What I have been working on

For my next article in The Shed magazine, I have been designing and building this water wheel

water wheel-1 copyThe whole thing is about 1100mm high, and it can kick along at a fair rate of knots, even just with a hose as the water supply.

I’ve designed it to use either water weight (quantity, slow moving), as well as water velocity (smaller quantity, flowing at speed).

It has a square drive on one side of the shaft, so it can be used to do real work, and at some stage I’ll add some traditional gears to do just that.

water wheel-1-2No glue used in this project – it is all coach bolts.  About 170 or so in all.

Busy work

Haven’t posted anything for a while – longer than I realised it seems!  Not that I haven’t been working in the shed, but sometimes I just need to get my head down and power through to make some progress.

The latest work that I have been doing is for the next issue of The Shed magazine – those deadline come around so quickly!

For a bit of a sneak peek, I am working on a water wheel – will end up being a garden feature, but I am trying to make it with some thought behind the design, and not just a basic layout.  You may well ask, just how many ways can you actually make a water wheel, and the more I think about it, and the more research I do on the topic, the more surprised I become about the breadth of the topic.

I found a particularly interesting reference, quite the authority on the topic.  It is The Engineer’s and Mechanic’s Encyclopædia: Comprehending Practical Illustrations of the Machinery and Processes Employed in Every Description of Manufacuture of the British Empire, Volumes 1-2

by Luke Herbert, and the title is quite the mouthful!  Interesting to find a book that has such a strong understanding of the science of water wheels.  Of course, that it was written in 1836 might have something to do with it!  I found some of the relevant text online so was able to glean what I could from that, and I have the book on order from Amazon – looking forward to seeing what other gems it contains!

I’ve been playing around with fin design, with this as an early model

File 8-09-2015 09 48 33This was with a fin angle of 22.5o.  I’ve since refined the angle to 30o, and the result is a lot better, with the inner circle now having a much greater diameter.

I am designing it as an overshot water wheel, so the turning moment of the water is important – the further away from the point of rotation that the water is maintained, the greater turning force it exerts due to gravity.  In any respect, it is quite a fun evolution!

I’ve also been making a number of models on the CNC while all this has been going on, in preparation for an upcoming school fête fundraiser.

So as I said, I might have been a bit quiet on here, but that doesn’t mean that it has been so in the shed! Bags and bags of sawdust coming out (especially now I have the new collector, and the cyclone separator makes removing the full bags a breeze).


I don’t think there is any craft or vehicle that captured my imagination more as a child than the Voyager spacecraft.  Launched in 1977, the two identical probes were sent on a journey that to date has taken them 1.97×1010 km away from Earth, past the gas giants of the solar system and then way beyond.


There is a lot of information about them on Wikipedia these days, so if interested you can read up more there.

What I was excited about recently, is that the Voyager probe is one of the models on the Makecnc.com website.  So I made it.

Over 200 individual parts, cut from 3mm MDF, using the 45190 1/16″ router bit from Toolstoday.com (which is still going strong).  Cut on the TorqueCNC.

It took me 2 nights to assemble the model, and a lot of hot glue (which I have been finding to be an excellent way to assemble these models).

I had my friend Kara Rasmanis take a couple of photos of the model, suspended in front of a green screen, and she has then inserted in some royalty-free backgrounds, for a truly stunning result showcasing the model from the front, and back.

Even made from 3mm MDF, it is 900mm across.

FromSpace AboveEarth

For a model, cut from MDF, that is awesome!  Currently sits in my office – when I can part with it, it will be off to my daughter’s school science classroom.

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

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


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?



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.

Sopwith Camel Article

The latest edition of The Shed magazine has just come out (in newsagents in Australia soon).

Has my 10 page article on the Sopwith Camel build.

Also includes the first two ever letters to the editor about any of my articles.  Unfortunately neither positive.  Seems coin collectors were concerned about my choice of materials (rightly so). Ah well – can’t always be right!

Photo 4-08-2015 01 46 17

T Shirt Wisdom

Photo 6-08-2015 18 43 26s4e1-jaime-hand-2


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