’t stock it otherwise).  With a 1/2″ ball nose router bit, I cut a matrix of tracks, 5mm deep, and about 20mm apart, both horizontally and vertically, stopping about 10mm from the edge.

Next, the edges of this board were sealed.  I know people use some edge tape, or shellac for this, but I thought PVA glue would suffice!

This board was then screwed down to the bed of the CNC machine, and a hole just big enough for the end of a vacuum hose was drilled, all the way down and right through the table.  The hose of the vacuum (connected up to a cyclone separator) was jammed into this hole from underneath.

A second thick board of MDF was laid on top of this bed, and the vacuum switched on.

Test one – does it suck? Yes it can! The first proof of concept is a winner.

Into this second board I cut the same matrix of slots.  By then flipping this board over, each of the passageways is doubled in size (adding together the bottom and top halves), and also exposes a significant area of the soft, porous core of the MDF.  Each passage is now 10mm diameter, so that gives significant passageways for the air to pass through.

The vacuum was switched on again, and the top surface of this second board (the sacrificial board) was machined away with a surfacing bit (otherwise called a spoilboard bit).  And that is what this upper board actually is – a spoilboard.  When it gets too badly cut up, it can be flattened again, and this repeated until it is too thin, when it is then thrown away and a new board takes over.  By planing away 0.5mm of the upper surface of the spoilboard, the hard, compressed (and more non-porous) upper surface is removed.

Now I have seen a number of vacuum tables, and spoilboards with a large matrix of holes drilled though it.  Don’t need it.  The core of the MDF is so porous, that the vacuum can draw air directly through the MDF.  And that in a nutshell, is my vacuum table!

Upper board (spoilboard) from underneath, and the upper surface of the lower portion of the vacuum table

Upper board (spoilboard) from underneath, and the upper surface of the lower portion of the vacuum table


vac-4

Detail of vacuum table


Vacuum connection

Vacuum connection

I’m using a basic Shopvac for this, so I do have a bit of a concern that this will shorten the life of the vac.  I possibly need a vacuum pump, but this will do in the meantime.  The cyclone separator is to try to keep as much MDF away from the vacuum, to try to stop it being killed even more prematurely.

The proof is in the trial.

With a sheet of 3mm MDF laid on top, the vacuum switched on, and voila – it sucked big time, right through the MDF.  The board to be cut was held firmly, enough to run a trail nesting job.

Without tabs.

It was a complete success.  Other than the noise of the vacuum cleaner, I could not fault the process.  The vacuum will soon find itself in the shed next to the workshop, and switched on and off with the remote power switch I happen to have in there (the actual switch is right near the CNC as it happens).

Test job, no tabs

Test job, no tabs

I cut out about 5 patterns in total, and each time it worked perfectly.

Next, I tried another idea.  If the only reason for the material between each piece is to support the piece as it is being cut, it is really necessary if the piece is supported by the vac?

So I ran a large job with a full sheet, no tabs, and only 2mm between each piece (or more precisely, between each path the CNC was trying to follow).  And 5mm from the edge.

The result?

vac-5

Yield

Pretty much nothing left, what is gone is the project, leaving this sad skeleton.

So there you have it – my poor mans successful attempt at making a vacuum table.

Beam Pump

The beam pump is one of those really simple mechanisms that have been around for donkey’s years.  They are in heavy use in the American South.sxo0redqpl_oil_and_gas 5a9b9-wideopenoil

The beam pump (like the beam engine) takes the rotary motion from the prime mover, and transfers it into a linear motion.

mediumThinking about it, a piston in a combustion engine is just a beam engine in reverse.

In the goldfields, a beam pump is one way that was used to pump water out of the mines (one of the disadvantages for mining below the water table).  A steam engine makes a good prime mover, and a counterweighted beam pump can have a significant stroke to draw water up from the deep.

At Sovereign Hill there is a working beam pump which you could almost miss, given how big it is!

SH-47 SH-64

Should have gotten some video of the beam pump itself in operation – slowly shunting back and forth.  I did have a closer look at the prime mover.  The comparatively small size of the engine just goes to show how powerful steam engines can be.

SH-50 SH-51 SH-52

Line Shaft Live

Probably the thing that I enjoy seeing more than anything else at Sovereign Hill, are all the line shaft driven machinery.  I’d love to have a workshop straight out of the 1890s.  I’d feel right at home.

This is one of the many working workshops at Sovereign Hill, powered by steam, and line shafts.

Shot by my daughter on an iPhone (without any encouragement from me – something starting to rub off?!! :) )

 

A guard for your hands and eyes

Incra are well known for their significant contributions to woodworking, particularly at the highly engineered end of the spectrum, with their precision tools (such as accurate fence positioning).

So when they bring out a new tool, it is worth taking note, so I was interested when Incra released a push block to see just what they have bought to the party.

rta_pushguard_main_zoomSold in Australia by Professional Woodworkers Supplies

The first thing that you notice is the clear shield.  It can be easily removed when the job doesn’t need it (or moreso, if it would be in the way), but for jobs that result in the cutter being exposed in particular, having added protection to prevent wayward wood chips flying in the direction of your eyes is a neat addition.

rta_pushguard_detail1_zoomThe handle is a decent size, not only so you can (just) fit two hands, but also so you can get a good positive grip on it, to control the workpiece.

Speaking of controlling the workpiece, and that is where the 178x75mm working surface comes into play, providing a decent contact area.  Often, you would want to work with two of these guards, not only further increasing the working area, but so you can further control the orientation of the workpiece relative to the tool, and prevent it twisting out from under the pushblock.

Unlike most pushblocks, the Incra one also has a double-walled ABS hand guard (grey) further protecting your rather valuable tools (hands).

rta_pushguard_detail3_zoom

I’d see a definite use for these on the router table, and the jointer particularly.  In an ideal world, I’d have 4 of these, two with the clear guard attached, and two without to cover all the jobs I’d want to use these on, without having to remove and replace the clear guard, but they are pretty easy to remove and replace even so.

Safety equipment is always something that comes secondary to the tools that allow us more capability in the workshop, but as I was told years ago when I got my motorbike license, if you can’t afford the safety equipment, you can’t afford the bike, and the same thing applies to woodworking.

Catching up on Festool

Seems that a few things have come out from Festool recently that I haven’t been across.

First is a high speed oscillating tool, the Vecturo, akin to the Fein Supercut.  It also has a Festool style price tag, but also includes some interesting developments as well, depth stops and blade stabilising.  I haven’t looked into it too far as yet, particularly any side-by-side comparisons with the Fein.

down_os_vecturoos400_563000_p_01a-setdown_os_vecturoos400_563000_a__10aOne of the interesting things in the photo above, is the plate that the blade is resting against is actually magnetic, keeping the blade from vibrating perpendicularly to the cutting oscillations, helping establish a cleaner entry slot.  This also is a depth stop for the blade.  There is another depth stop for circular type blades.

down_os_vecturoos400_563000_a__11aThese can all be removed if you want a more traditional oscillating tool setup.

The next is a redesign to the ETS 150/3 and 150/5, now the ETS EC 150/3 and 150/5

down_se_ets1503a_571870_p_07b-with-systainerThe EC refers to the EC-TEC brushless motor, so it has even more power and runs quieter. At least that would be my expectation if I get to play with one.

A new version of the dust hose, that includes a plug-it cable.  I have the older version, which I find keeps things neat when both powering the tool and extracting dust at the same time.  This version also has a material shroud for extra protection of the hose.  Interested to know if this helps with tool movement, where the external spiral of the hose can catch edges occasionally.  I’m sure the shroud wouldn’t help in the situation where I did damage a hose – doubt the shroud is designed to protect against a few hundred degrees of local heat when my hose got too close to a space heater!

down_s_d2722x35asgq_500269_z_01aFinally, although this isn’t new as such, it is an interesting storage for the various tools.  I keep dropping my sander onto the floor when I catch the hose, so the sander storage would be invaluable!

ae_ucr1000p_498966_a_04a ucr-1000And a small CT17 Cleantec, which would be quite handy connected to the Torque CNC (and overall quite a portable extractor).

zoom__s_ct17e_767992_p_01a_81

There is another small driver, called the TXS, which is seemingly replacing the CXS.  There are always so many new drills and drivers I can’t keep up!

If you are looking for more info on any of the above, have a chat with Anthony over at Ideal Tools – he’s always right across the latest developments in the Festool camp.

The Karate Kid of Sharpening Systems

wax on wax offWax on, Wax off

There are so many sharpening systems out there, it can be rather daunting.  Powered or unpowered, hollow grind or flat, single bevel or secondary micro-bevel, oil, water or dry, friable or fixed surface, open or closed grit, wax on or wax off.

I’ve come across another system recently, which has an interesting take on the process.  It is the Precision Sharpening System from M Power.

PSS1-Diamond-Cross-precision-Sharpening-System

It is based on diamond stones, and has two fixed angles 25° as a primary angle, and 30° as a secondary angle (such as for a microbevel).  The stones are exceptionally easy to change, held in place magnetically.  There are grits from 100 through to 1000 available (with the unit coming with a 220 grit and a 450 grit stone).

Where the system is somewhat different, is the direction of sharpening.  Most systems have the grinding direction in line with the chisel, where the PSS works perpendicular to the blade.  Secondly, most systems have the stone (grinding surface) stationary, and the blade is bought into contact and moved against the abrasive.  The PSS has the tool stationary, and instead the stone is bought to the tool, back and forth, creating a flat grind.

PSS1-Sharpen-small-chisel-484It is an interesting grinding direction.  Takes a little getting used to, but I can’t see that there is any particular disadvantage to the resulting tool edge.

The carriage is captive in the base, but has a bit of movement, which allows the sharpening surface to float fully on the tool. You can then apply as little or as much pressure as you like or need.

The body of the sharpener is best secured down, and there is a hole and screw made available for just that.

PSS1-Diamond-Cross-484

The system has a particular distinct advantage – speed of setup.  There is no jig that needs to be set up, or clamped to the blade.  The tool is placed on the flat bed, held against the lip at the side to keep it perpendicular to the sharpening stone, and a few swipes and you are done.

Remove the stone carriage, flick it around and a few swipes for a micro-bevel.  Change stones in seconds to move between grades.  It will not take every type of blade, but anything straight, such as a chisel or plane blade up to 2.5″ wide is no problem (3mm to 64mm).  The ease of setup and repeatability means regular, quick touchups are no problem, and you may find you use it more regularly given the ease of use.  With the result being continually, satisfyingly, sharp blades.

Available (in Oz) from Professional Woodworkers Supplies.

 

 

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